xref: /linux/net/mac80211/tx.c (revision cb299ba8b5ef2239429484072fea394cd7581bd7)
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 <net/net_namespace.h>
22 #include <net/ieee80211_radiotap.h>
23 #include <net/cfg80211.h>
24 #include <net/mac80211.h>
25 #include <asm/unaligned.h>
26 
27 #include "ieee80211_i.h"
28 #include "driver-ops.h"
29 #include "led.h"
30 #include "mesh.h"
31 #include "wep.h"
32 #include "wpa.h"
33 #include "wme.h"
34 #include "rate.h"
35 
36 #define IEEE80211_TX_OK		0
37 #define IEEE80211_TX_AGAIN	1
38 #define IEEE80211_TX_PENDING	2
39 
40 /* misc utils */
41 
42 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
43 				 int next_frag_len)
44 {
45 	int rate, mrate, erp, dur, i;
46 	struct ieee80211_rate *txrate;
47 	struct ieee80211_local *local = tx->local;
48 	struct ieee80211_supported_band *sband;
49 	struct ieee80211_hdr *hdr;
50 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
51 
52 	/* assume HW handles this */
53 	if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
54 		return 0;
55 
56 	/* uh huh? */
57 	if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
58 		return 0;
59 
60 	sband = local->hw.wiphy->bands[tx->channel->band];
61 	txrate = &sband->bitrates[info->control.rates[0].idx];
62 
63 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
64 
65 	/*
66 	 * data and mgmt (except PS Poll):
67 	 * - during CFP: 32768
68 	 * - during contention period:
69 	 *   if addr1 is group address: 0
70 	 *   if more fragments = 0 and addr1 is individual address: time to
71 	 *      transmit one ACK plus SIFS
72 	 *   if more fragments = 1 and addr1 is individual address: time to
73 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
74 	 *
75 	 * IEEE 802.11, 9.6:
76 	 * - control response frame (CTS or ACK) shall be transmitted using the
77 	 *   same rate as the immediately previous frame in the frame exchange
78 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
79 	 *   at the highest possible rate belonging to the PHY rates in the
80 	 *   BSSBasicRateSet
81 	 */
82 	hdr = (struct ieee80211_hdr *)tx->skb->data;
83 	if (ieee80211_is_ctl(hdr->frame_control)) {
84 		/* TODO: These control frames are not currently sent by
85 		 * mac80211, but should they be implemented, this function
86 		 * needs to be updated to support duration field calculation.
87 		 *
88 		 * RTS: time needed to transmit pending data/mgmt frame plus
89 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
90 		 * CTS: duration of immediately previous RTS minus time
91 		 *    required to transmit CTS and its SIFS
92 		 * ACK: 0 if immediately previous directed data/mgmt had
93 		 *    more=0, with more=1 duration in ACK frame is duration
94 		 *    from previous frame minus time needed to transmit ACK
95 		 *    and its SIFS
96 		 * PS Poll: BIT(15) | BIT(14) | aid
97 		 */
98 		return 0;
99 	}
100 
101 	/* data/mgmt */
102 	if (0 /* FIX: data/mgmt during CFP */)
103 		return cpu_to_le16(32768);
104 
105 	if (group_addr) /* Group address as the destination - no ACK */
106 		return 0;
107 
108 	/* Individual destination address:
109 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
110 	 * CTS and ACK frames shall be transmitted using the highest rate in
111 	 * basic rate set that is less than or equal to the rate of the
112 	 * immediately previous frame and that is using the same modulation
113 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
114 	 * the highest mandatory rate of the PHY that is less than or equal to
115 	 * the rate of the previous frame is used.
116 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
117 	 */
118 	rate = -1;
119 	/* use lowest available if everything fails */
120 	mrate = sband->bitrates[0].bitrate;
121 	for (i = 0; i < sband->n_bitrates; i++) {
122 		struct ieee80211_rate *r = &sband->bitrates[i];
123 
124 		if (r->bitrate > txrate->bitrate)
125 			break;
126 
127 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
128 			rate = r->bitrate;
129 
130 		switch (sband->band) {
131 		case IEEE80211_BAND_2GHZ: {
132 			u32 flag;
133 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
134 				flag = IEEE80211_RATE_MANDATORY_G;
135 			else
136 				flag = IEEE80211_RATE_MANDATORY_B;
137 			if (r->flags & flag)
138 				mrate = r->bitrate;
139 			break;
140 		}
141 		case IEEE80211_BAND_5GHZ:
142 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
143 				mrate = r->bitrate;
144 			break;
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 	/* Time needed to transmit ACK
157 	 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
158 	 * to closest integer */
159 
160 	dur = ieee80211_frame_duration(local, 10, rate, erp,
161 				tx->sdata->vif.bss_conf.use_short_preamble);
162 
163 	if (next_frag_len) {
164 		/* Frame is fragmented: duration increases with time needed to
165 		 * transmit next fragment plus ACK and 2 x SIFS. */
166 		dur *= 2; /* ACK + SIFS */
167 		/* next fragment */
168 		dur += ieee80211_frame_duration(local, next_frag_len,
169 				txrate->bitrate, erp,
170 				tx->sdata->vif.bss_conf.use_short_preamble);
171 	}
172 
173 	return cpu_to_le16(dur);
174 }
175 
176 static int inline is_ieee80211_device(struct ieee80211_local *local,
177 				      struct net_device *dev)
178 {
179 	return local == wdev_priv(dev->ieee80211_ptr);
180 }
181 
182 /* tx handlers */
183 static ieee80211_tx_result debug_noinline
184 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
185 {
186 	struct ieee80211_local *local = tx->local;
187 	struct ieee80211_if_managed *ifmgd;
188 
189 	/* driver doesn't support power save */
190 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
191 		return TX_CONTINUE;
192 
193 	/* hardware does dynamic power save */
194 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
195 		return TX_CONTINUE;
196 
197 	/* dynamic power save disabled */
198 	if (local->hw.conf.dynamic_ps_timeout <= 0)
199 		return TX_CONTINUE;
200 
201 	/* we are scanning, don't enable power save */
202 	if (local->scanning)
203 		return TX_CONTINUE;
204 
205 	if (!local->ps_sdata)
206 		return TX_CONTINUE;
207 
208 	/* No point if we're going to suspend */
209 	if (local->quiescing)
210 		return TX_CONTINUE;
211 
212 	/* dynamic ps is supported only in managed mode */
213 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
214 		return TX_CONTINUE;
215 
216 	ifmgd = &tx->sdata->u.mgd;
217 
218 	/*
219 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
220 	 * u-apsd enabled and the frame is in voip class. This effectively
221 	 * means that even if all access categories have u-apsd enabled, in
222 	 * practise u-apsd is only used with the voip ac. This is a
223 	 * workaround for the case when received voip class packets do not
224 	 * have correct qos tag for some reason, due the network or the
225 	 * peer application.
226 	 *
227 	 * Note: local->uapsd_queues access is racy here. If the value is
228 	 * changed via debugfs, user needs to reassociate manually to have
229 	 * everything in sync.
230 	 */
231 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED)
232 	    && (local->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO)
233 	    && skb_get_queue_mapping(tx->skb) == 0)
234 		return TX_CONTINUE;
235 
236 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
237 		ieee80211_stop_queues_by_reason(&local->hw,
238 						IEEE80211_QUEUE_STOP_REASON_PS);
239 		ieee80211_queue_work(&local->hw,
240 				     &local->dynamic_ps_disable_work);
241 	}
242 
243 	mod_timer(&local->dynamic_ps_timer, jiffies +
244 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
245 
246 	return TX_CONTINUE;
247 }
248 
249 static ieee80211_tx_result debug_noinline
250 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
251 {
252 
253 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
254 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
255 	u32 sta_flags;
256 
257 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
258 		return TX_CONTINUE;
259 
260 	if (unlikely(test_bit(SCAN_OFF_CHANNEL, &tx->local->scanning)) &&
261 	    !ieee80211_is_probe_req(hdr->frame_control) &&
262 	    !ieee80211_is_nullfunc(hdr->frame_control))
263 		/*
264 		 * When software scanning only nullfunc frames (to notify
265 		 * the sleep state to the AP) and probe requests (for the
266 		 * active scan) are allowed, all other frames should not be
267 		 * sent and we should not get here, but if we do
268 		 * nonetheless, drop them to avoid sending them
269 		 * off-channel. See the link below and
270 		 * ieee80211_start_scan() for more.
271 		 *
272 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
273 		 */
274 		return TX_DROP;
275 
276 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
277 		return TX_CONTINUE;
278 
279 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
280 		return TX_CONTINUE;
281 
282 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
283 		return TX_CONTINUE;
284 
285 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
286 
287 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
288 		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
289 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
290 			     ieee80211_is_data(hdr->frame_control))) {
291 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
292 			printk(KERN_DEBUG "%s: dropped data frame to not "
293 			       "associated station %pM\n",
294 			       tx->sdata->name, hdr->addr1);
295 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
296 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
297 			return TX_DROP;
298 		}
299 	} else {
300 		if (unlikely(ieee80211_is_data(hdr->frame_control) &&
301 			     tx->local->num_sta == 0 &&
302 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
303 			/*
304 			 * No associated STAs - no need to send multicast
305 			 * frames.
306 			 */
307 			return TX_DROP;
308 		}
309 		return TX_CONTINUE;
310 	}
311 
312 	return TX_CONTINUE;
313 }
314 
315 /* This function is called whenever the AP is about to exceed the maximum limit
316  * of buffered frames for power saving STAs. This situation should not really
317  * happen often during normal operation, so dropping the oldest buffered packet
318  * from each queue should be OK to make some room for new frames. */
319 static void purge_old_ps_buffers(struct ieee80211_local *local)
320 {
321 	int total = 0, purged = 0;
322 	struct sk_buff *skb;
323 	struct ieee80211_sub_if_data *sdata;
324 	struct sta_info *sta;
325 
326 	/*
327 	 * virtual interfaces are protected by RCU
328 	 */
329 	rcu_read_lock();
330 
331 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
332 		struct ieee80211_if_ap *ap;
333 		if (sdata->vif.type != NL80211_IFTYPE_AP)
334 			continue;
335 		ap = &sdata->u.ap;
336 		skb = skb_dequeue(&ap->ps_bc_buf);
337 		if (skb) {
338 			purged++;
339 			dev_kfree_skb(skb);
340 		}
341 		total += skb_queue_len(&ap->ps_bc_buf);
342 	}
343 
344 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
345 		skb = skb_dequeue(&sta->ps_tx_buf);
346 		if (skb) {
347 			purged++;
348 			dev_kfree_skb(skb);
349 		}
350 		total += skb_queue_len(&sta->ps_tx_buf);
351 	}
352 
353 	rcu_read_unlock();
354 
355 	local->total_ps_buffered = total;
356 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
357 	wiphy_debug(local->hw.wiphy, "PS buffers full - purged %d frames\n",
358 		    purged);
359 #endif
360 }
361 
362 static ieee80211_tx_result
363 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
364 {
365 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
366 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
367 
368 	/*
369 	 * broadcast/multicast frame
370 	 *
371 	 * If any of the associated stations is in power save mode,
372 	 * the frame is buffered to be sent after DTIM beacon frame.
373 	 * This is done either by the hardware or us.
374 	 */
375 
376 	/* powersaving STAs only in AP/VLAN mode */
377 	if (!tx->sdata->bss)
378 		return TX_CONTINUE;
379 
380 	/* no buffering for ordered frames */
381 	if (ieee80211_has_order(hdr->frame_control))
382 		return TX_CONTINUE;
383 
384 	/* no stations in PS mode */
385 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
386 		return TX_CONTINUE;
387 
388 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
389 
390 	/* device releases frame after DTIM beacon */
391 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
392 		return TX_CONTINUE;
393 
394 	/* buffered in mac80211 */
395 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
396 		purge_old_ps_buffers(tx->local);
397 
398 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
399 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
400 		if (net_ratelimit())
401 			printk(KERN_DEBUG "%s: BC TX buffer full - dropping the oldest frame\n",
402 			       tx->sdata->name);
403 #endif
404 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
405 	} else
406 		tx->local->total_ps_buffered++;
407 
408 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
409 
410 	return TX_QUEUED;
411 }
412 
413 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
414 			     struct sk_buff *skb)
415 {
416 	if (!ieee80211_is_mgmt(fc))
417 		return 0;
418 
419 	if (sta == NULL || !test_sta_flags(sta, WLAN_STA_MFP))
420 		return 0;
421 
422 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
423 					    skb->data))
424 		return 0;
425 
426 	return 1;
427 }
428 
429 static ieee80211_tx_result
430 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
431 {
432 	struct sta_info *sta = tx->sta;
433 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
434 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
435 	struct ieee80211_local *local = tx->local;
436 	u32 staflags;
437 
438 	if (unlikely(!sta ||
439 		     ieee80211_is_probe_resp(hdr->frame_control) ||
440 		     ieee80211_is_auth(hdr->frame_control) ||
441 		     ieee80211_is_assoc_resp(hdr->frame_control) ||
442 		     ieee80211_is_reassoc_resp(hdr->frame_control)))
443 		return TX_CONTINUE;
444 
445 	staflags = get_sta_flags(sta);
446 
447 	if (unlikely((staflags & (WLAN_STA_PS_STA | WLAN_STA_PS_DRIVER)) &&
448 		     !(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) {
449 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
450 		printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
451 		       "before %d)\n",
452 		       sta->sta.addr, sta->sta.aid,
453 		       skb_queue_len(&sta->ps_tx_buf));
454 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
455 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
456 			purge_old_ps_buffers(tx->local);
457 		if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
458 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
459 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
460 			if (net_ratelimit()) {
461 				printk(KERN_DEBUG "%s: STA %pM TX "
462 				       "buffer full - dropping oldest frame\n",
463 				       tx->sdata->name, sta->sta.addr);
464 			}
465 #endif
466 			dev_kfree_skb(old);
467 		} else
468 			tx->local->total_ps_buffered++;
469 
470 		/*
471 		 * Queue frame to be sent after STA wakes up/polls,
472 		 * but don't set the TIM bit if the driver is blocking
473 		 * wakeup or poll response transmissions anyway.
474 		 */
475 		if (skb_queue_empty(&sta->ps_tx_buf) &&
476 		    !(staflags & WLAN_STA_PS_DRIVER))
477 			sta_info_set_tim_bit(sta);
478 
479 		info->control.jiffies = jiffies;
480 		info->control.vif = &tx->sdata->vif;
481 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
482 		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
483 
484 		if (!timer_pending(&local->sta_cleanup))
485 			mod_timer(&local->sta_cleanup,
486 				  round_jiffies(jiffies +
487 						STA_INFO_CLEANUP_INTERVAL));
488 
489 		return TX_QUEUED;
490 	}
491 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
492 	else if (unlikely(staflags & WLAN_STA_PS_STA)) {
493 		printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
494 		       "set -> send frame\n", tx->sdata->name,
495 		       sta->sta.addr);
496 	}
497 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
498 
499 	return TX_CONTINUE;
500 }
501 
502 static ieee80211_tx_result debug_noinline
503 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
504 {
505 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
506 		return TX_CONTINUE;
507 
508 	if (tx->flags & IEEE80211_TX_UNICAST)
509 		return ieee80211_tx_h_unicast_ps_buf(tx);
510 	else
511 		return ieee80211_tx_h_multicast_ps_buf(tx);
512 }
513 
514 static ieee80211_tx_result debug_noinline
515 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
516 {
517 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
518 
519 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
520 		     tx->sdata->control_port_no_encrypt))
521 		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
522 
523 	return TX_CONTINUE;
524 }
525 
526 static ieee80211_tx_result debug_noinline
527 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
528 {
529 	struct ieee80211_key *key = NULL;
530 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
531 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
532 
533 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
534 		tx->key = NULL;
535 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
536 		tx->key = key;
537 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
538 		 is_multicast_ether_addr(hdr->addr1) &&
539 		 ieee80211_is_robust_mgmt_frame(hdr) &&
540 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
541 		tx->key = key;
542 	else if ((key = rcu_dereference(tx->sdata->default_key)))
543 		tx->key = key;
544 	else if (tx->sdata->drop_unencrypted &&
545 		 (tx->skb->protocol != tx->sdata->control_port_protocol) &&
546 		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
547 		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
548 		  (ieee80211_is_action(hdr->frame_control) &&
549 		   tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) {
550 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
551 		return TX_DROP;
552 	} else
553 		tx->key = NULL;
554 
555 	if (tx->key) {
556 		bool skip_hw = false;
557 
558 		tx->key->tx_rx_count++;
559 		/* TODO: add threshold stuff again */
560 
561 		switch (tx->key->conf.cipher) {
562 		case WLAN_CIPHER_SUITE_WEP40:
563 		case WLAN_CIPHER_SUITE_WEP104:
564 			if (ieee80211_is_auth(hdr->frame_control))
565 				break;
566 		case WLAN_CIPHER_SUITE_TKIP:
567 			if (!ieee80211_is_data_present(hdr->frame_control))
568 				tx->key = NULL;
569 			break;
570 		case WLAN_CIPHER_SUITE_CCMP:
571 			if (!ieee80211_is_data_present(hdr->frame_control) &&
572 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
573 					       tx->skb))
574 				tx->key = NULL;
575 			else
576 				skip_hw = (tx->key->conf.flags &
577 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
578 					ieee80211_is_mgmt(hdr->frame_control);
579 			break;
580 		case WLAN_CIPHER_SUITE_AES_CMAC:
581 			if (!ieee80211_is_mgmt(hdr->frame_control))
582 				tx->key = NULL;
583 			break;
584 		}
585 
586 		if (!skip_hw && tx->key &&
587 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
588 			info->control.hw_key = &tx->key->conf;
589 	}
590 
591 	return TX_CONTINUE;
592 }
593 
594 static ieee80211_tx_result debug_noinline
595 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
596 {
597 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
598 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
599 	struct ieee80211_supported_band *sband;
600 	struct ieee80211_rate *rate;
601 	int i;
602 	u32 len;
603 	bool inval = false, rts = false, short_preamble = false;
604 	struct ieee80211_tx_rate_control txrc;
605 	u32 sta_flags;
606 
607 	memset(&txrc, 0, sizeof(txrc));
608 
609 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
610 
611 	len = min_t(u32, tx->skb->len + FCS_LEN,
612 			 tx->local->hw.wiphy->frag_threshold);
613 
614 	/* set up the tx rate control struct we give the RC algo */
615 	txrc.hw = local_to_hw(tx->local);
616 	txrc.sband = sband;
617 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
618 	txrc.skb = tx->skb;
619 	txrc.reported_rate.idx = -1;
620 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
621 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
622 		txrc.max_rate_idx = -1;
623 	else
624 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
625 	txrc.ap = tx->sdata->vif.type == NL80211_IFTYPE_AP;
626 
627 	/* set up RTS protection if desired */
628 	if (len > tx->local->hw.wiphy->rts_threshold) {
629 		txrc.rts = rts = true;
630 	}
631 
632 	/*
633 	 * Use short preamble if the BSS can handle it, but not for
634 	 * management frames unless we know the receiver can handle
635 	 * that -- the management frame might be to a station that
636 	 * just wants a probe response.
637 	 */
638 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
639 	    (ieee80211_is_data(hdr->frame_control) ||
640 	     (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
641 		txrc.short_preamble = short_preamble = true;
642 
643 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
644 
645 	/*
646 	 * Lets not bother rate control if we're associated and cannot
647 	 * talk to the sta. This should not happen.
648 	 */
649 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) &&
650 		 (sta_flags & WLAN_STA_ASSOC) &&
651 		 !rate_usable_index_exists(sband, &tx->sta->sta),
652 		 "%s: Dropped data frame as no usable bitrate found while "
653 		 "scanning and associated. Target station: "
654 		 "%pM on %d GHz band\n",
655 		 tx->sdata->name, hdr->addr1,
656 		 tx->channel->band ? 5 : 2))
657 		return TX_DROP;
658 
659 	/*
660 	 * If we're associated with the sta at this point we know we can at
661 	 * least send the frame at the lowest bit rate.
662 	 */
663 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
664 
665 	if (unlikely(info->control.rates[0].idx < 0))
666 		return TX_DROP;
667 
668 	if (txrc.reported_rate.idx < 0)
669 		txrc.reported_rate = info->control.rates[0];
670 
671 	if (tx->sta)
672 		tx->sta->last_tx_rate = txrc.reported_rate;
673 
674 	if (unlikely(!info->control.rates[0].count))
675 		info->control.rates[0].count = 1;
676 
677 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
678 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
679 		info->control.rates[0].count = 1;
680 
681 	if (is_multicast_ether_addr(hdr->addr1)) {
682 		/*
683 		 * XXX: verify the rate is in the basic rateset
684 		 */
685 		return TX_CONTINUE;
686 	}
687 
688 	/*
689 	 * set up the RTS/CTS rate as the fastest basic rate
690 	 * that is not faster than the data rate
691 	 *
692 	 * XXX: Should this check all retry rates?
693 	 */
694 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
695 		s8 baserate = 0;
696 
697 		rate = &sband->bitrates[info->control.rates[0].idx];
698 
699 		for (i = 0; i < sband->n_bitrates; i++) {
700 			/* must be a basic rate */
701 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
702 				continue;
703 			/* must not be faster than the data rate */
704 			if (sband->bitrates[i].bitrate > rate->bitrate)
705 				continue;
706 			/* maximum */
707 			if (sband->bitrates[baserate].bitrate <
708 			     sband->bitrates[i].bitrate)
709 				baserate = i;
710 		}
711 
712 		info->control.rts_cts_rate_idx = baserate;
713 	}
714 
715 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
716 		/*
717 		 * make sure there's no valid rate following
718 		 * an invalid one, just in case drivers don't
719 		 * take the API seriously to stop at -1.
720 		 */
721 		if (inval) {
722 			info->control.rates[i].idx = -1;
723 			continue;
724 		}
725 		if (info->control.rates[i].idx < 0) {
726 			inval = true;
727 			continue;
728 		}
729 
730 		/*
731 		 * For now assume MCS is already set up correctly, this
732 		 * needs to be fixed.
733 		 */
734 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
735 			WARN_ON(info->control.rates[i].idx > 76);
736 			continue;
737 		}
738 
739 		/* set up RTS protection if desired */
740 		if (rts)
741 			info->control.rates[i].flags |=
742 				IEEE80211_TX_RC_USE_RTS_CTS;
743 
744 		/* RC is busted */
745 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
746 				 sband->n_bitrates)) {
747 			info->control.rates[i].idx = -1;
748 			continue;
749 		}
750 
751 		rate = &sband->bitrates[info->control.rates[i].idx];
752 
753 		/* set up short preamble */
754 		if (short_preamble &&
755 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
756 			info->control.rates[i].flags |=
757 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
758 
759 		/* set up G protection */
760 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
761 		    rate->flags & IEEE80211_RATE_ERP_G)
762 			info->control.rates[i].flags |=
763 				IEEE80211_TX_RC_USE_CTS_PROTECT;
764 	}
765 
766 	return TX_CONTINUE;
767 }
768 
769 static ieee80211_tx_result debug_noinline
770 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
771 {
772 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
773 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
774 	u16 *seq;
775 	u8 *qc;
776 	int tid;
777 
778 	/*
779 	 * Packet injection may want to control the sequence
780 	 * number, if we have no matching interface then we
781 	 * neither assign one ourselves nor ask the driver to.
782 	 */
783 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
784 		return TX_CONTINUE;
785 
786 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
787 		return TX_CONTINUE;
788 
789 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
790 		return TX_CONTINUE;
791 
792 	/*
793 	 * Anything but QoS data that has a sequence number field
794 	 * (is long enough) gets a sequence number from the global
795 	 * counter.
796 	 */
797 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
798 		/* driver should assign sequence number */
799 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
800 		/* for pure STA mode without beacons, we can do it */
801 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
802 		tx->sdata->sequence_number += 0x10;
803 		return TX_CONTINUE;
804 	}
805 
806 	/*
807 	 * This should be true for injected/management frames only, for
808 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
809 	 * above since they are not QoS-data frames.
810 	 */
811 	if (!tx->sta)
812 		return TX_CONTINUE;
813 
814 	/* include per-STA, per-TID sequence counter */
815 
816 	qc = ieee80211_get_qos_ctl(hdr);
817 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
818 	seq = &tx->sta->tid_seq[tid];
819 
820 	hdr->seq_ctrl = cpu_to_le16(*seq);
821 
822 	/* Increase the sequence number. */
823 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
824 
825 	return TX_CONTINUE;
826 }
827 
828 static int ieee80211_fragment(struct ieee80211_local *local,
829 			      struct sk_buff *skb, int hdrlen,
830 			      int frag_threshold)
831 {
832 	struct sk_buff *tail = skb, *tmp;
833 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
834 	int pos = hdrlen + per_fragm;
835 	int rem = skb->len - hdrlen - per_fragm;
836 
837 	if (WARN_ON(rem < 0))
838 		return -EINVAL;
839 
840 	while (rem) {
841 		int fraglen = per_fragm;
842 
843 		if (fraglen > rem)
844 			fraglen = rem;
845 		rem -= fraglen;
846 		tmp = dev_alloc_skb(local->tx_headroom +
847 				    frag_threshold +
848 				    IEEE80211_ENCRYPT_HEADROOM +
849 				    IEEE80211_ENCRYPT_TAILROOM);
850 		if (!tmp)
851 			return -ENOMEM;
852 		tail->next = tmp;
853 		tail = tmp;
854 		skb_reserve(tmp, local->tx_headroom +
855 				 IEEE80211_ENCRYPT_HEADROOM);
856 		/* copy control information */
857 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
858 		skb_copy_queue_mapping(tmp, skb);
859 		tmp->priority = skb->priority;
860 		tmp->dev = skb->dev;
861 
862 		/* copy header and data */
863 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
864 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
865 
866 		pos += fraglen;
867 	}
868 
869 	skb->len = hdrlen + per_fragm;
870 	return 0;
871 }
872 
873 static ieee80211_tx_result debug_noinline
874 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
875 {
876 	struct sk_buff *skb = tx->skb;
877 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
878 	struct ieee80211_hdr *hdr = (void *)skb->data;
879 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
880 	int hdrlen;
881 	int fragnum;
882 
883 	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
884 		return TX_CONTINUE;
885 
886 	/*
887 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
888 	 * This scenario is handled in ieee80211_tx_prepare but extra
889 	 * caution taken here as fragmented ampdu may cause Tx stop.
890 	 */
891 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
892 		return TX_DROP;
893 
894 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
895 
896 	/* internal error, why is TX_FRAGMENTED set? */
897 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
898 		return TX_DROP;
899 
900 	/*
901 	 * Now fragment the frame. This will allocate all the fragments and
902 	 * chain them (using skb as the first fragment) to skb->next.
903 	 * During transmission, we will remove the successfully transmitted
904 	 * fragments from this list. When the low-level driver rejects one
905 	 * of the fragments then we will simply pretend to accept the skb
906 	 * but store it away as pending.
907 	 */
908 	if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
909 		return TX_DROP;
910 
911 	/* update duration/seq/flags of fragments */
912 	fragnum = 0;
913 	do {
914 		int next_len;
915 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
916 
917 		hdr = (void *)skb->data;
918 		info = IEEE80211_SKB_CB(skb);
919 
920 		if (skb->next) {
921 			hdr->frame_control |= morefrags;
922 			next_len = skb->next->len;
923 			/*
924 			 * No multi-rate retries for fragmented frames, that
925 			 * would completely throw off the NAV at other STAs.
926 			 */
927 			info->control.rates[1].idx = -1;
928 			info->control.rates[2].idx = -1;
929 			info->control.rates[3].idx = -1;
930 			info->control.rates[4].idx = -1;
931 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
932 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
933 		} else {
934 			hdr->frame_control &= ~morefrags;
935 			next_len = 0;
936 		}
937 		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
938 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
939 		fragnum++;
940 	} while ((skb = skb->next));
941 
942 	return TX_CONTINUE;
943 }
944 
945 static ieee80211_tx_result debug_noinline
946 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
947 {
948 	struct sk_buff *skb = tx->skb;
949 
950 	if (!tx->sta)
951 		return TX_CONTINUE;
952 
953 	tx->sta->tx_packets++;
954 	do {
955 		tx->sta->tx_fragments++;
956 		tx->sta->tx_bytes += skb->len;
957 	} while ((skb = skb->next));
958 
959 	return TX_CONTINUE;
960 }
961 
962 static ieee80211_tx_result debug_noinline
963 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
964 {
965 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
966 
967 	if (!tx->key)
968 		return TX_CONTINUE;
969 
970 	switch (tx->key->conf.cipher) {
971 	case WLAN_CIPHER_SUITE_WEP40:
972 	case WLAN_CIPHER_SUITE_WEP104:
973 		return ieee80211_crypto_wep_encrypt(tx);
974 	case WLAN_CIPHER_SUITE_TKIP:
975 		return ieee80211_crypto_tkip_encrypt(tx);
976 	case WLAN_CIPHER_SUITE_CCMP:
977 		return ieee80211_crypto_ccmp_encrypt(tx);
978 	case WLAN_CIPHER_SUITE_AES_CMAC:
979 		return ieee80211_crypto_aes_cmac_encrypt(tx);
980 	default:
981 		/* handle hw-only algorithm */
982 		if (info->control.hw_key) {
983 			ieee80211_tx_set_protected(tx);
984 			return TX_CONTINUE;
985 		}
986 		break;
987 
988 	}
989 
990 	return TX_DROP;
991 }
992 
993 static ieee80211_tx_result debug_noinline
994 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
995 {
996 	struct sk_buff *skb = tx->skb;
997 	struct ieee80211_hdr *hdr;
998 	int next_len;
999 	bool group_addr;
1000 
1001 	do {
1002 		hdr = (void *) skb->data;
1003 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1004 			break; /* must not overwrite AID */
1005 		next_len = skb->next ? skb->next->len : 0;
1006 		group_addr = is_multicast_ether_addr(hdr->addr1);
1007 
1008 		hdr->duration_id =
1009 			ieee80211_duration(tx, group_addr, next_len);
1010 	} while ((skb = skb->next));
1011 
1012 	return TX_CONTINUE;
1013 }
1014 
1015 /* actual transmit path */
1016 
1017 /*
1018  * deal with packet injection down monitor interface
1019  * with Radiotap Header -- only called for monitor mode interface
1020  */
1021 static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
1022 					  struct sk_buff *skb)
1023 {
1024 	/*
1025 	 * this is the moment to interpret and discard the radiotap header that
1026 	 * must be at the start of the packet injected in Monitor mode
1027 	 *
1028 	 * Need to take some care with endian-ness since radiotap
1029 	 * args are little-endian
1030 	 */
1031 
1032 	struct ieee80211_radiotap_iterator iterator;
1033 	struct ieee80211_radiotap_header *rthdr =
1034 		(struct ieee80211_radiotap_header *) skb->data;
1035 	struct ieee80211_supported_band *sband;
1036 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1037 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1038 						   NULL);
1039 
1040 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
1041 
1042 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1043 	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1044 
1045 	/*
1046 	 * for every radiotap entry that is present
1047 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1048 	 * entries present, or -EINVAL on error)
1049 	 */
1050 
1051 	while (!ret) {
1052 		ret = ieee80211_radiotap_iterator_next(&iterator);
1053 
1054 		if (ret)
1055 			continue;
1056 
1057 		/* see if this argument is something we can use */
1058 		switch (iterator.this_arg_index) {
1059 		/*
1060 		 * You must take care when dereferencing iterator.this_arg
1061 		 * for multibyte types... the pointer is not aligned.  Use
1062 		 * get_unaligned((type *)iterator.this_arg) to dereference
1063 		 * iterator.this_arg for type "type" safely on all arches.
1064 		*/
1065 		case IEEE80211_RADIOTAP_FLAGS:
1066 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1067 				/*
1068 				 * this indicates that the skb we have been
1069 				 * handed has the 32-bit FCS CRC at the end...
1070 				 * we should react to that by snipping it off
1071 				 * because it will be recomputed and added
1072 				 * on transmission
1073 				 */
1074 				if (skb->len < (iterator._max_length + FCS_LEN))
1075 					return false;
1076 
1077 				skb_trim(skb, skb->len - FCS_LEN);
1078 			}
1079 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1080 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1081 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1082 				tx->flags |= IEEE80211_TX_FRAGMENTED;
1083 			break;
1084 
1085 		/*
1086 		 * Please update the file
1087 		 * Documentation/networking/mac80211-injection.txt
1088 		 * when parsing new fields here.
1089 		 */
1090 
1091 		default:
1092 			break;
1093 		}
1094 	}
1095 
1096 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1097 		return false;
1098 
1099 	/*
1100 	 * remove the radiotap header
1101 	 * iterator->_max_length was sanity-checked against
1102 	 * skb->len by iterator init
1103 	 */
1104 	skb_pull(skb, iterator._max_length);
1105 
1106 	return true;
1107 }
1108 
1109 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1110 				  struct sk_buff *skb,
1111 				  struct ieee80211_tx_info *info,
1112 				  struct tid_ampdu_tx *tid_tx,
1113 				  int tid)
1114 {
1115 	bool queued = false;
1116 
1117 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1118 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1119 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1120 		/*
1121 		 * nothing -- this aggregation session is being started
1122 		 * but that might still fail with the driver
1123 		 */
1124 	} else {
1125 		spin_lock(&tx->sta->lock);
1126 		/*
1127 		 * Need to re-check now, because we may get here
1128 		 *
1129 		 *  1) in the window during which the setup is actually
1130 		 *     already done, but not marked yet because not all
1131 		 *     packets are spliced over to the driver pending
1132 		 *     queue yet -- if this happened we acquire the lock
1133 		 *     either before or after the splice happens, but
1134 		 *     need to recheck which of these cases happened.
1135 		 *
1136 		 *  2) during session teardown, if the OPERATIONAL bit
1137 		 *     was cleared due to the teardown but the pointer
1138 		 *     hasn't been assigned NULL yet (or we loaded it
1139 		 *     before it was assigned) -- in this case it may
1140 		 *     now be NULL which means we should just let the
1141 		 *     packet pass through because splicing the frames
1142 		 *     back is already done.
1143 		 */
1144 		tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
1145 
1146 		if (!tid_tx) {
1147 			/* do nothing, let packet pass through */
1148 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1149 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1150 		} else {
1151 			queued = true;
1152 			info->control.vif = &tx->sdata->vif;
1153 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1154 			__skb_queue_tail(&tid_tx->pending, skb);
1155 		}
1156 		spin_unlock(&tx->sta->lock);
1157 	}
1158 
1159 	return queued;
1160 }
1161 
1162 /*
1163  * initialises @tx
1164  */
1165 static ieee80211_tx_result
1166 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1167 		     struct ieee80211_tx_data *tx,
1168 		     struct sk_buff *skb)
1169 {
1170 	struct ieee80211_local *local = sdata->local;
1171 	struct ieee80211_hdr *hdr;
1172 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1173 	int hdrlen, tid;
1174 	u8 *qc;
1175 
1176 	memset(tx, 0, sizeof(*tx));
1177 	tx->skb = skb;
1178 	tx->local = local;
1179 	tx->sdata = sdata;
1180 	tx->channel = local->hw.conf.channel;
1181 	/*
1182 	 * Set this flag (used below to indicate "automatic fragmentation"),
1183 	 * it will be cleared/left by radiotap as desired.
1184 	 */
1185 	tx->flags |= IEEE80211_TX_FRAGMENTED;
1186 
1187 	/* process and remove the injection radiotap header */
1188 	if (unlikely(info->flags & IEEE80211_TX_INTFL_HAS_RADIOTAP)) {
1189 		if (!__ieee80211_parse_tx_radiotap(tx, skb))
1190 			return TX_DROP;
1191 
1192 		/*
1193 		 * __ieee80211_parse_tx_radiotap has now removed
1194 		 * the radiotap header that was present and pre-filled
1195 		 * 'tx' with tx control information.
1196 		 */
1197 		info->flags &= ~IEEE80211_TX_INTFL_HAS_RADIOTAP;
1198 	}
1199 
1200 	/*
1201 	 * If this flag is set to true anywhere, and we get here,
1202 	 * we are doing the needed processing, so remove the flag
1203 	 * now.
1204 	 */
1205 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1206 
1207 	hdr = (struct ieee80211_hdr *) skb->data;
1208 
1209 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1210 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1211 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1212 			return TX_DROP;
1213 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED) {
1214 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1215 	}
1216 	if (!tx->sta)
1217 		tx->sta = sta_info_get(sdata, hdr->addr1);
1218 
1219 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1220 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1221 		struct tid_ampdu_tx *tid_tx;
1222 
1223 		qc = ieee80211_get_qos_ctl(hdr);
1224 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1225 
1226 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1227 		if (tid_tx) {
1228 			bool queued;
1229 
1230 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1231 						       tid_tx, tid);
1232 
1233 			if (unlikely(queued))
1234 				return TX_QUEUED;
1235 		}
1236 	}
1237 
1238 	if (is_multicast_ether_addr(hdr->addr1)) {
1239 		tx->flags &= ~IEEE80211_TX_UNICAST;
1240 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1241 	} else {
1242 		tx->flags |= IEEE80211_TX_UNICAST;
1243 		if (unlikely(local->wifi_wme_noack_test))
1244 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
1245 		else
1246 			info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1247 	}
1248 
1249 	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
1250 		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1251 		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1252 		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1253 			tx->flags |= IEEE80211_TX_FRAGMENTED;
1254 		else
1255 			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1256 	}
1257 
1258 	if (!tx->sta)
1259 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1260 	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1261 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1262 
1263 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1264 	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
1265 		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
1266 		tx->ethertype = (pos[0] << 8) | pos[1];
1267 	}
1268 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1269 
1270 	return TX_CONTINUE;
1271 }
1272 
1273 static int __ieee80211_tx(struct ieee80211_local *local,
1274 			  struct sk_buff **skbp,
1275 			  struct sta_info *sta,
1276 			  bool txpending)
1277 {
1278 	struct sk_buff *skb = *skbp, *next;
1279 	struct ieee80211_tx_info *info;
1280 	struct ieee80211_sub_if_data *sdata;
1281 	unsigned long flags;
1282 	int ret, len;
1283 	bool fragm = false;
1284 
1285 	while (skb) {
1286 		int q = skb_get_queue_mapping(skb);
1287 
1288 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1289 		ret = IEEE80211_TX_OK;
1290 		if (local->queue_stop_reasons[q] ||
1291 		    (!txpending && !skb_queue_empty(&local->pending[q])))
1292 			ret = IEEE80211_TX_PENDING;
1293 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1294 		if (ret != IEEE80211_TX_OK)
1295 			return ret;
1296 
1297 		info = IEEE80211_SKB_CB(skb);
1298 
1299 		if (fragm)
1300 			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1301 					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1302 
1303 		next = skb->next;
1304 		len = skb->len;
1305 
1306 		if (next)
1307 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
1308 
1309 		sdata = vif_to_sdata(info->control.vif);
1310 
1311 		switch (sdata->vif.type) {
1312 		case NL80211_IFTYPE_MONITOR:
1313 			info->control.vif = NULL;
1314 			break;
1315 		case NL80211_IFTYPE_AP_VLAN:
1316 			info->control.vif = &container_of(sdata->bss,
1317 				struct ieee80211_sub_if_data, u.ap)->vif;
1318 			break;
1319 		default:
1320 			/* keep */
1321 			break;
1322 		}
1323 
1324 		if (sta && sta->uploaded)
1325 			info->control.sta = &sta->sta;
1326 		else
1327 			info->control.sta = NULL;
1328 
1329 		ret = drv_tx(local, skb);
1330 		if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
1331 			dev_kfree_skb(skb);
1332 			ret = NETDEV_TX_OK;
1333 		}
1334 		if (ret != NETDEV_TX_OK) {
1335 			info->control.vif = &sdata->vif;
1336 			return IEEE80211_TX_AGAIN;
1337 		}
1338 
1339 		*skbp = skb = next;
1340 		ieee80211_led_tx(local, 1);
1341 		fragm = true;
1342 	}
1343 
1344 	return IEEE80211_TX_OK;
1345 }
1346 
1347 /*
1348  * Invoke TX handlers, return 0 on success and non-zero if the
1349  * frame was dropped or queued.
1350  */
1351 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1352 {
1353 	struct sk_buff *skb = tx->skb;
1354 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1355 	ieee80211_tx_result res = TX_DROP;
1356 
1357 #define CALL_TXH(txh) \
1358 	do {				\
1359 		res = txh(tx);		\
1360 		if (res != TX_CONTINUE)	\
1361 			goto txh_done;	\
1362 	} while (0)
1363 
1364 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1365 	CALL_TXH(ieee80211_tx_h_check_assoc);
1366 	CALL_TXH(ieee80211_tx_h_ps_buf);
1367 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1368 	CALL_TXH(ieee80211_tx_h_select_key);
1369 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1370 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1371 
1372 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION))
1373 		goto txh_done;
1374 
1375 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1376 	CALL_TXH(ieee80211_tx_h_sequence);
1377 	CALL_TXH(ieee80211_tx_h_fragment);
1378 	/* handlers after fragment must be aware of tx info fragmentation! */
1379 	CALL_TXH(ieee80211_tx_h_stats);
1380 	CALL_TXH(ieee80211_tx_h_encrypt);
1381 	CALL_TXH(ieee80211_tx_h_calculate_duration);
1382 #undef CALL_TXH
1383 
1384  txh_done:
1385 	if (unlikely(res == TX_DROP)) {
1386 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1387 		while (skb) {
1388 			struct sk_buff *next;
1389 
1390 			next = skb->next;
1391 			dev_kfree_skb(skb);
1392 			skb = next;
1393 		}
1394 		return -1;
1395 	} else if (unlikely(res == TX_QUEUED)) {
1396 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1397 		return -1;
1398 	}
1399 
1400 	return 0;
1401 }
1402 
1403 static void ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1404 			 struct sk_buff *skb, bool txpending)
1405 {
1406 	struct ieee80211_local *local = sdata->local;
1407 	struct ieee80211_tx_data tx;
1408 	ieee80211_tx_result res_prepare;
1409 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1410 	struct sk_buff *next;
1411 	unsigned long flags;
1412 	int ret, retries;
1413 	u16 queue;
1414 
1415 	queue = skb_get_queue_mapping(skb);
1416 
1417 	if (unlikely(skb->len < 10)) {
1418 		dev_kfree_skb(skb);
1419 		return;
1420 	}
1421 
1422 	rcu_read_lock();
1423 
1424 	/* initialises tx */
1425 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1426 
1427 	if (unlikely(res_prepare == TX_DROP)) {
1428 		dev_kfree_skb(skb);
1429 		rcu_read_unlock();
1430 		return;
1431 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1432 		rcu_read_unlock();
1433 		return;
1434 	}
1435 
1436 	tx.channel = local->hw.conf.channel;
1437 	info->band = tx.channel->band;
1438 
1439 	if (invoke_tx_handlers(&tx))
1440 		goto out;
1441 
1442 	retries = 0;
1443  retry:
1444 	ret = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
1445 	switch (ret) {
1446 	case IEEE80211_TX_OK:
1447 		break;
1448 	case IEEE80211_TX_AGAIN:
1449 		/*
1450 		 * Since there are no fragmented frames on A-MPDU
1451 		 * queues, there's no reason for a driver to reject
1452 		 * a frame there, warn and drop it.
1453 		 */
1454 		if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
1455 			goto drop;
1456 		/* fall through */
1457 	case IEEE80211_TX_PENDING:
1458 		skb = tx.skb;
1459 
1460 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1461 
1462 		if (local->queue_stop_reasons[queue] ||
1463 		    !skb_queue_empty(&local->pending[queue])) {
1464 			/*
1465 			 * if queue is stopped, queue up frames for later
1466 			 * transmission from the tasklet
1467 			 */
1468 			do {
1469 				next = skb->next;
1470 				skb->next = NULL;
1471 				if (unlikely(txpending))
1472 					__skb_queue_head(&local->pending[queue],
1473 							 skb);
1474 				else
1475 					__skb_queue_tail(&local->pending[queue],
1476 							 skb);
1477 			} while ((skb = next));
1478 
1479 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1480 					       flags);
1481 		} else {
1482 			/*
1483 			 * otherwise retry, but this is a race condition or
1484 			 * a driver bug (which we warn about if it persists)
1485 			 */
1486 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1487 					       flags);
1488 
1489 			retries++;
1490 			if (WARN(retries > 10, "tx refused but queue active\n"))
1491 				goto drop;
1492 			goto retry;
1493 		}
1494 	}
1495  out:
1496 	rcu_read_unlock();
1497 	return;
1498 
1499  drop:
1500 	rcu_read_unlock();
1501 
1502 	skb = tx.skb;
1503 	while (skb) {
1504 		next = skb->next;
1505 		dev_kfree_skb(skb);
1506 		skb = next;
1507 	}
1508 }
1509 
1510 /* device xmit handlers */
1511 
1512 static int ieee80211_skb_resize(struct ieee80211_local *local,
1513 				struct sk_buff *skb,
1514 				int head_need, bool may_encrypt)
1515 {
1516 	int tail_need = 0;
1517 
1518 	/*
1519 	 * This could be optimised, devices that do full hardware
1520 	 * crypto (including TKIP MMIC) need no tailroom... But we
1521 	 * have no drivers for such devices currently.
1522 	 */
1523 	if (may_encrypt) {
1524 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1525 		tail_need -= skb_tailroom(skb);
1526 		tail_need = max_t(int, tail_need, 0);
1527 	}
1528 
1529 	if (head_need || tail_need) {
1530 		/* Sorry. Can't account for this any more */
1531 		skb_orphan(skb);
1532 	}
1533 
1534 	if (skb_header_cloned(skb))
1535 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1536 	else
1537 		I802_DEBUG_INC(local->tx_expand_skb_head);
1538 
1539 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1540 		wiphy_debug(local->hw.wiphy,
1541 			    "failed to reallocate TX buffer\n");
1542 		return -ENOMEM;
1543 	}
1544 
1545 	/* update truesize too */
1546 	skb->truesize += head_need + tail_need;
1547 
1548 	return 0;
1549 }
1550 
1551 static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
1552 			   struct sk_buff *skb)
1553 {
1554 	struct ieee80211_local *local = sdata->local;
1555 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1556 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1557 	struct ieee80211_sub_if_data *tmp_sdata;
1558 	int headroom;
1559 	bool may_encrypt;
1560 
1561 	rcu_read_lock();
1562 
1563 	if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1564 		int hdrlen;
1565 		u16 len_rthdr;
1566 
1567 		info->flags |= IEEE80211_TX_CTL_INJECTED |
1568 			       IEEE80211_TX_INTFL_HAS_RADIOTAP;
1569 
1570 		len_rthdr = ieee80211_get_radiotap_len(skb->data);
1571 		hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1572 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
1573 
1574 		/* check the header is complete in the frame */
1575 		if (likely(skb->len >= len_rthdr + hdrlen)) {
1576 			/*
1577 			 * We process outgoing injected frames that have a
1578 			 * local address we handle as though they are our
1579 			 * own frames.
1580 			 * This code here isn't entirely correct, the local
1581 			 * MAC address is not necessarily enough to find
1582 			 * the interface to use; for that proper VLAN/WDS
1583 			 * support we will need a different mechanism.
1584 			 */
1585 
1586 			list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
1587 						list) {
1588 				if (!ieee80211_sdata_running(tmp_sdata))
1589 					continue;
1590 				if (tmp_sdata->vif.type != NL80211_IFTYPE_AP)
1591 					continue;
1592 				if (compare_ether_addr(tmp_sdata->vif.addr,
1593 						       hdr->addr2) == 0) {
1594 					sdata = tmp_sdata;
1595 					break;
1596 				}
1597 			}
1598 		}
1599 	}
1600 
1601 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1602 
1603 	headroom = local->tx_headroom;
1604 	if (may_encrypt)
1605 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1606 	headroom -= skb_headroom(skb);
1607 	headroom = max_t(int, 0, headroom);
1608 
1609 	if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
1610 		dev_kfree_skb(skb);
1611 		rcu_read_unlock();
1612 		return;
1613 	}
1614 
1615 	hdr = (struct ieee80211_hdr *) skb->data;
1616 	info->control.vif = &sdata->vif;
1617 
1618 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1619 	    ieee80211_is_data(hdr->frame_control) &&
1620 		!is_multicast_ether_addr(hdr->addr1))
1621 			if (mesh_nexthop_lookup(skb, sdata)) {
1622 				/* skb queued: don't free */
1623 				rcu_read_unlock();
1624 				return;
1625 			}
1626 
1627 	ieee80211_set_qos_hdr(local, skb);
1628 	ieee80211_tx(sdata, skb, false);
1629 	rcu_read_unlock();
1630 }
1631 
1632 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1633 					 struct net_device *dev)
1634 {
1635 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1636 	struct ieee80211_channel *chan = local->hw.conf.channel;
1637 	struct ieee80211_radiotap_header *prthdr =
1638 		(struct ieee80211_radiotap_header *)skb->data;
1639 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1640 	u16 len_rthdr;
1641 
1642 	/*
1643 	 * Frame injection is not allowed if beaconing is not allowed
1644 	 * or if we need radar detection. Beaconing is usually not allowed when
1645 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1646 	 * Passive scan is also used in world regulatory domains where
1647 	 * your country is not known and as such it should be treated as
1648 	 * NO TX unless the channel is explicitly allowed in which case
1649 	 * your current regulatory domain would not have the passive scan
1650 	 * flag.
1651 	 *
1652 	 * Since AP mode uses monitor interfaces to inject/TX management
1653 	 * frames we can make AP mode the exception to this rule once it
1654 	 * supports radar detection as its implementation can deal with
1655 	 * radar detection by itself. We can do that later by adding a
1656 	 * monitor flag interfaces used for AP support.
1657 	 */
1658 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1659 	     IEEE80211_CHAN_PASSIVE_SCAN)))
1660 		goto fail;
1661 
1662 	/* check for not even having the fixed radiotap header part */
1663 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1664 		goto fail; /* too short to be possibly valid */
1665 
1666 	/* is it a header version we can trust to find length from? */
1667 	if (unlikely(prthdr->it_version))
1668 		goto fail; /* only version 0 is supported */
1669 
1670 	/* then there must be a radiotap header with a length we can use */
1671 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1672 
1673 	/* does the skb contain enough to deliver on the alleged length? */
1674 	if (unlikely(skb->len < len_rthdr))
1675 		goto fail; /* skb too short for claimed rt header extent */
1676 
1677 	/*
1678 	 * fix up the pointers accounting for the radiotap
1679 	 * header still being in there.  We are being given
1680 	 * a precooked IEEE80211 header so no need for
1681 	 * normal processing
1682 	 */
1683 	skb_set_mac_header(skb, len_rthdr);
1684 	/*
1685 	 * these are just fixed to the end of the rt area since we
1686 	 * don't have any better information and at this point, nobody cares
1687 	 */
1688 	skb_set_network_header(skb, len_rthdr);
1689 	skb_set_transport_header(skb, len_rthdr);
1690 
1691 	memset(info, 0, sizeof(*info));
1692 
1693 	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1694 
1695 	/* pass the radiotap header up to xmit */
1696 	ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), skb);
1697 	return NETDEV_TX_OK;
1698 
1699 fail:
1700 	dev_kfree_skb(skb);
1701 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1702 }
1703 
1704 /**
1705  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1706  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1707  * @skb: packet to be sent
1708  * @dev: incoming interface
1709  *
1710  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1711  * not be freed, and caller is responsible for either retrying later or freeing
1712  * skb).
1713  *
1714  * This function takes in an Ethernet header and encapsulates it with suitable
1715  * IEEE 802.11 header based on which interface the packet is coming in. The
1716  * encapsulated packet will then be passed to master interface, wlan#.11, for
1717  * transmission (through low-level driver).
1718  */
1719 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1720 				    struct net_device *dev)
1721 {
1722 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1723 	struct ieee80211_local *local = sdata->local;
1724 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1725 	int ret = NETDEV_TX_BUSY, head_need;
1726 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1727 	__le16 fc;
1728 	struct ieee80211_hdr hdr;
1729 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1730 	const u8 *encaps_data;
1731 	int encaps_len, skip_header_bytes;
1732 	int nh_pos, h_pos;
1733 	struct sta_info *sta = NULL;
1734 	u32 sta_flags = 0;
1735 
1736 	if (unlikely(skb->len < ETH_HLEN)) {
1737 		ret = NETDEV_TX_OK;
1738 		goto fail;
1739 	}
1740 
1741 	nh_pos = skb_network_header(skb) - skb->data;
1742 	h_pos = skb_transport_header(skb) - skb->data;
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 			sta_flags = get_sta_flags(sta);
1762 		}
1763 		rcu_read_unlock();
1764 		if (sta)
1765 			break;
1766 		/* fall through */
1767 	case NL80211_IFTYPE_AP:
1768 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1769 		/* DA BSSID SA */
1770 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1771 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1772 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1773 		hdrlen = 24;
1774 		break;
1775 	case NL80211_IFTYPE_WDS:
1776 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1777 		/* RA TA DA SA */
1778 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1779 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1780 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1781 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1782 		hdrlen = 30;
1783 		break;
1784 #ifdef CONFIG_MAC80211_MESH
1785 	case NL80211_IFTYPE_MESH_POINT:
1786 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1787 			/* Do not send frames with mesh_ttl == 0 */
1788 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1789 			ret = NETDEV_TX_OK;
1790 			goto fail;
1791 		}
1792 
1793 		if (compare_ether_addr(sdata->vif.addr,
1794 				       skb->data + ETH_ALEN) == 0) {
1795 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1796 					skb->data, skb->data + ETH_ALEN);
1797 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1798 					sdata, NULL, NULL, NULL);
1799 		} else {
1800 			/* packet from other interface */
1801 			struct mesh_path *mppath;
1802 			int is_mesh_mcast = 1;
1803 			const u8 *mesh_da;
1804 
1805 			rcu_read_lock();
1806 			if (is_multicast_ether_addr(skb->data))
1807 				/* DA TA mSA AE:SA */
1808 				mesh_da = skb->data;
1809 			else {
1810 				static const u8 bcast[ETH_ALEN] =
1811 					{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1812 
1813 				mppath = mpp_path_lookup(skb->data, sdata);
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 							NULL);
1833 			else
1834 				meshhdrlen =
1835 					ieee80211_new_mesh_header(&mesh_hdr,
1836 							sdata,
1837 							NULL,
1838 							skb->data,
1839 							skb->data + ETH_ALEN);
1840 
1841 		}
1842 		break;
1843 #endif
1844 	case NL80211_IFTYPE_STATION:
1845 		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1846 		if (sdata->u.mgd.use_4addr &&
1847 		    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1848 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1849 			/* RA TA DA SA */
1850 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1851 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1852 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1853 			hdrlen = 30;
1854 		} else {
1855 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1856 			/* BSSID SA DA */
1857 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1858 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1859 			hdrlen = 24;
1860 		}
1861 		break;
1862 	case NL80211_IFTYPE_ADHOC:
1863 		/* DA SA BSSID */
1864 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1865 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1866 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1867 		hdrlen = 24;
1868 		break;
1869 	default:
1870 		ret = NETDEV_TX_OK;
1871 		goto fail;
1872 	}
1873 
1874 	/*
1875 	 * There's no need to try to look up the destination
1876 	 * if it is a multicast address (which can only happen
1877 	 * in AP mode)
1878 	 */
1879 	if (!is_multicast_ether_addr(hdr.addr1)) {
1880 		rcu_read_lock();
1881 		sta = sta_info_get(sdata, hdr.addr1);
1882 		if (sta)
1883 			sta_flags = get_sta_flags(sta);
1884 		rcu_read_unlock();
1885 	}
1886 
1887 	/* receiver and we are QoS enabled, use a QoS type frame */
1888 	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1889 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1890 		hdrlen += 2;
1891 	}
1892 
1893 	/*
1894 	 * Drop unicast frames to unauthorised stations unless they are
1895 	 * EAPOL frames from the local station.
1896 	 */
1897 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
1898 		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1899 		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
1900 		      !(cpu_to_be16(ethertype) == sdata->control_port_protocol &&
1901 		       compare_ether_addr(sdata->vif.addr,
1902 					  skb->data + ETH_ALEN) == 0))) {
1903 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1904 		if (net_ratelimit())
1905 			printk(KERN_DEBUG "%s: dropped frame to %pM"
1906 			       " (unauthorized port)\n", dev->name,
1907 			       hdr.addr1);
1908 #endif
1909 
1910 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1911 
1912 		ret = NETDEV_TX_OK;
1913 		goto fail;
1914 	}
1915 
1916 	hdr.frame_control = fc;
1917 	hdr.duration_id = 0;
1918 	hdr.seq_ctrl = 0;
1919 
1920 	skip_header_bytes = ETH_HLEN;
1921 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
1922 		encaps_data = bridge_tunnel_header;
1923 		encaps_len = sizeof(bridge_tunnel_header);
1924 		skip_header_bytes -= 2;
1925 	} else if (ethertype >= 0x600) {
1926 		encaps_data = rfc1042_header;
1927 		encaps_len = sizeof(rfc1042_header);
1928 		skip_header_bytes -= 2;
1929 	} else {
1930 		encaps_data = NULL;
1931 		encaps_len = 0;
1932 	}
1933 
1934 	skb_pull(skb, skip_header_bytes);
1935 	nh_pos -= skip_header_bytes;
1936 	h_pos -= skip_header_bytes;
1937 
1938 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1939 
1940 	/*
1941 	 * So we need to modify the skb header and hence need a copy of
1942 	 * that. The head_need variable above doesn't, so far, include
1943 	 * the needed header space that we don't need right away. If we
1944 	 * can, then we don't reallocate right now but only after the
1945 	 * frame arrives at the master device (if it does...)
1946 	 *
1947 	 * If we cannot, however, then we will reallocate to include all
1948 	 * the ever needed space. Also, if we need to reallocate it anyway,
1949 	 * make it big enough for everything we may ever need.
1950 	 */
1951 
1952 	if (head_need > 0 || skb_cloned(skb)) {
1953 		head_need += IEEE80211_ENCRYPT_HEADROOM;
1954 		head_need += local->tx_headroom;
1955 		head_need = max_t(int, 0, head_need);
1956 		if (ieee80211_skb_resize(local, skb, head_need, true))
1957 			goto fail;
1958 	}
1959 
1960 	if (encaps_data) {
1961 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
1962 		nh_pos += encaps_len;
1963 		h_pos += encaps_len;
1964 	}
1965 
1966 #ifdef CONFIG_MAC80211_MESH
1967 	if (meshhdrlen > 0) {
1968 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
1969 		nh_pos += meshhdrlen;
1970 		h_pos += meshhdrlen;
1971 	}
1972 #endif
1973 
1974 	if (ieee80211_is_data_qos(fc)) {
1975 		__le16 *qos_control;
1976 
1977 		qos_control = (__le16*) skb_push(skb, 2);
1978 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
1979 		/*
1980 		 * Maybe we could actually set some fields here, for now just
1981 		 * initialise to zero to indicate no special operation.
1982 		 */
1983 		*qos_control = 0;
1984 	} else
1985 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
1986 
1987 	nh_pos += hdrlen;
1988 	h_pos += hdrlen;
1989 
1990 	dev->stats.tx_packets++;
1991 	dev->stats.tx_bytes += skb->len;
1992 
1993 	/* Update skb pointers to various headers since this modified frame
1994 	 * is going to go through Linux networking code that may potentially
1995 	 * need things like pointer to IP header. */
1996 	skb_set_mac_header(skb, 0);
1997 	skb_set_network_header(skb, nh_pos);
1998 	skb_set_transport_header(skb, h_pos);
1999 
2000 	memset(info, 0, sizeof(*info));
2001 
2002 	dev->trans_start = jiffies;
2003 	ieee80211_xmit(sdata, skb);
2004 
2005 	return NETDEV_TX_OK;
2006 
2007  fail:
2008 	if (ret == NETDEV_TX_OK)
2009 		dev_kfree_skb(skb);
2010 
2011 	return ret;
2012 }
2013 
2014 
2015 /*
2016  * ieee80211_clear_tx_pending may not be called in a context where
2017  * it is possible that it packets could come in again.
2018  */
2019 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2020 {
2021 	int i;
2022 
2023 	for (i = 0; i < local->hw.queues; i++)
2024 		skb_queue_purge(&local->pending[i]);
2025 }
2026 
2027 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2028 				     struct sk_buff *skb)
2029 {
2030 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2031 	struct ieee80211_sub_if_data *sdata;
2032 	struct sta_info *sta;
2033 	struct ieee80211_hdr *hdr;
2034 	int ret;
2035 	bool result = true;
2036 
2037 	sdata = vif_to_sdata(info->control.vif);
2038 
2039 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2040 		ieee80211_tx(sdata, skb, true);
2041 	} else {
2042 		hdr = (struct ieee80211_hdr *)skb->data;
2043 		sta = sta_info_get(sdata, hdr->addr1);
2044 
2045 		ret = __ieee80211_tx(local, &skb, sta, true);
2046 		if (ret != IEEE80211_TX_OK)
2047 			result = false;
2048 	}
2049 
2050 	return result;
2051 }
2052 
2053 /*
2054  * Transmit all pending packets. Called from tasklet.
2055  */
2056 void ieee80211_tx_pending(unsigned long data)
2057 {
2058 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2059 	struct ieee80211_sub_if_data *sdata;
2060 	unsigned long flags;
2061 	int i;
2062 	bool txok;
2063 
2064 	rcu_read_lock();
2065 
2066 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2067 	for (i = 0; i < local->hw.queues; i++) {
2068 		/*
2069 		 * If queue is stopped by something other than due to pending
2070 		 * frames, or we have no pending frames, proceed to next queue.
2071 		 */
2072 		if (local->queue_stop_reasons[i] ||
2073 		    skb_queue_empty(&local->pending[i]))
2074 			continue;
2075 
2076 		while (!skb_queue_empty(&local->pending[i])) {
2077 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2078 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2079 
2080 			if (WARN_ON(!info->control.vif)) {
2081 				kfree_skb(skb);
2082 				continue;
2083 			}
2084 
2085 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2086 						flags);
2087 
2088 			txok = ieee80211_tx_pending_skb(local, skb);
2089 			if (!txok)
2090 				__skb_queue_head(&local->pending[i], skb);
2091 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2092 					  flags);
2093 			if (!txok)
2094 				break;
2095 		}
2096 
2097 		if (skb_queue_empty(&local->pending[i]))
2098 			list_for_each_entry_rcu(sdata, &local->interfaces, list)
2099 				netif_wake_subqueue(sdata->dev, i);
2100 	}
2101 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2102 
2103 	rcu_read_unlock();
2104 }
2105 
2106 /* functions for drivers to get certain frames */
2107 
2108 static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
2109 				     struct sk_buff *skb,
2110 				     struct beacon_data *beacon)
2111 {
2112 	u8 *pos, *tim;
2113 	int aid0 = 0;
2114 	int i, have_bits = 0, n1, n2;
2115 
2116 	/* Generate bitmap for TIM only if there are any STAs in power save
2117 	 * mode. */
2118 	if (atomic_read(&bss->num_sta_ps) > 0)
2119 		/* in the hope that this is faster than
2120 		 * checking byte-for-byte */
2121 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2122 					  IEEE80211_MAX_AID+1);
2123 
2124 	if (bss->dtim_count == 0)
2125 		bss->dtim_count = beacon->dtim_period - 1;
2126 	else
2127 		bss->dtim_count--;
2128 
2129 	tim = pos = (u8 *) skb_put(skb, 6);
2130 	*pos++ = WLAN_EID_TIM;
2131 	*pos++ = 4;
2132 	*pos++ = bss->dtim_count;
2133 	*pos++ = beacon->dtim_period;
2134 
2135 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2136 		aid0 = 1;
2137 
2138 	if (have_bits) {
2139 		/* Find largest even number N1 so that bits numbered 1 through
2140 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2141 		 * (N2 + 1) x 8 through 2007 are 0. */
2142 		n1 = 0;
2143 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2144 			if (bss->tim[i]) {
2145 				n1 = i & 0xfe;
2146 				break;
2147 			}
2148 		}
2149 		n2 = n1;
2150 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2151 			if (bss->tim[i]) {
2152 				n2 = i;
2153 				break;
2154 			}
2155 		}
2156 
2157 		/* Bitmap control */
2158 		*pos++ = n1 | aid0;
2159 		/* Part Virt Bitmap */
2160 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2161 
2162 		tim[1] = n2 - n1 + 4;
2163 		skb_put(skb, n2 - n1);
2164 	} else {
2165 		*pos++ = aid0; /* Bitmap control */
2166 		*pos++ = 0; /* Part Virt Bitmap */
2167 	}
2168 }
2169 
2170 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2171 					 struct ieee80211_vif *vif,
2172 					 u16 *tim_offset, u16 *tim_length)
2173 {
2174 	struct ieee80211_local *local = hw_to_local(hw);
2175 	struct sk_buff *skb = NULL;
2176 	struct ieee80211_tx_info *info;
2177 	struct ieee80211_sub_if_data *sdata = NULL;
2178 	struct ieee80211_if_ap *ap = NULL;
2179 	struct beacon_data *beacon;
2180 	struct ieee80211_supported_band *sband;
2181 	enum ieee80211_band band = local->hw.conf.channel->band;
2182 	struct ieee80211_tx_rate_control txrc;
2183 
2184 	sband = local->hw.wiphy->bands[band];
2185 
2186 	rcu_read_lock();
2187 
2188 	sdata = vif_to_sdata(vif);
2189 
2190 	if (tim_offset)
2191 		*tim_offset = 0;
2192 	if (tim_length)
2193 		*tim_length = 0;
2194 
2195 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2196 		ap = &sdata->u.ap;
2197 		beacon = rcu_dereference(ap->beacon);
2198 		if (ap && beacon) {
2199 			/*
2200 			 * headroom, head length,
2201 			 * tail length and maximum TIM length
2202 			 */
2203 			skb = dev_alloc_skb(local->tx_headroom +
2204 					    beacon->head_len +
2205 					    beacon->tail_len + 256);
2206 			if (!skb)
2207 				goto out;
2208 
2209 			skb_reserve(skb, local->tx_headroom);
2210 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2211 			       beacon->head_len);
2212 
2213 			/*
2214 			 * Not very nice, but we want to allow the driver to call
2215 			 * ieee80211_beacon_get() as a response to the set_tim()
2216 			 * callback. That, however, is already invoked under the
2217 			 * sta_lock to guarantee consistent and race-free update
2218 			 * of the tim bitmap in mac80211 and the driver.
2219 			 */
2220 			if (local->tim_in_locked_section) {
2221 				ieee80211_beacon_add_tim(ap, skb, beacon);
2222 			} else {
2223 				unsigned long flags;
2224 
2225 				spin_lock_irqsave(&local->sta_lock, flags);
2226 				ieee80211_beacon_add_tim(ap, skb, beacon);
2227 				spin_unlock_irqrestore(&local->sta_lock, flags);
2228 			}
2229 
2230 			if (tim_offset)
2231 				*tim_offset = beacon->head_len;
2232 			if (tim_length)
2233 				*tim_length = skb->len - beacon->head_len;
2234 
2235 			if (beacon->tail)
2236 				memcpy(skb_put(skb, beacon->tail_len),
2237 				       beacon->tail, beacon->tail_len);
2238 		} else
2239 			goto out;
2240 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2241 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2242 		struct ieee80211_hdr *hdr;
2243 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2244 
2245 		if (!presp)
2246 			goto out;
2247 
2248 		skb = skb_copy(presp, GFP_ATOMIC);
2249 		if (!skb)
2250 			goto out;
2251 
2252 		hdr = (struct ieee80211_hdr *) skb->data;
2253 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2254 						 IEEE80211_STYPE_BEACON);
2255 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2256 		struct ieee80211_mgmt *mgmt;
2257 		u8 *pos;
2258 
2259 		/* headroom, head length, tail length and maximum TIM length */
2260 		skb = dev_alloc_skb(local->tx_headroom + 400);
2261 		if (!skb)
2262 			goto out;
2263 
2264 		skb_reserve(skb, local->hw.extra_tx_headroom);
2265 		mgmt = (struct ieee80211_mgmt *)
2266 			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
2267 		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2268 		mgmt->frame_control =
2269 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2270 		memset(mgmt->da, 0xff, ETH_ALEN);
2271 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2272 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2273 		mgmt->u.beacon.beacon_int =
2274 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2275 		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
2276 
2277 		pos = skb_put(skb, 2);
2278 		*pos++ = WLAN_EID_SSID;
2279 		*pos++ = 0x0;
2280 
2281 		mesh_mgmt_ies_add(skb, sdata);
2282 	} else {
2283 		WARN_ON(1);
2284 		goto out;
2285 	}
2286 
2287 	info = IEEE80211_SKB_CB(skb);
2288 
2289 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2290 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2291 	info->band = band;
2292 
2293 	memset(&txrc, 0, sizeof(txrc));
2294 	txrc.hw = hw;
2295 	txrc.sband = sband;
2296 	txrc.bss_conf = &sdata->vif.bss_conf;
2297 	txrc.skb = skb;
2298 	txrc.reported_rate.idx = -1;
2299 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2300 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2301 		txrc.max_rate_idx = -1;
2302 	else
2303 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2304 	txrc.ap = true;
2305 	rate_control_get_rate(sdata, NULL, &txrc);
2306 
2307 	info->control.vif = vif;
2308 
2309 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2310 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2311 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2312  out:
2313 	rcu_read_unlock();
2314 	return skb;
2315 }
2316 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2317 
2318 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2319 				     struct ieee80211_vif *vif)
2320 {
2321 	struct ieee80211_sub_if_data *sdata;
2322 	struct ieee80211_if_managed *ifmgd;
2323 	struct ieee80211_pspoll *pspoll;
2324 	struct ieee80211_local *local;
2325 	struct sk_buff *skb;
2326 
2327 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2328 		return NULL;
2329 
2330 	sdata = vif_to_sdata(vif);
2331 	ifmgd = &sdata->u.mgd;
2332 	local = sdata->local;
2333 
2334 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2335 	if (!skb) {
2336 		printk(KERN_DEBUG "%s: failed to allocate buffer for "
2337 		       "pspoll template\n", sdata->name);
2338 		return NULL;
2339 	}
2340 	skb_reserve(skb, local->hw.extra_tx_headroom);
2341 
2342 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2343 	memset(pspoll, 0, sizeof(*pspoll));
2344 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2345 					    IEEE80211_STYPE_PSPOLL);
2346 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2347 
2348 	/* aid in PS-Poll has its two MSBs each set to 1 */
2349 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2350 
2351 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2352 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2353 
2354 	return skb;
2355 }
2356 EXPORT_SYMBOL(ieee80211_pspoll_get);
2357 
2358 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2359 				       struct ieee80211_vif *vif)
2360 {
2361 	struct ieee80211_hdr_3addr *nullfunc;
2362 	struct ieee80211_sub_if_data *sdata;
2363 	struct ieee80211_if_managed *ifmgd;
2364 	struct ieee80211_local *local;
2365 	struct sk_buff *skb;
2366 
2367 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2368 		return NULL;
2369 
2370 	sdata = vif_to_sdata(vif);
2371 	ifmgd = &sdata->u.mgd;
2372 	local = sdata->local;
2373 
2374 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2375 	if (!skb) {
2376 		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
2377 		       "template\n", sdata->name);
2378 		return NULL;
2379 	}
2380 	skb_reserve(skb, local->hw.extra_tx_headroom);
2381 
2382 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2383 							  sizeof(*nullfunc));
2384 	memset(nullfunc, 0, sizeof(*nullfunc));
2385 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2386 					      IEEE80211_STYPE_NULLFUNC |
2387 					      IEEE80211_FCTL_TODS);
2388 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2389 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2390 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2391 
2392 	return skb;
2393 }
2394 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2395 
2396 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2397 				       struct ieee80211_vif *vif,
2398 				       const u8 *ssid, size_t ssid_len,
2399 				       const u8 *ie, size_t ie_len)
2400 {
2401 	struct ieee80211_sub_if_data *sdata;
2402 	struct ieee80211_local *local;
2403 	struct ieee80211_hdr_3addr *hdr;
2404 	struct sk_buff *skb;
2405 	size_t ie_ssid_len;
2406 	u8 *pos;
2407 
2408 	sdata = vif_to_sdata(vif);
2409 	local = sdata->local;
2410 	ie_ssid_len = 2 + ssid_len;
2411 
2412 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2413 			    ie_ssid_len + ie_len);
2414 	if (!skb) {
2415 		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
2416 		       "request template\n", sdata->name);
2417 		return NULL;
2418 	}
2419 
2420 	skb_reserve(skb, local->hw.extra_tx_headroom);
2421 
2422 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2423 	memset(hdr, 0, sizeof(*hdr));
2424 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2425 					 IEEE80211_STYPE_PROBE_REQ);
2426 	memset(hdr->addr1, 0xff, ETH_ALEN);
2427 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2428 	memset(hdr->addr3, 0xff, ETH_ALEN);
2429 
2430 	pos = skb_put(skb, ie_ssid_len);
2431 	*pos++ = WLAN_EID_SSID;
2432 	*pos++ = ssid_len;
2433 	if (ssid)
2434 		memcpy(pos, ssid, ssid_len);
2435 	pos += ssid_len;
2436 
2437 	if (ie) {
2438 		pos = skb_put(skb, ie_len);
2439 		memcpy(pos, ie, ie_len);
2440 	}
2441 
2442 	return skb;
2443 }
2444 EXPORT_SYMBOL(ieee80211_probereq_get);
2445 
2446 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2447 		       const void *frame, size_t frame_len,
2448 		       const struct ieee80211_tx_info *frame_txctl,
2449 		       struct ieee80211_rts *rts)
2450 {
2451 	const struct ieee80211_hdr *hdr = frame;
2452 
2453 	rts->frame_control =
2454 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2455 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2456 					       frame_txctl);
2457 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2458 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2459 }
2460 EXPORT_SYMBOL(ieee80211_rts_get);
2461 
2462 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2463 			     const void *frame, size_t frame_len,
2464 			     const struct ieee80211_tx_info *frame_txctl,
2465 			     struct ieee80211_cts *cts)
2466 {
2467 	const struct ieee80211_hdr *hdr = frame;
2468 
2469 	cts->frame_control =
2470 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2471 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2472 						     frame_len, frame_txctl);
2473 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2474 }
2475 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2476 
2477 struct sk_buff *
2478 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2479 			  struct ieee80211_vif *vif)
2480 {
2481 	struct ieee80211_local *local = hw_to_local(hw);
2482 	struct sk_buff *skb = NULL;
2483 	struct sta_info *sta;
2484 	struct ieee80211_tx_data tx;
2485 	struct ieee80211_sub_if_data *sdata;
2486 	struct ieee80211_if_ap *bss = NULL;
2487 	struct beacon_data *beacon;
2488 	struct ieee80211_tx_info *info;
2489 
2490 	sdata = vif_to_sdata(vif);
2491 	bss = &sdata->u.ap;
2492 
2493 	rcu_read_lock();
2494 	beacon = rcu_dereference(bss->beacon);
2495 
2496 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2497 		goto out;
2498 
2499 	if (bss->dtim_count != 0)
2500 		goto out; /* send buffered bc/mc only after DTIM beacon */
2501 
2502 	while (1) {
2503 		skb = skb_dequeue(&bss->ps_bc_buf);
2504 		if (!skb)
2505 			goto out;
2506 		local->total_ps_buffered--;
2507 
2508 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2509 			struct ieee80211_hdr *hdr =
2510 				(struct ieee80211_hdr *) skb->data;
2511 			/* more buffered multicast/broadcast frames ==> set
2512 			 * MoreData flag in IEEE 802.11 header to inform PS
2513 			 * STAs */
2514 			hdr->frame_control |=
2515 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2516 		}
2517 
2518 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2519 			break;
2520 		dev_kfree_skb_any(skb);
2521 	}
2522 
2523 	info = IEEE80211_SKB_CB(skb);
2524 
2525 	sta = tx.sta;
2526 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2527 	tx.channel = local->hw.conf.channel;
2528 	info->band = tx.channel->band;
2529 
2530 	if (invoke_tx_handlers(&tx))
2531 		skb = NULL;
2532  out:
2533 	rcu_read_unlock();
2534 
2535 	return skb;
2536 }
2537 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2538 
2539 void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
2540 {
2541 	skb_set_mac_header(skb, 0);
2542 	skb_set_network_header(skb, 0);
2543 	skb_set_transport_header(skb, 0);
2544 
2545 	/* send all internal mgmt frames on VO */
2546 	skb_set_queue_mapping(skb, 0);
2547 
2548 	/*
2549 	 * The other path calling ieee80211_xmit is from the tasklet,
2550 	 * and while we can handle concurrent transmissions locking
2551 	 * requirements are that we do not come into tx with bhs on.
2552 	 */
2553 	local_bh_disable();
2554 	ieee80211_xmit(sdata, skb);
2555 	local_bh_enable();
2556 }
2557