xref: /openbmc/linux/net/mac80211/tx.c (revision e4c0d0e2)
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 	/* Don't restart the timer if we're not disassociated */
241 	if (!ifmgd->associated)
242 		return TX_CONTINUE;
243 
244 	mod_timer(&local->dynamic_ps_timer, jiffies +
245 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
246 
247 	return TX_CONTINUE;
248 }
249 
250 static ieee80211_tx_result debug_noinline
251 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
252 {
253 
254 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
255 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
256 	u32 sta_flags;
257 
258 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
259 		return TX_CONTINUE;
260 
261 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
262 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
263 	    !ieee80211_is_probe_req(hdr->frame_control) &&
264 	    !ieee80211_is_nullfunc(hdr->frame_control))
265 		/*
266 		 * When software scanning only nullfunc frames (to notify
267 		 * the sleep state to the AP) and probe requests (for the
268 		 * active scan) are allowed, all other frames should not be
269 		 * sent and we should not get here, but if we do
270 		 * nonetheless, drop them to avoid sending them
271 		 * off-channel. See the link below and
272 		 * ieee80211_start_scan() for more.
273 		 *
274 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
275 		 */
276 		return TX_DROP;
277 
278 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
279 		return TX_CONTINUE;
280 
281 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
282 		return TX_CONTINUE;
283 
284 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
285 		return TX_CONTINUE;
286 
287 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
288 
289 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
290 		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
291 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
292 			     ieee80211_is_data(hdr->frame_control))) {
293 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
294 			printk(KERN_DEBUG "%s: dropped data frame to not "
295 			       "associated station %pM\n",
296 			       tx->sdata->name, hdr->addr1);
297 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
298 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
299 			return TX_DROP;
300 		}
301 	} else {
302 		if (unlikely(ieee80211_is_data(hdr->frame_control) &&
303 			     tx->local->num_sta == 0 &&
304 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
305 			/*
306 			 * No associated STAs - no need to send multicast
307 			 * frames.
308 			 */
309 			return TX_DROP;
310 		}
311 		return TX_CONTINUE;
312 	}
313 
314 	return TX_CONTINUE;
315 }
316 
317 /* This function is called whenever the AP is about to exceed the maximum limit
318  * of buffered frames for power saving STAs. This situation should not really
319  * happen often during normal operation, so dropping the oldest buffered packet
320  * from each queue should be OK to make some room for new frames. */
321 static void purge_old_ps_buffers(struct ieee80211_local *local)
322 {
323 	int total = 0, purged = 0;
324 	struct sk_buff *skb;
325 	struct ieee80211_sub_if_data *sdata;
326 	struct sta_info *sta;
327 
328 	/*
329 	 * virtual interfaces are protected by RCU
330 	 */
331 	rcu_read_lock();
332 
333 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
334 		struct ieee80211_if_ap *ap;
335 		if (sdata->vif.type != NL80211_IFTYPE_AP)
336 			continue;
337 		ap = &sdata->u.ap;
338 		skb = skb_dequeue(&ap->ps_bc_buf);
339 		if (skb) {
340 			purged++;
341 			dev_kfree_skb(skb);
342 		}
343 		total += skb_queue_len(&ap->ps_bc_buf);
344 	}
345 
346 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
347 		skb = skb_dequeue(&sta->ps_tx_buf);
348 		if (skb) {
349 			purged++;
350 			dev_kfree_skb(skb);
351 		}
352 		total += skb_queue_len(&sta->ps_tx_buf);
353 	}
354 
355 	rcu_read_unlock();
356 
357 	local->total_ps_buffered = total;
358 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
359 	wiphy_debug(local->hw.wiphy, "PS buffers full - purged %d frames\n",
360 		    purged);
361 #endif
362 }
363 
364 static ieee80211_tx_result
365 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
366 {
367 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
368 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
369 
370 	/*
371 	 * broadcast/multicast frame
372 	 *
373 	 * If any of the associated stations is in power save mode,
374 	 * the frame is buffered to be sent after DTIM beacon frame.
375 	 * This is done either by the hardware or us.
376 	 */
377 
378 	/* powersaving STAs only in AP/VLAN mode */
379 	if (!tx->sdata->bss)
380 		return TX_CONTINUE;
381 
382 	/* no buffering for ordered frames */
383 	if (ieee80211_has_order(hdr->frame_control))
384 		return TX_CONTINUE;
385 
386 	/* no stations in PS mode */
387 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
388 		return TX_CONTINUE;
389 
390 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
391 
392 	/* device releases frame after DTIM beacon */
393 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
394 		return TX_CONTINUE;
395 
396 	/* buffered in mac80211 */
397 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
398 		purge_old_ps_buffers(tx->local);
399 
400 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
401 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
402 		if (net_ratelimit())
403 			printk(KERN_DEBUG "%s: BC TX buffer full - dropping the oldest frame\n",
404 			       tx->sdata->name);
405 #endif
406 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
407 	} else
408 		tx->local->total_ps_buffered++;
409 
410 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
411 
412 	return TX_QUEUED;
413 }
414 
415 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
416 			     struct sk_buff *skb)
417 {
418 	if (!ieee80211_is_mgmt(fc))
419 		return 0;
420 
421 	if (sta == NULL || !test_sta_flags(sta, WLAN_STA_MFP))
422 		return 0;
423 
424 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
425 					    skb->data))
426 		return 0;
427 
428 	return 1;
429 }
430 
431 static ieee80211_tx_result
432 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
433 {
434 	struct sta_info *sta = tx->sta;
435 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
436 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
437 	struct ieee80211_local *local = tx->local;
438 	u32 staflags;
439 
440 	if (unlikely(!sta ||
441 		     ieee80211_is_probe_resp(hdr->frame_control) ||
442 		     ieee80211_is_auth(hdr->frame_control) ||
443 		     ieee80211_is_assoc_resp(hdr->frame_control) ||
444 		     ieee80211_is_reassoc_resp(hdr->frame_control)))
445 		return TX_CONTINUE;
446 
447 	staflags = get_sta_flags(sta);
448 
449 	if (unlikely((staflags & (WLAN_STA_PS_STA | WLAN_STA_PS_DRIVER)) &&
450 		     !(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) {
451 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
452 		printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
453 		       "before %d)\n",
454 		       sta->sta.addr, sta->sta.aid,
455 		       skb_queue_len(&sta->ps_tx_buf));
456 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
457 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
458 			purge_old_ps_buffers(tx->local);
459 		if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
460 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
461 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
462 			if (net_ratelimit()) {
463 				printk(KERN_DEBUG "%s: STA %pM TX "
464 				       "buffer full - dropping oldest frame\n",
465 				       tx->sdata->name, sta->sta.addr);
466 			}
467 #endif
468 			dev_kfree_skb(old);
469 		} else
470 			tx->local->total_ps_buffered++;
471 
472 		/*
473 		 * Queue frame to be sent after STA wakes up/polls,
474 		 * but don't set the TIM bit if the driver is blocking
475 		 * wakeup or poll response transmissions anyway.
476 		 */
477 		if (skb_queue_empty(&sta->ps_tx_buf) &&
478 		    !(staflags & WLAN_STA_PS_DRIVER))
479 			sta_info_set_tim_bit(sta);
480 
481 		info->control.jiffies = jiffies;
482 		info->control.vif = &tx->sdata->vif;
483 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
484 		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
485 
486 		if (!timer_pending(&local->sta_cleanup))
487 			mod_timer(&local->sta_cleanup,
488 				  round_jiffies(jiffies +
489 						STA_INFO_CLEANUP_INTERVAL));
490 
491 		return TX_QUEUED;
492 	}
493 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
494 	else if (unlikely(staflags & WLAN_STA_PS_STA)) {
495 		printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
496 		       "set -> send frame\n", tx->sdata->name,
497 		       sta->sta.addr);
498 	}
499 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
500 
501 	return TX_CONTINUE;
502 }
503 
504 static ieee80211_tx_result debug_noinline
505 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
506 {
507 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
508 		return TX_CONTINUE;
509 
510 	if (tx->flags & IEEE80211_TX_UNICAST)
511 		return ieee80211_tx_h_unicast_ps_buf(tx);
512 	else
513 		return ieee80211_tx_h_multicast_ps_buf(tx);
514 }
515 
516 static ieee80211_tx_result debug_noinline
517 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
518 {
519 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
520 
521 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
522 		     tx->sdata->control_port_no_encrypt))
523 		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
524 
525 	return TX_CONTINUE;
526 }
527 
528 static ieee80211_tx_result debug_noinline
529 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
530 {
531 	struct ieee80211_key *key = NULL;
532 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
533 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
534 
535 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
536 		tx->key = NULL;
537 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
538 		tx->key = key;
539 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
540 		 is_multicast_ether_addr(hdr->addr1) &&
541 		 ieee80211_is_robust_mgmt_frame(hdr) &&
542 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
543 		tx->key = key;
544 	else if (is_multicast_ether_addr(hdr->addr1) &&
545 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
546 		tx->key = key;
547 	else if (!is_multicast_ether_addr(hdr->addr1) &&
548 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
549 		tx->key = key;
550 	else if (tx->sdata->drop_unencrypted &&
551 		 (tx->skb->protocol != tx->sdata->control_port_protocol) &&
552 		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
553 		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
554 		  (ieee80211_is_action(hdr->frame_control) &&
555 		   tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) {
556 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
557 		return TX_DROP;
558 	} else
559 		tx->key = NULL;
560 
561 	if (tx->key) {
562 		bool skip_hw = false;
563 
564 		tx->key->tx_rx_count++;
565 		/* TODO: add threshold stuff again */
566 
567 		switch (tx->key->conf.cipher) {
568 		case WLAN_CIPHER_SUITE_WEP40:
569 		case WLAN_CIPHER_SUITE_WEP104:
570 			if (ieee80211_is_auth(hdr->frame_control))
571 				break;
572 		case WLAN_CIPHER_SUITE_TKIP:
573 			if (!ieee80211_is_data_present(hdr->frame_control))
574 				tx->key = NULL;
575 			break;
576 		case WLAN_CIPHER_SUITE_CCMP:
577 			if (!ieee80211_is_data_present(hdr->frame_control) &&
578 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
579 					       tx->skb))
580 				tx->key = NULL;
581 			else
582 				skip_hw = (tx->key->conf.flags &
583 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
584 					ieee80211_is_mgmt(hdr->frame_control);
585 			break;
586 		case WLAN_CIPHER_SUITE_AES_CMAC:
587 			if (!ieee80211_is_mgmt(hdr->frame_control))
588 				tx->key = NULL;
589 			break;
590 		}
591 
592 		if (!skip_hw && tx->key &&
593 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
594 			info->control.hw_key = &tx->key->conf;
595 	}
596 
597 	return TX_CONTINUE;
598 }
599 
600 static ieee80211_tx_result debug_noinline
601 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
602 {
603 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
604 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
605 	struct ieee80211_supported_band *sband;
606 	struct ieee80211_rate *rate;
607 	int i;
608 	u32 len;
609 	bool inval = false, rts = false, short_preamble = false;
610 	struct ieee80211_tx_rate_control txrc;
611 	u32 sta_flags;
612 
613 	memset(&txrc, 0, sizeof(txrc));
614 
615 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
616 
617 	len = min_t(u32, tx->skb->len + FCS_LEN,
618 			 tx->local->hw.wiphy->frag_threshold);
619 
620 	/* set up the tx rate control struct we give the RC algo */
621 	txrc.hw = local_to_hw(tx->local);
622 	txrc.sband = sband;
623 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
624 	txrc.skb = tx->skb;
625 	txrc.reported_rate.idx = -1;
626 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
627 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
628 		txrc.max_rate_idx = -1;
629 	else
630 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
631 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
632 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
633 
634 	/* set up RTS protection if desired */
635 	if (len > tx->local->hw.wiphy->rts_threshold) {
636 		txrc.rts = rts = true;
637 	}
638 
639 	/*
640 	 * Use short preamble if the BSS can handle it, but not for
641 	 * management frames unless we know the receiver can handle
642 	 * that -- the management frame might be to a station that
643 	 * just wants a probe response.
644 	 */
645 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
646 	    (ieee80211_is_data(hdr->frame_control) ||
647 	     (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
648 		txrc.short_preamble = short_preamble = true;
649 
650 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
651 
652 	/*
653 	 * Lets not bother rate control if we're associated and cannot
654 	 * talk to the sta. This should not happen.
655 	 */
656 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) &&
657 		 (sta_flags & WLAN_STA_ASSOC) &&
658 		 !rate_usable_index_exists(sband, &tx->sta->sta),
659 		 "%s: Dropped data frame as no usable bitrate found while "
660 		 "scanning and associated. Target station: "
661 		 "%pM on %d GHz band\n",
662 		 tx->sdata->name, hdr->addr1,
663 		 tx->channel->band ? 5 : 2))
664 		return TX_DROP;
665 
666 	/*
667 	 * If we're associated with the sta at this point we know we can at
668 	 * least send the frame at the lowest bit rate.
669 	 */
670 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
671 
672 	if (unlikely(info->control.rates[0].idx < 0))
673 		return TX_DROP;
674 
675 	if (txrc.reported_rate.idx < 0) {
676 		txrc.reported_rate = info->control.rates[0];
677 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
678 			tx->sta->last_tx_rate = txrc.reported_rate;
679 	} else if (tx->sta)
680 		tx->sta->last_tx_rate = txrc.reported_rate;
681 
682 	if (unlikely(!info->control.rates[0].count))
683 		info->control.rates[0].count = 1;
684 
685 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
686 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
687 		info->control.rates[0].count = 1;
688 
689 	if (is_multicast_ether_addr(hdr->addr1)) {
690 		/*
691 		 * XXX: verify the rate is in the basic rateset
692 		 */
693 		return TX_CONTINUE;
694 	}
695 
696 	/*
697 	 * set up the RTS/CTS rate as the fastest basic rate
698 	 * that is not faster than the data rate
699 	 *
700 	 * XXX: Should this check all retry rates?
701 	 */
702 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
703 		s8 baserate = 0;
704 
705 		rate = &sband->bitrates[info->control.rates[0].idx];
706 
707 		for (i = 0; i < sband->n_bitrates; i++) {
708 			/* must be a basic rate */
709 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
710 				continue;
711 			/* must not be faster than the data rate */
712 			if (sband->bitrates[i].bitrate > rate->bitrate)
713 				continue;
714 			/* maximum */
715 			if (sband->bitrates[baserate].bitrate <
716 			     sband->bitrates[i].bitrate)
717 				baserate = i;
718 		}
719 
720 		info->control.rts_cts_rate_idx = baserate;
721 	}
722 
723 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
724 		/*
725 		 * make sure there's no valid rate following
726 		 * an invalid one, just in case drivers don't
727 		 * take the API seriously to stop at -1.
728 		 */
729 		if (inval) {
730 			info->control.rates[i].idx = -1;
731 			continue;
732 		}
733 		if (info->control.rates[i].idx < 0) {
734 			inval = true;
735 			continue;
736 		}
737 
738 		/*
739 		 * For now assume MCS is already set up correctly, this
740 		 * needs to be fixed.
741 		 */
742 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
743 			WARN_ON(info->control.rates[i].idx > 76);
744 			continue;
745 		}
746 
747 		/* set up RTS protection if desired */
748 		if (rts)
749 			info->control.rates[i].flags |=
750 				IEEE80211_TX_RC_USE_RTS_CTS;
751 
752 		/* RC is busted */
753 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
754 				 sband->n_bitrates)) {
755 			info->control.rates[i].idx = -1;
756 			continue;
757 		}
758 
759 		rate = &sband->bitrates[info->control.rates[i].idx];
760 
761 		/* set up short preamble */
762 		if (short_preamble &&
763 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
764 			info->control.rates[i].flags |=
765 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
766 
767 		/* set up G protection */
768 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
769 		    rate->flags & IEEE80211_RATE_ERP_G)
770 			info->control.rates[i].flags |=
771 				IEEE80211_TX_RC_USE_CTS_PROTECT;
772 	}
773 
774 	return TX_CONTINUE;
775 }
776 
777 static ieee80211_tx_result debug_noinline
778 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
779 {
780 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
781 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
782 	u16 *seq;
783 	u8 *qc;
784 	int tid;
785 
786 	/*
787 	 * Packet injection may want to control the sequence
788 	 * number, if we have no matching interface then we
789 	 * neither assign one ourselves nor ask the driver to.
790 	 */
791 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
792 		return TX_CONTINUE;
793 
794 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
795 		return TX_CONTINUE;
796 
797 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
798 		return TX_CONTINUE;
799 
800 	/*
801 	 * Anything but QoS data that has a sequence number field
802 	 * (is long enough) gets a sequence number from the global
803 	 * counter.
804 	 */
805 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
806 		/* driver should assign sequence number */
807 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
808 		/* for pure STA mode without beacons, we can do it */
809 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
810 		tx->sdata->sequence_number += 0x10;
811 		return TX_CONTINUE;
812 	}
813 
814 	/*
815 	 * This should be true for injected/management frames only, for
816 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
817 	 * above since they are not QoS-data frames.
818 	 */
819 	if (!tx->sta)
820 		return TX_CONTINUE;
821 
822 	/* include per-STA, per-TID sequence counter */
823 
824 	qc = ieee80211_get_qos_ctl(hdr);
825 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
826 	seq = &tx->sta->tid_seq[tid];
827 
828 	hdr->seq_ctrl = cpu_to_le16(*seq);
829 
830 	/* Increase the sequence number. */
831 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
832 
833 	return TX_CONTINUE;
834 }
835 
836 static int ieee80211_fragment(struct ieee80211_local *local,
837 			      struct sk_buff *skb, int hdrlen,
838 			      int frag_threshold)
839 {
840 	struct sk_buff *tail = skb, *tmp;
841 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
842 	int pos = hdrlen + per_fragm;
843 	int rem = skb->len - hdrlen - per_fragm;
844 
845 	if (WARN_ON(rem < 0))
846 		return -EINVAL;
847 
848 	while (rem) {
849 		int fraglen = per_fragm;
850 
851 		if (fraglen > rem)
852 			fraglen = rem;
853 		rem -= fraglen;
854 		tmp = dev_alloc_skb(local->tx_headroom +
855 				    frag_threshold +
856 				    IEEE80211_ENCRYPT_HEADROOM +
857 				    IEEE80211_ENCRYPT_TAILROOM);
858 		if (!tmp)
859 			return -ENOMEM;
860 		tail->next = tmp;
861 		tail = tmp;
862 		skb_reserve(tmp, local->tx_headroom +
863 				 IEEE80211_ENCRYPT_HEADROOM);
864 		/* copy control information */
865 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
866 		skb_copy_queue_mapping(tmp, skb);
867 		tmp->priority = skb->priority;
868 		tmp->dev = skb->dev;
869 
870 		/* copy header and data */
871 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
872 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
873 
874 		pos += fraglen;
875 	}
876 
877 	skb->len = hdrlen + per_fragm;
878 	return 0;
879 }
880 
881 static ieee80211_tx_result debug_noinline
882 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
883 {
884 	struct sk_buff *skb = tx->skb;
885 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
886 	struct ieee80211_hdr *hdr = (void *)skb->data;
887 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
888 	int hdrlen;
889 	int fragnum;
890 
891 	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
892 		return TX_CONTINUE;
893 
894 	/*
895 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
896 	 * This scenario is handled in ieee80211_tx_prepare but extra
897 	 * caution taken here as fragmented ampdu may cause Tx stop.
898 	 */
899 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
900 		return TX_DROP;
901 
902 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
903 
904 	/* internal error, why is TX_FRAGMENTED set? */
905 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
906 		return TX_DROP;
907 
908 	/*
909 	 * Now fragment the frame. This will allocate all the fragments and
910 	 * chain them (using skb as the first fragment) to skb->next.
911 	 * During transmission, we will remove the successfully transmitted
912 	 * fragments from this list. When the low-level driver rejects one
913 	 * of the fragments then we will simply pretend to accept the skb
914 	 * but store it away as pending.
915 	 */
916 	if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
917 		return TX_DROP;
918 
919 	/* update duration/seq/flags of fragments */
920 	fragnum = 0;
921 	do {
922 		int next_len;
923 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
924 
925 		hdr = (void *)skb->data;
926 		info = IEEE80211_SKB_CB(skb);
927 
928 		if (skb->next) {
929 			hdr->frame_control |= morefrags;
930 			next_len = skb->next->len;
931 			/*
932 			 * No multi-rate retries for fragmented frames, that
933 			 * would completely throw off the NAV at other STAs.
934 			 */
935 			info->control.rates[1].idx = -1;
936 			info->control.rates[2].idx = -1;
937 			info->control.rates[3].idx = -1;
938 			info->control.rates[4].idx = -1;
939 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
940 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
941 		} else {
942 			hdr->frame_control &= ~morefrags;
943 			next_len = 0;
944 		}
945 		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
946 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
947 		fragnum++;
948 	} while ((skb = skb->next));
949 
950 	return TX_CONTINUE;
951 }
952 
953 static ieee80211_tx_result debug_noinline
954 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
955 {
956 	struct sk_buff *skb = tx->skb;
957 
958 	if (!tx->sta)
959 		return TX_CONTINUE;
960 
961 	tx->sta->tx_packets++;
962 	do {
963 		tx->sta->tx_fragments++;
964 		tx->sta->tx_bytes += skb->len;
965 	} while ((skb = skb->next));
966 
967 	return TX_CONTINUE;
968 }
969 
970 static ieee80211_tx_result debug_noinline
971 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
972 {
973 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
974 
975 	if (!tx->key)
976 		return TX_CONTINUE;
977 
978 	switch (tx->key->conf.cipher) {
979 	case WLAN_CIPHER_SUITE_WEP40:
980 	case WLAN_CIPHER_SUITE_WEP104:
981 		return ieee80211_crypto_wep_encrypt(tx);
982 	case WLAN_CIPHER_SUITE_TKIP:
983 		return ieee80211_crypto_tkip_encrypt(tx);
984 	case WLAN_CIPHER_SUITE_CCMP:
985 		return ieee80211_crypto_ccmp_encrypt(tx);
986 	case WLAN_CIPHER_SUITE_AES_CMAC:
987 		return ieee80211_crypto_aes_cmac_encrypt(tx);
988 	default:
989 		/* handle hw-only algorithm */
990 		if (info->control.hw_key) {
991 			ieee80211_tx_set_protected(tx);
992 			return TX_CONTINUE;
993 		}
994 		break;
995 
996 	}
997 
998 	return TX_DROP;
999 }
1000 
1001 static ieee80211_tx_result debug_noinline
1002 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1003 {
1004 	struct sk_buff *skb = tx->skb;
1005 	struct ieee80211_hdr *hdr;
1006 	int next_len;
1007 	bool group_addr;
1008 
1009 	do {
1010 		hdr = (void *) skb->data;
1011 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1012 			break; /* must not overwrite AID */
1013 		next_len = skb->next ? skb->next->len : 0;
1014 		group_addr = is_multicast_ether_addr(hdr->addr1);
1015 
1016 		hdr->duration_id =
1017 			ieee80211_duration(tx, group_addr, next_len);
1018 	} while ((skb = skb->next));
1019 
1020 	return TX_CONTINUE;
1021 }
1022 
1023 /* actual transmit path */
1024 
1025 /*
1026  * deal with packet injection down monitor interface
1027  * with Radiotap Header -- only called for monitor mode interface
1028  */
1029 static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
1030 					  struct sk_buff *skb)
1031 {
1032 	/*
1033 	 * this is the moment to interpret and discard the radiotap header that
1034 	 * must be at the start of the packet injected in Monitor mode
1035 	 *
1036 	 * Need to take some care with endian-ness since radiotap
1037 	 * args are little-endian
1038 	 */
1039 
1040 	struct ieee80211_radiotap_iterator iterator;
1041 	struct ieee80211_radiotap_header *rthdr =
1042 		(struct ieee80211_radiotap_header *) skb->data;
1043 	bool hw_frag;
1044 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1045 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1046 						   NULL);
1047 
1048 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1049 	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1050 
1051 	/* packet is fragmented in HW if we have a non-NULL driver callback */
1052 	hw_frag = (tx->local->ops->set_frag_threshold != NULL);
1053 
1054 	/*
1055 	 * for every radiotap entry that is present
1056 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1057 	 * entries present, or -EINVAL on error)
1058 	 */
1059 
1060 	while (!ret) {
1061 		ret = ieee80211_radiotap_iterator_next(&iterator);
1062 
1063 		if (ret)
1064 			continue;
1065 
1066 		/* see if this argument is something we can use */
1067 		switch (iterator.this_arg_index) {
1068 		/*
1069 		 * You must take care when dereferencing iterator.this_arg
1070 		 * for multibyte types... the pointer is not aligned.  Use
1071 		 * get_unaligned((type *)iterator.this_arg) to dereference
1072 		 * iterator.this_arg for type "type" safely on all arches.
1073 		*/
1074 		case IEEE80211_RADIOTAP_FLAGS:
1075 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1076 				/*
1077 				 * this indicates that the skb we have been
1078 				 * handed has the 32-bit FCS CRC at the end...
1079 				 * we should react to that by snipping it off
1080 				 * because it will be recomputed and added
1081 				 * on transmission
1082 				 */
1083 				if (skb->len < (iterator._max_length + FCS_LEN))
1084 					return false;
1085 
1086 				skb_trim(skb, skb->len - FCS_LEN);
1087 			}
1088 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1089 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1090 			if ((*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG) &&
1091 								!hw_frag)
1092 				tx->flags |= IEEE80211_TX_FRAGMENTED;
1093 			break;
1094 
1095 		/*
1096 		 * Please update the file
1097 		 * Documentation/networking/mac80211-injection.txt
1098 		 * when parsing new fields here.
1099 		 */
1100 
1101 		default:
1102 			break;
1103 		}
1104 	}
1105 
1106 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1107 		return false;
1108 
1109 	/*
1110 	 * remove the radiotap header
1111 	 * iterator->_max_length was sanity-checked against
1112 	 * skb->len by iterator init
1113 	 */
1114 	skb_pull(skb, iterator._max_length);
1115 
1116 	return true;
1117 }
1118 
1119 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1120 				  struct sk_buff *skb,
1121 				  struct ieee80211_tx_info *info,
1122 				  struct tid_ampdu_tx *tid_tx,
1123 				  int tid)
1124 {
1125 	bool queued = false;
1126 
1127 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1128 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1129 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1130 		/*
1131 		 * nothing -- this aggregation session is being started
1132 		 * but that might still fail with the driver
1133 		 */
1134 	} else {
1135 		spin_lock(&tx->sta->lock);
1136 		/*
1137 		 * Need to re-check now, because we may get here
1138 		 *
1139 		 *  1) in the window during which the setup is actually
1140 		 *     already done, but not marked yet because not all
1141 		 *     packets are spliced over to the driver pending
1142 		 *     queue yet -- if this happened we acquire the lock
1143 		 *     either before or after the splice happens, but
1144 		 *     need to recheck which of these cases happened.
1145 		 *
1146 		 *  2) during session teardown, if the OPERATIONAL bit
1147 		 *     was cleared due to the teardown but the pointer
1148 		 *     hasn't been assigned NULL yet (or we loaded it
1149 		 *     before it was assigned) -- in this case it may
1150 		 *     now be NULL which means we should just let the
1151 		 *     packet pass through because splicing the frames
1152 		 *     back is already done.
1153 		 */
1154 		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1155 
1156 		if (!tid_tx) {
1157 			/* do nothing, let packet pass through */
1158 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1159 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1160 		} else {
1161 			queued = true;
1162 			info->control.vif = &tx->sdata->vif;
1163 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1164 			__skb_queue_tail(&tid_tx->pending, skb);
1165 		}
1166 		spin_unlock(&tx->sta->lock);
1167 	}
1168 
1169 	return queued;
1170 }
1171 
1172 /*
1173  * initialises @tx
1174  */
1175 static ieee80211_tx_result
1176 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1177 		     struct ieee80211_tx_data *tx,
1178 		     struct sk_buff *skb)
1179 {
1180 	struct ieee80211_local *local = sdata->local;
1181 	struct ieee80211_hdr *hdr;
1182 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1183 	int hdrlen, tid;
1184 	u8 *qc;
1185 
1186 	memset(tx, 0, sizeof(*tx));
1187 	tx->skb = skb;
1188 	tx->local = local;
1189 	tx->sdata = sdata;
1190 	tx->channel = local->hw.conf.channel;
1191 	/*
1192 	 * Set this flag (used below to indicate "automatic fragmentation"),
1193 	 * it will be cleared/left by radiotap as desired.
1194 	 * Only valid when fragmentation is done by the stack.
1195 	 */
1196 	if (!local->ops->set_frag_threshold)
1197 		tx->flags |= IEEE80211_TX_FRAGMENTED;
1198 
1199 	/* process and remove the injection radiotap header */
1200 	if (unlikely(info->flags & IEEE80211_TX_INTFL_HAS_RADIOTAP)) {
1201 		if (!__ieee80211_parse_tx_radiotap(tx, skb))
1202 			return TX_DROP;
1203 
1204 		/*
1205 		 * __ieee80211_parse_tx_radiotap has now removed
1206 		 * the radiotap header that was present and pre-filled
1207 		 * 'tx' with tx control information.
1208 		 */
1209 		info->flags &= ~IEEE80211_TX_INTFL_HAS_RADIOTAP;
1210 	}
1211 
1212 	/*
1213 	 * If this flag is set to true anywhere, and we get here,
1214 	 * we are doing the needed processing, so remove the flag
1215 	 * now.
1216 	 */
1217 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1218 
1219 	hdr = (struct ieee80211_hdr *) skb->data;
1220 
1221 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1222 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1223 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1224 			return TX_DROP;
1225 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED) {
1226 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1227 	}
1228 	if (!tx->sta)
1229 		tx->sta = sta_info_get(sdata, hdr->addr1);
1230 
1231 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1232 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1233 		struct tid_ampdu_tx *tid_tx;
1234 
1235 		qc = ieee80211_get_qos_ctl(hdr);
1236 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1237 
1238 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1239 		if (tid_tx) {
1240 			bool queued;
1241 
1242 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1243 						       tid_tx, tid);
1244 
1245 			if (unlikely(queued))
1246 				return TX_QUEUED;
1247 		}
1248 	}
1249 
1250 	if (is_multicast_ether_addr(hdr->addr1)) {
1251 		tx->flags &= ~IEEE80211_TX_UNICAST;
1252 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1253 	} else {
1254 		tx->flags |= IEEE80211_TX_UNICAST;
1255 		if (unlikely(local->wifi_wme_noack_test))
1256 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
1257 		else
1258 			info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1259 	}
1260 
1261 	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
1262 		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1263 		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1264 		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1265 			tx->flags |= IEEE80211_TX_FRAGMENTED;
1266 		else
1267 			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1268 	}
1269 
1270 	if (!tx->sta)
1271 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1272 	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1273 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1274 
1275 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1276 	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
1277 		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
1278 		tx->ethertype = (pos[0] << 8) | pos[1];
1279 	}
1280 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1281 
1282 	return TX_CONTINUE;
1283 }
1284 
1285 /*
1286  * Returns false if the frame couldn't be transmitted but was queued instead.
1287  */
1288 static bool __ieee80211_tx(struct ieee80211_local *local, struct sk_buff **skbp,
1289 			   struct sta_info *sta, bool txpending)
1290 {
1291 	struct sk_buff *skb = *skbp, *next;
1292 	struct ieee80211_tx_info *info;
1293 	struct ieee80211_sub_if_data *sdata;
1294 	unsigned long flags;
1295 	int len;
1296 	bool fragm = false;
1297 
1298 	while (skb) {
1299 		int q = skb_get_queue_mapping(skb);
1300 		__le16 fc;
1301 
1302 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1303 		if (local->queue_stop_reasons[q] ||
1304 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1305 			/*
1306 			 * Since queue is stopped, queue up frames for later
1307 			 * transmission from the tx-pending tasklet when the
1308 			 * queue is woken again.
1309 			 */
1310 
1311 			do {
1312 				next = skb->next;
1313 				skb->next = NULL;
1314 				/*
1315 				 * NB: If txpending is true, next must already
1316 				 * be NULL since we must've gone through this
1317 				 * loop before already; therefore we can just
1318 				 * queue the frame to the head without worrying
1319 				 * about reordering of fragments.
1320 				 */
1321 				if (unlikely(txpending))
1322 					__skb_queue_head(&local->pending[q],
1323 							 skb);
1324 				else
1325 					__skb_queue_tail(&local->pending[q],
1326 							 skb);
1327 			} while ((skb = next));
1328 
1329 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1330 					       flags);
1331 			return false;
1332 		}
1333 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1334 
1335 		info = IEEE80211_SKB_CB(skb);
1336 
1337 		if (fragm)
1338 			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1339 					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1340 
1341 		next = skb->next;
1342 		len = skb->len;
1343 
1344 		if (next)
1345 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
1346 
1347 		sdata = vif_to_sdata(info->control.vif);
1348 
1349 		switch (sdata->vif.type) {
1350 		case NL80211_IFTYPE_MONITOR:
1351 			info->control.vif = NULL;
1352 			break;
1353 		case NL80211_IFTYPE_AP_VLAN:
1354 			info->control.vif = &container_of(sdata->bss,
1355 				struct ieee80211_sub_if_data, u.ap)->vif;
1356 			break;
1357 		default:
1358 			/* keep */
1359 			break;
1360 		}
1361 
1362 		if (sta && sta->uploaded)
1363 			info->control.sta = &sta->sta;
1364 		else
1365 			info->control.sta = NULL;
1366 
1367 		fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1368 		drv_tx(local, skb);
1369 
1370 		ieee80211_tpt_led_trig_tx(local, fc, len);
1371 		*skbp = skb = next;
1372 		ieee80211_led_tx(local, 1);
1373 		fragm = true;
1374 	}
1375 
1376 	return true;
1377 }
1378 
1379 /*
1380  * Invoke TX handlers, return 0 on success and non-zero if the
1381  * frame was dropped or queued.
1382  */
1383 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1384 {
1385 	struct sk_buff *skb = tx->skb;
1386 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1387 	ieee80211_tx_result res = TX_DROP;
1388 
1389 #define CALL_TXH(txh) \
1390 	do {				\
1391 		res = txh(tx);		\
1392 		if (res != TX_CONTINUE)	\
1393 			goto txh_done;	\
1394 	} while (0)
1395 
1396 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1397 	CALL_TXH(ieee80211_tx_h_check_assoc);
1398 	CALL_TXH(ieee80211_tx_h_ps_buf);
1399 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1400 	CALL_TXH(ieee80211_tx_h_select_key);
1401 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1402 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1403 
1404 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION))
1405 		goto txh_done;
1406 
1407 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1408 	CALL_TXH(ieee80211_tx_h_sequence);
1409 	CALL_TXH(ieee80211_tx_h_fragment);
1410 	/* handlers after fragment must be aware of tx info fragmentation! */
1411 	CALL_TXH(ieee80211_tx_h_stats);
1412 	CALL_TXH(ieee80211_tx_h_encrypt);
1413 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1414 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1415 #undef CALL_TXH
1416 
1417  txh_done:
1418 	if (unlikely(res == TX_DROP)) {
1419 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1420 		while (skb) {
1421 			struct sk_buff *next;
1422 
1423 			next = skb->next;
1424 			dev_kfree_skb(skb);
1425 			skb = next;
1426 		}
1427 		return -1;
1428 	} else if (unlikely(res == TX_QUEUED)) {
1429 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1430 		return -1;
1431 	}
1432 
1433 	return 0;
1434 }
1435 
1436 /*
1437  * Returns false if the frame couldn't be transmitted but was queued instead.
1438  */
1439 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1440 			 struct sk_buff *skb, bool txpending)
1441 {
1442 	struct ieee80211_local *local = sdata->local;
1443 	struct ieee80211_tx_data tx;
1444 	ieee80211_tx_result res_prepare;
1445 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1446 	bool result = true;
1447 
1448 	if (unlikely(skb->len < 10)) {
1449 		dev_kfree_skb(skb);
1450 		return true;
1451 	}
1452 
1453 	rcu_read_lock();
1454 
1455 	/* initialises tx */
1456 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1457 
1458 	if (unlikely(res_prepare == TX_DROP)) {
1459 		dev_kfree_skb(skb);
1460 		goto out;
1461 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1462 		goto out;
1463 	}
1464 
1465 	tx.channel = local->hw.conf.channel;
1466 	info->band = tx.channel->band;
1467 
1468 	if (!invoke_tx_handlers(&tx))
1469 		result = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
1470  out:
1471 	rcu_read_unlock();
1472 	return result;
1473 }
1474 
1475 /* device xmit handlers */
1476 
1477 static int ieee80211_skb_resize(struct ieee80211_local *local,
1478 				struct sk_buff *skb,
1479 				int head_need, bool may_encrypt)
1480 {
1481 	int tail_need = 0;
1482 
1483 	/*
1484 	 * This could be optimised, devices that do full hardware
1485 	 * crypto (including TKIP MMIC) need no tailroom... But we
1486 	 * have no drivers for such devices currently.
1487 	 */
1488 	if (may_encrypt) {
1489 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1490 		tail_need -= skb_tailroom(skb);
1491 		tail_need = max_t(int, tail_need, 0);
1492 	}
1493 
1494 	if (head_need || tail_need) {
1495 		/* Sorry. Can't account for this any more */
1496 		skb_orphan(skb);
1497 	}
1498 
1499 	if (skb_cloned(skb))
1500 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1501 	else if (head_need || tail_need)
1502 		I802_DEBUG_INC(local->tx_expand_skb_head);
1503 	else
1504 		return 0;
1505 
1506 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1507 		wiphy_debug(local->hw.wiphy,
1508 			    "failed to reallocate TX buffer\n");
1509 		return -ENOMEM;
1510 	}
1511 
1512 	/* update truesize too */
1513 	skb->truesize += head_need + tail_need;
1514 
1515 	return 0;
1516 }
1517 
1518 static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
1519 			   struct sk_buff *skb)
1520 {
1521 	struct ieee80211_local *local = sdata->local;
1522 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1523 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1524 	struct ieee80211_sub_if_data *tmp_sdata;
1525 	int headroom;
1526 	bool may_encrypt;
1527 
1528 	rcu_read_lock();
1529 
1530 	if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1531 		int hdrlen;
1532 		u16 len_rthdr;
1533 
1534 		info->flags |= IEEE80211_TX_CTL_INJECTED |
1535 			       IEEE80211_TX_INTFL_HAS_RADIOTAP;
1536 
1537 		len_rthdr = ieee80211_get_radiotap_len(skb->data);
1538 		hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1539 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
1540 
1541 		/* check the header is complete in the frame */
1542 		if (likely(skb->len >= len_rthdr + hdrlen)) {
1543 			/*
1544 			 * We process outgoing injected frames that have a
1545 			 * local address we handle as though they are our
1546 			 * own frames.
1547 			 * This code here isn't entirely correct, the local
1548 			 * MAC address is not necessarily enough to find
1549 			 * the interface to use; for that proper VLAN/WDS
1550 			 * support we will need a different mechanism.
1551 			 */
1552 
1553 			list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
1554 						list) {
1555 				if (!ieee80211_sdata_running(tmp_sdata))
1556 					continue;
1557 				if (tmp_sdata->vif.type ==
1558 				    NL80211_IFTYPE_MONITOR ||
1559 				    tmp_sdata->vif.type ==
1560 				    NL80211_IFTYPE_AP_VLAN ||
1561 					tmp_sdata->vif.type ==
1562 				    NL80211_IFTYPE_WDS)
1563 					continue;
1564 				if (compare_ether_addr(tmp_sdata->vif.addr,
1565 						       hdr->addr2) == 0) {
1566 					sdata = tmp_sdata;
1567 					break;
1568 				}
1569 			}
1570 		}
1571 	}
1572 
1573 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1574 
1575 	headroom = local->tx_headroom;
1576 	if (may_encrypt)
1577 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1578 	headroom -= skb_headroom(skb);
1579 	headroom = max_t(int, 0, headroom);
1580 
1581 	if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
1582 		dev_kfree_skb(skb);
1583 		rcu_read_unlock();
1584 		return;
1585 	}
1586 
1587 	hdr = (struct ieee80211_hdr *) skb->data;
1588 	info->control.vif = &sdata->vif;
1589 
1590 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1591 	    ieee80211_is_data(hdr->frame_control) &&
1592 		!is_multicast_ether_addr(hdr->addr1))
1593 			if (mesh_nexthop_lookup(skb, sdata)) {
1594 				/* skb queued: don't free */
1595 				rcu_read_unlock();
1596 				return;
1597 			}
1598 
1599 	ieee80211_set_qos_hdr(local, skb);
1600 	ieee80211_tx(sdata, skb, false);
1601 	rcu_read_unlock();
1602 }
1603 
1604 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1605 					 struct net_device *dev)
1606 {
1607 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1608 	struct ieee80211_channel *chan = local->hw.conf.channel;
1609 	struct ieee80211_radiotap_header *prthdr =
1610 		(struct ieee80211_radiotap_header *)skb->data;
1611 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1612 	u16 len_rthdr;
1613 
1614 	/*
1615 	 * Frame injection is not allowed if beaconing is not allowed
1616 	 * or if we need radar detection. Beaconing is usually not allowed when
1617 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1618 	 * Passive scan is also used in world regulatory domains where
1619 	 * your country is not known and as such it should be treated as
1620 	 * NO TX unless the channel is explicitly allowed in which case
1621 	 * your current regulatory domain would not have the passive scan
1622 	 * flag.
1623 	 *
1624 	 * Since AP mode uses monitor interfaces to inject/TX management
1625 	 * frames we can make AP mode the exception to this rule once it
1626 	 * supports radar detection as its implementation can deal with
1627 	 * radar detection by itself. We can do that later by adding a
1628 	 * monitor flag interfaces used for AP support.
1629 	 */
1630 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1631 	     IEEE80211_CHAN_PASSIVE_SCAN)))
1632 		goto fail;
1633 
1634 	/* check for not even having the fixed radiotap header part */
1635 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1636 		goto fail; /* too short to be possibly valid */
1637 
1638 	/* is it a header version we can trust to find length from? */
1639 	if (unlikely(prthdr->it_version))
1640 		goto fail; /* only version 0 is supported */
1641 
1642 	/* then there must be a radiotap header with a length we can use */
1643 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1644 
1645 	/* does the skb contain enough to deliver on the alleged length? */
1646 	if (unlikely(skb->len < len_rthdr))
1647 		goto fail; /* skb too short for claimed rt header extent */
1648 
1649 	/*
1650 	 * fix up the pointers accounting for the radiotap
1651 	 * header still being in there.  We are being given
1652 	 * a precooked IEEE80211 header so no need for
1653 	 * normal processing
1654 	 */
1655 	skb_set_mac_header(skb, len_rthdr);
1656 	/*
1657 	 * these are just fixed to the end of the rt area since we
1658 	 * don't have any better information and at this point, nobody cares
1659 	 */
1660 	skb_set_network_header(skb, len_rthdr);
1661 	skb_set_transport_header(skb, len_rthdr);
1662 
1663 	memset(info, 0, sizeof(*info));
1664 
1665 	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1666 
1667 	/* pass the radiotap header up to xmit */
1668 	ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), skb);
1669 	return NETDEV_TX_OK;
1670 
1671 fail:
1672 	dev_kfree_skb(skb);
1673 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1674 }
1675 
1676 /**
1677  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1678  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1679  * @skb: packet to be sent
1680  * @dev: incoming interface
1681  *
1682  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1683  * not be freed, and caller is responsible for either retrying later or freeing
1684  * skb).
1685  *
1686  * This function takes in an Ethernet header and encapsulates it with suitable
1687  * IEEE 802.11 header based on which interface the packet is coming in. The
1688  * encapsulated packet will then be passed to master interface, wlan#.11, for
1689  * transmission (through low-level driver).
1690  */
1691 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1692 				    struct net_device *dev)
1693 {
1694 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1695 	struct ieee80211_local *local = sdata->local;
1696 	struct ieee80211_tx_info *info;
1697 	int ret = NETDEV_TX_BUSY, head_need;
1698 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1699 	__le16 fc;
1700 	struct ieee80211_hdr hdr;
1701 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1702 	struct mesh_path __maybe_unused *mppath = NULL;
1703 	const u8 *encaps_data;
1704 	int encaps_len, skip_header_bytes;
1705 	int nh_pos, h_pos;
1706 	struct sta_info *sta = NULL;
1707 	u32 sta_flags = 0;
1708 	struct sk_buff *tmp_skb;
1709 
1710 	if (unlikely(skb->len < ETH_HLEN)) {
1711 		ret = NETDEV_TX_OK;
1712 		goto fail;
1713 	}
1714 
1715 	/* convert Ethernet header to proper 802.11 header (based on
1716 	 * operation mode) */
1717 	ethertype = (skb->data[12] << 8) | skb->data[13];
1718 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1719 
1720 	switch (sdata->vif.type) {
1721 	case NL80211_IFTYPE_AP_VLAN:
1722 		rcu_read_lock();
1723 		sta = rcu_dereference(sdata->u.vlan.sta);
1724 		if (sta) {
1725 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1726 			/* RA TA DA SA */
1727 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1728 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1729 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1730 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1731 			hdrlen = 30;
1732 			sta_flags = get_sta_flags(sta);
1733 		}
1734 		rcu_read_unlock();
1735 		if (sta)
1736 			break;
1737 		/* fall through */
1738 	case NL80211_IFTYPE_AP:
1739 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1740 		/* DA BSSID SA */
1741 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1742 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1743 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1744 		hdrlen = 24;
1745 		break;
1746 	case NL80211_IFTYPE_WDS:
1747 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1748 		/* RA TA DA SA */
1749 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1750 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1751 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1752 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1753 		hdrlen = 30;
1754 		break;
1755 #ifdef CONFIG_MAC80211_MESH
1756 	case NL80211_IFTYPE_MESH_POINT:
1757 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1758 			/* Do not send frames with mesh_ttl == 0 */
1759 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1760 			ret = NETDEV_TX_OK;
1761 			goto fail;
1762 		}
1763 		rcu_read_lock();
1764 		if (!is_multicast_ether_addr(skb->data))
1765 			mppath = mpp_path_lookup(skb->data, sdata);
1766 
1767 		/*
1768 		 * Use address extension if it is a packet from
1769 		 * another interface or if we know the destination
1770 		 * is being proxied by a portal (i.e. portal address
1771 		 * differs from proxied address)
1772 		 */
1773 		if (compare_ether_addr(sdata->vif.addr,
1774 				       skb->data + ETH_ALEN) == 0 &&
1775 		    !(mppath && compare_ether_addr(mppath->mpp, skb->data))) {
1776 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1777 					skb->data, skb->data + ETH_ALEN);
1778 			rcu_read_unlock();
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 			if (is_multicast_ether_addr(skb->data))
1786 				/* DA TA mSA AE:SA */
1787 				mesh_da = skb->data;
1788 			else {
1789 				static const u8 bcast[ETH_ALEN] =
1790 					{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1791 				if (mppath) {
1792 					/* RA TA mDA mSA AE:DA SA */
1793 					mesh_da = mppath->mpp;
1794 					is_mesh_mcast = 0;
1795 				} else {
1796 					/* DA TA mSA AE:SA */
1797 					mesh_da = bcast;
1798 				}
1799 			}
1800 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1801 					mesh_da, sdata->vif.addr);
1802 			rcu_read_unlock();
1803 			if (is_mesh_mcast)
1804 				meshhdrlen =
1805 					ieee80211_new_mesh_header(&mesh_hdr,
1806 							sdata,
1807 							skb->data + ETH_ALEN,
1808 							NULL);
1809 			else
1810 				meshhdrlen =
1811 					ieee80211_new_mesh_header(&mesh_hdr,
1812 							sdata,
1813 							skb->data,
1814 							skb->data + ETH_ALEN);
1815 
1816 		}
1817 		break;
1818 #endif
1819 	case NL80211_IFTYPE_STATION:
1820 		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1821 		if (sdata->u.mgd.use_4addr &&
1822 		    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1823 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1824 			/* RA TA DA SA */
1825 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1826 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1827 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1828 			hdrlen = 30;
1829 		} else {
1830 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1831 			/* BSSID SA DA */
1832 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1833 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1834 			hdrlen = 24;
1835 		}
1836 		break;
1837 	case NL80211_IFTYPE_ADHOC:
1838 		/* DA SA BSSID */
1839 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1840 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1841 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1842 		hdrlen = 24;
1843 		break;
1844 	default:
1845 		ret = NETDEV_TX_OK;
1846 		goto fail;
1847 	}
1848 
1849 	/*
1850 	 * There's no need to try to look up the destination
1851 	 * if it is a multicast address (which can only happen
1852 	 * in AP mode)
1853 	 */
1854 	if (!is_multicast_ether_addr(hdr.addr1)) {
1855 		rcu_read_lock();
1856 		sta = sta_info_get(sdata, hdr.addr1);
1857 		if (sta)
1858 			sta_flags = get_sta_flags(sta);
1859 		rcu_read_unlock();
1860 	}
1861 
1862 	/* receiver and we are QoS enabled, use a QoS type frame */
1863 	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1864 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1865 		hdrlen += 2;
1866 	}
1867 
1868 	/*
1869 	 * Drop unicast frames to unauthorised stations unless they are
1870 	 * EAPOL frames from the local station.
1871 	 */
1872 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
1873 		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1874 		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
1875 		      !(cpu_to_be16(ethertype) == sdata->control_port_protocol &&
1876 		       compare_ether_addr(sdata->vif.addr,
1877 					  skb->data + ETH_ALEN) == 0))) {
1878 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1879 		if (net_ratelimit())
1880 			printk(KERN_DEBUG "%s: dropped frame to %pM"
1881 			       " (unauthorized port)\n", dev->name,
1882 			       hdr.addr1);
1883 #endif
1884 
1885 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1886 
1887 		ret = NETDEV_TX_OK;
1888 		goto fail;
1889 	}
1890 
1891 	/*
1892 	 * If the skb is shared we need to obtain our own copy.
1893 	 */
1894 	if (skb_shared(skb)) {
1895 		tmp_skb = skb;
1896 		skb = skb_clone(skb, GFP_ATOMIC);
1897 		kfree_skb(tmp_skb);
1898 
1899 		if (!skb) {
1900 			ret = NETDEV_TX_OK;
1901 			goto fail;
1902 		}
1903 	}
1904 
1905 	hdr.frame_control = fc;
1906 	hdr.duration_id = 0;
1907 	hdr.seq_ctrl = 0;
1908 
1909 	skip_header_bytes = ETH_HLEN;
1910 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
1911 		encaps_data = bridge_tunnel_header;
1912 		encaps_len = sizeof(bridge_tunnel_header);
1913 		skip_header_bytes -= 2;
1914 	} else if (ethertype >= 0x600) {
1915 		encaps_data = rfc1042_header;
1916 		encaps_len = sizeof(rfc1042_header);
1917 		skip_header_bytes -= 2;
1918 	} else {
1919 		encaps_data = NULL;
1920 		encaps_len = 0;
1921 	}
1922 
1923 	nh_pos = skb_network_header(skb) - skb->data;
1924 	h_pos = skb_transport_header(skb) - skb->data;
1925 
1926 	skb_pull(skb, skip_header_bytes);
1927 	nh_pos -= skip_header_bytes;
1928 	h_pos -= skip_header_bytes;
1929 
1930 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1931 
1932 	/*
1933 	 * So we need to modify the skb header and hence need a copy of
1934 	 * that. The head_need variable above doesn't, so far, include
1935 	 * the needed header space that we don't need right away. If we
1936 	 * can, then we don't reallocate right now but only after the
1937 	 * frame arrives at the master device (if it does...)
1938 	 *
1939 	 * If we cannot, however, then we will reallocate to include all
1940 	 * the ever needed space. Also, if we need to reallocate it anyway,
1941 	 * make it big enough for everything we may ever need.
1942 	 */
1943 
1944 	if (head_need > 0 || skb_cloned(skb)) {
1945 		head_need += IEEE80211_ENCRYPT_HEADROOM;
1946 		head_need += local->tx_headroom;
1947 		head_need = max_t(int, 0, head_need);
1948 		if (ieee80211_skb_resize(local, skb, head_need, true))
1949 			goto fail;
1950 	}
1951 
1952 	if (encaps_data) {
1953 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
1954 		nh_pos += encaps_len;
1955 		h_pos += encaps_len;
1956 	}
1957 
1958 #ifdef CONFIG_MAC80211_MESH
1959 	if (meshhdrlen > 0) {
1960 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
1961 		nh_pos += meshhdrlen;
1962 		h_pos += meshhdrlen;
1963 	}
1964 #endif
1965 
1966 	if (ieee80211_is_data_qos(fc)) {
1967 		__le16 *qos_control;
1968 
1969 		qos_control = (__le16*) skb_push(skb, 2);
1970 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
1971 		/*
1972 		 * Maybe we could actually set some fields here, for now just
1973 		 * initialise to zero to indicate no special operation.
1974 		 */
1975 		*qos_control = 0;
1976 	} else
1977 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
1978 
1979 	nh_pos += hdrlen;
1980 	h_pos += hdrlen;
1981 
1982 	dev->stats.tx_packets++;
1983 	dev->stats.tx_bytes += skb->len;
1984 
1985 	/* Update skb pointers to various headers since this modified frame
1986 	 * is going to go through Linux networking code that may potentially
1987 	 * need things like pointer to IP header. */
1988 	skb_set_mac_header(skb, 0);
1989 	skb_set_network_header(skb, nh_pos);
1990 	skb_set_transport_header(skb, h_pos);
1991 
1992 	info = IEEE80211_SKB_CB(skb);
1993 	memset(info, 0, sizeof(*info));
1994 
1995 	dev->trans_start = jiffies;
1996 	ieee80211_xmit(sdata, skb);
1997 
1998 	return NETDEV_TX_OK;
1999 
2000  fail:
2001 	if (ret == NETDEV_TX_OK)
2002 		dev_kfree_skb(skb);
2003 
2004 	return ret;
2005 }
2006 
2007 
2008 /*
2009  * ieee80211_clear_tx_pending may not be called in a context where
2010  * it is possible that it packets could come in again.
2011  */
2012 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2013 {
2014 	int i;
2015 
2016 	for (i = 0; i < local->hw.queues; i++)
2017 		skb_queue_purge(&local->pending[i]);
2018 }
2019 
2020 /*
2021  * Returns false if the frame couldn't be transmitted but was queued instead,
2022  * which in this case means re-queued -- take as an indication to stop sending
2023  * more pending frames.
2024  */
2025 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2026 				     struct sk_buff *skb)
2027 {
2028 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2029 	struct ieee80211_sub_if_data *sdata;
2030 	struct sta_info *sta;
2031 	struct ieee80211_hdr *hdr;
2032 	bool result;
2033 
2034 	sdata = vif_to_sdata(info->control.vif);
2035 
2036 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2037 		result = ieee80211_tx(sdata, skb, true);
2038 	} else {
2039 		hdr = (struct ieee80211_hdr *)skb->data;
2040 		sta = sta_info_get(sdata, hdr->addr1);
2041 
2042 		result = __ieee80211_tx(local, &skb, sta, true);
2043 	}
2044 
2045 	return result;
2046 }
2047 
2048 /*
2049  * Transmit all pending packets. Called from tasklet.
2050  */
2051 void ieee80211_tx_pending(unsigned long data)
2052 {
2053 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2054 	struct ieee80211_sub_if_data *sdata;
2055 	unsigned long flags;
2056 	int i;
2057 	bool txok;
2058 
2059 	rcu_read_lock();
2060 
2061 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2062 	for (i = 0; i < local->hw.queues; i++) {
2063 		/*
2064 		 * If queue is stopped by something other than due to pending
2065 		 * frames, or we have no pending frames, proceed to next queue.
2066 		 */
2067 		if (local->queue_stop_reasons[i] ||
2068 		    skb_queue_empty(&local->pending[i]))
2069 			continue;
2070 
2071 		while (!skb_queue_empty(&local->pending[i])) {
2072 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2073 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2074 
2075 			if (WARN_ON(!info->control.vif)) {
2076 				kfree_skb(skb);
2077 				continue;
2078 			}
2079 
2080 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2081 						flags);
2082 
2083 			txok = ieee80211_tx_pending_skb(local, skb);
2084 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2085 					  flags);
2086 			if (!txok)
2087 				break;
2088 		}
2089 
2090 		if (skb_queue_empty(&local->pending[i]))
2091 			list_for_each_entry_rcu(sdata, &local->interfaces, list)
2092 				netif_wake_subqueue(sdata->dev, i);
2093 	}
2094 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2095 
2096 	rcu_read_unlock();
2097 }
2098 
2099 /* functions for drivers to get certain frames */
2100 
2101 static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
2102 				     struct sk_buff *skb,
2103 				     struct beacon_data *beacon)
2104 {
2105 	u8 *pos, *tim;
2106 	int aid0 = 0;
2107 	int i, have_bits = 0, n1, n2;
2108 
2109 	/* Generate bitmap for TIM only if there are any STAs in power save
2110 	 * mode. */
2111 	if (atomic_read(&bss->num_sta_ps) > 0)
2112 		/* in the hope that this is faster than
2113 		 * checking byte-for-byte */
2114 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2115 					  IEEE80211_MAX_AID+1);
2116 
2117 	if (bss->dtim_count == 0)
2118 		bss->dtim_count = beacon->dtim_period - 1;
2119 	else
2120 		bss->dtim_count--;
2121 
2122 	tim = pos = (u8 *) skb_put(skb, 6);
2123 	*pos++ = WLAN_EID_TIM;
2124 	*pos++ = 4;
2125 	*pos++ = bss->dtim_count;
2126 	*pos++ = beacon->dtim_period;
2127 
2128 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2129 		aid0 = 1;
2130 
2131 	bss->dtim_bc_mc = aid0 == 1;
2132 
2133 	if (have_bits) {
2134 		/* Find largest even number N1 so that bits numbered 1 through
2135 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2136 		 * (N2 + 1) x 8 through 2007 are 0. */
2137 		n1 = 0;
2138 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2139 			if (bss->tim[i]) {
2140 				n1 = i & 0xfe;
2141 				break;
2142 			}
2143 		}
2144 		n2 = n1;
2145 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2146 			if (bss->tim[i]) {
2147 				n2 = i;
2148 				break;
2149 			}
2150 		}
2151 
2152 		/* Bitmap control */
2153 		*pos++ = n1 | aid0;
2154 		/* Part Virt Bitmap */
2155 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2156 
2157 		tim[1] = n2 - n1 + 4;
2158 		skb_put(skb, n2 - n1);
2159 	} else {
2160 		*pos++ = aid0; /* Bitmap control */
2161 		*pos++ = 0; /* Part Virt Bitmap */
2162 	}
2163 }
2164 
2165 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2166 					 struct ieee80211_vif *vif,
2167 					 u16 *tim_offset, u16 *tim_length)
2168 {
2169 	struct ieee80211_local *local = hw_to_local(hw);
2170 	struct sk_buff *skb = NULL;
2171 	struct ieee80211_tx_info *info;
2172 	struct ieee80211_sub_if_data *sdata = NULL;
2173 	struct ieee80211_if_ap *ap = NULL;
2174 	struct beacon_data *beacon;
2175 	struct ieee80211_supported_band *sband;
2176 	enum ieee80211_band band = local->hw.conf.channel->band;
2177 	struct ieee80211_tx_rate_control txrc;
2178 
2179 	sband = local->hw.wiphy->bands[band];
2180 
2181 	rcu_read_lock();
2182 
2183 	sdata = vif_to_sdata(vif);
2184 
2185 	if (!ieee80211_sdata_running(sdata))
2186 		goto out;
2187 
2188 	if (tim_offset)
2189 		*tim_offset = 0;
2190 	if (tim_length)
2191 		*tim_length = 0;
2192 
2193 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2194 		ap = &sdata->u.ap;
2195 		beacon = rcu_dereference(ap->beacon);
2196 		if (beacon) {
2197 			/*
2198 			 * headroom, head length,
2199 			 * tail length and maximum TIM length
2200 			 */
2201 			skb = dev_alloc_skb(local->tx_headroom +
2202 					    beacon->head_len +
2203 					    beacon->tail_len + 256);
2204 			if (!skb)
2205 				goto out;
2206 
2207 			skb_reserve(skb, local->tx_headroom);
2208 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2209 			       beacon->head_len);
2210 
2211 			/*
2212 			 * Not very nice, but we want to allow the driver to call
2213 			 * ieee80211_beacon_get() as a response to the set_tim()
2214 			 * callback. That, however, is already invoked under the
2215 			 * sta_lock to guarantee consistent and race-free update
2216 			 * of the tim bitmap in mac80211 and the driver.
2217 			 */
2218 			if (local->tim_in_locked_section) {
2219 				ieee80211_beacon_add_tim(ap, skb, beacon);
2220 			} else {
2221 				unsigned long flags;
2222 
2223 				spin_lock_irqsave(&local->sta_lock, flags);
2224 				ieee80211_beacon_add_tim(ap, skb, beacon);
2225 				spin_unlock_irqrestore(&local->sta_lock, flags);
2226 			}
2227 
2228 			if (tim_offset)
2229 				*tim_offset = beacon->head_len;
2230 			if (tim_length)
2231 				*tim_length = skb->len - beacon->head_len;
2232 
2233 			if (beacon->tail)
2234 				memcpy(skb_put(skb, beacon->tail_len),
2235 				       beacon->tail, beacon->tail_len);
2236 		} else
2237 			goto out;
2238 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2239 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2240 		struct ieee80211_hdr *hdr;
2241 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2242 
2243 		if (!presp)
2244 			goto out;
2245 
2246 		skb = skb_copy(presp, GFP_ATOMIC);
2247 		if (!skb)
2248 			goto out;
2249 
2250 		hdr = (struct ieee80211_hdr *) skb->data;
2251 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2252 						 IEEE80211_STYPE_BEACON);
2253 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2254 		struct ieee80211_mgmt *mgmt;
2255 		u8 *pos;
2256 
2257 #ifdef CONFIG_MAC80211_MESH
2258 		if (!sdata->u.mesh.mesh_id_len)
2259 			goto out;
2260 #endif
2261 
2262 		/* headroom, head length, tail length and maximum TIM length */
2263 		skb = dev_alloc_skb(local->tx_headroom + 400 +
2264 				sdata->u.mesh.ie_len);
2265 		if (!skb)
2266 			goto out;
2267 
2268 		skb_reserve(skb, local->hw.extra_tx_headroom);
2269 		mgmt = (struct ieee80211_mgmt *)
2270 			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
2271 		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2272 		mgmt->frame_control =
2273 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2274 		memset(mgmt->da, 0xff, ETH_ALEN);
2275 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2276 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2277 		mgmt->u.beacon.beacon_int =
2278 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2279 		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
2280 
2281 		pos = skb_put(skb, 2);
2282 		*pos++ = WLAN_EID_SSID;
2283 		*pos++ = 0x0;
2284 
2285 		mesh_mgmt_ies_add(skb, sdata);
2286 	} else {
2287 		WARN_ON(1);
2288 		goto out;
2289 	}
2290 
2291 	info = IEEE80211_SKB_CB(skb);
2292 
2293 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2294 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2295 	info->band = band;
2296 
2297 	memset(&txrc, 0, sizeof(txrc));
2298 	txrc.hw = hw;
2299 	txrc.sband = sband;
2300 	txrc.bss_conf = &sdata->vif.bss_conf;
2301 	txrc.skb = skb;
2302 	txrc.reported_rate.idx = -1;
2303 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2304 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2305 		txrc.max_rate_idx = -1;
2306 	else
2307 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2308 	txrc.bss = true;
2309 	rate_control_get_rate(sdata, NULL, &txrc);
2310 
2311 	info->control.vif = vif;
2312 
2313 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2314 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2315 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2316  out:
2317 	rcu_read_unlock();
2318 	return skb;
2319 }
2320 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2321 
2322 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2323 				     struct ieee80211_vif *vif)
2324 {
2325 	struct ieee80211_sub_if_data *sdata;
2326 	struct ieee80211_if_managed *ifmgd;
2327 	struct ieee80211_pspoll *pspoll;
2328 	struct ieee80211_local *local;
2329 	struct sk_buff *skb;
2330 
2331 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2332 		return NULL;
2333 
2334 	sdata = vif_to_sdata(vif);
2335 	ifmgd = &sdata->u.mgd;
2336 	local = sdata->local;
2337 
2338 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2339 	if (!skb) {
2340 		printk(KERN_DEBUG "%s: failed to allocate buffer for "
2341 		       "pspoll template\n", sdata->name);
2342 		return NULL;
2343 	}
2344 	skb_reserve(skb, local->hw.extra_tx_headroom);
2345 
2346 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2347 	memset(pspoll, 0, sizeof(*pspoll));
2348 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2349 					    IEEE80211_STYPE_PSPOLL);
2350 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2351 
2352 	/* aid in PS-Poll has its two MSBs each set to 1 */
2353 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2354 
2355 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2356 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2357 
2358 	return skb;
2359 }
2360 EXPORT_SYMBOL(ieee80211_pspoll_get);
2361 
2362 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2363 				       struct ieee80211_vif *vif)
2364 {
2365 	struct ieee80211_hdr_3addr *nullfunc;
2366 	struct ieee80211_sub_if_data *sdata;
2367 	struct ieee80211_if_managed *ifmgd;
2368 	struct ieee80211_local *local;
2369 	struct sk_buff *skb;
2370 
2371 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2372 		return NULL;
2373 
2374 	sdata = vif_to_sdata(vif);
2375 	ifmgd = &sdata->u.mgd;
2376 	local = sdata->local;
2377 
2378 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2379 	if (!skb) {
2380 		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
2381 		       "template\n", sdata->name);
2382 		return NULL;
2383 	}
2384 	skb_reserve(skb, local->hw.extra_tx_headroom);
2385 
2386 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2387 							  sizeof(*nullfunc));
2388 	memset(nullfunc, 0, sizeof(*nullfunc));
2389 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2390 					      IEEE80211_STYPE_NULLFUNC |
2391 					      IEEE80211_FCTL_TODS);
2392 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2393 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2394 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2395 
2396 	return skb;
2397 }
2398 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2399 
2400 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2401 				       struct ieee80211_vif *vif,
2402 				       const u8 *ssid, size_t ssid_len,
2403 				       const u8 *ie, size_t ie_len)
2404 {
2405 	struct ieee80211_sub_if_data *sdata;
2406 	struct ieee80211_local *local;
2407 	struct ieee80211_hdr_3addr *hdr;
2408 	struct sk_buff *skb;
2409 	size_t ie_ssid_len;
2410 	u8 *pos;
2411 
2412 	sdata = vif_to_sdata(vif);
2413 	local = sdata->local;
2414 	ie_ssid_len = 2 + ssid_len;
2415 
2416 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2417 			    ie_ssid_len + ie_len);
2418 	if (!skb) {
2419 		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
2420 		       "request template\n", sdata->name);
2421 		return NULL;
2422 	}
2423 
2424 	skb_reserve(skb, local->hw.extra_tx_headroom);
2425 
2426 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2427 	memset(hdr, 0, sizeof(*hdr));
2428 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2429 					 IEEE80211_STYPE_PROBE_REQ);
2430 	memset(hdr->addr1, 0xff, ETH_ALEN);
2431 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2432 	memset(hdr->addr3, 0xff, ETH_ALEN);
2433 
2434 	pos = skb_put(skb, ie_ssid_len);
2435 	*pos++ = WLAN_EID_SSID;
2436 	*pos++ = ssid_len;
2437 	if (ssid)
2438 		memcpy(pos, ssid, ssid_len);
2439 	pos += ssid_len;
2440 
2441 	if (ie) {
2442 		pos = skb_put(skb, ie_len);
2443 		memcpy(pos, ie, ie_len);
2444 	}
2445 
2446 	return skb;
2447 }
2448 EXPORT_SYMBOL(ieee80211_probereq_get);
2449 
2450 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2451 		       const void *frame, size_t frame_len,
2452 		       const struct ieee80211_tx_info *frame_txctl,
2453 		       struct ieee80211_rts *rts)
2454 {
2455 	const struct ieee80211_hdr *hdr = frame;
2456 
2457 	rts->frame_control =
2458 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2459 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2460 					       frame_txctl);
2461 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2462 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2463 }
2464 EXPORT_SYMBOL(ieee80211_rts_get);
2465 
2466 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2467 			     const void *frame, size_t frame_len,
2468 			     const struct ieee80211_tx_info *frame_txctl,
2469 			     struct ieee80211_cts *cts)
2470 {
2471 	const struct ieee80211_hdr *hdr = frame;
2472 
2473 	cts->frame_control =
2474 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2475 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2476 						     frame_len, frame_txctl);
2477 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2478 }
2479 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2480 
2481 struct sk_buff *
2482 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2483 			  struct ieee80211_vif *vif)
2484 {
2485 	struct ieee80211_local *local = hw_to_local(hw);
2486 	struct sk_buff *skb = NULL;
2487 	struct ieee80211_tx_data tx;
2488 	struct ieee80211_sub_if_data *sdata;
2489 	struct ieee80211_if_ap *bss = NULL;
2490 	struct beacon_data *beacon;
2491 	struct ieee80211_tx_info *info;
2492 
2493 	sdata = vif_to_sdata(vif);
2494 	bss = &sdata->u.ap;
2495 
2496 	rcu_read_lock();
2497 	beacon = rcu_dereference(bss->beacon);
2498 
2499 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2500 		goto out;
2501 
2502 	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
2503 		goto out; /* send buffered bc/mc only after DTIM beacon */
2504 
2505 	while (1) {
2506 		skb = skb_dequeue(&bss->ps_bc_buf);
2507 		if (!skb)
2508 			goto out;
2509 		local->total_ps_buffered--;
2510 
2511 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2512 			struct ieee80211_hdr *hdr =
2513 				(struct ieee80211_hdr *) skb->data;
2514 			/* more buffered multicast/broadcast frames ==> set
2515 			 * MoreData flag in IEEE 802.11 header to inform PS
2516 			 * STAs */
2517 			hdr->frame_control |=
2518 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2519 		}
2520 
2521 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2522 			break;
2523 		dev_kfree_skb_any(skb);
2524 	}
2525 
2526 	info = IEEE80211_SKB_CB(skb);
2527 
2528 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2529 	tx.channel = local->hw.conf.channel;
2530 	info->band = tx.channel->band;
2531 
2532 	if (invoke_tx_handlers(&tx))
2533 		skb = NULL;
2534  out:
2535 	rcu_read_unlock();
2536 
2537 	return skb;
2538 }
2539 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2540 
2541 void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
2542 {
2543 	skb_set_mac_header(skb, 0);
2544 	skb_set_network_header(skb, 0);
2545 	skb_set_transport_header(skb, 0);
2546 
2547 	/* Send all internal mgmt frames on VO. Accordingly set TID to 7. */
2548 	skb_set_queue_mapping(skb, IEEE80211_AC_VO);
2549 	skb->priority = 7;
2550 
2551 	/*
2552 	 * The other path calling ieee80211_xmit is from the tasklet,
2553 	 * and while we can handle concurrent transmissions locking
2554 	 * requirements are that we do not come into tx with bhs on.
2555 	 */
2556 	local_bh_disable();
2557 	ieee80211_xmit(sdata, skb);
2558 	local_bh_enable();
2559 }
2560