xref: /openbmc/linux/net/mac80211/tx.c (revision 565d76cb)
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 /* misc utils */
37 
38 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
39 				 int next_frag_len)
40 {
41 	int rate, mrate, erp, dur, i;
42 	struct ieee80211_rate *txrate;
43 	struct ieee80211_local *local = tx->local;
44 	struct ieee80211_supported_band *sband;
45 	struct ieee80211_hdr *hdr;
46 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
47 
48 	/* assume HW handles this */
49 	if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
50 		return 0;
51 
52 	/* uh huh? */
53 	if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
54 		return 0;
55 
56 	sband = local->hw.wiphy->bands[tx->channel->band];
57 	txrate = &sband->bitrates[info->control.rates[0].idx];
58 
59 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
60 
61 	/*
62 	 * data and mgmt (except PS Poll):
63 	 * - during CFP: 32768
64 	 * - during contention period:
65 	 *   if addr1 is group address: 0
66 	 *   if more fragments = 0 and addr1 is individual address: time to
67 	 *      transmit one ACK plus SIFS
68 	 *   if more fragments = 1 and addr1 is individual address: time to
69 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
70 	 *
71 	 * IEEE 802.11, 9.6:
72 	 * - control response frame (CTS or ACK) shall be transmitted using the
73 	 *   same rate as the immediately previous frame in the frame exchange
74 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
75 	 *   at the highest possible rate belonging to the PHY rates in the
76 	 *   BSSBasicRateSet
77 	 */
78 	hdr = (struct ieee80211_hdr *)tx->skb->data;
79 	if (ieee80211_is_ctl(hdr->frame_control)) {
80 		/* TODO: These control frames are not currently sent by
81 		 * mac80211, but should they be implemented, this function
82 		 * needs to be updated to support duration field calculation.
83 		 *
84 		 * RTS: time needed to transmit pending data/mgmt frame plus
85 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
86 		 * CTS: duration of immediately previous RTS minus time
87 		 *    required to transmit CTS and its SIFS
88 		 * ACK: 0 if immediately previous directed data/mgmt had
89 		 *    more=0, with more=1 duration in ACK frame is duration
90 		 *    from previous frame minus time needed to transmit ACK
91 		 *    and its SIFS
92 		 * PS Poll: BIT(15) | BIT(14) | aid
93 		 */
94 		return 0;
95 	}
96 
97 	/* data/mgmt */
98 	if (0 /* FIX: data/mgmt during CFP */)
99 		return cpu_to_le16(32768);
100 
101 	if (group_addr) /* Group address as the destination - no ACK */
102 		return 0;
103 
104 	/* Individual destination address:
105 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
106 	 * CTS and ACK frames shall be transmitted using the highest rate in
107 	 * basic rate set that is less than or equal to the rate of the
108 	 * immediately previous frame and that is using the same modulation
109 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
110 	 * the highest mandatory rate of the PHY that is less than or equal to
111 	 * the rate of the previous frame is used.
112 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
113 	 */
114 	rate = -1;
115 	/* use lowest available if everything fails */
116 	mrate = sband->bitrates[0].bitrate;
117 	for (i = 0; i < sband->n_bitrates; i++) {
118 		struct ieee80211_rate *r = &sband->bitrates[i];
119 
120 		if (r->bitrate > txrate->bitrate)
121 			break;
122 
123 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
124 			rate = r->bitrate;
125 
126 		switch (sband->band) {
127 		case IEEE80211_BAND_2GHZ: {
128 			u32 flag;
129 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
130 				flag = IEEE80211_RATE_MANDATORY_G;
131 			else
132 				flag = IEEE80211_RATE_MANDATORY_B;
133 			if (r->flags & flag)
134 				mrate = r->bitrate;
135 			break;
136 		}
137 		case IEEE80211_BAND_5GHZ:
138 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
139 				mrate = r->bitrate;
140 			break;
141 		case IEEE80211_NUM_BANDS:
142 			WARN_ON(1);
143 			break;
144 		}
145 	}
146 	if (rate == -1) {
147 		/* No matching basic rate found; use highest suitable mandatory
148 		 * PHY rate */
149 		rate = mrate;
150 	}
151 
152 	/* Time needed to transmit ACK
153 	 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
154 	 * to closest integer */
155 
156 	dur = ieee80211_frame_duration(local, 10, rate, erp,
157 				tx->sdata->vif.bss_conf.use_short_preamble);
158 
159 	if (next_frag_len) {
160 		/* Frame is fragmented: duration increases with time needed to
161 		 * transmit next fragment plus ACK and 2 x SIFS. */
162 		dur *= 2; /* ACK + SIFS */
163 		/* next fragment */
164 		dur += ieee80211_frame_duration(local, next_frag_len,
165 				txrate->bitrate, erp,
166 				tx->sdata->vif.bss_conf.use_short_preamble);
167 	}
168 
169 	return cpu_to_le16(dur);
170 }
171 
172 static inline int is_ieee80211_device(struct ieee80211_local *local,
173 				      struct net_device *dev)
174 {
175 	return local == wdev_priv(dev->ieee80211_ptr);
176 }
177 
178 /* tx handlers */
179 static ieee80211_tx_result debug_noinline
180 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
181 {
182 	struct ieee80211_local *local = tx->local;
183 	struct ieee80211_if_managed *ifmgd;
184 
185 	/* driver doesn't support power save */
186 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
187 		return TX_CONTINUE;
188 
189 	/* hardware does dynamic power save */
190 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
191 		return TX_CONTINUE;
192 
193 	/* dynamic power save disabled */
194 	if (local->hw.conf.dynamic_ps_timeout <= 0)
195 		return TX_CONTINUE;
196 
197 	/* we are scanning, don't enable power save */
198 	if (local->scanning)
199 		return TX_CONTINUE;
200 
201 	if (!local->ps_sdata)
202 		return TX_CONTINUE;
203 
204 	/* No point if we're going to suspend */
205 	if (local->quiescing)
206 		return TX_CONTINUE;
207 
208 	/* dynamic ps is supported only in managed mode */
209 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
210 		return TX_CONTINUE;
211 
212 	ifmgd = &tx->sdata->u.mgd;
213 
214 	/*
215 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
216 	 * u-apsd enabled and the frame is in voip class. This effectively
217 	 * means that even if all access categories have u-apsd enabled, in
218 	 * practise u-apsd is only used with the voip ac. This is a
219 	 * workaround for the case when received voip class packets do not
220 	 * have correct qos tag for some reason, due the network or the
221 	 * peer application.
222 	 *
223 	 * Note: local->uapsd_queues access is racy here. If the value is
224 	 * changed via debugfs, user needs to reassociate manually to have
225 	 * everything in sync.
226 	 */
227 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED)
228 	    && (local->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO)
229 	    && skb_get_queue_mapping(tx->skb) == 0)
230 		return TX_CONTINUE;
231 
232 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
233 		ieee80211_stop_queues_by_reason(&local->hw,
234 						IEEE80211_QUEUE_STOP_REASON_PS);
235 		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
236 		ieee80211_queue_work(&local->hw,
237 				     &local->dynamic_ps_disable_work);
238 	}
239 
240 	mod_timer(&local->dynamic_ps_timer, jiffies +
241 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
242 
243 	return TX_CONTINUE;
244 }
245 
246 static ieee80211_tx_result debug_noinline
247 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
248 {
249 
250 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
251 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
252 	u32 sta_flags;
253 
254 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
255 		return TX_CONTINUE;
256 
257 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
258 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
259 	    !ieee80211_is_probe_req(hdr->frame_control) &&
260 	    !ieee80211_is_nullfunc(hdr->frame_control))
261 		/*
262 		 * When software scanning only nullfunc frames (to notify
263 		 * the sleep state to the AP) and probe requests (for the
264 		 * active scan) are allowed, all other frames should not be
265 		 * sent and we should not get here, but if we do
266 		 * nonetheless, drop them to avoid sending them
267 		 * off-channel. See the link below and
268 		 * ieee80211_start_scan() for more.
269 		 *
270 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
271 		 */
272 		return TX_DROP;
273 
274 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
275 		return TX_CONTINUE;
276 
277 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
278 		return TX_CONTINUE;
279 
280 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
281 		return TX_CONTINUE;
282 
283 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
284 
285 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
286 		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
287 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
288 			     ieee80211_is_data(hdr->frame_control))) {
289 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
290 			printk(KERN_DEBUG "%s: dropped data frame to not "
291 			       "associated station %pM\n",
292 			       tx->sdata->name, hdr->addr1);
293 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
294 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
295 			return TX_DROP;
296 		}
297 	} else {
298 		if (unlikely(ieee80211_is_data(hdr->frame_control) &&
299 			     tx->local->num_sta == 0 &&
300 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
301 			/*
302 			 * No associated STAs - no need to send multicast
303 			 * frames.
304 			 */
305 			return TX_DROP;
306 		}
307 		return TX_CONTINUE;
308 	}
309 
310 	return TX_CONTINUE;
311 }
312 
313 /* This function is called whenever the AP is about to exceed the maximum limit
314  * of buffered frames for power saving STAs. This situation should not really
315  * happen often during normal operation, so dropping the oldest buffered packet
316  * from each queue should be OK to make some room for new frames. */
317 static void purge_old_ps_buffers(struct ieee80211_local *local)
318 {
319 	int total = 0, purged = 0;
320 	struct sk_buff *skb;
321 	struct ieee80211_sub_if_data *sdata;
322 	struct sta_info *sta;
323 
324 	/*
325 	 * virtual interfaces are protected by RCU
326 	 */
327 	rcu_read_lock();
328 
329 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
330 		struct ieee80211_if_ap *ap;
331 		if (sdata->vif.type != NL80211_IFTYPE_AP)
332 			continue;
333 		ap = &sdata->u.ap;
334 		skb = skb_dequeue(&ap->ps_bc_buf);
335 		if (skb) {
336 			purged++;
337 			dev_kfree_skb(skb);
338 		}
339 		total += skb_queue_len(&ap->ps_bc_buf);
340 	}
341 
342 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
343 		skb = skb_dequeue(&sta->ps_tx_buf);
344 		if (skb) {
345 			purged++;
346 			dev_kfree_skb(skb);
347 		}
348 		total += skb_queue_len(&sta->ps_tx_buf);
349 	}
350 
351 	rcu_read_unlock();
352 
353 	local->total_ps_buffered = total;
354 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
355 	wiphy_debug(local->hw.wiphy, "PS buffers full - purged %d frames\n",
356 		    purged);
357 #endif
358 }
359 
360 static ieee80211_tx_result
361 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
362 {
363 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
364 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
365 
366 	/*
367 	 * broadcast/multicast frame
368 	 *
369 	 * If any of the associated stations is in power save mode,
370 	 * the frame is buffered to be sent after DTIM beacon frame.
371 	 * This is done either by the hardware or us.
372 	 */
373 
374 	/* powersaving STAs only in AP/VLAN mode */
375 	if (!tx->sdata->bss)
376 		return TX_CONTINUE;
377 
378 	/* no buffering for ordered frames */
379 	if (ieee80211_has_order(hdr->frame_control))
380 		return TX_CONTINUE;
381 
382 	/* no stations in PS mode */
383 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
384 		return TX_CONTINUE;
385 
386 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
387 
388 	/* device releases frame after DTIM beacon */
389 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
390 		return TX_CONTINUE;
391 
392 	/* buffered in mac80211 */
393 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
394 		purge_old_ps_buffers(tx->local);
395 
396 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
397 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
398 		if (net_ratelimit())
399 			printk(KERN_DEBUG "%s: BC TX buffer full - dropping the oldest frame\n",
400 			       tx->sdata->name);
401 #endif
402 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
403 	} else
404 		tx->local->total_ps_buffered++;
405 
406 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
407 
408 	return TX_QUEUED;
409 }
410 
411 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
412 			     struct sk_buff *skb)
413 {
414 	if (!ieee80211_is_mgmt(fc))
415 		return 0;
416 
417 	if (sta == NULL || !test_sta_flags(sta, WLAN_STA_MFP))
418 		return 0;
419 
420 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
421 					    skb->data))
422 		return 0;
423 
424 	return 1;
425 }
426 
427 static ieee80211_tx_result
428 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
429 {
430 	struct sta_info *sta = tx->sta;
431 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
432 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
433 	struct ieee80211_local *local = tx->local;
434 	u32 staflags;
435 
436 	if (unlikely(!sta ||
437 		     ieee80211_is_probe_resp(hdr->frame_control) ||
438 		     ieee80211_is_auth(hdr->frame_control) ||
439 		     ieee80211_is_assoc_resp(hdr->frame_control) ||
440 		     ieee80211_is_reassoc_resp(hdr->frame_control)))
441 		return TX_CONTINUE;
442 
443 	staflags = get_sta_flags(sta);
444 
445 	if (unlikely((staflags & (WLAN_STA_PS_STA | WLAN_STA_PS_DRIVER)) &&
446 		     !(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) {
447 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
448 		printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
449 		       "before %d)\n",
450 		       sta->sta.addr, sta->sta.aid,
451 		       skb_queue_len(&sta->ps_tx_buf));
452 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
453 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
454 			purge_old_ps_buffers(tx->local);
455 		if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
456 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
457 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
458 			if (net_ratelimit()) {
459 				printk(KERN_DEBUG "%s: STA %pM TX "
460 				       "buffer full - dropping oldest frame\n",
461 				       tx->sdata->name, sta->sta.addr);
462 			}
463 #endif
464 			dev_kfree_skb(old);
465 		} else
466 			tx->local->total_ps_buffered++;
467 
468 		/*
469 		 * Queue frame to be sent after STA wakes up/polls,
470 		 * but don't set the TIM bit if the driver is blocking
471 		 * wakeup or poll response transmissions anyway.
472 		 */
473 		if (skb_queue_empty(&sta->ps_tx_buf) &&
474 		    !(staflags & WLAN_STA_PS_DRIVER))
475 			sta_info_set_tim_bit(sta);
476 
477 		info->control.jiffies = jiffies;
478 		info->control.vif = &tx->sdata->vif;
479 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
480 		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
481 
482 		if (!timer_pending(&local->sta_cleanup))
483 			mod_timer(&local->sta_cleanup,
484 				  round_jiffies(jiffies +
485 						STA_INFO_CLEANUP_INTERVAL));
486 
487 		return TX_QUEUED;
488 	}
489 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
490 	else if (unlikely(staflags & WLAN_STA_PS_STA)) {
491 		printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
492 		       "set -> send frame\n", tx->sdata->name,
493 		       sta->sta.addr);
494 	}
495 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
496 
497 	return TX_CONTINUE;
498 }
499 
500 static ieee80211_tx_result debug_noinline
501 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
502 {
503 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
504 		return TX_CONTINUE;
505 
506 	if (tx->flags & IEEE80211_TX_UNICAST)
507 		return ieee80211_tx_h_unicast_ps_buf(tx);
508 	else
509 		return ieee80211_tx_h_multicast_ps_buf(tx);
510 }
511 
512 static ieee80211_tx_result debug_noinline
513 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
514 {
515 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
516 
517 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
518 		     tx->sdata->control_port_no_encrypt))
519 		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
520 
521 	return TX_CONTINUE;
522 }
523 
524 static ieee80211_tx_result debug_noinline
525 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
526 {
527 	struct ieee80211_key *key = NULL;
528 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
529 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
530 
531 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
532 		tx->key = NULL;
533 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
534 		tx->key = key;
535 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
536 		 is_multicast_ether_addr(hdr->addr1) &&
537 		 ieee80211_is_robust_mgmt_frame(hdr) &&
538 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
539 		tx->key = key;
540 	else if (is_multicast_ether_addr(hdr->addr1) &&
541 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
542 		tx->key = key;
543 	else if (!is_multicast_ether_addr(hdr->addr1) &&
544 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
545 		tx->key = key;
546 	else if (tx->sdata->drop_unencrypted &&
547 		 (tx->skb->protocol != tx->sdata->control_port_protocol) &&
548 		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
549 		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
550 		  (ieee80211_is_action(hdr->frame_control) &&
551 		   tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) {
552 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
553 		return TX_DROP;
554 	} else
555 		tx->key = NULL;
556 
557 	if (tx->key) {
558 		bool skip_hw = false;
559 
560 		tx->key->tx_rx_count++;
561 		/* TODO: add threshold stuff again */
562 
563 		switch (tx->key->conf.cipher) {
564 		case WLAN_CIPHER_SUITE_WEP40:
565 		case WLAN_CIPHER_SUITE_WEP104:
566 			if (ieee80211_is_auth(hdr->frame_control))
567 				break;
568 		case WLAN_CIPHER_SUITE_TKIP:
569 			if (!ieee80211_is_data_present(hdr->frame_control))
570 				tx->key = NULL;
571 			break;
572 		case WLAN_CIPHER_SUITE_CCMP:
573 			if (!ieee80211_is_data_present(hdr->frame_control) &&
574 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
575 					       tx->skb))
576 				tx->key = NULL;
577 			else
578 				skip_hw = (tx->key->conf.flags &
579 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
580 					ieee80211_is_mgmt(hdr->frame_control);
581 			break;
582 		case WLAN_CIPHER_SUITE_AES_CMAC:
583 			if (!ieee80211_is_mgmt(hdr->frame_control))
584 				tx->key = NULL;
585 			break;
586 		}
587 
588 		if (!skip_hw && tx->key &&
589 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
590 			info->control.hw_key = &tx->key->conf;
591 	}
592 
593 	return TX_CONTINUE;
594 }
595 
596 static ieee80211_tx_result debug_noinline
597 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
598 {
599 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
600 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
601 	struct ieee80211_supported_band *sband;
602 	struct ieee80211_rate *rate;
603 	int i;
604 	u32 len;
605 	bool inval = false, rts = false, short_preamble = false;
606 	struct ieee80211_tx_rate_control txrc;
607 	u32 sta_flags;
608 
609 	memset(&txrc, 0, sizeof(txrc));
610 
611 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
612 
613 	len = min_t(u32, tx->skb->len + FCS_LEN,
614 			 tx->local->hw.wiphy->frag_threshold);
615 
616 	/* set up the tx rate control struct we give the RC algo */
617 	txrc.hw = local_to_hw(tx->local);
618 	txrc.sband = sband;
619 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
620 	txrc.skb = tx->skb;
621 	txrc.reported_rate.idx = -1;
622 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
623 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
624 		txrc.max_rate_idx = -1;
625 	else
626 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
627 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
628 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
629 
630 	/* set up RTS protection if desired */
631 	if (len > tx->local->hw.wiphy->rts_threshold) {
632 		txrc.rts = rts = true;
633 	}
634 
635 	/*
636 	 * Use short preamble if the BSS can handle it, but not for
637 	 * management frames unless we know the receiver can handle
638 	 * that -- the management frame might be to a station that
639 	 * just wants a probe response.
640 	 */
641 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
642 	    (ieee80211_is_data(hdr->frame_control) ||
643 	     (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
644 		txrc.short_preamble = short_preamble = true;
645 
646 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
647 
648 	/*
649 	 * Lets not bother rate control if we're associated and cannot
650 	 * talk to the sta. This should not happen.
651 	 */
652 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) &&
653 		 (sta_flags & WLAN_STA_ASSOC) &&
654 		 !rate_usable_index_exists(sband, &tx->sta->sta),
655 		 "%s: Dropped data frame as no usable bitrate found while "
656 		 "scanning and associated. Target station: "
657 		 "%pM on %d GHz band\n",
658 		 tx->sdata->name, hdr->addr1,
659 		 tx->channel->band ? 5 : 2))
660 		return TX_DROP;
661 
662 	/*
663 	 * If we're associated with the sta at this point we know we can at
664 	 * least send the frame at the lowest bit rate.
665 	 */
666 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
667 
668 	if (unlikely(info->control.rates[0].idx < 0))
669 		return TX_DROP;
670 
671 	if (txrc.reported_rate.idx < 0) {
672 		txrc.reported_rate = info->control.rates[0];
673 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
674 			tx->sta->last_tx_rate = txrc.reported_rate;
675 	} else if (tx->sta)
676 		tx->sta->last_tx_rate = txrc.reported_rate;
677 
678 	if (unlikely(!info->control.rates[0].count))
679 		info->control.rates[0].count = 1;
680 
681 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
682 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
683 		info->control.rates[0].count = 1;
684 
685 	if (is_multicast_ether_addr(hdr->addr1)) {
686 		/*
687 		 * XXX: verify the rate is in the basic rateset
688 		 */
689 		return TX_CONTINUE;
690 	}
691 
692 	/*
693 	 * set up the RTS/CTS rate as the fastest basic rate
694 	 * that is not faster than the data rate
695 	 *
696 	 * XXX: Should this check all retry rates?
697 	 */
698 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
699 		s8 baserate = 0;
700 
701 		rate = &sband->bitrates[info->control.rates[0].idx];
702 
703 		for (i = 0; i < sband->n_bitrates; i++) {
704 			/* must be a basic rate */
705 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
706 				continue;
707 			/* must not be faster than the data rate */
708 			if (sband->bitrates[i].bitrate > rate->bitrate)
709 				continue;
710 			/* maximum */
711 			if (sband->bitrates[baserate].bitrate <
712 			     sband->bitrates[i].bitrate)
713 				baserate = i;
714 		}
715 
716 		info->control.rts_cts_rate_idx = baserate;
717 	}
718 
719 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
720 		/*
721 		 * make sure there's no valid rate following
722 		 * an invalid one, just in case drivers don't
723 		 * take the API seriously to stop at -1.
724 		 */
725 		if (inval) {
726 			info->control.rates[i].idx = -1;
727 			continue;
728 		}
729 		if (info->control.rates[i].idx < 0) {
730 			inval = true;
731 			continue;
732 		}
733 
734 		/*
735 		 * For now assume MCS is already set up correctly, this
736 		 * needs to be fixed.
737 		 */
738 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
739 			WARN_ON(info->control.rates[i].idx > 76);
740 			continue;
741 		}
742 
743 		/* set up RTS protection if desired */
744 		if (rts)
745 			info->control.rates[i].flags |=
746 				IEEE80211_TX_RC_USE_RTS_CTS;
747 
748 		/* RC is busted */
749 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
750 				 sband->n_bitrates)) {
751 			info->control.rates[i].idx = -1;
752 			continue;
753 		}
754 
755 		rate = &sband->bitrates[info->control.rates[i].idx];
756 
757 		/* set up short preamble */
758 		if (short_preamble &&
759 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
760 			info->control.rates[i].flags |=
761 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
762 
763 		/* set up G protection */
764 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
765 		    rate->flags & IEEE80211_RATE_ERP_G)
766 			info->control.rates[i].flags |=
767 				IEEE80211_TX_RC_USE_CTS_PROTECT;
768 	}
769 
770 	return TX_CONTINUE;
771 }
772 
773 static ieee80211_tx_result debug_noinline
774 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
775 {
776 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
777 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
778 	u16 *seq;
779 	u8 *qc;
780 	int tid;
781 
782 	/*
783 	 * Packet injection may want to control the sequence
784 	 * number, if we have no matching interface then we
785 	 * neither assign one ourselves nor ask the driver to.
786 	 */
787 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
788 		return TX_CONTINUE;
789 
790 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
791 		return TX_CONTINUE;
792 
793 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
794 		return TX_CONTINUE;
795 
796 	/*
797 	 * Anything but QoS data that has a sequence number field
798 	 * (is long enough) gets a sequence number from the global
799 	 * counter.
800 	 */
801 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
802 		/* driver should assign sequence number */
803 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
804 		/* for pure STA mode without beacons, we can do it */
805 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
806 		tx->sdata->sequence_number += 0x10;
807 		return TX_CONTINUE;
808 	}
809 
810 	/*
811 	 * This should be true for injected/management frames only, for
812 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
813 	 * above since they are not QoS-data frames.
814 	 */
815 	if (!tx->sta)
816 		return TX_CONTINUE;
817 
818 	/* include per-STA, per-TID sequence counter */
819 
820 	qc = ieee80211_get_qos_ctl(hdr);
821 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
822 	seq = &tx->sta->tid_seq[tid];
823 
824 	hdr->seq_ctrl = cpu_to_le16(*seq);
825 
826 	/* Increase the sequence number. */
827 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
828 
829 	return TX_CONTINUE;
830 }
831 
832 static int ieee80211_fragment(struct ieee80211_local *local,
833 			      struct sk_buff *skb, int hdrlen,
834 			      int frag_threshold)
835 {
836 	struct sk_buff *tail = skb, *tmp;
837 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
838 	int pos = hdrlen + per_fragm;
839 	int rem = skb->len - hdrlen - per_fragm;
840 
841 	if (WARN_ON(rem < 0))
842 		return -EINVAL;
843 
844 	while (rem) {
845 		int fraglen = per_fragm;
846 
847 		if (fraglen > rem)
848 			fraglen = rem;
849 		rem -= fraglen;
850 		tmp = dev_alloc_skb(local->tx_headroom +
851 				    frag_threshold +
852 				    IEEE80211_ENCRYPT_HEADROOM +
853 				    IEEE80211_ENCRYPT_TAILROOM);
854 		if (!tmp)
855 			return -ENOMEM;
856 		tail->next = tmp;
857 		tail = tmp;
858 		skb_reserve(tmp, local->tx_headroom +
859 				 IEEE80211_ENCRYPT_HEADROOM);
860 		/* copy control information */
861 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
862 		skb_copy_queue_mapping(tmp, skb);
863 		tmp->priority = skb->priority;
864 		tmp->dev = skb->dev;
865 
866 		/* copy header and data */
867 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
868 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
869 
870 		pos += fraglen;
871 	}
872 
873 	skb->len = hdrlen + per_fragm;
874 	return 0;
875 }
876 
877 static ieee80211_tx_result debug_noinline
878 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
879 {
880 	struct sk_buff *skb = tx->skb;
881 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
882 	struct ieee80211_hdr *hdr = (void *)skb->data;
883 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
884 	int hdrlen;
885 	int fragnum;
886 
887 	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
888 		return TX_CONTINUE;
889 
890 	/*
891 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
892 	 * This scenario is handled in ieee80211_tx_prepare but extra
893 	 * caution taken here as fragmented ampdu may cause Tx stop.
894 	 */
895 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
896 		return TX_DROP;
897 
898 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
899 
900 	/* internal error, why is TX_FRAGMENTED set? */
901 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
902 		return TX_DROP;
903 
904 	/*
905 	 * Now fragment the frame. This will allocate all the fragments and
906 	 * chain them (using skb as the first fragment) to skb->next.
907 	 * During transmission, we will remove the successfully transmitted
908 	 * fragments from this list. When the low-level driver rejects one
909 	 * of the fragments then we will simply pretend to accept the skb
910 	 * but store it away as pending.
911 	 */
912 	if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
913 		return TX_DROP;
914 
915 	/* update duration/seq/flags of fragments */
916 	fragnum = 0;
917 	do {
918 		int next_len;
919 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
920 
921 		hdr = (void *)skb->data;
922 		info = IEEE80211_SKB_CB(skb);
923 
924 		if (skb->next) {
925 			hdr->frame_control |= morefrags;
926 			next_len = skb->next->len;
927 			/*
928 			 * No multi-rate retries for fragmented frames, that
929 			 * would completely throw off the NAV at other STAs.
930 			 */
931 			info->control.rates[1].idx = -1;
932 			info->control.rates[2].idx = -1;
933 			info->control.rates[3].idx = -1;
934 			info->control.rates[4].idx = -1;
935 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
936 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
937 		} else {
938 			hdr->frame_control &= ~morefrags;
939 			next_len = 0;
940 		}
941 		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
942 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
943 		fragnum++;
944 	} while ((skb = skb->next));
945 
946 	return TX_CONTINUE;
947 }
948 
949 static ieee80211_tx_result debug_noinline
950 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
951 {
952 	struct sk_buff *skb = tx->skb;
953 
954 	if (!tx->sta)
955 		return TX_CONTINUE;
956 
957 	tx->sta->tx_packets++;
958 	do {
959 		tx->sta->tx_fragments++;
960 		tx->sta->tx_bytes += skb->len;
961 	} while ((skb = skb->next));
962 
963 	return TX_CONTINUE;
964 }
965 
966 static ieee80211_tx_result debug_noinline
967 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
968 {
969 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
970 
971 	if (!tx->key)
972 		return TX_CONTINUE;
973 
974 	switch (tx->key->conf.cipher) {
975 	case WLAN_CIPHER_SUITE_WEP40:
976 	case WLAN_CIPHER_SUITE_WEP104:
977 		return ieee80211_crypto_wep_encrypt(tx);
978 	case WLAN_CIPHER_SUITE_TKIP:
979 		return ieee80211_crypto_tkip_encrypt(tx);
980 	case WLAN_CIPHER_SUITE_CCMP:
981 		return ieee80211_crypto_ccmp_encrypt(tx);
982 	case WLAN_CIPHER_SUITE_AES_CMAC:
983 		return ieee80211_crypto_aes_cmac_encrypt(tx);
984 	default:
985 		/* handle hw-only algorithm */
986 		if (info->control.hw_key) {
987 			ieee80211_tx_set_protected(tx);
988 			return TX_CONTINUE;
989 		}
990 		break;
991 
992 	}
993 
994 	return TX_DROP;
995 }
996 
997 static ieee80211_tx_result debug_noinline
998 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
999 {
1000 	struct sk_buff *skb = tx->skb;
1001 	struct ieee80211_hdr *hdr;
1002 	int next_len;
1003 	bool group_addr;
1004 
1005 	do {
1006 		hdr = (void *) skb->data;
1007 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1008 			break; /* must not overwrite AID */
1009 		next_len = skb->next ? skb->next->len : 0;
1010 		group_addr = is_multicast_ether_addr(hdr->addr1);
1011 
1012 		hdr->duration_id =
1013 			ieee80211_duration(tx, group_addr, next_len);
1014 	} while ((skb = skb->next));
1015 
1016 	return TX_CONTINUE;
1017 }
1018 
1019 /* actual transmit path */
1020 
1021 /*
1022  * deal with packet injection down monitor interface
1023  * with Radiotap Header -- only called for monitor mode interface
1024  */
1025 static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
1026 					  struct sk_buff *skb)
1027 {
1028 	/*
1029 	 * this is the moment to interpret and discard the radiotap header that
1030 	 * must be at the start of the packet injected in Monitor mode
1031 	 *
1032 	 * Need to take some care with endian-ness since radiotap
1033 	 * args are little-endian
1034 	 */
1035 
1036 	struct ieee80211_radiotap_iterator iterator;
1037 	struct ieee80211_radiotap_header *rthdr =
1038 		(struct ieee80211_radiotap_header *) skb->data;
1039 	struct ieee80211_supported_band *sband;
1040 	bool hw_frag;
1041 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1042 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1043 						   NULL);
1044 
1045 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
1046 
1047 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1048 	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1049 
1050 	/* packet is fragmented in HW if we have a non-NULL driver callback */
1051 	hw_frag = (tx->local->ops->set_frag_threshold != NULL);
1052 
1053 	/*
1054 	 * for every radiotap entry that is present
1055 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1056 	 * entries present, or -EINVAL on error)
1057 	 */
1058 
1059 	while (!ret) {
1060 		ret = ieee80211_radiotap_iterator_next(&iterator);
1061 
1062 		if (ret)
1063 			continue;
1064 
1065 		/* see if this argument is something we can use */
1066 		switch (iterator.this_arg_index) {
1067 		/*
1068 		 * You must take care when dereferencing iterator.this_arg
1069 		 * for multibyte types... the pointer is not aligned.  Use
1070 		 * get_unaligned((type *)iterator.this_arg) to dereference
1071 		 * iterator.this_arg for type "type" safely on all arches.
1072 		*/
1073 		case IEEE80211_RADIOTAP_FLAGS:
1074 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1075 				/*
1076 				 * this indicates that the skb we have been
1077 				 * handed has the 32-bit FCS CRC at the end...
1078 				 * we should react to that by snipping it off
1079 				 * because it will be recomputed and added
1080 				 * on transmission
1081 				 */
1082 				if (skb->len < (iterator._max_length + FCS_LEN))
1083 					return false;
1084 
1085 				skb_trim(skb, skb->len - FCS_LEN);
1086 			}
1087 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1088 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1089 			if ((*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG) &&
1090 								!hw_frag)
1091 				tx->flags |= IEEE80211_TX_FRAGMENTED;
1092 			break;
1093 
1094 		/*
1095 		 * Please update the file
1096 		 * Documentation/networking/mac80211-injection.txt
1097 		 * when parsing new fields here.
1098 		 */
1099 
1100 		default:
1101 			break;
1102 		}
1103 	}
1104 
1105 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1106 		return false;
1107 
1108 	/*
1109 	 * remove the radiotap header
1110 	 * iterator->_max_length was sanity-checked against
1111 	 * skb->len by iterator init
1112 	 */
1113 	skb_pull(skb, iterator._max_length);
1114 
1115 	return true;
1116 }
1117 
1118 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1119 				  struct sk_buff *skb,
1120 				  struct ieee80211_tx_info *info,
1121 				  struct tid_ampdu_tx *tid_tx,
1122 				  int tid)
1123 {
1124 	bool queued = false;
1125 
1126 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1127 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1128 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1129 		/*
1130 		 * nothing -- this aggregation session is being started
1131 		 * but that might still fail with the driver
1132 		 */
1133 	} else {
1134 		spin_lock(&tx->sta->lock);
1135 		/*
1136 		 * Need to re-check now, because we may get here
1137 		 *
1138 		 *  1) in the window during which the setup is actually
1139 		 *     already done, but not marked yet because not all
1140 		 *     packets are spliced over to the driver pending
1141 		 *     queue yet -- if this happened we acquire the lock
1142 		 *     either before or after the splice happens, but
1143 		 *     need to recheck which of these cases happened.
1144 		 *
1145 		 *  2) during session teardown, if the OPERATIONAL bit
1146 		 *     was cleared due to the teardown but the pointer
1147 		 *     hasn't been assigned NULL yet (or we loaded it
1148 		 *     before it was assigned) -- in this case it may
1149 		 *     now be NULL which means we should just let the
1150 		 *     packet pass through because splicing the frames
1151 		 *     back is already done.
1152 		 */
1153 		tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
1154 
1155 		if (!tid_tx) {
1156 			/* do nothing, let packet pass through */
1157 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1158 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1159 		} else {
1160 			queued = true;
1161 			info->control.vif = &tx->sdata->vif;
1162 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1163 			__skb_queue_tail(&tid_tx->pending, skb);
1164 		}
1165 		spin_unlock(&tx->sta->lock);
1166 	}
1167 
1168 	return queued;
1169 }
1170 
1171 /*
1172  * initialises @tx
1173  */
1174 static ieee80211_tx_result
1175 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1176 		     struct ieee80211_tx_data *tx,
1177 		     struct sk_buff *skb)
1178 {
1179 	struct ieee80211_local *local = sdata->local;
1180 	struct ieee80211_hdr *hdr;
1181 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1182 	int hdrlen, tid;
1183 	u8 *qc;
1184 
1185 	memset(tx, 0, sizeof(*tx));
1186 	tx->skb = skb;
1187 	tx->local = local;
1188 	tx->sdata = sdata;
1189 	tx->channel = local->hw.conf.channel;
1190 	/*
1191 	 * Set this flag (used below to indicate "automatic fragmentation"),
1192 	 * it will be cleared/left by radiotap as desired.
1193 	 * Only valid when fragmentation is done by the stack.
1194 	 */
1195 	if (!local->ops->set_frag_threshold)
1196 		tx->flags |= IEEE80211_TX_FRAGMENTED;
1197 
1198 	/* process and remove the injection radiotap header */
1199 	if (unlikely(info->flags & IEEE80211_TX_INTFL_HAS_RADIOTAP)) {
1200 		if (!__ieee80211_parse_tx_radiotap(tx, skb))
1201 			return TX_DROP;
1202 
1203 		/*
1204 		 * __ieee80211_parse_tx_radiotap has now removed
1205 		 * the radiotap header that was present and pre-filled
1206 		 * 'tx' with tx control information.
1207 		 */
1208 		info->flags &= ~IEEE80211_TX_INTFL_HAS_RADIOTAP;
1209 	}
1210 
1211 	/*
1212 	 * If this flag is set to true anywhere, and we get here,
1213 	 * we are doing the needed processing, so remove the flag
1214 	 * now.
1215 	 */
1216 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1217 
1218 	hdr = (struct ieee80211_hdr *) skb->data;
1219 
1220 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1221 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1222 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1223 			return TX_DROP;
1224 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED) {
1225 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1226 	}
1227 	if (!tx->sta)
1228 		tx->sta = sta_info_get(sdata, hdr->addr1);
1229 
1230 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1231 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1232 		struct tid_ampdu_tx *tid_tx;
1233 
1234 		qc = ieee80211_get_qos_ctl(hdr);
1235 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1236 
1237 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1238 		if (tid_tx) {
1239 			bool queued;
1240 
1241 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1242 						       tid_tx, tid);
1243 
1244 			if (unlikely(queued))
1245 				return TX_QUEUED;
1246 		}
1247 	}
1248 
1249 	if (is_multicast_ether_addr(hdr->addr1)) {
1250 		tx->flags &= ~IEEE80211_TX_UNICAST;
1251 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1252 	} else {
1253 		tx->flags |= IEEE80211_TX_UNICAST;
1254 		if (unlikely(local->wifi_wme_noack_test))
1255 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
1256 		else
1257 			info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1258 	}
1259 
1260 	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
1261 		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1262 		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1263 		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1264 			tx->flags |= IEEE80211_TX_FRAGMENTED;
1265 		else
1266 			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1267 	}
1268 
1269 	if (!tx->sta)
1270 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1271 	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1272 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1273 
1274 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1275 	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
1276 		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
1277 		tx->ethertype = (pos[0] << 8) | pos[1];
1278 	}
1279 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1280 
1281 	return TX_CONTINUE;
1282 }
1283 
1284 /*
1285  * Returns false if the frame couldn't be transmitted but was queued instead.
1286  */
1287 static bool __ieee80211_tx(struct ieee80211_local *local, struct sk_buff **skbp,
1288 			   struct sta_info *sta, bool txpending)
1289 {
1290 	struct sk_buff *skb = *skbp, *next;
1291 	struct ieee80211_tx_info *info;
1292 	struct ieee80211_sub_if_data *sdata;
1293 	unsigned long flags;
1294 	int len;
1295 	bool fragm = false;
1296 
1297 	while (skb) {
1298 		int q = skb_get_queue_mapping(skb);
1299 		__le16 fc;
1300 
1301 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1302 		if (local->queue_stop_reasons[q] ||
1303 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1304 			/*
1305 			 * Since queue is stopped, queue up frames for later
1306 			 * transmission from the tx-pending tasklet when the
1307 			 * queue is woken again.
1308 			 */
1309 
1310 			do {
1311 				next = skb->next;
1312 				skb->next = NULL;
1313 				/*
1314 				 * NB: If txpending is true, next must already
1315 				 * be NULL since we must've gone through this
1316 				 * loop before already; therefore we can just
1317 				 * queue the frame to the head without worrying
1318 				 * about reordering of fragments.
1319 				 */
1320 				if (unlikely(txpending))
1321 					__skb_queue_head(&local->pending[q],
1322 							 skb);
1323 				else
1324 					__skb_queue_tail(&local->pending[q],
1325 							 skb);
1326 			} while ((skb = next));
1327 
1328 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1329 					       flags);
1330 			return false;
1331 		}
1332 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1333 
1334 		info = IEEE80211_SKB_CB(skb);
1335 
1336 		if (fragm)
1337 			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1338 					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1339 
1340 		next = skb->next;
1341 		len = skb->len;
1342 
1343 		if (next)
1344 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
1345 
1346 		sdata = vif_to_sdata(info->control.vif);
1347 
1348 		switch (sdata->vif.type) {
1349 		case NL80211_IFTYPE_MONITOR:
1350 			info->control.vif = NULL;
1351 			break;
1352 		case NL80211_IFTYPE_AP_VLAN:
1353 			info->control.vif = &container_of(sdata->bss,
1354 				struct ieee80211_sub_if_data, u.ap)->vif;
1355 			break;
1356 		default:
1357 			/* keep */
1358 			break;
1359 		}
1360 
1361 		if (sta && sta->uploaded)
1362 			info->control.sta = &sta->sta;
1363 		else
1364 			info->control.sta = NULL;
1365 
1366 		fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1367 		drv_tx(local, skb);
1368 
1369 		ieee80211_tpt_led_trig_tx(local, fc, len);
1370 		*skbp = skb = next;
1371 		ieee80211_led_tx(local, 1);
1372 		fragm = true;
1373 	}
1374 
1375 	return true;
1376 }
1377 
1378 /*
1379  * Invoke TX handlers, return 0 on success and non-zero if the
1380  * frame was dropped or queued.
1381  */
1382 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1383 {
1384 	struct sk_buff *skb = tx->skb;
1385 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1386 	ieee80211_tx_result res = TX_DROP;
1387 
1388 #define CALL_TXH(txh) \
1389 	do {				\
1390 		res = txh(tx);		\
1391 		if (res != TX_CONTINUE)	\
1392 			goto txh_done;	\
1393 	} while (0)
1394 
1395 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1396 	CALL_TXH(ieee80211_tx_h_check_assoc);
1397 	CALL_TXH(ieee80211_tx_h_ps_buf);
1398 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1399 	CALL_TXH(ieee80211_tx_h_select_key);
1400 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1401 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1402 
1403 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION))
1404 		goto txh_done;
1405 
1406 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1407 	CALL_TXH(ieee80211_tx_h_sequence);
1408 	CALL_TXH(ieee80211_tx_h_fragment);
1409 	/* handlers after fragment must be aware of tx info fragmentation! */
1410 	CALL_TXH(ieee80211_tx_h_stats);
1411 	CALL_TXH(ieee80211_tx_h_encrypt);
1412 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1413 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1414 #undef CALL_TXH
1415 
1416  txh_done:
1417 	if (unlikely(res == TX_DROP)) {
1418 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1419 		while (skb) {
1420 			struct sk_buff *next;
1421 
1422 			next = skb->next;
1423 			dev_kfree_skb(skb);
1424 			skb = next;
1425 		}
1426 		return -1;
1427 	} else if (unlikely(res == TX_QUEUED)) {
1428 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1429 		return -1;
1430 	}
1431 
1432 	return 0;
1433 }
1434 
1435 /*
1436  * Returns false if the frame couldn't be transmitted but was queued instead.
1437  */
1438 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1439 			 struct sk_buff *skb, bool txpending)
1440 {
1441 	struct ieee80211_local *local = sdata->local;
1442 	struct ieee80211_tx_data tx;
1443 	ieee80211_tx_result res_prepare;
1444 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1445 	u16 queue;
1446 	bool result = true;
1447 
1448 	queue = skb_get_queue_mapping(skb);
1449 
1450 	if (unlikely(skb->len < 10)) {
1451 		dev_kfree_skb(skb);
1452 		return true;
1453 	}
1454 
1455 	rcu_read_lock();
1456 
1457 	/* initialises tx */
1458 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1459 
1460 	if (unlikely(res_prepare == TX_DROP)) {
1461 		dev_kfree_skb(skb);
1462 		goto out;
1463 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1464 		goto out;
1465 	}
1466 
1467 	tx.channel = local->hw.conf.channel;
1468 	info->band = tx.channel->band;
1469 
1470 	if (!invoke_tx_handlers(&tx))
1471 		result = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
1472  out:
1473 	rcu_read_unlock();
1474 	return result;
1475 }
1476 
1477 /* device xmit handlers */
1478 
1479 static int ieee80211_skb_resize(struct ieee80211_local *local,
1480 				struct sk_buff *skb,
1481 				int head_need, bool may_encrypt)
1482 {
1483 	int tail_need = 0;
1484 
1485 	/*
1486 	 * This could be optimised, devices that do full hardware
1487 	 * crypto (including TKIP MMIC) need no tailroom... But we
1488 	 * have no drivers for such devices currently.
1489 	 */
1490 	if (may_encrypt) {
1491 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1492 		tail_need -= skb_tailroom(skb);
1493 		tail_need = max_t(int, tail_need, 0);
1494 	}
1495 
1496 	if (head_need || tail_need) {
1497 		/* Sorry. Can't account for this any more */
1498 		skb_orphan(skb);
1499 	}
1500 
1501 	if (skb_cloned(skb))
1502 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1503 	else if (head_need || tail_need)
1504 		I802_DEBUG_INC(local->tx_expand_skb_head);
1505 	else
1506 		return 0;
1507 
1508 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1509 		wiphy_debug(local->hw.wiphy,
1510 			    "failed to reallocate TX buffer\n");
1511 		return -ENOMEM;
1512 	}
1513 
1514 	/* update truesize too */
1515 	skb->truesize += head_need + tail_need;
1516 
1517 	return 0;
1518 }
1519 
1520 static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
1521 			   struct sk_buff *skb)
1522 {
1523 	struct ieee80211_local *local = sdata->local;
1524 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1525 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1526 	struct ieee80211_sub_if_data *tmp_sdata;
1527 	int headroom;
1528 	bool may_encrypt;
1529 
1530 	rcu_read_lock();
1531 
1532 	if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1533 		int hdrlen;
1534 		u16 len_rthdr;
1535 
1536 		info->flags |= IEEE80211_TX_CTL_INJECTED |
1537 			       IEEE80211_TX_INTFL_HAS_RADIOTAP;
1538 
1539 		len_rthdr = ieee80211_get_radiotap_len(skb->data);
1540 		hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1541 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
1542 
1543 		/* check the header is complete in the frame */
1544 		if (likely(skb->len >= len_rthdr + hdrlen)) {
1545 			/*
1546 			 * We process outgoing injected frames that have a
1547 			 * local address we handle as though they are our
1548 			 * own frames.
1549 			 * This code here isn't entirely correct, the local
1550 			 * MAC address is not necessarily enough to find
1551 			 * the interface to use; for that proper VLAN/WDS
1552 			 * support we will need a different mechanism.
1553 			 */
1554 
1555 			list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
1556 						list) {
1557 				if (!ieee80211_sdata_running(tmp_sdata))
1558 					continue;
1559 				if (tmp_sdata->vif.type ==
1560 				    NL80211_IFTYPE_MONITOR ||
1561 				    tmp_sdata->vif.type ==
1562 				    NL80211_IFTYPE_AP_VLAN ||
1563 					tmp_sdata->vif.type ==
1564 				    NL80211_IFTYPE_WDS)
1565 					continue;
1566 				if (compare_ether_addr(tmp_sdata->vif.addr,
1567 						       hdr->addr2) == 0) {
1568 					sdata = tmp_sdata;
1569 					break;
1570 				}
1571 			}
1572 		}
1573 	}
1574 
1575 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1576 
1577 	headroom = local->tx_headroom;
1578 	if (may_encrypt)
1579 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1580 	headroom -= skb_headroom(skb);
1581 	headroom = max_t(int, 0, headroom);
1582 
1583 	if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
1584 		dev_kfree_skb(skb);
1585 		rcu_read_unlock();
1586 		return;
1587 	}
1588 
1589 	hdr = (struct ieee80211_hdr *) skb->data;
1590 	info->control.vif = &sdata->vif;
1591 
1592 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1593 	    ieee80211_is_data(hdr->frame_control) &&
1594 		!is_multicast_ether_addr(hdr->addr1))
1595 			if (mesh_nexthop_lookup(skb, sdata)) {
1596 				/* skb queued: don't free */
1597 				rcu_read_unlock();
1598 				return;
1599 			}
1600 
1601 	ieee80211_set_qos_hdr(local, skb);
1602 	ieee80211_tx(sdata, skb, false);
1603 	rcu_read_unlock();
1604 }
1605 
1606 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1607 					 struct net_device *dev)
1608 {
1609 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1610 	struct ieee80211_channel *chan = local->hw.conf.channel;
1611 	struct ieee80211_radiotap_header *prthdr =
1612 		(struct ieee80211_radiotap_header *)skb->data;
1613 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1614 	u16 len_rthdr;
1615 
1616 	/*
1617 	 * Frame injection is not allowed if beaconing is not allowed
1618 	 * or if we need radar detection. Beaconing is usually not allowed when
1619 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1620 	 * Passive scan is also used in world regulatory domains where
1621 	 * your country is not known and as such it should be treated as
1622 	 * NO TX unless the channel is explicitly allowed in which case
1623 	 * your current regulatory domain would not have the passive scan
1624 	 * flag.
1625 	 *
1626 	 * Since AP mode uses monitor interfaces to inject/TX management
1627 	 * frames we can make AP mode the exception to this rule once it
1628 	 * supports radar detection as its implementation can deal with
1629 	 * radar detection by itself. We can do that later by adding a
1630 	 * monitor flag interfaces used for AP support.
1631 	 */
1632 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1633 	     IEEE80211_CHAN_PASSIVE_SCAN)))
1634 		goto fail;
1635 
1636 	/* check for not even having the fixed radiotap header part */
1637 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1638 		goto fail; /* too short to be possibly valid */
1639 
1640 	/* is it a header version we can trust to find length from? */
1641 	if (unlikely(prthdr->it_version))
1642 		goto fail; /* only version 0 is supported */
1643 
1644 	/* then there must be a radiotap header with a length we can use */
1645 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1646 
1647 	/* does the skb contain enough to deliver on the alleged length? */
1648 	if (unlikely(skb->len < len_rthdr))
1649 		goto fail; /* skb too short for claimed rt header extent */
1650 
1651 	/*
1652 	 * fix up the pointers accounting for the radiotap
1653 	 * header still being in there.  We are being given
1654 	 * a precooked IEEE80211 header so no need for
1655 	 * normal processing
1656 	 */
1657 	skb_set_mac_header(skb, len_rthdr);
1658 	/*
1659 	 * these are just fixed to the end of the rt area since we
1660 	 * don't have any better information and at this point, nobody cares
1661 	 */
1662 	skb_set_network_header(skb, len_rthdr);
1663 	skb_set_transport_header(skb, len_rthdr);
1664 
1665 	memset(info, 0, sizeof(*info));
1666 
1667 	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1668 
1669 	/* pass the radiotap header up to xmit */
1670 	ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), skb);
1671 	return NETDEV_TX_OK;
1672 
1673 fail:
1674 	dev_kfree_skb(skb);
1675 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1676 }
1677 
1678 /**
1679  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1680  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1681  * @skb: packet to be sent
1682  * @dev: incoming interface
1683  *
1684  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1685  * not be freed, and caller is responsible for either retrying later or freeing
1686  * skb).
1687  *
1688  * This function takes in an Ethernet header and encapsulates it with suitable
1689  * IEEE 802.11 header based on which interface the packet is coming in. The
1690  * encapsulated packet will then be passed to master interface, wlan#.11, for
1691  * transmission (through low-level driver).
1692  */
1693 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1694 				    struct net_device *dev)
1695 {
1696 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1697 	struct ieee80211_local *local = sdata->local;
1698 	struct ieee80211_tx_info *info;
1699 	int ret = NETDEV_TX_BUSY, head_need;
1700 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1701 	__le16 fc;
1702 	struct ieee80211_hdr hdr;
1703 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1704 	struct mesh_path __maybe_unused *mppath = NULL;
1705 	const u8 *encaps_data;
1706 	int encaps_len, skip_header_bytes;
1707 	int nh_pos, h_pos;
1708 	struct sta_info *sta = NULL;
1709 	u32 sta_flags = 0;
1710 	struct sk_buff *tmp_skb;
1711 
1712 	if (unlikely(skb->len < ETH_HLEN)) {
1713 		ret = NETDEV_TX_OK;
1714 		goto fail;
1715 	}
1716 
1717 	/* convert Ethernet header to proper 802.11 header (based on
1718 	 * operation mode) */
1719 	ethertype = (skb->data[12] << 8) | skb->data[13];
1720 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1721 
1722 	switch (sdata->vif.type) {
1723 	case NL80211_IFTYPE_AP_VLAN:
1724 		rcu_read_lock();
1725 		sta = rcu_dereference(sdata->u.vlan.sta);
1726 		if (sta) {
1727 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1728 			/* RA TA DA SA */
1729 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1730 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1731 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1732 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1733 			hdrlen = 30;
1734 			sta_flags = get_sta_flags(sta);
1735 		}
1736 		rcu_read_unlock();
1737 		if (sta)
1738 			break;
1739 		/* fall through */
1740 	case NL80211_IFTYPE_AP:
1741 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1742 		/* DA BSSID SA */
1743 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1744 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1745 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1746 		hdrlen = 24;
1747 		break;
1748 	case NL80211_IFTYPE_WDS:
1749 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1750 		/* RA TA DA SA */
1751 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1752 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1753 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1754 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1755 		hdrlen = 30;
1756 		break;
1757 #ifdef CONFIG_MAC80211_MESH
1758 	case NL80211_IFTYPE_MESH_POINT:
1759 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1760 			/* Do not send frames with mesh_ttl == 0 */
1761 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1762 			ret = NETDEV_TX_OK;
1763 			goto fail;
1764 		}
1765 		if (!is_multicast_ether_addr(skb->data))
1766 			mppath = mpp_path_lookup(skb->data, sdata);
1767 
1768 		/*
1769 		 * Use address extension if it is a packet from
1770 		 * another interface or if we know the destination
1771 		 * is being proxied by a portal (i.e. portal address
1772 		 * differs from proxied address)
1773 		 */
1774 		if (compare_ether_addr(sdata->vif.addr,
1775 				       skb->data + ETH_ALEN) == 0 &&
1776 		    !(mppath && compare_ether_addr(mppath->mpp, skb->data))) {
1777 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1778 					skb->data, skb->data + ETH_ALEN);
1779 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1780 					sdata, NULL, NULL);
1781 		} else {
1782 			int is_mesh_mcast = 1;
1783 			const u8 *mesh_da;
1784 
1785 			rcu_read_lock();
1786 			if (is_multicast_ether_addr(skb->data))
1787 				/* DA TA mSA AE:SA */
1788 				mesh_da = skb->data;
1789 			else {
1790 				static const u8 bcast[ETH_ALEN] =
1791 					{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1792 				if (mppath) {
1793 					/* RA TA mDA mSA AE:DA SA */
1794 					mesh_da = mppath->mpp;
1795 					is_mesh_mcast = 0;
1796 				} else {
1797 					/* DA TA mSA AE:SA */
1798 					mesh_da = bcast;
1799 				}
1800 			}
1801 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1802 					mesh_da, sdata->vif.addr);
1803 			rcu_read_unlock();
1804 			if (is_mesh_mcast)
1805 				meshhdrlen =
1806 					ieee80211_new_mesh_header(&mesh_hdr,
1807 							sdata,
1808 							skb->data + ETH_ALEN,
1809 							NULL);
1810 			else
1811 				meshhdrlen =
1812 					ieee80211_new_mesh_header(&mesh_hdr,
1813 							sdata,
1814 							skb->data,
1815 							skb->data + ETH_ALEN);
1816 
1817 		}
1818 		break;
1819 #endif
1820 	case NL80211_IFTYPE_STATION:
1821 		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1822 		if (sdata->u.mgd.use_4addr &&
1823 		    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1824 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1825 			/* RA TA DA SA */
1826 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1827 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1828 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1829 			hdrlen = 30;
1830 		} else {
1831 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1832 			/* BSSID SA DA */
1833 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1834 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1835 			hdrlen = 24;
1836 		}
1837 		break;
1838 	case NL80211_IFTYPE_ADHOC:
1839 		/* DA SA BSSID */
1840 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1841 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1842 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1843 		hdrlen = 24;
1844 		break;
1845 	default:
1846 		ret = NETDEV_TX_OK;
1847 		goto fail;
1848 	}
1849 
1850 	/*
1851 	 * There's no need to try to look up the destination
1852 	 * if it is a multicast address (which can only happen
1853 	 * in AP mode)
1854 	 */
1855 	if (!is_multicast_ether_addr(hdr.addr1)) {
1856 		rcu_read_lock();
1857 		sta = sta_info_get(sdata, hdr.addr1);
1858 		if (sta)
1859 			sta_flags = get_sta_flags(sta);
1860 		rcu_read_unlock();
1861 	}
1862 
1863 	/* receiver and we are QoS enabled, use a QoS type frame */
1864 	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1865 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1866 		hdrlen += 2;
1867 	}
1868 
1869 	/*
1870 	 * Drop unicast frames to unauthorised stations unless they are
1871 	 * EAPOL frames from the local station.
1872 	 */
1873 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
1874 		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1875 		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
1876 		      !(cpu_to_be16(ethertype) == sdata->control_port_protocol &&
1877 		       compare_ether_addr(sdata->vif.addr,
1878 					  skb->data + ETH_ALEN) == 0))) {
1879 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1880 		if (net_ratelimit())
1881 			printk(KERN_DEBUG "%s: dropped frame to %pM"
1882 			       " (unauthorized port)\n", dev->name,
1883 			       hdr.addr1);
1884 #endif
1885 
1886 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1887 
1888 		ret = NETDEV_TX_OK;
1889 		goto fail;
1890 	}
1891 
1892 	/*
1893 	 * If the skb is shared we need to obtain our own copy.
1894 	 */
1895 	if (skb_shared(skb)) {
1896 		tmp_skb = skb;
1897 		skb = skb_clone(skb, GFP_ATOMIC);
1898 		kfree_skb(tmp_skb);
1899 
1900 		if (!skb) {
1901 			ret = NETDEV_TX_OK;
1902 			goto fail;
1903 		}
1904 	}
1905 
1906 	hdr.frame_control = fc;
1907 	hdr.duration_id = 0;
1908 	hdr.seq_ctrl = 0;
1909 
1910 	skip_header_bytes = ETH_HLEN;
1911 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
1912 		encaps_data = bridge_tunnel_header;
1913 		encaps_len = sizeof(bridge_tunnel_header);
1914 		skip_header_bytes -= 2;
1915 	} else if (ethertype >= 0x600) {
1916 		encaps_data = rfc1042_header;
1917 		encaps_len = sizeof(rfc1042_header);
1918 		skip_header_bytes -= 2;
1919 	} else {
1920 		encaps_data = NULL;
1921 		encaps_len = 0;
1922 	}
1923 
1924 	nh_pos = skb_network_header(skb) - skb->data;
1925 	h_pos = skb_transport_header(skb) - skb->data;
1926 
1927 	skb_pull(skb, skip_header_bytes);
1928 	nh_pos -= skip_header_bytes;
1929 	h_pos -= skip_header_bytes;
1930 
1931 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1932 
1933 	/*
1934 	 * So we need to modify the skb header and hence need a copy of
1935 	 * that. The head_need variable above doesn't, so far, include
1936 	 * the needed header space that we don't need right away. If we
1937 	 * can, then we don't reallocate right now but only after the
1938 	 * frame arrives at the master device (if it does...)
1939 	 *
1940 	 * If we cannot, however, then we will reallocate to include all
1941 	 * the ever needed space. Also, if we need to reallocate it anyway,
1942 	 * make it big enough for everything we may ever need.
1943 	 */
1944 
1945 	if (head_need > 0 || skb_cloned(skb)) {
1946 		head_need += IEEE80211_ENCRYPT_HEADROOM;
1947 		head_need += local->tx_headroom;
1948 		head_need = max_t(int, 0, head_need);
1949 		if (ieee80211_skb_resize(local, skb, head_need, true))
1950 			goto fail;
1951 	}
1952 
1953 	if (encaps_data) {
1954 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
1955 		nh_pos += encaps_len;
1956 		h_pos += encaps_len;
1957 	}
1958 
1959 #ifdef CONFIG_MAC80211_MESH
1960 	if (meshhdrlen > 0) {
1961 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
1962 		nh_pos += meshhdrlen;
1963 		h_pos += meshhdrlen;
1964 	}
1965 #endif
1966 
1967 	if (ieee80211_is_data_qos(fc)) {
1968 		__le16 *qos_control;
1969 
1970 		qos_control = (__le16*) skb_push(skb, 2);
1971 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
1972 		/*
1973 		 * Maybe we could actually set some fields here, for now just
1974 		 * initialise to zero to indicate no special operation.
1975 		 */
1976 		*qos_control = 0;
1977 	} else
1978 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
1979 
1980 	nh_pos += hdrlen;
1981 	h_pos += hdrlen;
1982 
1983 	dev->stats.tx_packets++;
1984 	dev->stats.tx_bytes += skb->len;
1985 
1986 	/* Update skb pointers to various headers since this modified frame
1987 	 * is going to go through Linux networking code that may potentially
1988 	 * need things like pointer to IP header. */
1989 	skb_set_mac_header(skb, 0);
1990 	skb_set_network_header(skb, nh_pos);
1991 	skb_set_transport_header(skb, h_pos);
1992 
1993 	info = IEEE80211_SKB_CB(skb);
1994 	memset(info, 0, sizeof(*info));
1995 
1996 	dev->trans_start = jiffies;
1997 	ieee80211_xmit(sdata, skb);
1998 
1999 	return NETDEV_TX_OK;
2000 
2001  fail:
2002 	if (ret == NETDEV_TX_OK)
2003 		dev_kfree_skb(skb);
2004 
2005 	return ret;
2006 }
2007 
2008 
2009 /*
2010  * ieee80211_clear_tx_pending may not be called in a context where
2011  * it is possible that it packets could come in again.
2012  */
2013 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2014 {
2015 	int i;
2016 
2017 	for (i = 0; i < local->hw.queues; i++)
2018 		skb_queue_purge(&local->pending[i]);
2019 }
2020 
2021 /*
2022  * Returns false if the frame couldn't be transmitted but was queued instead,
2023  * which in this case means re-queued -- take as an indication to stop sending
2024  * more pending frames.
2025  */
2026 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2027 				     struct sk_buff *skb)
2028 {
2029 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2030 	struct ieee80211_sub_if_data *sdata;
2031 	struct sta_info *sta;
2032 	struct ieee80211_hdr *hdr;
2033 	bool result;
2034 
2035 	sdata = vif_to_sdata(info->control.vif);
2036 
2037 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2038 		result = ieee80211_tx(sdata, skb, true);
2039 	} else {
2040 		hdr = (struct ieee80211_hdr *)skb->data;
2041 		sta = sta_info_get(sdata, hdr->addr1);
2042 
2043 		result = __ieee80211_tx(local, &skb, sta, true);
2044 	}
2045 
2046 	return result;
2047 }
2048 
2049 /*
2050  * Transmit all pending packets. Called from tasklet.
2051  */
2052 void ieee80211_tx_pending(unsigned long data)
2053 {
2054 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2055 	struct ieee80211_sub_if_data *sdata;
2056 	unsigned long flags;
2057 	int i;
2058 	bool txok;
2059 
2060 	rcu_read_lock();
2061 
2062 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2063 	for (i = 0; i < local->hw.queues; i++) {
2064 		/*
2065 		 * If queue is stopped by something other than due to pending
2066 		 * frames, or we have no pending frames, proceed to next queue.
2067 		 */
2068 		if (local->queue_stop_reasons[i] ||
2069 		    skb_queue_empty(&local->pending[i]))
2070 			continue;
2071 
2072 		while (!skb_queue_empty(&local->pending[i])) {
2073 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2074 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2075 
2076 			if (WARN_ON(!info->control.vif)) {
2077 				kfree_skb(skb);
2078 				continue;
2079 			}
2080 
2081 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2082 						flags);
2083 
2084 			txok = ieee80211_tx_pending_skb(local, skb);
2085 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2086 					  flags);
2087 			if (!txok)
2088 				break;
2089 		}
2090 
2091 		if (skb_queue_empty(&local->pending[i]))
2092 			list_for_each_entry_rcu(sdata, &local->interfaces, list)
2093 				netif_wake_subqueue(sdata->dev, i);
2094 	}
2095 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2096 
2097 	rcu_read_unlock();
2098 }
2099 
2100 /* functions for drivers to get certain frames */
2101 
2102 static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
2103 				     struct sk_buff *skb,
2104 				     struct beacon_data *beacon)
2105 {
2106 	u8 *pos, *tim;
2107 	int aid0 = 0;
2108 	int i, have_bits = 0, n1, n2;
2109 
2110 	/* Generate bitmap for TIM only if there are any STAs in power save
2111 	 * mode. */
2112 	if (atomic_read(&bss->num_sta_ps) > 0)
2113 		/* in the hope that this is faster than
2114 		 * checking byte-for-byte */
2115 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2116 					  IEEE80211_MAX_AID+1);
2117 
2118 	if (bss->dtim_count == 0)
2119 		bss->dtim_count = beacon->dtim_period - 1;
2120 	else
2121 		bss->dtim_count--;
2122 
2123 	tim = pos = (u8 *) skb_put(skb, 6);
2124 	*pos++ = WLAN_EID_TIM;
2125 	*pos++ = 4;
2126 	*pos++ = bss->dtim_count;
2127 	*pos++ = beacon->dtim_period;
2128 
2129 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2130 		aid0 = 1;
2131 
2132 	bss->dtim_bc_mc = aid0 == 1;
2133 
2134 	if (have_bits) {
2135 		/* Find largest even number N1 so that bits numbered 1 through
2136 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2137 		 * (N2 + 1) x 8 through 2007 are 0. */
2138 		n1 = 0;
2139 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2140 			if (bss->tim[i]) {
2141 				n1 = i & 0xfe;
2142 				break;
2143 			}
2144 		}
2145 		n2 = n1;
2146 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2147 			if (bss->tim[i]) {
2148 				n2 = i;
2149 				break;
2150 			}
2151 		}
2152 
2153 		/* Bitmap control */
2154 		*pos++ = n1 | aid0;
2155 		/* Part Virt Bitmap */
2156 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2157 
2158 		tim[1] = n2 - n1 + 4;
2159 		skb_put(skb, n2 - n1);
2160 	} else {
2161 		*pos++ = aid0; /* Bitmap control */
2162 		*pos++ = 0; /* Part Virt Bitmap */
2163 	}
2164 }
2165 
2166 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2167 					 struct ieee80211_vif *vif,
2168 					 u16 *tim_offset, u16 *tim_length)
2169 {
2170 	struct ieee80211_local *local = hw_to_local(hw);
2171 	struct sk_buff *skb = NULL;
2172 	struct ieee80211_tx_info *info;
2173 	struct ieee80211_sub_if_data *sdata = NULL;
2174 	struct ieee80211_if_ap *ap = NULL;
2175 	struct beacon_data *beacon;
2176 	struct ieee80211_supported_band *sband;
2177 	enum ieee80211_band band = local->hw.conf.channel->band;
2178 	struct ieee80211_tx_rate_control txrc;
2179 
2180 	sband = local->hw.wiphy->bands[band];
2181 
2182 	rcu_read_lock();
2183 
2184 	sdata = vif_to_sdata(vif);
2185 
2186 	if (!ieee80211_sdata_running(sdata))
2187 		goto out;
2188 
2189 	if (tim_offset)
2190 		*tim_offset = 0;
2191 	if (tim_length)
2192 		*tim_length = 0;
2193 
2194 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2195 		ap = &sdata->u.ap;
2196 		beacon = rcu_dereference(ap->beacon);
2197 		if (beacon) {
2198 			/*
2199 			 * headroom, head length,
2200 			 * tail length and maximum TIM length
2201 			 */
2202 			skb = dev_alloc_skb(local->tx_headroom +
2203 					    beacon->head_len +
2204 					    beacon->tail_len + 256);
2205 			if (!skb)
2206 				goto out;
2207 
2208 			skb_reserve(skb, local->tx_headroom);
2209 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2210 			       beacon->head_len);
2211 
2212 			/*
2213 			 * Not very nice, but we want to allow the driver to call
2214 			 * ieee80211_beacon_get() as a response to the set_tim()
2215 			 * callback. That, however, is already invoked under the
2216 			 * sta_lock to guarantee consistent and race-free update
2217 			 * of the tim bitmap in mac80211 and the driver.
2218 			 */
2219 			if (local->tim_in_locked_section) {
2220 				ieee80211_beacon_add_tim(ap, skb, beacon);
2221 			} else {
2222 				unsigned long flags;
2223 
2224 				spin_lock_irqsave(&local->sta_lock, flags);
2225 				ieee80211_beacon_add_tim(ap, skb, beacon);
2226 				spin_unlock_irqrestore(&local->sta_lock, flags);
2227 			}
2228 
2229 			if (tim_offset)
2230 				*tim_offset = beacon->head_len;
2231 			if (tim_length)
2232 				*tim_length = skb->len - beacon->head_len;
2233 
2234 			if (beacon->tail)
2235 				memcpy(skb_put(skb, beacon->tail_len),
2236 				       beacon->tail, beacon->tail_len);
2237 		} else
2238 			goto out;
2239 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2240 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2241 		struct ieee80211_hdr *hdr;
2242 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2243 
2244 		if (!presp)
2245 			goto out;
2246 
2247 		skb = skb_copy(presp, GFP_ATOMIC);
2248 		if (!skb)
2249 			goto out;
2250 
2251 		hdr = (struct ieee80211_hdr *) skb->data;
2252 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2253 						 IEEE80211_STYPE_BEACON);
2254 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2255 		struct ieee80211_mgmt *mgmt;
2256 		u8 *pos;
2257 
2258 #ifdef CONFIG_MAC80211_MESH
2259 		if (!sdata->u.mesh.mesh_id_len)
2260 			goto out;
2261 #endif
2262 
2263 		/* headroom, head length, tail length and maximum TIM length */
2264 		skb = dev_alloc_skb(local->tx_headroom + 400 +
2265 				sdata->u.mesh.vendor_ie_len);
2266 		if (!skb)
2267 			goto out;
2268 
2269 		skb_reserve(skb, local->hw.extra_tx_headroom);
2270 		mgmt = (struct ieee80211_mgmt *)
2271 			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
2272 		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2273 		mgmt->frame_control =
2274 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2275 		memset(mgmt->da, 0xff, ETH_ALEN);
2276 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2277 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2278 		mgmt->u.beacon.beacon_int =
2279 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2280 		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
2281 
2282 		pos = skb_put(skb, 2);
2283 		*pos++ = WLAN_EID_SSID;
2284 		*pos++ = 0x0;
2285 
2286 		mesh_mgmt_ies_add(skb, sdata);
2287 	} else {
2288 		WARN_ON(1);
2289 		goto out;
2290 	}
2291 
2292 	info = IEEE80211_SKB_CB(skb);
2293 
2294 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2295 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2296 	info->band = band;
2297 
2298 	memset(&txrc, 0, sizeof(txrc));
2299 	txrc.hw = hw;
2300 	txrc.sband = sband;
2301 	txrc.bss_conf = &sdata->vif.bss_conf;
2302 	txrc.skb = skb;
2303 	txrc.reported_rate.idx = -1;
2304 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2305 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2306 		txrc.max_rate_idx = -1;
2307 	else
2308 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2309 	txrc.bss = true;
2310 	rate_control_get_rate(sdata, NULL, &txrc);
2311 
2312 	info->control.vif = vif;
2313 
2314 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2315 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2316 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2317  out:
2318 	rcu_read_unlock();
2319 	return skb;
2320 }
2321 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2322 
2323 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2324 				     struct ieee80211_vif *vif)
2325 {
2326 	struct ieee80211_sub_if_data *sdata;
2327 	struct ieee80211_if_managed *ifmgd;
2328 	struct ieee80211_pspoll *pspoll;
2329 	struct ieee80211_local *local;
2330 	struct sk_buff *skb;
2331 
2332 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2333 		return NULL;
2334 
2335 	sdata = vif_to_sdata(vif);
2336 	ifmgd = &sdata->u.mgd;
2337 	local = sdata->local;
2338 
2339 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2340 	if (!skb) {
2341 		printk(KERN_DEBUG "%s: failed to allocate buffer for "
2342 		       "pspoll template\n", sdata->name);
2343 		return NULL;
2344 	}
2345 	skb_reserve(skb, local->hw.extra_tx_headroom);
2346 
2347 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2348 	memset(pspoll, 0, sizeof(*pspoll));
2349 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2350 					    IEEE80211_STYPE_PSPOLL);
2351 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2352 
2353 	/* aid in PS-Poll has its two MSBs each set to 1 */
2354 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2355 
2356 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2357 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2358 
2359 	return skb;
2360 }
2361 EXPORT_SYMBOL(ieee80211_pspoll_get);
2362 
2363 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2364 				       struct ieee80211_vif *vif)
2365 {
2366 	struct ieee80211_hdr_3addr *nullfunc;
2367 	struct ieee80211_sub_if_data *sdata;
2368 	struct ieee80211_if_managed *ifmgd;
2369 	struct ieee80211_local *local;
2370 	struct sk_buff *skb;
2371 
2372 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2373 		return NULL;
2374 
2375 	sdata = vif_to_sdata(vif);
2376 	ifmgd = &sdata->u.mgd;
2377 	local = sdata->local;
2378 
2379 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2380 	if (!skb) {
2381 		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
2382 		       "template\n", sdata->name);
2383 		return NULL;
2384 	}
2385 	skb_reserve(skb, local->hw.extra_tx_headroom);
2386 
2387 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2388 							  sizeof(*nullfunc));
2389 	memset(nullfunc, 0, sizeof(*nullfunc));
2390 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2391 					      IEEE80211_STYPE_NULLFUNC |
2392 					      IEEE80211_FCTL_TODS);
2393 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2394 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2395 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2396 
2397 	return skb;
2398 }
2399 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2400 
2401 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2402 				       struct ieee80211_vif *vif,
2403 				       const u8 *ssid, size_t ssid_len,
2404 				       const u8 *ie, size_t ie_len)
2405 {
2406 	struct ieee80211_sub_if_data *sdata;
2407 	struct ieee80211_local *local;
2408 	struct ieee80211_hdr_3addr *hdr;
2409 	struct sk_buff *skb;
2410 	size_t ie_ssid_len;
2411 	u8 *pos;
2412 
2413 	sdata = vif_to_sdata(vif);
2414 	local = sdata->local;
2415 	ie_ssid_len = 2 + ssid_len;
2416 
2417 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2418 			    ie_ssid_len + ie_len);
2419 	if (!skb) {
2420 		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
2421 		       "request template\n", sdata->name);
2422 		return NULL;
2423 	}
2424 
2425 	skb_reserve(skb, local->hw.extra_tx_headroom);
2426 
2427 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2428 	memset(hdr, 0, sizeof(*hdr));
2429 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2430 					 IEEE80211_STYPE_PROBE_REQ);
2431 	memset(hdr->addr1, 0xff, ETH_ALEN);
2432 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2433 	memset(hdr->addr3, 0xff, ETH_ALEN);
2434 
2435 	pos = skb_put(skb, ie_ssid_len);
2436 	*pos++ = WLAN_EID_SSID;
2437 	*pos++ = ssid_len;
2438 	if (ssid)
2439 		memcpy(pos, ssid, ssid_len);
2440 	pos += ssid_len;
2441 
2442 	if (ie) {
2443 		pos = skb_put(skb, ie_len);
2444 		memcpy(pos, ie, ie_len);
2445 	}
2446 
2447 	return skb;
2448 }
2449 EXPORT_SYMBOL(ieee80211_probereq_get);
2450 
2451 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2452 		       const void *frame, size_t frame_len,
2453 		       const struct ieee80211_tx_info *frame_txctl,
2454 		       struct ieee80211_rts *rts)
2455 {
2456 	const struct ieee80211_hdr *hdr = frame;
2457 
2458 	rts->frame_control =
2459 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2460 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2461 					       frame_txctl);
2462 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2463 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2464 }
2465 EXPORT_SYMBOL(ieee80211_rts_get);
2466 
2467 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2468 			     const void *frame, size_t frame_len,
2469 			     const struct ieee80211_tx_info *frame_txctl,
2470 			     struct ieee80211_cts *cts)
2471 {
2472 	const struct ieee80211_hdr *hdr = frame;
2473 
2474 	cts->frame_control =
2475 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2476 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2477 						     frame_len, frame_txctl);
2478 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2479 }
2480 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2481 
2482 struct sk_buff *
2483 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2484 			  struct ieee80211_vif *vif)
2485 {
2486 	struct ieee80211_local *local = hw_to_local(hw);
2487 	struct sk_buff *skb = NULL;
2488 	struct sta_info *sta;
2489 	struct ieee80211_tx_data tx;
2490 	struct ieee80211_sub_if_data *sdata;
2491 	struct ieee80211_if_ap *bss = NULL;
2492 	struct beacon_data *beacon;
2493 	struct ieee80211_tx_info *info;
2494 
2495 	sdata = vif_to_sdata(vif);
2496 	bss = &sdata->u.ap;
2497 
2498 	rcu_read_lock();
2499 	beacon = rcu_dereference(bss->beacon);
2500 
2501 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2502 		goto out;
2503 
2504 	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
2505 		goto out; /* send buffered bc/mc only after DTIM beacon */
2506 
2507 	while (1) {
2508 		skb = skb_dequeue(&bss->ps_bc_buf);
2509 		if (!skb)
2510 			goto out;
2511 		local->total_ps_buffered--;
2512 
2513 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2514 			struct ieee80211_hdr *hdr =
2515 				(struct ieee80211_hdr *) skb->data;
2516 			/* more buffered multicast/broadcast frames ==> set
2517 			 * MoreData flag in IEEE 802.11 header to inform PS
2518 			 * STAs */
2519 			hdr->frame_control |=
2520 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2521 		}
2522 
2523 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2524 			break;
2525 		dev_kfree_skb_any(skb);
2526 	}
2527 
2528 	info = IEEE80211_SKB_CB(skb);
2529 
2530 	sta = tx.sta;
2531 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2532 	tx.channel = local->hw.conf.channel;
2533 	info->band = tx.channel->band;
2534 
2535 	if (invoke_tx_handlers(&tx))
2536 		skb = NULL;
2537  out:
2538 	rcu_read_unlock();
2539 
2540 	return skb;
2541 }
2542 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2543 
2544 void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
2545 {
2546 	skb_set_mac_header(skb, 0);
2547 	skb_set_network_header(skb, 0);
2548 	skb_set_transport_header(skb, 0);
2549 
2550 	/* send all internal mgmt frames on VO */
2551 	skb_set_queue_mapping(skb, 0);
2552 
2553 	/*
2554 	 * The other path calling ieee80211_xmit is from the tasklet,
2555 	 * and while we can handle concurrent transmissions locking
2556 	 * requirements are that we do not come into tx with bhs on.
2557 	 */
2558 	local_bh_disable();
2559 	ieee80211_xmit(sdata, skb);
2560 	local_bh_enable();
2561 }
2562