xref: /openbmc/linux/net/mac80211/tx.c (revision acc6a093)
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_MESH_POINT)
277 		return TX_CONTINUE;
278 
279 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
280 		return TX_CONTINUE;
281 
282 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
283 
284 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
285 		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
286 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
287 			     ieee80211_is_data(hdr->frame_control))) {
288 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
289 			printk(KERN_DEBUG "%s: dropped data frame to not "
290 			       "associated station %pM\n",
291 			       tx->sdata->name, hdr->addr1);
292 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
293 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
294 			return TX_DROP;
295 		}
296 	} else {
297 		if (unlikely(ieee80211_is_data(hdr->frame_control) &&
298 			     tx->local->num_sta == 0 &&
299 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
300 			/*
301 			 * No associated STAs - no need to send multicast
302 			 * frames.
303 			 */
304 			return TX_DROP;
305 		}
306 		return TX_CONTINUE;
307 	}
308 
309 	return TX_CONTINUE;
310 }
311 
312 /* This function is called whenever the AP is about to exceed the maximum limit
313  * of buffered frames for power saving STAs. This situation should not really
314  * happen often during normal operation, so dropping the oldest buffered packet
315  * from each queue should be OK to make some room for new frames. */
316 static void purge_old_ps_buffers(struct ieee80211_local *local)
317 {
318 	int total = 0, purged = 0;
319 	struct sk_buff *skb;
320 	struct ieee80211_sub_if_data *sdata;
321 	struct sta_info *sta;
322 
323 	/*
324 	 * virtual interfaces are protected by RCU
325 	 */
326 	rcu_read_lock();
327 
328 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
329 		struct ieee80211_if_ap *ap;
330 		if (sdata->vif.type != NL80211_IFTYPE_AP)
331 			continue;
332 		ap = &sdata->u.ap;
333 		skb = skb_dequeue(&ap->ps_bc_buf);
334 		if (skb) {
335 			purged++;
336 			dev_kfree_skb(skb);
337 		}
338 		total += skb_queue_len(&ap->ps_bc_buf);
339 	}
340 
341 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
342 		skb = skb_dequeue(&sta->ps_tx_buf);
343 		if (skb) {
344 			purged++;
345 			dev_kfree_skb(skb);
346 		}
347 		total += skb_queue_len(&sta->ps_tx_buf);
348 	}
349 
350 	rcu_read_unlock();
351 
352 	local->total_ps_buffered = total;
353 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
354 	printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
355 	       wiphy_name(local->hw.wiphy), purged);
356 #endif
357 }
358 
359 static ieee80211_tx_result
360 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
361 {
362 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
363 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
364 
365 	/*
366 	 * broadcast/multicast frame
367 	 *
368 	 * If any of the associated stations is in power save mode,
369 	 * the frame is buffered to be sent after DTIM beacon frame.
370 	 * This is done either by the hardware or us.
371 	 */
372 
373 	/* powersaving STAs only in AP/VLAN mode */
374 	if (!tx->sdata->bss)
375 		return TX_CONTINUE;
376 
377 	/* no buffering for ordered frames */
378 	if (ieee80211_has_order(hdr->frame_control))
379 		return TX_CONTINUE;
380 
381 	/* no stations in PS mode */
382 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
383 		return TX_CONTINUE;
384 
385 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
386 
387 	/* device releases frame after DTIM beacon */
388 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
389 		return TX_CONTINUE;
390 
391 	/* buffered in mac80211 */
392 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
393 		purge_old_ps_buffers(tx->local);
394 
395 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
396 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
397 		if (net_ratelimit())
398 			printk(KERN_DEBUG "%s: BC TX buffer full - dropping the oldest frame\n",
399 			       tx->sdata->name);
400 #endif
401 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
402 	} else
403 		tx->local->total_ps_buffered++;
404 
405 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
406 
407 	return TX_QUEUED;
408 }
409 
410 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
411 			     struct sk_buff *skb)
412 {
413 	if (!ieee80211_is_mgmt(fc))
414 		return 0;
415 
416 	if (sta == NULL || !test_sta_flags(sta, WLAN_STA_MFP))
417 		return 0;
418 
419 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
420 					    skb->data))
421 		return 0;
422 
423 	return 1;
424 }
425 
426 static ieee80211_tx_result
427 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
428 {
429 	struct sta_info *sta = tx->sta;
430 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
431 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
432 	u32 staflags;
433 
434 	if (unlikely(!sta ||
435 		     ieee80211_is_probe_resp(hdr->frame_control) ||
436 		     ieee80211_is_auth(hdr->frame_control) ||
437 		     ieee80211_is_assoc_resp(hdr->frame_control) ||
438 		     ieee80211_is_reassoc_resp(hdr->frame_control)))
439 		return TX_CONTINUE;
440 
441 	staflags = get_sta_flags(sta);
442 
443 	if (unlikely((staflags & (WLAN_STA_PS_STA | WLAN_STA_PS_DRIVER)) &&
444 		     !(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) {
445 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
446 		printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
447 		       "before %d)\n",
448 		       sta->sta.addr, sta->sta.aid,
449 		       skb_queue_len(&sta->ps_tx_buf));
450 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
451 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
452 			purge_old_ps_buffers(tx->local);
453 		if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
454 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
455 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
456 			if (net_ratelimit()) {
457 				printk(KERN_DEBUG "%s: STA %pM TX "
458 				       "buffer full - dropping oldest frame\n",
459 				       tx->sdata->name, sta->sta.addr);
460 			}
461 #endif
462 			dev_kfree_skb(old);
463 		} else
464 			tx->local->total_ps_buffered++;
465 
466 		/*
467 		 * Queue frame to be sent after STA wakes up/polls,
468 		 * but don't set the TIM bit if the driver is blocking
469 		 * wakeup or poll response transmissions anyway.
470 		 */
471 		if (skb_queue_empty(&sta->ps_tx_buf) &&
472 		    !(staflags & WLAN_STA_PS_DRIVER))
473 			sta_info_set_tim_bit(sta);
474 
475 		info->control.jiffies = jiffies;
476 		info->control.vif = &tx->sdata->vif;
477 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
478 		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
479 		return TX_QUEUED;
480 	}
481 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
482 	else if (unlikely(staflags & WLAN_STA_PS_STA)) {
483 		printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
484 		       "set -> send frame\n", tx->sdata->name,
485 		       sta->sta.addr);
486 	}
487 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
488 
489 	return TX_CONTINUE;
490 }
491 
492 static ieee80211_tx_result debug_noinline
493 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
494 {
495 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
496 		return TX_CONTINUE;
497 
498 	if (tx->flags & IEEE80211_TX_UNICAST)
499 		return ieee80211_tx_h_unicast_ps_buf(tx);
500 	else
501 		return ieee80211_tx_h_multicast_ps_buf(tx);
502 }
503 
504 static ieee80211_tx_result debug_noinline
505 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
506 {
507 	struct ieee80211_key *key = NULL;
508 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
509 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
510 
511 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
512 		tx->key = NULL;
513 	else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
514 		tx->key = key;
515 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
516 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
517 		tx->key = key;
518 	else if ((key = rcu_dereference(tx->sdata->default_key)))
519 		tx->key = key;
520 	else if (tx->sdata->drop_unencrypted &&
521 		 (tx->skb->protocol != cpu_to_be16(ETH_P_PAE)) &&
522 		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
523 		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
524 		  (ieee80211_is_action(hdr->frame_control) &&
525 		   tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) {
526 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
527 		return TX_DROP;
528 	} else
529 		tx->key = NULL;
530 
531 	if (tx->key) {
532 		bool skip_hw = false;
533 
534 		tx->key->tx_rx_count++;
535 		/* TODO: add threshold stuff again */
536 
537 		switch (tx->key->conf.alg) {
538 		case ALG_WEP:
539 			if (ieee80211_is_auth(hdr->frame_control))
540 				break;
541 		case ALG_TKIP:
542 			if (!ieee80211_is_data_present(hdr->frame_control))
543 				tx->key = NULL;
544 			break;
545 		case ALG_CCMP:
546 			if (!ieee80211_is_data_present(hdr->frame_control) &&
547 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
548 					       tx->skb))
549 				tx->key = NULL;
550 			else
551 				skip_hw = (tx->key->conf.flags &
552 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
553 					ieee80211_is_mgmt(hdr->frame_control);
554 			break;
555 		case ALG_AES_CMAC:
556 			if (!ieee80211_is_mgmt(hdr->frame_control))
557 				tx->key = NULL;
558 			break;
559 		}
560 
561 		if (!skip_hw && tx->key &&
562 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
563 			info->control.hw_key = &tx->key->conf;
564 	}
565 
566 	return TX_CONTINUE;
567 }
568 
569 static ieee80211_tx_result debug_noinline
570 ieee80211_tx_h_sta(struct ieee80211_tx_data *tx)
571 {
572 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
573 
574 	if (tx->sta && tx->sta->uploaded)
575 		info->control.sta = &tx->sta->sta;
576 
577 	return TX_CONTINUE;
578 }
579 
580 static ieee80211_tx_result debug_noinline
581 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
582 {
583 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
584 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
585 	struct ieee80211_supported_band *sband;
586 	struct ieee80211_rate *rate;
587 	int i, len;
588 	bool inval = false, rts = false, short_preamble = false;
589 	struct ieee80211_tx_rate_control txrc;
590 	u32 sta_flags;
591 
592 	memset(&txrc, 0, sizeof(txrc));
593 
594 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
595 
596 	len = min_t(int, tx->skb->len + FCS_LEN,
597 			 tx->local->hw.wiphy->frag_threshold);
598 
599 	/* set up the tx rate control struct we give the RC algo */
600 	txrc.hw = local_to_hw(tx->local);
601 	txrc.sband = sband;
602 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
603 	txrc.skb = tx->skb;
604 	txrc.reported_rate.idx = -1;
605 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
606 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
607 		txrc.max_rate_idx = -1;
608 	else
609 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
610 	txrc.ap = tx->sdata->vif.type == NL80211_IFTYPE_AP;
611 
612 	/* set up RTS protection if desired */
613 	if (len > tx->local->hw.wiphy->rts_threshold) {
614 		txrc.rts = rts = true;
615 	}
616 
617 	/*
618 	 * Use short preamble if the BSS can handle it, but not for
619 	 * management frames unless we know the receiver can handle
620 	 * that -- the management frame might be to a station that
621 	 * just wants a probe response.
622 	 */
623 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
624 	    (ieee80211_is_data(hdr->frame_control) ||
625 	     (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
626 		txrc.short_preamble = short_preamble = true;
627 
628 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
629 
630 	/*
631 	 * Lets not bother rate control if we're associated and cannot
632 	 * talk to the sta. This should not happen.
633 	 */
634 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) &&
635 		 (sta_flags & WLAN_STA_ASSOC) &&
636 		 !rate_usable_index_exists(sband, &tx->sta->sta),
637 		 "%s: Dropped data frame as no usable bitrate found while "
638 		 "scanning and associated. Target station: "
639 		 "%pM on %d GHz band\n",
640 		 tx->sdata->name, hdr->addr1,
641 		 tx->channel->band ? 5 : 2))
642 		return TX_DROP;
643 
644 	/*
645 	 * If we're associated with the sta at this point we know we can at
646 	 * least send the frame at the lowest bit rate.
647 	 */
648 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
649 
650 	if (unlikely(info->control.rates[0].idx < 0))
651 		return TX_DROP;
652 
653 	if (txrc.reported_rate.idx < 0)
654 		txrc.reported_rate = info->control.rates[0];
655 
656 	if (tx->sta)
657 		tx->sta->last_tx_rate = txrc.reported_rate;
658 
659 	if (unlikely(!info->control.rates[0].count))
660 		info->control.rates[0].count = 1;
661 
662 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
663 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
664 		info->control.rates[0].count = 1;
665 
666 	if (is_multicast_ether_addr(hdr->addr1)) {
667 		/*
668 		 * XXX: verify the rate is in the basic rateset
669 		 */
670 		return TX_CONTINUE;
671 	}
672 
673 	/*
674 	 * set up the RTS/CTS rate as the fastest basic rate
675 	 * that is not faster than the data rate
676 	 *
677 	 * XXX: Should this check all retry rates?
678 	 */
679 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
680 		s8 baserate = 0;
681 
682 		rate = &sband->bitrates[info->control.rates[0].idx];
683 
684 		for (i = 0; i < sband->n_bitrates; i++) {
685 			/* must be a basic rate */
686 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
687 				continue;
688 			/* must not be faster than the data rate */
689 			if (sband->bitrates[i].bitrate > rate->bitrate)
690 				continue;
691 			/* maximum */
692 			if (sband->bitrates[baserate].bitrate <
693 			     sband->bitrates[i].bitrate)
694 				baserate = i;
695 		}
696 
697 		info->control.rts_cts_rate_idx = baserate;
698 	}
699 
700 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
701 		/*
702 		 * make sure there's no valid rate following
703 		 * an invalid one, just in case drivers don't
704 		 * take the API seriously to stop at -1.
705 		 */
706 		if (inval) {
707 			info->control.rates[i].idx = -1;
708 			continue;
709 		}
710 		if (info->control.rates[i].idx < 0) {
711 			inval = true;
712 			continue;
713 		}
714 
715 		/*
716 		 * For now assume MCS is already set up correctly, this
717 		 * needs to be fixed.
718 		 */
719 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
720 			WARN_ON(info->control.rates[i].idx > 76);
721 			continue;
722 		}
723 
724 		/* set up RTS protection if desired */
725 		if (rts)
726 			info->control.rates[i].flags |=
727 				IEEE80211_TX_RC_USE_RTS_CTS;
728 
729 		/* RC is busted */
730 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
731 				 sband->n_bitrates)) {
732 			info->control.rates[i].idx = -1;
733 			continue;
734 		}
735 
736 		rate = &sband->bitrates[info->control.rates[i].idx];
737 
738 		/* set up short preamble */
739 		if (short_preamble &&
740 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
741 			info->control.rates[i].flags |=
742 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
743 
744 		/* set up G protection */
745 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
746 		    rate->flags & IEEE80211_RATE_ERP_G)
747 			info->control.rates[i].flags |=
748 				IEEE80211_TX_RC_USE_CTS_PROTECT;
749 	}
750 
751 	return TX_CONTINUE;
752 }
753 
754 static ieee80211_tx_result debug_noinline
755 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
756 {
757 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
758 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
759 	u16 *seq;
760 	u8 *qc;
761 	int tid;
762 
763 	/*
764 	 * Packet injection may want to control the sequence
765 	 * number, if we have no matching interface then we
766 	 * neither assign one ourselves nor ask the driver to.
767 	 */
768 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
769 		return TX_CONTINUE;
770 
771 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
772 		return TX_CONTINUE;
773 
774 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
775 		return TX_CONTINUE;
776 
777 	/*
778 	 * Anything but QoS data that has a sequence number field
779 	 * (is long enough) gets a sequence number from the global
780 	 * counter.
781 	 */
782 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
783 		/* driver should assign sequence number */
784 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
785 		/* for pure STA mode without beacons, we can do it */
786 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
787 		tx->sdata->sequence_number += 0x10;
788 		return TX_CONTINUE;
789 	}
790 
791 	/*
792 	 * This should be true for injected/management frames only, for
793 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
794 	 * above since they are not QoS-data frames.
795 	 */
796 	if (!tx->sta)
797 		return TX_CONTINUE;
798 
799 	/* include per-STA, per-TID sequence counter */
800 
801 	qc = ieee80211_get_qos_ctl(hdr);
802 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
803 	seq = &tx->sta->tid_seq[tid];
804 
805 	hdr->seq_ctrl = cpu_to_le16(*seq);
806 
807 	/* Increase the sequence number. */
808 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
809 
810 	return TX_CONTINUE;
811 }
812 
813 static int ieee80211_fragment(struct ieee80211_local *local,
814 			      struct sk_buff *skb, int hdrlen,
815 			      int frag_threshold)
816 {
817 	struct sk_buff *tail = skb, *tmp;
818 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
819 	int pos = hdrlen + per_fragm;
820 	int rem = skb->len - hdrlen - per_fragm;
821 
822 	if (WARN_ON(rem < 0))
823 		return -EINVAL;
824 
825 	while (rem) {
826 		int fraglen = per_fragm;
827 
828 		if (fraglen > rem)
829 			fraglen = rem;
830 		rem -= fraglen;
831 		tmp = dev_alloc_skb(local->tx_headroom +
832 				    frag_threshold +
833 				    IEEE80211_ENCRYPT_HEADROOM +
834 				    IEEE80211_ENCRYPT_TAILROOM);
835 		if (!tmp)
836 			return -ENOMEM;
837 		tail->next = tmp;
838 		tail = tmp;
839 		skb_reserve(tmp, local->tx_headroom +
840 				 IEEE80211_ENCRYPT_HEADROOM);
841 		/* copy control information */
842 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
843 		skb_copy_queue_mapping(tmp, skb);
844 		tmp->priority = skb->priority;
845 		tmp->dev = skb->dev;
846 
847 		/* copy header and data */
848 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
849 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
850 
851 		pos += fraglen;
852 	}
853 
854 	skb->len = hdrlen + per_fragm;
855 	return 0;
856 }
857 
858 static ieee80211_tx_result debug_noinline
859 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
860 {
861 	struct sk_buff *skb = tx->skb;
862 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
863 	struct ieee80211_hdr *hdr = (void *)skb->data;
864 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
865 	int hdrlen;
866 	int fragnum;
867 
868 	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
869 		return TX_CONTINUE;
870 
871 	/*
872 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
873 	 * This scenario is handled in ieee80211_tx_prepare but extra
874 	 * caution taken here as fragmented ampdu may cause Tx stop.
875 	 */
876 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
877 		return TX_DROP;
878 
879 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
880 
881 	/* internal error, why is TX_FRAGMENTED set? */
882 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
883 		return TX_DROP;
884 
885 	/*
886 	 * Now fragment the frame. This will allocate all the fragments and
887 	 * chain them (using skb as the first fragment) to skb->next.
888 	 * During transmission, we will remove the successfully transmitted
889 	 * fragments from this list. When the low-level driver rejects one
890 	 * of the fragments then we will simply pretend to accept the skb
891 	 * but store it away as pending.
892 	 */
893 	if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
894 		return TX_DROP;
895 
896 	/* update duration/seq/flags of fragments */
897 	fragnum = 0;
898 	do {
899 		int next_len;
900 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
901 
902 		hdr = (void *)skb->data;
903 		info = IEEE80211_SKB_CB(skb);
904 
905 		if (skb->next) {
906 			hdr->frame_control |= morefrags;
907 			next_len = skb->next->len;
908 			/*
909 			 * No multi-rate retries for fragmented frames, that
910 			 * would completely throw off the NAV at other STAs.
911 			 */
912 			info->control.rates[1].idx = -1;
913 			info->control.rates[2].idx = -1;
914 			info->control.rates[3].idx = -1;
915 			info->control.rates[4].idx = -1;
916 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
917 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
918 		} else {
919 			hdr->frame_control &= ~morefrags;
920 			next_len = 0;
921 		}
922 		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
923 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
924 		fragnum++;
925 	} while ((skb = skb->next));
926 
927 	return TX_CONTINUE;
928 }
929 
930 static ieee80211_tx_result debug_noinline
931 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
932 {
933 	struct sk_buff *skb = tx->skb;
934 
935 	if (!tx->sta)
936 		return TX_CONTINUE;
937 
938 	tx->sta->tx_packets++;
939 	do {
940 		tx->sta->tx_fragments++;
941 		tx->sta->tx_bytes += skb->len;
942 	} while ((skb = skb->next));
943 
944 	return TX_CONTINUE;
945 }
946 
947 static ieee80211_tx_result debug_noinline
948 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
949 {
950 	if (!tx->key)
951 		return TX_CONTINUE;
952 
953 	switch (tx->key->conf.alg) {
954 	case ALG_WEP:
955 		return ieee80211_crypto_wep_encrypt(tx);
956 	case ALG_TKIP:
957 		return ieee80211_crypto_tkip_encrypt(tx);
958 	case ALG_CCMP:
959 		return ieee80211_crypto_ccmp_encrypt(tx);
960 	case ALG_AES_CMAC:
961 		return ieee80211_crypto_aes_cmac_encrypt(tx);
962 	}
963 
964 	/* not reached */
965 	WARN_ON(1);
966 	return TX_DROP;
967 }
968 
969 static ieee80211_tx_result debug_noinline
970 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
971 {
972 	struct sk_buff *skb = tx->skb;
973 	struct ieee80211_hdr *hdr;
974 	int next_len;
975 	bool group_addr;
976 
977 	do {
978 		hdr = (void *) skb->data;
979 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
980 			break; /* must not overwrite AID */
981 		next_len = skb->next ? skb->next->len : 0;
982 		group_addr = is_multicast_ether_addr(hdr->addr1);
983 
984 		hdr->duration_id =
985 			ieee80211_duration(tx, group_addr, next_len);
986 	} while ((skb = skb->next));
987 
988 	return TX_CONTINUE;
989 }
990 
991 /* actual transmit path */
992 
993 /*
994  * deal with packet injection down monitor interface
995  * with Radiotap Header -- only called for monitor mode interface
996  */
997 static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
998 					  struct sk_buff *skb)
999 {
1000 	/*
1001 	 * this is the moment to interpret and discard the radiotap header that
1002 	 * must be at the start of the packet injected in Monitor mode
1003 	 *
1004 	 * Need to take some care with endian-ness since radiotap
1005 	 * args are little-endian
1006 	 */
1007 
1008 	struct ieee80211_radiotap_iterator iterator;
1009 	struct ieee80211_radiotap_header *rthdr =
1010 		(struct ieee80211_radiotap_header *) skb->data;
1011 	struct ieee80211_supported_band *sband;
1012 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1013 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1014 						   NULL);
1015 
1016 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
1017 
1018 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1019 	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1020 
1021 	/*
1022 	 * for every radiotap entry that is present
1023 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1024 	 * entries present, or -EINVAL on error)
1025 	 */
1026 
1027 	while (!ret) {
1028 		ret = ieee80211_radiotap_iterator_next(&iterator);
1029 
1030 		if (ret)
1031 			continue;
1032 
1033 		/* see if this argument is something we can use */
1034 		switch (iterator.this_arg_index) {
1035 		/*
1036 		 * You must take care when dereferencing iterator.this_arg
1037 		 * for multibyte types... the pointer is not aligned.  Use
1038 		 * get_unaligned((type *)iterator.this_arg) to dereference
1039 		 * iterator.this_arg for type "type" safely on all arches.
1040 		*/
1041 		case IEEE80211_RADIOTAP_FLAGS:
1042 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1043 				/*
1044 				 * this indicates that the skb we have been
1045 				 * handed has the 32-bit FCS CRC at the end...
1046 				 * we should react to that by snipping it off
1047 				 * because it will be recomputed and added
1048 				 * on transmission
1049 				 */
1050 				if (skb->len < (iterator._max_length + FCS_LEN))
1051 					return false;
1052 
1053 				skb_trim(skb, skb->len - FCS_LEN);
1054 			}
1055 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1056 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1057 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1058 				tx->flags |= IEEE80211_TX_FRAGMENTED;
1059 			break;
1060 
1061 		/*
1062 		 * Please update the file
1063 		 * Documentation/networking/mac80211-injection.txt
1064 		 * when parsing new fields here.
1065 		 */
1066 
1067 		default:
1068 			break;
1069 		}
1070 	}
1071 
1072 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1073 		return false;
1074 
1075 	/*
1076 	 * remove the radiotap header
1077 	 * iterator->_max_length was sanity-checked against
1078 	 * skb->len by iterator init
1079 	 */
1080 	skb_pull(skb, iterator._max_length);
1081 
1082 	return true;
1083 }
1084 
1085 /*
1086  * initialises @tx
1087  */
1088 static ieee80211_tx_result
1089 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1090 		     struct ieee80211_tx_data *tx,
1091 		     struct sk_buff *skb)
1092 {
1093 	struct ieee80211_local *local = sdata->local;
1094 	struct ieee80211_hdr *hdr;
1095 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1096 	int hdrlen, tid;
1097 	u8 *qc, *state;
1098 	bool queued = false;
1099 
1100 	memset(tx, 0, sizeof(*tx));
1101 	tx->skb = skb;
1102 	tx->local = local;
1103 	tx->sdata = sdata;
1104 	tx->channel = local->hw.conf.channel;
1105 	/*
1106 	 * Set this flag (used below to indicate "automatic fragmentation"),
1107 	 * it will be cleared/left by radiotap as desired.
1108 	 */
1109 	tx->flags |= IEEE80211_TX_FRAGMENTED;
1110 
1111 	/* process and remove the injection radiotap header */
1112 	if (unlikely(info->flags & IEEE80211_TX_INTFL_HAS_RADIOTAP)) {
1113 		if (!__ieee80211_parse_tx_radiotap(tx, skb))
1114 			return TX_DROP;
1115 
1116 		/*
1117 		 * __ieee80211_parse_tx_radiotap has now removed
1118 		 * the radiotap header that was present and pre-filled
1119 		 * 'tx' with tx control information.
1120 		 */
1121 		info->flags &= ~IEEE80211_TX_INTFL_HAS_RADIOTAP;
1122 	}
1123 
1124 	/*
1125 	 * If this flag is set to true anywhere, and we get here,
1126 	 * we are doing the needed processing, so remove the flag
1127 	 * now.
1128 	 */
1129 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1130 
1131 	hdr = (struct ieee80211_hdr *) skb->data;
1132 
1133 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1134 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1135 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1136 			return TX_DROP;
1137 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED) {
1138 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1139 	}
1140 	if (!tx->sta)
1141 		tx->sta = sta_info_get(sdata, hdr->addr1);
1142 
1143 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1144 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1145 		unsigned long flags;
1146 		struct tid_ampdu_tx *tid_tx;
1147 
1148 		qc = ieee80211_get_qos_ctl(hdr);
1149 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1150 
1151 		spin_lock_irqsave(&tx->sta->lock, flags);
1152 		/*
1153 		 * XXX: This spinlock could be fairly expensive, but see the
1154 		 *	comment in agg-tx.c:ieee80211_agg_tx_operational().
1155 		 *	One way to solve this would be to do something RCU-like
1156 		 *	for managing the tid_tx struct and using atomic bitops
1157 		 *	for the actual state -- by introducing an actual
1158 		 *	'operational' bit that would be possible. It would
1159 		 *	require changing ieee80211_agg_tx_operational() to
1160 		 *	set that bit, and changing the way tid_tx is managed
1161 		 *	everywhere, including races between that bit and
1162 		 *	tid_tx going away (tid_tx being added can be easily
1163 		 *	committed to memory before the 'operational' bit).
1164 		 */
1165 		tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
1166 		state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
1167 		if (*state == HT_AGG_STATE_OPERATIONAL) {
1168 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1169 		} else if (*state != HT_AGG_STATE_IDLE) {
1170 			/* in progress */
1171 			queued = true;
1172 			info->control.vif = &sdata->vif;
1173 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1174 			__skb_queue_tail(&tid_tx->pending, skb);
1175 		}
1176 		spin_unlock_irqrestore(&tx->sta->lock, flags);
1177 
1178 		if (unlikely(queued))
1179 			return TX_QUEUED;
1180 	}
1181 
1182 	if (is_multicast_ether_addr(hdr->addr1)) {
1183 		tx->flags &= ~IEEE80211_TX_UNICAST;
1184 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1185 	} else {
1186 		tx->flags |= IEEE80211_TX_UNICAST;
1187 		if (unlikely(local->wifi_wme_noack_test))
1188 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
1189 		else
1190 			info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1191 	}
1192 
1193 	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
1194 		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1195 		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1196 		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1197 			tx->flags |= IEEE80211_TX_FRAGMENTED;
1198 		else
1199 			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1200 	}
1201 
1202 	if (!tx->sta)
1203 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1204 	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1205 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1206 
1207 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1208 	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
1209 		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
1210 		tx->ethertype = (pos[0] << 8) | pos[1];
1211 	}
1212 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1213 
1214 	return TX_CONTINUE;
1215 }
1216 
1217 static int __ieee80211_tx(struct ieee80211_local *local,
1218 			  struct sk_buff **skbp,
1219 			  struct sta_info *sta,
1220 			  bool txpending)
1221 {
1222 	struct sk_buff *skb = *skbp, *next;
1223 	struct ieee80211_tx_info *info;
1224 	struct ieee80211_sub_if_data *sdata;
1225 	unsigned long flags;
1226 	int ret, len;
1227 	bool fragm = false;
1228 
1229 	while (skb) {
1230 		int q = skb_get_queue_mapping(skb);
1231 
1232 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1233 		ret = IEEE80211_TX_OK;
1234 		if (local->queue_stop_reasons[q] ||
1235 		    (!txpending && !skb_queue_empty(&local->pending[q])))
1236 			ret = IEEE80211_TX_PENDING;
1237 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1238 		if (ret != IEEE80211_TX_OK)
1239 			return ret;
1240 
1241 		info = IEEE80211_SKB_CB(skb);
1242 
1243 		if (fragm)
1244 			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1245 					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1246 
1247 		next = skb->next;
1248 		len = skb->len;
1249 
1250 		if (next)
1251 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
1252 
1253 		sdata = vif_to_sdata(info->control.vif);
1254 
1255 		switch (sdata->vif.type) {
1256 		case NL80211_IFTYPE_MONITOR:
1257 			info->control.vif = NULL;
1258 			break;
1259 		case NL80211_IFTYPE_AP_VLAN:
1260 			info->control.vif = &container_of(sdata->bss,
1261 				struct ieee80211_sub_if_data, u.ap)->vif;
1262 			break;
1263 		default:
1264 			/* keep */
1265 			break;
1266 		}
1267 
1268 		ret = drv_tx(local, skb);
1269 		if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
1270 			dev_kfree_skb(skb);
1271 			ret = NETDEV_TX_OK;
1272 		}
1273 		if (ret != NETDEV_TX_OK) {
1274 			info->control.vif = &sdata->vif;
1275 			return IEEE80211_TX_AGAIN;
1276 		}
1277 
1278 		*skbp = skb = next;
1279 		ieee80211_led_tx(local, 1);
1280 		fragm = true;
1281 	}
1282 
1283 	return IEEE80211_TX_OK;
1284 }
1285 
1286 /*
1287  * Invoke TX handlers, return 0 on success and non-zero if the
1288  * frame was dropped or queued.
1289  */
1290 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1291 {
1292 	struct sk_buff *skb = tx->skb;
1293 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1294 	ieee80211_tx_result res = TX_DROP;
1295 
1296 #define CALL_TXH(txh) \
1297 	do {				\
1298 		res = txh(tx);		\
1299 		if (res != TX_CONTINUE)	\
1300 			goto txh_done;	\
1301 	} while (0)
1302 
1303 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1304 	CALL_TXH(ieee80211_tx_h_check_assoc);
1305 	CALL_TXH(ieee80211_tx_h_ps_buf);
1306 	CALL_TXH(ieee80211_tx_h_select_key);
1307 	CALL_TXH(ieee80211_tx_h_sta);
1308 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1309 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1310 
1311 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION))
1312 		goto txh_done;
1313 
1314 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1315 	CALL_TXH(ieee80211_tx_h_sequence);
1316 	CALL_TXH(ieee80211_tx_h_fragment);
1317 	/* handlers after fragment must be aware of tx info fragmentation! */
1318 	CALL_TXH(ieee80211_tx_h_stats);
1319 	CALL_TXH(ieee80211_tx_h_encrypt);
1320 	CALL_TXH(ieee80211_tx_h_calculate_duration);
1321 #undef CALL_TXH
1322 
1323  txh_done:
1324 	if (unlikely(res == TX_DROP)) {
1325 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1326 		while (skb) {
1327 			struct sk_buff *next;
1328 
1329 			next = skb->next;
1330 			dev_kfree_skb(skb);
1331 			skb = next;
1332 		}
1333 		return -1;
1334 	} else if (unlikely(res == TX_QUEUED)) {
1335 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1336 		return -1;
1337 	}
1338 
1339 	return 0;
1340 }
1341 
1342 static void ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1343 			 struct sk_buff *skb, bool txpending)
1344 {
1345 	struct ieee80211_local *local = sdata->local;
1346 	struct ieee80211_tx_data tx;
1347 	ieee80211_tx_result res_prepare;
1348 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1349 	struct sk_buff *next;
1350 	unsigned long flags;
1351 	int ret, retries;
1352 	u16 queue;
1353 
1354 	queue = skb_get_queue_mapping(skb);
1355 
1356 	if (unlikely(skb->len < 10)) {
1357 		dev_kfree_skb(skb);
1358 		return;
1359 	}
1360 
1361 	rcu_read_lock();
1362 
1363 	/* initialises tx */
1364 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1365 
1366 	if (unlikely(res_prepare == TX_DROP)) {
1367 		dev_kfree_skb(skb);
1368 		rcu_read_unlock();
1369 		return;
1370 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1371 		rcu_read_unlock();
1372 		return;
1373 	}
1374 
1375 	tx.channel = local->hw.conf.channel;
1376 	info->band = tx.channel->band;
1377 
1378 	if (invoke_tx_handlers(&tx))
1379 		goto out;
1380 
1381 	retries = 0;
1382  retry:
1383 	ret = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
1384 	switch (ret) {
1385 	case IEEE80211_TX_OK:
1386 		break;
1387 	case IEEE80211_TX_AGAIN:
1388 		/*
1389 		 * Since there are no fragmented frames on A-MPDU
1390 		 * queues, there's no reason for a driver to reject
1391 		 * a frame there, warn and drop it.
1392 		 */
1393 		if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
1394 			goto drop;
1395 		/* fall through */
1396 	case IEEE80211_TX_PENDING:
1397 		skb = tx.skb;
1398 
1399 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1400 
1401 		if (local->queue_stop_reasons[queue] ||
1402 		    !skb_queue_empty(&local->pending[queue])) {
1403 			/*
1404 			 * if queue is stopped, queue up frames for later
1405 			 * transmission from the tasklet
1406 			 */
1407 			do {
1408 				next = skb->next;
1409 				skb->next = NULL;
1410 				if (unlikely(txpending))
1411 					__skb_queue_head(&local->pending[queue],
1412 							 skb);
1413 				else
1414 					__skb_queue_tail(&local->pending[queue],
1415 							 skb);
1416 			} while ((skb = next));
1417 
1418 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1419 					       flags);
1420 		} else {
1421 			/*
1422 			 * otherwise retry, but this is a race condition or
1423 			 * a driver bug (which we warn about if it persists)
1424 			 */
1425 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1426 					       flags);
1427 
1428 			retries++;
1429 			if (WARN(retries > 10, "tx refused but queue active\n"))
1430 				goto drop;
1431 			goto retry;
1432 		}
1433 	}
1434  out:
1435 	rcu_read_unlock();
1436 	return;
1437 
1438  drop:
1439 	rcu_read_unlock();
1440 
1441 	skb = tx.skb;
1442 	while (skb) {
1443 		next = skb->next;
1444 		dev_kfree_skb(skb);
1445 		skb = next;
1446 	}
1447 }
1448 
1449 /* device xmit handlers */
1450 
1451 static int ieee80211_skb_resize(struct ieee80211_local *local,
1452 				struct sk_buff *skb,
1453 				int head_need, bool may_encrypt)
1454 {
1455 	int tail_need = 0;
1456 
1457 	/*
1458 	 * This could be optimised, devices that do full hardware
1459 	 * crypto (including TKIP MMIC) need no tailroom... But we
1460 	 * have no drivers for such devices currently.
1461 	 */
1462 	if (may_encrypt) {
1463 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1464 		tail_need -= skb_tailroom(skb);
1465 		tail_need = max_t(int, tail_need, 0);
1466 	}
1467 
1468 	if (head_need || tail_need) {
1469 		/* Sorry. Can't account for this any more */
1470 		skb_orphan(skb);
1471 	}
1472 
1473 	if (skb_header_cloned(skb))
1474 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1475 	else
1476 		I802_DEBUG_INC(local->tx_expand_skb_head);
1477 
1478 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1479 		printk(KERN_DEBUG "%s: failed to reallocate TX buffer\n",
1480 		       wiphy_name(local->hw.wiphy));
1481 		return -ENOMEM;
1482 	}
1483 
1484 	/* update truesize too */
1485 	skb->truesize += head_need + tail_need;
1486 
1487 	return 0;
1488 }
1489 
1490 static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
1491 			   struct sk_buff *skb)
1492 {
1493 	struct ieee80211_local *local = sdata->local;
1494 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1495 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1496 	struct ieee80211_sub_if_data *tmp_sdata;
1497 	int headroom;
1498 	bool may_encrypt;
1499 
1500 	rcu_read_lock();
1501 
1502 	if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1503 		int hdrlen;
1504 		u16 len_rthdr;
1505 
1506 		info->flags |= IEEE80211_TX_CTL_INJECTED |
1507 			       IEEE80211_TX_INTFL_HAS_RADIOTAP;
1508 
1509 		len_rthdr = ieee80211_get_radiotap_len(skb->data);
1510 		hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1511 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
1512 
1513 		/* check the header is complete in the frame */
1514 		if (likely(skb->len >= len_rthdr + hdrlen)) {
1515 			/*
1516 			 * We process outgoing injected frames that have a
1517 			 * local address we handle as though they are our
1518 			 * own frames.
1519 			 * This code here isn't entirely correct, the local
1520 			 * MAC address is not necessarily enough to find
1521 			 * the interface to use; for that proper VLAN/WDS
1522 			 * support we will need a different mechanism.
1523 			 */
1524 
1525 			list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
1526 						list) {
1527 				if (!ieee80211_sdata_running(tmp_sdata))
1528 					continue;
1529 				if (tmp_sdata->vif.type != NL80211_IFTYPE_AP)
1530 					continue;
1531 				if (compare_ether_addr(tmp_sdata->vif.addr,
1532 						       hdr->addr2) == 0) {
1533 					sdata = tmp_sdata;
1534 					break;
1535 				}
1536 			}
1537 		}
1538 	}
1539 
1540 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1541 
1542 	headroom = local->tx_headroom;
1543 	if (may_encrypt)
1544 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1545 	headroom -= skb_headroom(skb);
1546 	headroom = max_t(int, 0, headroom);
1547 
1548 	if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
1549 		dev_kfree_skb(skb);
1550 		rcu_read_unlock();
1551 		return;
1552 	}
1553 
1554 	info->control.vif = &sdata->vif;
1555 
1556 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1557 	    ieee80211_is_data(hdr->frame_control) &&
1558 		!is_multicast_ether_addr(hdr->addr1))
1559 			if (mesh_nexthop_lookup(skb, sdata)) {
1560 				/* skb queued: don't free */
1561 				rcu_read_unlock();
1562 				return;
1563 			}
1564 
1565 	ieee80211_set_qos_hdr(local, skb);
1566 	ieee80211_tx(sdata, skb, false);
1567 	rcu_read_unlock();
1568 }
1569 
1570 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1571 					 struct net_device *dev)
1572 {
1573 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1574 	struct ieee80211_channel *chan = local->hw.conf.channel;
1575 	struct ieee80211_radiotap_header *prthdr =
1576 		(struct ieee80211_radiotap_header *)skb->data;
1577 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1578 	u16 len_rthdr;
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 	memset(info, 0, sizeof(*info));
1630 
1631 	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1632 
1633 	/* pass the radiotap header up to xmit */
1634 	ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), skb);
1635 	return NETDEV_TX_OK;
1636 
1637 fail:
1638 	dev_kfree_skb(skb);
1639 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1640 }
1641 
1642 /**
1643  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1644  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1645  * @skb: packet to be sent
1646  * @dev: incoming interface
1647  *
1648  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1649  * not be freed, and caller is responsible for either retrying later or freeing
1650  * skb).
1651  *
1652  * This function takes in an Ethernet header and encapsulates it with suitable
1653  * IEEE 802.11 header based on which interface the packet is coming in. The
1654  * encapsulated packet will then be passed to master interface, wlan#.11, for
1655  * transmission (through low-level driver).
1656  */
1657 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1658 				    struct net_device *dev)
1659 {
1660 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1661 	struct ieee80211_local *local = sdata->local;
1662 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1663 	int ret = NETDEV_TX_BUSY, head_need;
1664 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1665 	__le16 fc;
1666 	struct ieee80211_hdr hdr;
1667 	struct ieee80211s_hdr mesh_hdr;
1668 	const u8 *encaps_data;
1669 	int encaps_len, skip_header_bytes;
1670 	int nh_pos, h_pos;
1671 	struct sta_info *sta = NULL;
1672 	u32 sta_flags = 0;
1673 
1674 	if (unlikely(skb->len < ETH_HLEN)) {
1675 		ret = NETDEV_TX_OK;
1676 		goto fail;
1677 	}
1678 
1679 	nh_pos = skb_network_header(skb) - skb->data;
1680 	h_pos = skb_transport_header(skb) - skb->data;
1681 
1682 	/* convert Ethernet header to proper 802.11 header (based on
1683 	 * operation mode) */
1684 	ethertype = (skb->data[12] << 8) | skb->data[13];
1685 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1686 
1687 	switch (sdata->vif.type) {
1688 	case NL80211_IFTYPE_AP_VLAN:
1689 		rcu_read_lock();
1690 		sta = rcu_dereference(sdata->u.vlan.sta);
1691 		if (sta) {
1692 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1693 			/* RA TA DA SA */
1694 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1695 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1696 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1697 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1698 			hdrlen = 30;
1699 			sta_flags = get_sta_flags(sta);
1700 		}
1701 		rcu_read_unlock();
1702 		if (sta)
1703 			break;
1704 		/* fall through */
1705 	case NL80211_IFTYPE_AP:
1706 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1707 		/* DA BSSID SA */
1708 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1709 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1710 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1711 		hdrlen = 24;
1712 		break;
1713 	case NL80211_IFTYPE_WDS:
1714 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1715 		/* RA TA DA SA */
1716 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1717 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1718 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1719 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1720 		hdrlen = 30;
1721 		break;
1722 #ifdef CONFIG_MAC80211_MESH
1723 	case NL80211_IFTYPE_MESH_POINT:
1724 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1725 			/* Do not send frames with mesh_ttl == 0 */
1726 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1727 			ret = NETDEV_TX_OK;
1728 			goto fail;
1729 		}
1730 
1731 		if (compare_ether_addr(sdata->vif.addr,
1732 				       skb->data + ETH_ALEN) == 0) {
1733 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1734 					skb->data, skb->data + ETH_ALEN);
1735 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1736 					sdata, NULL, NULL, NULL);
1737 		} else {
1738 			/* packet from other interface */
1739 			struct mesh_path *mppath;
1740 			int is_mesh_mcast = 1;
1741 			const u8 *mesh_da;
1742 
1743 			rcu_read_lock();
1744 			if (is_multicast_ether_addr(skb->data))
1745 				/* DA TA mSA AE:SA */
1746 				mesh_da = skb->data;
1747 			else {
1748 				static const u8 bcast[ETH_ALEN] =
1749 					{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1750 
1751 				mppath = mpp_path_lookup(skb->data, sdata);
1752 				if (mppath) {
1753 					/* RA TA mDA mSA AE:DA SA */
1754 					mesh_da = mppath->mpp;
1755 					is_mesh_mcast = 0;
1756 				} else {
1757 					/* DA TA mSA AE:SA */
1758 					mesh_da = bcast;
1759 				}
1760 			}
1761 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1762 					mesh_da, sdata->vif.addr);
1763 			rcu_read_unlock();
1764 			if (is_mesh_mcast)
1765 				meshhdrlen =
1766 					ieee80211_new_mesh_header(&mesh_hdr,
1767 							sdata,
1768 							skb->data + ETH_ALEN,
1769 							NULL,
1770 							NULL);
1771 			else
1772 				meshhdrlen =
1773 					ieee80211_new_mesh_header(&mesh_hdr,
1774 							sdata,
1775 							NULL,
1776 							skb->data,
1777 							skb->data + ETH_ALEN);
1778 
1779 		}
1780 		break;
1781 #endif
1782 	case NL80211_IFTYPE_STATION:
1783 		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1784 		if (sdata->u.mgd.use_4addr && ethertype != ETH_P_PAE) {
1785 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1786 			/* RA TA DA SA */
1787 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1788 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1789 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1790 			hdrlen = 30;
1791 		} else {
1792 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1793 			/* BSSID SA DA */
1794 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1795 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1796 			hdrlen = 24;
1797 		}
1798 		break;
1799 	case NL80211_IFTYPE_ADHOC:
1800 		/* DA SA BSSID */
1801 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1802 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1803 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1804 		hdrlen = 24;
1805 		break;
1806 	default:
1807 		ret = NETDEV_TX_OK;
1808 		goto fail;
1809 	}
1810 
1811 	/*
1812 	 * There's no need to try to look up the destination
1813 	 * if it is a multicast address (which can only happen
1814 	 * in AP mode)
1815 	 */
1816 	if (!is_multicast_ether_addr(hdr.addr1)) {
1817 		rcu_read_lock();
1818 		sta = sta_info_get(sdata, hdr.addr1);
1819 		if (sta)
1820 			sta_flags = get_sta_flags(sta);
1821 		rcu_read_unlock();
1822 	}
1823 
1824 	/* receiver and we are QoS enabled, use a QoS type frame */
1825 	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1826 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1827 		hdrlen += 2;
1828 	}
1829 
1830 	/*
1831 	 * Drop unicast frames to unauthorised stations unless they are
1832 	 * EAPOL frames from the local station.
1833 	 */
1834 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
1835 		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1836 		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
1837 		      !(ethertype == ETH_P_PAE &&
1838 		       compare_ether_addr(sdata->vif.addr,
1839 					  skb->data + ETH_ALEN) == 0))) {
1840 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1841 		if (net_ratelimit())
1842 			printk(KERN_DEBUG "%s: dropped frame to %pM"
1843 			       " (unauthorized port)\n", dev->name,
1844 			       hdr.addr1);
1845 #endif
1846 
1847 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1848 
1849 		ret = NETDEV_TX_OK;
1850 		goto fail;
1851 	}
1852 
1853 	hdr.frame_control = fc;
1854 	hdr.duration_id = 0;
1855 	hdr.seq_ctrl = 0;
1856 
1857 	skip_header_bytes = ETH_HLEN;
1858 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
1859 		encaps_data = bridge_tunnel_header;
1860 		encaps_len = sizeof(bridge_tunnel_header);
1861 		skip_header_bytes -= 2;
1862 	} else if (ethertype >= 0x600) {
1863 		encaps_data = rfc1042_header;
1864 		encaps_len = sizeof(rfc1042_header);
1865 		skip_header_bytes -= 2;
1866 	} else {
1867 		encaps_data = NULL;
1868 		encaps_len = 0;
1869 	}
1870 
1871 	skb_pull(skb, skip_header_bytes);
1872 	nh_pos -= skip_header_bytes;
1873 	h_pos -= skip_header_bytes;
1874 
1875 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1876 
1877 	/*
1878 	 * So we need to modify the skb header and hence need a copy of
1879 	 * that. The head_need variable above doesn't, so far, include
1880 	 * the needed header space that we don't need right away. If we
1881 	 * can, then we don't reallocate right now but only after the
1882 	 * frame arrives at the master device (if it does...)
1883 	 *
1884 	 * If we cannot, however, then we will reallocate to include all
1885 	 * the ever needed space. Also, if we need to reallocate it anyway,
1886 	 * make it big enough for everything we may ever need.
1887 	 */
1888 
1889 	if (head_need > 0 || skb_cloned(skb)) {
1890 		head_need += IEEE80211_ENCRYPT_HEADROOM;
1891 		head_need += local->tx_headroom;
1892 		head_need = max_t(int, 0, head_need);
1893 		if (ieee80211_skb_resize(local, skb, head_need, true))
1894 			goto fail;
1895 	}
1896 
1897 	if (encaps_data) {
1898 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
1899 		nh_pos += encaps_len;
1900 		h_pos += encaps_len;
1901 	}
1902 
1903 	if (meshhdrlen > 0) {
1904 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
1905 		nh_pos += meshhdrlen;
1906 		h_pos += meshhdrlen;
1907 	}
1908 
1909 	if (ieee80211_is_data_qos(fc)) {
1910 		__le16 *qos_control;
1911 
1912 		qos_control = (__le16*) skb_push(skb, 2);
1913 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
1914 		/*
1915 		 * Maybe we could actually set some fields here, for now just
1916 		 * initialise to zero to indicate no special operation.
1917 		 */
1918 		*qos_control = 0;
1919 	} else
1920 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
1921 
1922 	nh_pos += hdrlen;
1923 	h_pos += hdrlen;
1924 
1925 	dev->stats.tx_packets++;
1926 	dev->stats.tx_bytes += skb->len;
1927 
1928 	/* Update skb pointers to various headers since this modified frame
1929 	 * is going to go through Linux networking code that may potentially
1930 	 * need things like pointer to IP header. */
1931 	skb_set_mac_header(skb, 0);
1932 	skb_set_network_header(skb, nh_pos);
1933 	skb_set_transport_header(skb, h_pos);
1934 
1935 	memset(info, 0, sizeof(*info));
1936 
1937 	dev->trans_start = jiffies;
1938 	ieee80211_xmit(sdata, skb);
1939 
1940 	return NETDEV_TX_OK;
1941 
1942  fail:
1943 	if (ret == NETDEV_TX_OK)
1944 		dev_kfree_skb(skb);
1945 
1946 	return ret;
1947 }
1948 
1949 
1950 /*
1951  * ieee80211_clear_tx_pending may not be called in a context where
1952  * it is possible that it packets could come in again.
1953  */
1954 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
1955 {
1956 	int i;
1957 
1958 	for (i = 0; i < local->hw.queues; i++)
1959 		skb_queue_purge(&local->pending[i]);
1960 }
1961 
1962 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
1963 				     struct sk_buff *skb)
1964 {
1965 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1966 	struct ieee80211_sub_if_data *sdata;
1967 	struct sta_info *sta;
1968 	struct ieee80211_hdr *hdr;
1969 	int ret;
1970 	bool result = true;
1971 
1972 	sdata = vif_to_sdata(info->control.vif);
1973 
1974 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
1975 		ieee80211_tx(sdata, skb, true);
1976 	} else {
1977 		hdr = (struct ieee80211_hdr *)skb->data;
1978 		sta = sta_info_get(sdata, hdr->addr1);
1979 
1980 		ret = __ieee80211_tx(local, &skb, sta, true);
1981 		if (ret != IEEE80211_TX_OK)
1982 			result = false;
1983 	}
1984 
1985 	return result;
1986 }
1987 
1988 /*
1989  * Transmit all pending packets. Called from tasklet.
1990  */
1991 void ieee80211_tx_pending(unsigned long data)
1992 {
1993 	struct ieee80211_local *local = (struct ieee80211_local *)data;
1994 	unsigned long flags;
1995 	int i;
1996 	bool txok;
1997 
1998 	rcu_read_lock();
1999 
2000 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2001 	for (i = 0; i < local->hw.queues; i++) {
2002 		/*
2003 		 * If queue is stopped by something other than due to pending
2004 		 * frames, or we have no pending frames, proceed to next queue.
2005 		 */
2006 		if (local->queue_stop_reasons[i] ||
2007 		    skb_queue_empty(&local->pending[i]))
2008 			continue;
2009 
2010 		while (!skb_queue_empty(&local->pending[i])) {
2011 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2012 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2013 			struct ieee80211_sub_if_data *sdata;
2014 
2015 			if (WARN_ON(!info->control.vif)) {
2016 				kfree_skb(skb);
2017 				continue;
2018 			}
2019 
2020 			sdata = vif_to_sdata(info->control.vif);
2021 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2022 						flags);
2023 
2024 			txok = ieee80211_tx_pending_skb(local, skb);
2025 			if (!txok)
2026 				__skb_queue_head(&local->pending[i], skb);
2027 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2028 					  flags);
2029 			if (!txok)
2030 				break;
2031 		}
2032 	}
2033 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2034 
2035 	rcu_read_unlock();
2036 }
2037 
2038 /* functions for drivers to get certain frames */
2039 
2040 static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
2041 				     struct sk_buff *skb,
2042 				     struct beacon_data *beacon)
2043 {
2044 	u8 *pos, *tim;
2045 	int aid0 = 0;
2046 	int i, have_bits = 0, n1, n2;
2047 
2048 	/* Generate bitmap for TIM only if there are any STAs in power save
2049 	 * mode. */
2050 	if (atomic_read(&bss->num_sta_ps) > 0)
2051 		/* in the hope that this is faster than
2052 		 * checking byte-for-byte */
2053 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2054 					  IEEE80211_MAX_AID+1);
2055 
2056 	if (bss->dtim_count == 0)
2057 		bss->dtim_count = beacon->dtim_period - 1;
2058 	else
2059 		bss->dtim_count--;
2060 
2061 	tim = pos = (u8 *) skb_put(skb, 6);
2062 	*pos++ = WLAN_EID_TIM;
2063 	*pos++ = 4;
2064 	*pos++ = bss->dtim_count;
2065 	*pos++ = beacon->dtim_period;
2066 
2067 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2068 		aid0 = 1;
2069 
2070 	if (have_bits) {
2071 		/* Find largest even number N1 so that bits numbered 1 through
2072 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2073 		 * (N2 + 1) x 8 through 2007 are 0. */
2074 		n1 = 0;
2075 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2076 			if (bss->tim[i]) {
2077 				n1 = i & 0xfe;
2078 				break;
2079 			}
2080 		}
2081 		n2 = n1;
2082 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2083 			if (bss->tim[i]) {
2084 				n2 = i;
2085 				break;
2086 			}
2087 		}
2088 
2089 		/* Bitmap control */
2090 		*pos++ = n1 | aid0;
2091 		/* Part Virt Bitmap */
2092 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2093 
2094 		tim[1] = n2 - n1 + 4;
2095 		skb_put(skb, n2 - n1);
2096 	} else {
2097 		*pos++ = aid0; /* Bitmap control */
2098 		*pos++ = 0; /* Part Virt Bitmap */
2099 	}
2100 }
2101 
2102 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2103 					 struct ieee80211_vif *vif,
2104 					 u16 *tim_offset, u16 *tim_length)
2105 {
2106 	struct ieee80211_local *local = hw_to_local(hw);
2107 	struct sk_buff *skb = NULL;
2108 	struct ieee80211_tx_info *info;
2109 	struct ieee80211_sub_if_data *sdata = NULL;
2110 	struct ieee80211_if_ap *ap = NULL;
2111 	struct beacon_data *beacon;
2112 	struct ieee80211_supported_band *sband;
2113 	enum ieee80211_band band = local->hw.conf.channel->band;
2114 	struct ieee80211_tx_rate_control txrc;
2115 
2116 	sband = local->hw.wiphy->bands[band];
2117 
2118 	rcu_read_lock();
2119 
2120 	sdata = vif_to_sdata(vif);
2121 
2122 	if (tim_offset)
2123 		*tim_offset = 0;
2124 	if (tim_length)
2125 		*tim_length = 0;
2126 
2127 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2128 		ap = &sdata->u.ap;
2129 		beacon = rcu_dereference(ap->beacon);
2130 		if (ap && beacon) {
2131 			/*
2132 			 * headroom, head length,
2133 			 * tail length and maximum TIM length
2134 			 */
2135 			skb = dev_alloc_skb(local->tx_headroom +
2136 					    beacon->head_len +
2137 					    beacon->tail_len + 256);
2138 			if (!skb)
2139 				goto out;
2140 
2141 			skb_reserve(skb, local->tx_headroom);
2142 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2143 			       beacon->head_len);
2144 
2145 			/*
2146 			 * Not very nice, but we want to allow the driver to call
2147 			 * ieee80211_beacon_get() as a response to the set_tim()
2148 			 * callback. That, however, is already invoked under the
2149 			 * sta_lock to guarantee consistent and race-free update
2150 			 * of the tim bitmap in mac80211 and the driver.
2151 			 */
2152 			if (local->tim_in_locked_section) {
2153 				ieee80211_beacon_add_tim(ap, skb, beacon);
2154 			} else {
2155 				unsigned long flags;
2156 
2157 				spin_lock_irqsave(&local->sta_lock, flags);
2158 				ieee80211_beacon_add_tim(ap, skb, beacon);
2159 				spin_unlock_irqrestore(&local->sta_lock, flags);
2160 			}
2161 
2162 			if (tim_offset)
2163 				*tim_offset = beacon->head_len;
2164 			if (tim_length)
2165 				*tim_length = skb->len - beacon->head_len;
2166 
2167 			if (beacon->tail)
2168 				memcpy(skb_put(skb, beacon->tail_len),
2169 				       beacon->tail, beacon->tail_len);
2170 		} else
2171 			goto out;
2172 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2173 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2174 		struct ieee80211_hdr *hdr;
2175 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2176 
2177 		if (!presp)
2178 			goto out;
2179 
2180 		skb = skb_copy(presp, GFP_ATOMIC);
2181 		if (!skb)
2182 			goto out;
2183 
2184 		hdr = (struct ieee80211_hdr *) skb->data;
2185 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2186 						 IEEE80211_STYPE_BEACON);
2187 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2188 		struct ieee80211_mgmt *mgmt;
2189 		u8 *pos;
2190 
2191 		/* headroom, head length, tail length and maximum TIM length */
2192 		skb = dev_alloc_skb(local->tx_headroom + 400);
2193 		if (!skb)
2194 			goto out;
2195 
2196 		skb_reserve(skb, local->hw.extra_tx_headroom);
2197 		mgmt = (struct ieee80211_mgmt *)
2198 			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
2199 		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2200 		mgmt->frame_control =
2201 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2202 		memset(mgmt->da, 0xff, ETH_ALEN);
2203 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2204 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2205 		mgmt->u.beacon.beacon_int =
2206 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2207 		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
2208 
2209 		pos = skb_put(skb, 2);
2210 		*pos++ = WLAN_EID_SSID;
2211 		*pos++ = 0x0;
2212 
2213 		mesh_mgmt_ies_add(skb, sdata);
2214 	} else {
2215 		WARN_ON(1);
2216 		goto out;
2217 	}
2218 
2219 	info = IEEE80211_SKB_CB(skb);
2220 
2221 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2222 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2223 	info->band = band;
2224 
2225 	memset(&txrc, 0, sizeof(txrc));
2226 	txrc.hw = hw;
2227 	txrc.sband = sband;
2228 	txrc.bss_conf = &sdata->vif.bss_conf;
2229 	txrc.skb = skb;
2230 	txrc.reported_rate.idx = -1;
2231 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2232 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2233 		txrc.max_rate_idx = -1;
2234 	else
2235 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2236 	txrc.ap = true;
2237 	rate_control_get_rate(sdata, NULL, &txrc);
2238 
2239 	info->control.vif = vif;
2240 
2241 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
2242 	info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
2243  out:
2244 	rcu_read_unlock();
2245 	return skb;
2246 }
2247 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2248 
2249 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2250 				     struct ieee80211_vif *vif)
2251 {
2252 	struct ieee80211_sub_if_data *sdata;
2253 	struct ieee80211_if_managed *ifmgd;
2254 	struct ieee80211_pspoll *pspoll;
2255 	struct ieee80211_local *local;
2256 	struct sk_buff *skb;
2257 
2258 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2259 		return NULL;
2260 
2261 	sdata = vif_to_sdata(vif);
2262 	ifmgd = &sdata->u.mgd;
2263 	local = sdata->local;
2264 
2265 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2266 	if (!skb) {
2267 		printk(KERN_DEBUG "%s: failed to allocate buffer for "
2268 		       "pspoll template\n", sdata->name);
2269 		return NULL;
2270 	}
2271 	skb_reserve(skb, local->hw.extra_tx_headroom);
2272 
2273 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2274 	memset(pspoll, 0, sizeof(*pspoll));
2275 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2276 					    IEEE80211_STYPE_PSPOLL);
2277 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2278 
2279 	/* aid in PS-Poll has its two MSBs each set to 1 */
2280 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2281 
2282 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2283 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2284 
2285 	return skb;
2286 }
2287 EXPORT_SYMBOL(ieee80211_pspoll_get);
2288 
2289 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2290 				       struct ieee80211_vif *vif)
2291 {
2292 	struct ieee80211_hdr_3addr *nullfunc;
2293 	struct ieee80211_sub_if_data *sdata;
2294 	struct ieee80211_if_managed *ifmgd;
2295 	struct ieee80211_local *local;
2296 	struct sk_buff *skb;
2297 
2298 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2299 		return NULL;
2300 
2301 	sdata = vif_to_sdata(vif);
2302 	ifmgd = &sdata->u.mgd;
2303 	local = sdata->local;
2304 
2305 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2306 	if (!skb) {
2307 		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
2308 		       "template\n", sdata->name);
2309 		return NULL;
2310 	}
2311 	skb_reserve(skb, local->hw.extra_tx_headroom);
2312 
2313 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2314 							  sizeof(*nullfunc));
2315 	memset(nullfunc, 0, sizeof(*nullfunc));
2316 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2317 					      IEEE80211_STYPE_NULLFUNC |
2318 					      IEEE80211_FCTL_TODS);
2319 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2320 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2321 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2322 
2323 	return skb;
2324 }
2325 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2326 
2327 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2328 				       struct ieee80211_vif *vif,
2329 				       const u8 *ssid, size_t ssid_len,
2330 				       const u8 *ie, size_t ie_len)
2331 {
2332 	struct ieee80211_sub_if_data *sdata;
2333 	struct ieee80211_local *local;
2334 	struct ieee80211_hdr_3addr *hdr;
2335 	struct sk_buff *skb;
2336 	size_t ie_ssid_len;
2337 	u8 *pos;
2338 
2339 	sdata = vif_to_sdata(vif);
2340 	local = sdata->local;
2341 	ie_ssid_len = 2 + ssid_len;
2342 
2343 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2344 			    ie_ssid_len + ie_len);
2345 	if (!skb) {
2346 		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
2347 		       "request template\n", sdata->name);
2348 		return NULL;
2349 	}
2350 
2351 	skb_reserve(skb, local->hw.extra_tx_headroom);
2352 
2353 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2354 	memset(hdr, 0, sizeof(*hdr));
2355 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2356 					 IEEE80211_STYPE_PROBE_REQ);
2357 	memset(hdr->addr1, 0xff, ETH_ALEN);
2358 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2359 	memset(hdr->addr3, 0xff, ETH_ALEN);
2360 
2361 	pos = skb_put(skb, ie_ssid_len);
2362 	*pos++ = WLAN_EID_SSID;
2363 	*pos++ = ssid_len;
2364 	if (ssid)
2365 		memcpy(pos, ssid, ssid_len);
2366 	pos += ssid_len;
2367 
2368 	if (ie) {
2369 		pos = skb_put(skb, ie_len);
2370 		memcpy(pos, ie, ie_len);
2371 	}
2372 
2373 	return skb;
2374 }
2375 EXPORT_SYMBOL(ieee80211_probereq_get);
2376 
2377 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2378 		       const void *frame, size_t frame_len,
2379 		       const struct ieee80211_tx_info *frame_txctl,
2380 		       struct ieee80211_rts *rts)
2381 {
2382 	const struct ieee80211_hdr *hdr = frame;
2383 
2384 	rts->frame_control =
2385 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2386 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2387 					       frame_txctl);
2388 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2389 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2390 }
2391 EXPORT_SYMBOL(ieee80211_rts_get);
2392 
2393 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2394 			     const void *frame, size_t frame_len,
2395 			     const struct ieee80211_tx_info *frame_txctl,
2396 			     struct ieee80211_cts *cts)
2397 {
2398 	const struct ieee80211_hdr *hdr = frame;
2399 
2400 	cts->frame_control =
2401 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2402 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2403 						     frame_len, frame_txctl);
2404 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2405 }
2406 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2407 
2408 struct sk_buff *
2409 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2410 			  struct ieee80211_vif *vif)
2411 {
2412 	struct ieee80211_local *local = hw_to_local(hw);
2413 	struct sk_buff *skb = NULL;
2414 	struct sta_info *sta;
2415 	struct ieee80211_tx_data tx;
2416 	struct ieee80211_sub_if_data *sdata;
2417 	struct ieee80211_if_ap *bss = NULL;
2418 	struct beacon_data *beacon;
2419 	struct ieee80211_tx_info *info;
2420 
2421 	sdata = vif_to_sdata(vif);
2422 	bss = &sdata->u.ap;
2423 
2424 	rcu_read_lock();
2425 	beacon = rcu_dereference(bss->beacon);
2426 
2427 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2428 		goto out;
2429 
2430 	if (bss->dtim_count != 0)
2431 		goto out; /* send buffered bc/mc only after DTIM beacon */
2432 
2433 	while (1) {
2434 		skb = skb_dequeue(&bss->ps_bc_buf);
2435 		if (!skb)
2436 			goto out;
2437 		local->total_ps_buffered--;
2438 
2439 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2440 			struct ieee80211_hdr *hdr =
2441 				(struct ieee80211_hdr *) skb->data;
2442 			/* more buffered multicast/broadcast frames ==> set
2443 			 * MoreData flag in IEEE 802.11 header to inform PS
2444 			 * STAs */
2445 			hdr->frame_control |=
2446 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2447 		}
2448 
2449 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2450 			break;
2451 		dev_kfree_skb_any(skb);
2452 	}
2453 
2454 	info = IEEE80211_SKB_CB(skb);
2455 
2456 	sta = tx.sta;
2457 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2458 	tx.channel = local->hw.conf.channel;
2459 	info->band = tx.channel->band;
2460 
2461 	if (invoke_tx_handlers(&tx))
2462 		skb = NULL;
2463  out:
2464 	rcu_read_unlock();
2465 
2466 	return skb;
2467 }
2468 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2469 
2470 void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
2471 {
2472 	skb_set_mac_header(skb, 0);
2473 	skb_set_network_header(skb, 0);
2474 	skb_set_transport_header(skb, 0);
2475 
2476 	/* send all internal mgmt frames on VO */
2477 	skb_set_queue_mapping(skb, 0);
2478 
2479 	/*
2480 	 * The other path calling ieee80211_xmit is from the tasklet,
2481 	 * and while we can handle concurrent transmissions locking
2482 	 * requirements are that we do not come into tx with bhs on.
2483 	 */
2484 	local_bh_disable();
2485 	ieee80211_xmit(sdata, skb);
2486 	local_bh_enable();
2487 }
2488