xref: /openbmc/linux/net/mac80211/tx.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  *
12  * Transmit and frame generation functions.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/skbuff.h>
18 #include <linux/etherdevice.h>
19 #include <linux/bitmap.h>
20 #include <linux/rcupdate.h>
21 #include <net/net_namespace.h>
22 #include <net/ieee80211_radiotap.h>
23 #include <net/cfg80211.h>
24 #include <net/mac80211.h>
25 #include <asm/unaligned.h>
26 
27 #include "ieee80211_i.h"
28 #include "driver-ops.h"
29 #include "led.h"
30 #include "mesh.h"
31 #include "wep.h"
32 #include "wpa.h"
33 #include "wme.h"
34 #include "rate.h"
35 
36 #define IEEE80211_TX_OK		0
37 #define IEEE80211_TX_AGAIN	1
38 #define IEEE80211_TX_PENDING	2
39 
40 /* misc utils */
41 
42 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
43 				 int next_frag_len)
44 {
45 	int rate, mrate, erp, dur, i;
46 	struct ieee80211_rate *txrate;
47 	struct ieee80211_local *local = tx->local;
48 	struct ieee80211_supported_band *sband;
49 	struct ieee80211_hdr *hdr;
50 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
51 
52 	/* assume HW handles this */
53 	if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
54 		return 0;
55 
56 	/* uh huh? */
57 	if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
58 		return 0;
59 
60 	sband = local->hw.wiphy->bands[tx->channel->band];
61 	txrate = &sband->bitrates[info->control.rates[0].idx];
62 
63 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
64 
65 	/*
66 	 * data and mgmt (except PS Poll):
67 	 * - during CFP: 32768
68 	 * - during contention period:
69 	 *   if addr1 is group address: 0
70 	 *   if more fragments = 0 and addr1 is individual address: time to
71 	 *      transmit one ACK plus SIFS
72 	 *   if more fragments = 1 and addr1 is individual address: time to
73 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
74 	 *
75 	 * IEEE 802.11, 9.6:
76 	 * - control response frame (CTS or ACK) shall be transmitted using the
77 	 *   same rate as the immediately previous frame in the frame exchange
78 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
79 	 *   at the highest possible rate belonging to the PHY rates in the
80 	 *   BSSBasicRateSet
81 	 */
82 	hdr = (struct ieee80211_hdr *)tx->skb->data;
83 	if (ieee80211_is_ctl(hdr->frame_control)) {
84 		/* TODO: These control frames are not currently sent by
85 		 * mac80211, but should they be implemented, this function
86 		 * needs to be updated to support duration field calculation.
87 		 *
88 		 * RTS: time needed to transmit pending data/mgmt frame plus
89 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
90 		 * CTS: duration of immediately previous RTS minus time
91 		 *    required to transmit CTS and its SIFS
92 		 * ACK: 0 if immediately previous directed data/mgmt had
93 		 *    more=0, with more=1 duration in ACK frame is duration
94 		 *    from previous frame minus time needed to transmit ACK
95 		 *    and its SIFS
96 		 * PS Poll: BIT(15) | BIT(14) | aid
97 		 */
98 		return 0;
99 	}
100 
101 	/* data/mgmt */
102 	if (0 /* FIX: data/mgmt during CFP */)
103 		return cpu_to_le16(32768);
104 
105 	if (group_addr) /* Group address as the destination - no ACK */
106 		return 0;
107 
108 	/* Individual destination address:
109 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
110 	 * CTS and ACK frames shall be transmitted using the highest rate in
111 	 * basic rate set that is less than or equal to the rate of the
112 	 * immediately previous frame and that is using the same modulation
113 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
114 	 * the highest mandatory rate of the PHY that is less than or equal to
115 	 * the rate of the previous frame is used.
116 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
117 	 */
118 	rate = -1;
119 	/* use lowest available if everything fails */
120 	mrate = sband->bitrates[0].bitrate;
121 	for (i = 0; i < sband->n_bitrates; i++) {
122 		struct ieee80211_rate *r = &sband->bitrates[i];
123 
124 		if (r->bitrate > txrate->bitrate)
125 			break;
126 
127 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
128 			rate = r->bitrate;
129 
130 		switch (sband->band) {
131 		case IEEE80211_BAND_2GHZ: {
132 			u32 flag;
133 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
134 				flag = IEEE80211_RATE_MANDATORY_G;
135 			else
136 				flag = IEEE80211_RATE_MANDATORY_B;
137 			if (r->flags & flag)
138 				mrate = r->bitrate;
139 			break;
140 		}
141 		case IEEE80211_BAND_5GHZ:
142 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
143 				mrate = r->bitrate;
144 			break;
145 		case IEEE80211_NUM_BANDS:
146 			WARN_ON(1);
147 			break;
148 		}
149 	}
150 	if (rate == -1) {
151 		/* No matching basic rate found; use highest suitable mandatory
152 		 * PHY rate */
153 		rate = mrate;
154 	}
155 
156 	/* Time needed to transmit ACK
157 	 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
158 	 * to closest integer */
159 
160 	dur = ieee80211_frame_duration(local, 10, rate, erp,
161 				tx->sdata->vif.bss_conf.use_short_preamble);
162 
163 	if (next_frag_len) {
164 		/* Frame is fragmented: duration increases with time needed to
165 		 * transmit next fragment plus ACK and 2 x SIFS. */
166 		dur *= 2; /* ACK + SIFS */
167 		/* next fragment */
168 		dur += ieee80211_frame_duration(local, next_frag_len,
169 				txrate->bitrate, erp,
170 				tx->sdata->vif.bss_conf.use_short_preamble);
171 	}
172 
173 	return cpu_to_le16(dur);
174 }
175 
176 static int inline is_ieee80211_device(struct ieee80211_local *local,
177 				      struct net_device *dev)
178 {
179 	return local == wdev_priv(dev->ieee80211_ptr);
180 }
181 
182 /* tx handlers */
183 static ieee80211_tx_result debug_noinline
184 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
185 {
186 	struct ieee80211_local *local = tx->local;
187 	struct ieee80211_if_managed *ifmgd;
188 
189 	/* driver doesn't support power save */
190 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
191 		return TX_CONTINUE;
192 
193 	/* hardware does dynamic power save */
194 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
195 		return TX_CONTINUE;
196 
197 	/* dynamic power save disabled */
198 	if (local->hw.conf.dynamic_ps_timeout <= 0)
199 		return TX_CONTINUE;
200 
201 	/* we are scanning, don't enable power save */
202 	if (local->scanning)
203 		return TX_CONTINUE;
204 
205 	if (!local->ps_sdata)
206 		return TX_CONTINUE;
207 
208 	/* No point if we're going to suspend */
209 	if (local->quiescing)
210 		return TX_CONTINUE;
211 
212 	/* dynamic ps is supported only in managed mode */
213 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
214 		return TX_CONTINUE;
215 
216 	ifmgd = &tx->sdata->u.mgd;
217 
218 	/*
219 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
220 	 * u-apsd enabled and the frame is in voip class. This effectively
221 	 * means that even if all access categories have u-apsd enabled, in
222 	 * practise u-apsd is only used with the voip ac. This is a
223 	 * workaround for the case when received voip class packets do not
224 	 * have correct qos tag for some reason, due the network or the
225 	 * peer application.
226 	 *
227 	 * Note: local->uapsd_queues access is racy here. If the value is
228 	 * changed via debugfs, user needs to reassociate manually to have
229 	 * everything in sync.
230 	 */
231 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED)
232 	    && (local->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO)
233 	    && skb_get_queue_mapping(tx->skb) == 0)
234 		return TX_CONTINUE;
235 
236 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
237 		ieee80211_stop_queues_by_reason(&local->hw,
238 						IEEE80211_QUEUE_STOP_REASON_PS);
239 		ieee80211_queue_work(&local->hw,
240 				     &local->dynamic_ps_disable_work);
241 	}
242 
243 	mod_timer(&local->dynamic_ps_timer, jiffies +
244 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
245 
246 	return TX_CONTINUE;
247 }
248 
249 static ieee80211_tx_result debug_noinline
250 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
251 {
252 
253 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
254 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
255 	u32 sta_flags;
256 
257 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
258 		return TX_CONTINUE;
259 
260 	if (unlikely(test_bit(SCAN_OFF_CHANNEL, &tx->local->scanning)) &&
261 	    !ieee80211_is_probe_req(hdr->frame_control) &&
262 	    !ieee80211_is_nullfunc(hdr->frame_control))
263 		/*
264 		 * When software scanning only nullfunc frames (to notify
265 		 * the sleep state to the AP) and probe requests (for the
266 		 * active scan) are allowed, all other frames should not be
267 		 * sent and we should not get here, but if we do
268 		 * nonetheless, drop them to avoid sending them
269 		 * off-channel. See the link below and
270 		 * ieee80211_start_scan() for more.
271 		 *
272 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
273 		 */
274 		return TX_DROP;
275 
276 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
277 		return TX_CONTINUE;
278 
279 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
280 		return TX_CONTINUE;
281 
282 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
283 		return TX_CONTINUE;
284 
285 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
286 
287 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
288 		if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
289 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
290 			     ieee80211_is_data(hdr->frame_control))) {
291 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
292 			printk(KERN_DEBUG "%s: dropped data frame to not "
293 			       "associated station %pM\n",
294 			       tx->sdata->name, hdr->addr1);
295 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
296 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
297 			return TX_DROP;
298 		}
299 	} else {
300 		if (unlikely(ieee80211_is_data(hdr->frame_control) &&
301 			     tx->local->num_sta == 0 &&
302 			     tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
303 			/*
304 			 * No associated STAs - no need to send multicast
305 			 * frames.
306 			 */
307 			return TX_DROP;
308 		}
309 		return TX_CONTINUE;
310 	}
311 
312 	return TX_CONTINUE;
313 }
314 
315 /* This function is called whenever the AP is about to exceed the maximum limit
316  * of buffered frames for power saving STAs. This situation should not really
317  * happen often during normal operation, so dropping the oldest buffered packet
318  * from each queue should be OK to make some room for new frames. */
319 static void purge_old_ps_buffers(struct ieee80211_local *local)
320 {
321 	int total = 0, purged = 0;
322 	struct sk_buff *skb;
323 	struct ieee80211_sub_if_data *sdata;
324 	struct sta_info *sta;
325 
326 	/*
327 	 * virtual interfaces are protected by RCU
328 	 */
329 	rcu_read_lock();
330 
331 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
332 		struct ieee80211_if_ap *ap;
333 		if (sdata->vif.type != NL80211_IFTYPE_AP)
334 			continue;
335 		ap = &sdata->u.ap;
336 		skb = skb_dequeue(&ap->ps_bc_buf);
337 		if (skb) {
338 			purged++;
339 			dev_kfree_skb(skb);
340 		}
341 		total += skb_queue_len(&ap->ps_bc_buf);
342 	}
343 
344 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
345 		skb = skb_dequeue(&sta->ps_tx_buf);
346 		if (skb) {
347 			purged++;
348 			dev_kfree_skb(skb);
349 		}
350 		total += skb_queue_len(&sta->ps_tx_buf);
351 	}
352 
353 	rcu_read_unlock();
354 
355 	local->total_ps_buffered = total;
356 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
357 	wiphy_debug(local->hw.wiphy, "PS buffers full - purged %d frames\n",
358 		    purged);
359 #endif
360 }
361 
362 static ieee80211_tx_result
363 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
364 {
365 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
366 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
367 
368 	/*
369 	 * broadcast/multicast frame
370 	 *
371 	 * If any of the associated stations is in power save mode,
372 	 * the frame is buffered to be sent after DTIM beacon frame.
373 	 * This is done either by the hardware or us.
374 	 */
375 
376 	/* powersaving STAs only in AP/VLAN mode */
377 	if (!tx->sdata->bss)
378 		return TX_CONTINUE;
379 
380 	/* no buffering for ordered frames */
381 	if (ieee80211_has_order(hdr->frame_control))
382 		return TX_CONTINUE;
383 
384 	/* no stations in PS mode */
385 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
386 		return TX_CONTINUE;
387 
388 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
389 
390 	/* device releases frame after DTIM beacon */
391 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
392 		return TX_CONTINUE;
393 
394 	/* buffered in mac80211 */
395 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
396 		purge_old_ps_buffers(tx->local);
397 
398 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
399 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
400 		if (net_ratelimit())
401 			printk(KERN_DEBUG "%s: BC TX buffer full - dropping the oldest frame\n",
402 			       tx->sdata->name);
403 #endif
404 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
405 	} else
406 		tx->local->total_ps_buffered++;
407 
408 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
409 
410 	return TX_QUEUED;
411 }
412 
413 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
414 			     struct sk_buff *skb)
415 {
416 	if (!ieee80211_is_mgmt(fc))
417 		return 0;
418 
419 	if (sta == NULL || !test_sta_flags(sta, WLAN_STA_MFP))
420 		return 0;
421 
422 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
423 					    skb->data))
424 		return 0;
425 
426 	return 1;
427 }
428 
429 static ieee80211_tx_result
430 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
431 {
432 	struct sta_info *sta = tx->sta;
433 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
434 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
435 	struct ieee80211_local *local = tx->local;
436 	u32 staflags;
437 
438 	if (unlikely(!sta ||
439 		     ieee80211_is_probe_resp(hdr->frame_control) ||
440 		     ieee80211_is_auth(hdr->frame_control) ||
441 		     ieee80211_is_assoc_resp(hdr->frame_control) ||
442 		     ieee80211_is_reassoc_resp(hdr->frame_control)))
443 		return TX_CONTINUE;
444 
445 	staflags = get_sta_flags(sta);
446 
447 	if (unlikely((staflags & (WLAN_STA_PS_STA | WLAN_STA_PS_DRIVER)) &&
448 		     !(info->flags & IEEE80211_TX_CTL_PSPOLL_RESPONSE))) {
449 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
450 		printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
451 		       "before %d)\n",
452 		       sta->sta.addr, sta->sta.aid,
453 		       skb_queue_len(&sta->ps_tx_buf));
454 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
455 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
456 			purge_old_ps_buffers(tx->local);
457 		if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
458 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
459 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
460 			if (net_ratelimit()) {
461 				printk(KERN_DEBUG "%s: STA %pM TX "
462 				       "buffer full - dropping oldest frame\n",
463 				       tx->sdata->name, sta->sta.addr);
464 			}
465 #endif
466 			dev_kfree_skb(old);
467 		} else
468 			tx->local->total_ps_buffered++;
469 
470 		/*
471 		 * Queue frame to be sent after STA wakes up/polls,
472 		 * but don't set the TIM bit if the driver is blocking
473 		 * wakeup or poll response transmissions anyway.
474 		 */
475 		if (skb_queue_empty(&sta->ps_tx_buf) &&
476 		    !(staflags & WLAN_STA_PS_DRIVER))
477 			sta_info_set_tim_bit(sta);
478 
479 		info->control.jiffies = jiffies;
480 		info->control.vif = &tx->sdata->vif;
481 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
482 		skb_queue_tail(&sta->ps_tx_buf, tx->skb);
483 
484 		if (!timer_pending(&local->sta_cleanup))
485 			mod_timer(&local->sta_cleanup,
486 				  round_jiffies(jiffies +
487 						STA_INFO_CLEANUP_INTERVAL));
488 
489 		return TX_QUEUED;
490 	}
491 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
492 	else if (unlikely(staflags & WLAN_STA_PS_STA)) {
493 		printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
494 		       "set -> send frame\n", tx->sdata->name,
495 		       sta->sta.addr);
496 	}
497 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
498 
499 	return TX_CONTINUE;
500 }
501 
502 static ieee80211_tx_result debug_noinline
503 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
504 {
505 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
506 		return TX_CONTINUE;
507 
508 	if (tx->flags & IEEE80211_TX_UNICAST)
509 		return ieee80211_tx_h_unicast_ps_buf(tx);
510 	else
511 		return ieee80211_tx_h_multicast_ps_buf(tx);
512 }
513 
514 static ieee80211_tx_result debug_noinline
515 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
516 {
517 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
518 
519 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
520 		     tx->sdata->control_port_no_encrypt))
521 		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
522 
523 	return TX_CONTINUE;
524 }
525 
526 static ieee80211_tx_result debug_noinline
527 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
528 {
529 	struct ieee80211_key *key = NULL;
530 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
531 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
532 
533 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
534 		tx->key = NULL;
535 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
536 		tx->key = key;
537 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
538 		 is_multicast_ether_addr(hdr->addr1) &&
539 		 ieee80211_is_robust_mgmt_frame(hdr) &&
540 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
541 		tx->key = key;
542 	else if (is_multicast_ether_addr(hdr->addr1) &&
543 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
544 		tx->key = key;
545 	else if (!is_multicast_ether_addr(hdr->addr1) &&
546 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
547 		tx->key = key;
548 	else if (tx->sdata->drop_unencrypted &&
549 		 (tx->skb->protocol != tx->sdata->control_port_protocol) &&
550 		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
551 		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
552 		  (ieee80211_is_action(hdr->frame_control) &&
553 		   tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) {
554 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
555 		return TX_DROP;
556 	} else
557 		tx->key = NULL;
558 
559 	if (tx->key) {
560 		bool skip_hw = false;
561 
562 		tx->key->tx_rx_count++;
563 		/* TODO: add threshold stuff again */
564 
565 		switch (tx->key->conf.cipher) {
566 		case WLAN_CIPHER_SUITE_WEP40:
567 		case WLAN_CIPHER_SUITE_WEP104:
568 			if (ieee80211_is_auth(hdr->frame_control))
569 				break;
570 		case WLAN_CIPHER_SUITE_TKIP:
571 			if (!ieee80211_is_data_present(hdr->frame_control))
572 				tx->key = NULL;
573 			break;
574 		case WLAN_CIPHER_SUITE_CCMP:
575 			if (!ieee80211_is_data_present(hdr->frame_control) &&
576 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
577 					       tx->skb))
578 				tx->key = NULL;
579 			else
580 				skip_hw = (tx->key->conf.flags &
581 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
582 					ieee80211_is_mgmt(hdr->frame_control);
583 			break;
584 		case WLAN_CIPHER_SUITE_AES_CMAC:
585 			if (!ieee80211_is_mgmt(hdr->frame_control))
586 				tx->key = NULL;
587 			break;
588 		}
589 
590 		if (!skip_hw && tx->key &&
591 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
592 			info->control.hw_key = &tx->key->conf;
593 	}
594 
595 	return TX_CONTINUE;
596 }
597 
598 static ieee80211_tx_result debug_noinline
599 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
600 {
601 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
602 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
603 	struct ieee80211_supported_band *sband;
604 	struct ieee80211_rate *rate;
605 	int i;
606 	u32 len;
607 	bool inval = false, rts = false, short_preamble = false;
608 	struct ieee80211_tx_rate_control txrc;
609 	u32 sta_flags;
610 
611 	memset(&txrc, 0, sizeof(txrc));
612 
613 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
614 
615 	len = min_t(u32, tx->skb->len + FCS_LEN,
616 			 tx->local->hw.wiphy->frag_threshold);
617 
618 	/* set up the tx rate control struct we give the RC algo */
619 	txrc.hw = local_to_hw(tx->local);
620 	txrc.sband = sband;
621 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
622 	txrc.skb = tx->skb;
623 	txrc.reported_rate.idx = -1;
624 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
625 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
626 		txrc.max_rate_idx = -1;
627 	else
628 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
629 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
630 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
631 
632 	/* set up RTS protection if desired */
633 	if (len > tx->local->hw.wiphy->rts_threshold) {
634 		txrc.rts = rts = true;
635 	}
636 
637 	/*
638 	 * Use short preamble if the BSS can handle it, but not for
639 	 * management frames unless we know the receiver can handle
640 	 * that -- the management frame might be to a station that
641 	 * just wants a probe response.
642 	 */
643 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
644 	    (ieee80211_is_data(hdr->frame_control) ||
645 	     (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
646 		txrc.short_preamble = short_preamble = true;
647 
648 	sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
649 
650 	/*
651 	 * Lets not bother rate control if we're associated and cannot
652 	 * talk to the sta. This should not happen.
653 	 */
654 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) &&
655 		 (sta_flags & WLAN_STA_ASSOC) &&
656 		 !rate_usable_index_exists(sband, &tx->sta->sta),
657 		 "%s: Dropped data frame as no usable bitrate found while "
658 		 "scanning and associated. Target station: "
659 		 "%pM on %d GHz band\n",
660 		 tx->sdata->name, hdr->addr1,
661 		 tx->channel->band ? 5 : 2))
662 		return TX_DROP;
663 
664 	/*
665 	 * If we're associated with the sta at this point we know we can at
666 	 * least send the frame at the lowest bit rate.
667 	 */
668 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
669 
670 	if (unlikely(info->control.rates[0].idx < 0))
671 		return TX_DROP;
672 
673 	if (txrc.reported_rate.idx < 0) {
674 		txrc.reported_rate = info->control.rates[0];
675 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
676 			tx->sta->last_tx_rate = txrc.reported_rate;
677 	} else if (tx->sta)
678 		tx->sta->last_tx_rate = txrc.reported_rate;
679 
680 	if (unlikely(!info->control.rates[0].count))
681 		info->control.rates[0].count = 1;
682 
683 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
684 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
685 		info->control.rates[0].count = 1;
686 
687 	if (is_multicast_ether_addr(hdr->addr1)) {
688 		/*
689 		 * XXX: verify the rate is in the basic rateset
690 		 */
691 		return TX_CONTINUE;
692 	}
693 
694 	/*
695 	 * set up the RTS/CTS rate as the fastest basic rate
696 	 * that is not faster than the data rate
697 	 *
698 	 * XXX: Should this check all retry rates?
699 	 */
700 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
701 		s8 baserate = 0;
702 
703 		rate = &sband->bitrates[info->control.rates[0].idx];
704 
705 		for (i = 0; i < sband->n_bitrates; i++) {
706 			/* must be a basic rate */
707 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
708 				continue;
709 			/* must not be faster than the data rate */
710 			if (sband->bitrates[i].bitrate > rate->bitrate)
711 				continue;
712 			/* maximum */
713 			if (sband->bitrates[baserate].bitrate <
714 			     sband->bitrates[i].bitrate)
715 				baserate = i;
716 		}
717 
718 		info->control.rts_cts_rate_idx = baserate;
719 	}
720 
721 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
722 		/*
723 		 * make sure there's no valid rate following
724 		 * an invalid one, just in case drivers don't
725 		 * take the API seriously to stop at -1.
726 		 */
727 		if (inval) {
728 			info->control.rates[i].idx = -1;
729 			continue;
730 		}
731 		if (info->control.rates[i].idx < 0) {
732 			inval = true;
733 			continue;
734 		}
735 
736 		/*
737 		 * For now assume MCS is already set up correctly, this
738 		 * needs to be fixed.
739 		 */
740 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
741 			WARN_ON(info->control.rates[i].idx > 76);
742 			continue;
743 		}
744 
745 		/* set up RTS protection if desired */
746 		if (rts)
747 			info->control.rates[i].flags |=
748 				IEEE80211_TX_RC_USE_RTS_CTS;
749 
750 		/* RC is busted */
751 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
752 				 sband->n_bitrates)) {
753 			info->control.rates[i].idx = -1;
754 			continue;
755 		}
756 
757 		rate = &sband->bitrates[info->control.rates[i].idx];
758 
759 		/* set up short preamble */
760 		if (short_preamble &&
761 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
762 			info->control.rates[i].flags |=
763 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
764 
765 		/* set up G protection */
766 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
767 		    rate->flags & IEEE80211_RATE_ERP_G)
768 			info->control.rates[i].flags |=
769 				IEEE80211_TX_RC_USE_CTS_PROTECT;
770 	}
771 
772 	return TX_CONTINUE;
773 }
774 
775 static ieee80211_tx_result debug_noinline
776 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
777 {
778 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
779 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
780 	u16 *seq;
781 	u8 *qc;
782 	int tid;
783 
784 	/*
785 	 * Packet injection may want to control the sequence
786 	 * number, if we have no matching interface then we
787 	 * neither assign one ourselves nor ask the driver to.
788 	 */
789 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
790 		return TX_CONTINUE;
791 
792 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
793 		return TX_CONTINUE;
794 
795 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
796 		return TX_CONTINUE;
797 
798 	/*
799 	 * Anything but QoS data that has a sequence number field
800 	 * (is long enough) gets a sequence number from the global
801 	 * counter.
802 	 */
803 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
804 		/* driver should assign sequence number */
805 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
806 		/* for pure STA mode without beacons, we can do it */
807 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
808 		tx->sdata->sequence_number += 0x10;
809 		return TX_CONTINUE;
810 	}
811 
812 	/*
813 	 * This should be true for injected/management frames only, for
814 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
815 	 * above since they are not QoS-data frames.
816 	 */
817 	if (!tx->sta)
818 		return TX_CONTINUE;
819 
820 	/* include per-STA, per-TID sequence counter */
821 
822 	qc = ieee80211_get_qos_ctl(hdr);
823 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
824 	seq = &tx->sta->tid_seq[tid];
825 
826 	hdr->seq_ctrl = cpu_to_le16(*seq);
827 
828 	/* Increase the sequence number. */
829 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
830 
831 	return TX_CONTINUE;
832 }
833 
834 static int ieee80211_fragment(struct ieee80211_local *local,
835 			      struct sk_buff *skb, int hdrlen,
836 			      int frag_threshold)
837 {
838 	struct sk_buff *tail = skb, *tmp;
839 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
840 	int pos = hdrlen + per_fragm;
841 	int rem = skb->len - hdrlen - per_fragm;
842 
843 	if (WARN_ON(rem < 0))
844 		return -EINVAL;
845 
846 	while (rem) {
847 		int fraglen = per_fragm;
848 
849 		if (fraglen > rem)
850 			fraglen = rem;
851 		rem -= fraglen;
852 		tmp = dev_alloc_skb(local->tx_headroom +
853 				    frag_threshold +
854 				    IEEE80211_ENCRYPT_HEADROOM +
855 				    IEEE80211_ENCRYPT_TAILROOM);
856 		if (!tmp)
857 			return -ENOMEM;
858 		tail->next = tmp;
859 		tail = tmp;
860 		skb_reserve(tmp, local->tx_headroom +
861 				 IEEE80211_ENCRYPT_HEADROOM);
862 		/* copy control information */
863 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
864 		skb_copy_queue_mapping(tmp, skb);
865 		tmp->priority = skb->priority;
866 		tmp->dev = skb->dev;
867 
868 		/* copy header and data */
869 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
870 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
871 
872 		pos += fraglen;
873 	}
874 
875 	skb->len = hdrlen + per_fragm;
876 	return 0;
877 }
878 
879 static ieee80211_tx_result debug_noinline
880 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
881 {
882 	struct sk_buff *skb = tx->skb;
883 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
884 	struct ieee80211_hdr *hdr = (void *)skb->data;
885 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
886 	int hdrlen;
887 	int fragnum;
888 
889 	if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
890 		return TX_CONTINUE;
891 
892 	/*
893 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
894 	 * This scenario is handled in ieee80211_tx_prepare but extra
895 	 * caution taken here as fragmented ampdu may cause Tx stop.
896 	 */
897 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
898 		return TX_DROP;
899 
900 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
901 
902 	/* internal error, why is TX_FRAGMENTED set? */
903 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
904 		return TX_DROP;
905 
906 	/*
907 	 * Now fragment the frame. This will allocate all the fragments and
908 	 * chain them (using skb as the first fragment) to skb->next.
909 	 * During transmission, we will remove the successfully transmitted
910 	 * fragments from this list. When the low-level driver rejects one
911 	 * of the fragments then we will simply pretend to accept the skb
912 	 * but store it away as pending.
913 	 */
914 	if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
915 		return TX_DROP;
916 
917 	/* update duration/seq/flags of fragments */
918 	fragnum = 0;
919 	do {
920 		int next_len;
921 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
922 
923 		hdr = (void *)skb->data;
924 		info = IEEE80211_SKB_CB(skb);
925 
926 		if (skb->next) {
927 			hdr->frame_control |= morefrags;
928 			next_len = skb->next->len;
929 			/*
930 			 * No multi-rate retries for fragmented frames, that
931 			 * would completely throw off the NAV at other STAs.
932 			 */
933 			info->control.rates[1].idx = -1;
934 			info->control.rates[2].idx = -1;
935 			info->control.rates[3].idx = -1;
936 			info->control.rates[4].idx = -1;
937 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
938 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
939 		} else {
940 			hdr->frame_control &= ~morefrags;
941 			next_len = 0;
942 		}
943 		hdr->duration_id = ieee80211_duration(tx, 0, next_len);
944 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
945 		fragnum++;
946 	} while ((skb = skb->next));
947 
948 	return TX_CONTINUE;
949 }
950 
951 static ieee80211_tx_result debug_noinline
952 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
953 {
954 	struct sk_buff *skb = tx->skb;
955 
956 	if (!tx->sta)
957 		return TX_CONTINUE;
958 
959 	tx->sta->tx_packets++;
960 	do {
961 		tx->sta->tx_fragments++;
962 		tx->sta->tx_bytes += skb->len;
963 	} while ((skb = skb->next));
964 
965 	return TX_CONTINUE;
966 }
967 
968 static ieee80211_tx_result debug_noinline
969 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
970 {
971 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
972 
973 	if (!tx->key)
974 		return TX_CONTINUE;
975 
976 	switch (tx->key->conf.cipher) {
977 	case WLAN_CIPHER_SUITE_WEP40:
978 	case WLAN_CIPHER_SUITE_WEP104:
979 		return ieee80211_crypto_wep_encrypt(tx);
980 	case WLAN_CIPHER_SUITE_TKIP:
981 		return ieee80211_crypto_tkip_encrypt(tx);
982 	case WLAN_CIPHER_SUITE_CCMP:
983 		return ieee80211_crypto_ccmp_encrypt(tx);
984 	case WLAN_CIPHER_SUITE_AES_CMAC:
985 		return ieee80211_crypto_aes_cmac_encrypt(tx);
986 	default:
987 		/* handle hw-only algorithm */
988 		if (info->control.hw_key) {
989 			ieee80211_tx_set_protected(tx);
990 			return TX_CONTINUE;
991 		}
992 		break;
993 
994 	}
995 
996 	return TX_DROP;
997 }
998 
999 static ieee80211_tx_result debug_noinline
1000 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1001 {
1002 	struct sk_buff *skb = tx->skb;
1003 	struct ieee80211_hdr *hdr;
1004 	int next_len;
1005 	bool group_addr;
1006 
1007 	do {
1008 		hdr = (void *) skb->data;
1009 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1010 			break; /* must not overwrite AID */
1011 		next_len = skb->next ? skb->next->len : 0;
1012 		group_addr = is_multicast_ether_addr(hdr->addr1);
1013 
1014 		hdr->duration_id =
1015 			ieee80211_duration(tx, group_addr, next_len);
1016 	} while ((skb = skb->next));
1017 
1018 	return TX_CONTINUE;
1019 }
1020 
1021 /* actual transmit path */
1022 
1023 /*
1024  * deal with packet injection down monitor interface
1025  * with Radiotap Header -- only called for monitor mode interface
1026  */
1027 static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
1028 					  struct sk_buff *skb)
1029 {
1030 	/*
1031 	 * this is the moment to interpret and discard the radiotap header that
1032 	 * must be at the start of the packet injected in Monitor mode
1033 	 *
1034 	 * Need to take some care with endian-ness since radiotap
1035 	 * args are little-endian
1036 	 */
1037 
1038 	struct ieee80211_radiotap_iterator iterator;
1039 	struct ieee80211_radiotap_header *rthdr =
1040 		(struct ieee80211_radiotap_header *) skb->data;
1041 	struct ieee80211_supported_band *sband;
1042 	bool hw_frag;
1043 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1044 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1045 						   NULL);
1046 
1047 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
1048 
1049 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1050 	tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1051 
1052 	/* packet is fragmented in HW if we have a non-NULL driver callback */
1053 	hw_frag = (tx->local->ops->set_frag_threshold != NULL);
1054 
1055 	/*
1056 	 * for every radiotap entry that is present
1057 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1058 	 * entries present, or -EINVAL on error)
1059 	 */
1060 
1061 	while (!ret) {
1062 		ret = ieee80211_radiotap_iterator_next(&iterator);
1063 
1064 		if (ret)
1065 			continue;
1066 
1067 		/* see if this argument is something we can use */
1068 		switch (iterator.this_arg_index) {
1069 		/*
1070 		 * You must take care when dereferencing iterator.this_arg
1071 		 * for multibyte types... the pointer is not aligned.  Use
1072 		 * get_unaligned((type *)iterator.this_arg) to dereference
1073 		 * iterator.this_arg for type "type" safely on all arches.
1074 		*/
1075 		case IEEE80211_RADIOTAP_FLAGS:
1076 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1077 				/*
1078 				 * this indicates that the skb we have been
1079 				 * handed has the 32-bit FCS CRC at the end...
1080 				 * we should react to that by snipping it off
1081 				 * because it will be recomputed and added
1082 				 * on transmission
1083 				 */
1084 				if (skb->len < (iterator._max_length + FCS_LEN))
1085 					return false;
1086 
1087 				skb_trim(skb, skb->len - FCS_LEN);
1088 			}
1089 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1090 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1091 			if ((*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG) &&
1092 								!hw_frag)
1093 				tx->flags |= IEEE80211_TX_FRAGMENTED;
1094 			break;
1095 
1096 		/*
1097 		 * Please update the file
1098 		 * Documentation/networking/mac80211-injection.txt
1099 		 * when parsing new fields here.
1100 		 */
1101 
1102 		default:
1103 			break;
1104 		}
1105 	}
1106 
1107 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1108 		return false;
1109 
1110 	/*
1111 	 * remove the radiotap header
1112 	 * iterator->_max_length was sanity-checked against
1113 	 * skb->len by iterator init
1114 	 */
1115 	skb_pull(skb, iterator._max_length);
1116 
1117 	return true;
1118 }
1119 
1120 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1121 				  struct sk_buff *skb,
1122 				  struct ieee80211_tx_info *info,
1123 				  struct tid_ampdu_tx *tid_tx,
1124 				  int tid)
1125 {
1126 	bool queued = false;
1127 
1128 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1129 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1130 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1131 		/*
1132 		 * nothing -- this aggregation session is being started
1133 		 * but that might still fail with the driver
1134 		 */
1135 	} else {
1136 		spin_lock(&tx->sta->lock);
1137 		/*
1138 		 * Need to re-check now, because we may get here
1139 		 *
1140 		 *  1) in the window during which the setup is actually
1141 		 *     already done, but not marked yet because not all
1142 		 *     packets are spliced over to the driver pending
1143 		 *     queue yet -- if this happened we acquire the lock
1144 		 *     either before or after the splice happens, but
1145 		 *     need to recheck which of these cases happened.
1146 		 *
1147 		 *  2) during session teardown, if the OPERATIONAL bit
1148 		 *     was cleared due to the teardown but the pointer
1149 		 *     hasn't been assigned NULL yet (or we loaded it
1150 		 *     before it was assigned) -- in this case it may
1151 		 *     now be NULL which means we should just let the
1152 		 *     packet pass through because splicing the frames
1153 		 *     back is already done.
1154 		 */
1155 		tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
1156 
1157 		if (!tid_tx) {
1158 			/* do nothing, let packet pass through */
1159 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1160 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1161 		} else {
1162 			queued = true;
1163 			info->control.vif = &tx->sdata->vif;
1164 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1165 			__skb_queue_tail(&tid_tx->pending, skb);
1166 		}
1167 		spin_unlock(&tx->sta->lock);
1168 	}
1169 
1170 	return queued;
1171 }
1172 
1173 /*
1174  * initialises @tx
1175  */
1176 static ieee80211_tx_result
1177 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1178 		     struct ieee80211_tx_data *tx,
1179 		     struct sk_buff *skb)
1180 {
1181 	struct ieee80211_local *local = sdata->local;
1182 	struct ieee80211_hdr *hdr;
1183 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1184 	int hdrlen, tid;
1185 	u8 *qc;
1186 
1187 	memset(tx, 0, sizeof(*tx));
1188 	tx->skb = skb;
1189 	tx->local = local;
1190 	tx->sdata = sdata;
1191 	tx->channel = local->hw.conf.channel;
1192 	/*
1193 	 * Set this flag (used below to indicate "automatic fragmentation"),
1194 	 * it will be cleared/left by radiotap as desired.
1195 	 * Only valid when fragmentation is done by the stack.
1196 	 */
1197 	if (!local->ops->set_frag_threshold)
1198 		tx->flags |= IEEE80211_TX_FRAGMENTED;
1199 
1200 	/* process and remove the injection radiotap header */
1201 	if (unlikely(info->flags & IEEE80211_TX_INTFL_HAS_RADIOTAP)) {
1202 		if (!__ieee80211_parse_tx_radiotap(tx, skb))
1203 			return TX_DROP;
1204 
1205 		/*
1206 		 * __ieee80211_parse_tx_radiotap has now removed
1207 		 * the radiotap header that was present and pre-filled
1208 		 * 'tx' with tx control information.
1209 		 */
1210 		info->flags &= ~IEEE80211_TX_INTFL_HAS_RADIOTAP;
1211 	}
1212 
1213 	/*
1214 	 * If this flag is set to true anywhere, and we get here,
1215 	 * we are doing the needed processing, so remove the flag
1216 	 * now.
1217 	 */
1218 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1219 
1220 	hdr = (struct ieee80211_hdr *) skb->data;
1221 
1222 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1223 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1224 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1225 			return TX_DROP;
1226 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED) {
1227 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1228 	}
1229 	if (!tx->sta)
1230 		tx->sta = sta_info_get(sdata, hdr->addr1);
1231 
1232 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1233 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1234 		struct tid_ampdu_tx *tid_tx;
1235 
1236 		qc = ieee80211_get_qos_ctl(hdr);
1237 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1238 
1239 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1240 		if (tid_tx) {
1241 			bool queued;
1242 
1243 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1244 						       tid_tx, tid);
1245 
1246 			if (unlikely(queued))
1247 				return TX_QUEUED;
1248 		}
1249 	}
1250 
1251 	if (is_multicast_ether_addr(hdr->addr1)) {
1252 		tx->flags &= ~IEEE80211_TX_UNICAST;
1253 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1254 	} else {
1255 		tx->flags |= IEEE80211_TX_UNICAST;
1256 		if (unlikely(local->wifi_wme_noack_test))
1257 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
1258 		else
1259 			info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1260 	}
1261 
1262 	if (tx->flags & IEEE80211_TX_FRAGMENTED) {
1263 		if ((tx->flags & IEEE80211_TX_UNICAST) &&
1264 		    skb->len + FCS_LEN > local->hw.wiphy->frag_threshold &&
1265 		    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1266 			tx->flags |= IEEE80211_TX_FRAGMENTED;
1267 		else
1268 			tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1269 	}
1270 
1271 	if (!tx->sta)
1272 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1273 	else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1274 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1275 
1276 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1277 	if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
1278 		u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
1279 		tx->ethertype = (pos[0] << 8) | pos[1];
1280 	}
1281 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1282 
1283 	return TX_CONTINUE;
1284 }
1285 
1286 static int __ieee80211_tx(struct ieee80211_local *local,
1287 			  struct sk_buff **skbp,
1288 			  struct sta_info *sta,
1289 			  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 ret, 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 		ret = IEEE80211_TX_OK;
1304 		if (local->queue_stop_reasons[q] ||
1305 		    (!txpending && !skb_queue_empty(&local->pending[q])))
1306 			ret = IEEE80211_TX_PENDING;
1307 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1308 		if (ret != IEEE80211_TX_OK)
1309 			return ret;
1310 
1311 		info = IEEE80211_SKB_CB(skb);
1312 
1313 		if (fragm)
1314 			info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1315 					 IEEE80211_TX_CTL_FIRST_FRAGMENT);
1316 
1317 		next = skb->next;
1318 		len = skb->len;
1319 
1320 		if (next)
1321 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
1322 
1323 		sdata = vif_to_sdata(info->control.vif);
1324 
1325 		switch (sdata->vif.type) {
1326 		case NL80211_IFTYPE_MONITOR:
1327 			info->control.vif = NULL;
1328 			break;
1329 		case NL80211_IFTYPE_AP_VLAN:
1330 			info->control.vif = &container_of(sdata->bss,
1331 				struct ieee80211_sub_if_data, u.ap)->vif;
1332 			break;
1333 		default:
1334 			/* keep */
1335 			break;
1336 		}
1337 
1338 		if (sta && sta->uploaded)
1339 			info->control.sta = &sta->sta;
1340 		else
1341 			info->control.sta = NULL;
1342 
1343 		fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1344 		ret = drv_tx(local, skb);
1345 		if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
1346 			dev_kfree_skb(skb);
1347 			ret = NETDEV_TX_OK;
1348 		}
1349 		if (ret != NETDEV_TX_OK) {
1350 			info->control.vif = &sdata->vif;
1351 			return IEEE80211_TX_AGAIN;
1352 		}
1353 
1354 		ieee80211_tpt_led_trig_tx(local, fc, len);
1355 		*skbp = skb = next;
1356 		ieee80211_led_tx(local, 1);
1357 		fragm = true;
1358 	}
1359 
1360 	return IEEE80211_TX_OK;
1361 }
1362 
1363 /*
1364  * Invoke TX handlers, return 0 on success and non-zero if the
1365  * frame was dropped or queued.
1366  */
1367 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1368 {
1369 	struct sk_buff *skb = tx->skb;
1370 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1371 	ieee80211_tx_result res = TX_DROP;
1372 
1373 #define CALL_TXH(txh) \
1374 	do {				\
1375 		res = txh(tx);		\
1376 		if (res != TX_CONTINUE)	\
1377 			goto txh_done;	\
1378 	} while (0)
1379 
1380 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1381 	CALL_TXH(ieee80211_tx_h_check_assoc);
1382 	CALL_TXH(ieee80211_tx_h_ps_buf);
1383 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1384 	CALL_TXH(ieee80211_tx_h_select_key);
1385 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1386 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1387 
1388 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION))
1389 		goto txh_done;
1390 
1391 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1392 	CALL_TXH(ieee80211_tx_h_sequence);
1393 	CALL_TXH(ieee80211_tx_h_fragment);
1394 	/* handlers after fragment must be aware of tx info fragmentation! */
1395 	CALL_TXH(ieee80211_tx_h_stats);
1396 	CALL_TXH(ieee80211_tx_h_encrypt);
1397 	CALL_TXH(ieee80211_tx_h_calculate_duration);
1398 #undef CALL_TXH
1399 
1400  txh_done:
1401 	if (unlikely(res == TX_DROP)) {
1402 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1403 		while (skb) {
1404 			struct sk_buff *next;
1405 
1406 			next = skb->next;
1407 			dev_kfree_skb(skb);
1408 			skb = next;
1409 		}
1410 		return -1;
1411 	} else if (unlikely(res == TX_QUEUED)) {
1412 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1413 		return -1;
1414 	}
1415 
1416 	return 0;
1417 }
1418 
1419 static void ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1420 			 struct sk_buff *skb, bool txpending)
1421 {
1422 	struct ieee80211_local *local = sdata->local;
1423 	struct ieee80211_tx_data tx;
1424 	ieee80211_tx_result res_prepare;
1425 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1426 	struct sk_buff *next;
1427 	unsigned long flags;
1428 	int ret, retries;
1429 	u16 queue;
1430 
1431 	queue = skb_get_queue_mapping(skb);
1432 
1433 	if (unlikely(skb->len < 10)) {
1434 		dev_kfree_skb(skb);
1435 		return;
1436 	}
1437 
1438 	rcu_read_lock();
1439 
1440 	/* initialises tx */
1441 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1442 
1443 	if (unlikely(res_prepare == TX_DROP)) {
1444 		dev_kfree_skb(skb);
1445 		rcu_read_unlock();
1446 		return;
1447 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1448 		rcu_read_unlock();
1449 		return;
1450 	}
1451 
1452 	tx.channel = local->hw.conf.channel;
1453 	info->band = tx.channel->band;
1454 
1455 	if (invoke_tx_handlers(&tx))
1456 		goto out;
1457 
1458 	retries = 0;
1459  retry:
1460 	ret = __ieee80211_tx(local, &tx.skb, tx.sta, txpending);
1461 	switch (ret) {
1462 	case IEEE80211_TX_OK:
1463 		break;
1464 	case IEEE80211_TX_AGAIN:
1465 		/*
1466 		 * Since there are no fragmented frames on A-MPDU
1467 		 * queues, there's no reason for a driver to reject
1468 		 * a frame there, warn and drop it.
1469 		 */
1470 		if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
1471 			goto drop;
1472 		/* fall through */
1473 	case IEEE80211_TX_PENDING:
1474 		skb = tx.skb;
1475 
1476 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1477 
1478 		if (local->queue_stop_reasons[queue] ||
1479 		    !skb_queue_empty(&local->pending[queue])) {
1480 			/*
1481 			 * if queue is stopped, queue up frames for later
1482 			 * transmission from the tasklet
1483 			 */
1484 			do {
1485 				next = skb->next;
1486 				skb->next = NULL;
1487 				if (unlikely(txpending))
1488 					__skb_queue_head(&local->pending[queue],
1489 							 skb);
1490 				else
1491 					__skb_queue_tail(&local->pending[queue],
1492 							 skb);
1493 			} while ((skb = next));
1494 
1495 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1496 					       flags);
1497 		} else {
1498 			/*
1499 			 * otherwise retry, but this is a race condition or
1500 			 * a driver bug (which we warn about if it persists)
1501 			 */
1502 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1503 					       flags);
1504 
1505 			retries++;
1506 			if (WARN(retries > 10, "tx refused but queue active\n"))
1507 				goto drop;
1508 			goto retry;
1509 		}
1510 	}
1511  out:
1512 	rcu_read_unlock();
1513 	return;
1514 
1515  drop:
1516 	rcu_read_unlock();
1517 
1518 	skb = tx.skb;
1519 	while (skb) {
1520 		next = skb->next;
1521 		dev_kfree_skb(skb);
1522 		skb = next;
1523 	}
1524 }
1525 
1526 /* device xmit handlers */
1527 
1528 static int ieee80211_skb_resize(struct ieee80211_local *local,
1529 				struct sk_buff *skb,
1530 				int head_need, bool may_encrypt)
1531 {
1532 	int tail_need = 0;
1533 
1534 	/*
1535 	 * This could be optimised, devices that do full hardware
1536 	 * crypto (including TKIP MMIC) need no tailroom... But we
1537 	 * have no drivers for such devices currently.
1538 	 */
1539 	if (may_encrypt) {
1540 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1541 		tail_need -= skb_tailroom(skb);
1542 		tail_need = max_t(int, tail_need, 0);
1543 	}
1544 
1545 	if (head_need || tail_need) {
1546 		/* Sorry. Can't account for this any more */
1547 		skb_orphan(skb);
1548 	}
1549 
1550 	if (skb_header_cloned(skb))
1551 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1552 	else if (head_need || tail_need)
1553 		I802_DEBUG_INC(local->tx_expand_skb_head);
1554 	else
1555 		return 0;
1556 
1557 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1558 		wiphy_debug(local->hw.wiphy,
1559 			    "failed to reallocate TX buffer\n");
1560 		return -ENOMEM;
1561 	}
1562 
1563 	/* update truesize too */
1564 	skb->truesize += head_need + tail_need;
1565 
1566 	return 0;
1567 }
1568 
1569 static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
1570 			   struct sk_buff *skb)
1571 {
1572 	struct ieee80211_local *local = sdata->local;
1573 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1574 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1575 	struct ieee80211_sub_if_data *tmp_sdata;
1576 	int headroom;
1577 	bool may_encrypt;
1578 
1579 	rcu_read_lock();
1580 
1581 	if (unlikely(sdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1582 		int hdrlen;
1583 		u16 len_rthdr;
1584 
1585 		info->flags |= IEEE80211_TX_CTL_INJECTED |
1586 			       IEEE80211_TX_INTFL_HAS_RADIOTAP;
1587 
1588 		len_rthdr = ieee80211_get_radiotap_len(skb->data);
1589 		hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1590 		hdrlen = ieee80211_hdrlen(hdr->frame_control);
1591 
1592 		/* check the header is complete in the frame */
1593 		if (likely(skb->len >= len_rthdr + hdrlen)) {
1594 			/*
1595 			 * We process outgoing injected frames that have a
1596 			 * local address we handle as though they are our
1597 			 * own frames.
1598 			 * This code here isn't entirely correct, the local
1599 			 * MAC address is not necessarily enough to find
1600 			 * the interface to use; for that proper VLAN/WDS
1601 			 * support we will need a different mechanism.
1602 			 */
1603 
1604 			list_for_each_entry_rcu(tmp_sdata, &local->interfaces,
1605 						list) {
1606 				if (!ieee80211_sdata_running(tmp_sdata))
1607 					continue;
1608 				if (tmp_sdata->vif.type ==
1609 				    NL80211_IFTYPE_MONITOR ||
1610 				    tmp_sdata->vif.type ==
1611 				    NL80211_IFTYPE_AP_VLAN ||
1612 					tmp_sdata->vif.type ==
1613 				    NL80211_IFTYPE_WDS)
1614 					continue;
1615 				if (compare_ether_addr(tmp_sdata->vif.addr,
1616 						       hdr->addr2) == 0) {
1617 					sdata = tmp_sdata;
1618 					break;
1619 				}
1620 			}
1621 		}
1622 	}
1623 
1624 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1625 
1626 	headroom = local->tx_headroom;
1627 	if (may_encrypt)
1628 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1629 	headroom -= skb_headroom(skb);
1630 	headroom = max_t(int, 0, headroom);
1631 
1632 	if (ieee80211_skb_resize(local, skb, headroom, may_encrypt)) {
1633 		dev_kfree_skb(skb);
1634 		rcu_read_unlock();
1635 		return;
1636 	}
1637 
1638 	hdr = (struct ieee80211_hdr *) skb->data;
1639 	info->control.vif = &sdata->vif;
1640 
1641 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1642 	    ieee80211_is_data(hdr->frame_control) &&
1643 		!is_multicast_ether_addr(hdr->addr1))
1644 			if (mesh_nexthop_lookup(skb, sdata)) {
1645 				/* skb queued: don't free */
1646 				rcu_read_unlock();
1647 				return;
1648 			}
1649 
1650 	ieee80211_set_qos_hdr(local, skb);
1651 	ieee80211_tx(sdata, skb, false);
1652 	rcu_read_unlock();
1653 }
1654 
1655 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1656 					 struct net_device *dev)
1657 {
1658 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1659 	struct ieee80211_channel *chan = local->hw.conf.channel;
1660 	struct ieee80211_radiotap_header *prthdr =
1661 		(struct ieee80211_radiotap_header *)skb->data;
1662 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1663 	u16 len_rthdr;
1664 
1665 	/*
1666 	 * Frame injection is not allowed if beaconing is not allowed
1667 	 * or if we need radar detection. Beaconing is usually not allowed when
1668 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1669 	 * Passive scan is also used in world regulatory domains where
1670 	 * your country is not known and as such it should be treated as
1671 	 * NO TX unless the channel is explicitly allowed in which case
1672 	 * your current regulatory domain would not have the passive scan
1673 	 * flag.
1674 	 *
1675 	 * Since AP mode uses monitor interfaces to inject/TX management
1676 	 * frames we can make AP mode the exception to this rule once it
1677 	 * supports radar detection as its implementation can deal with
1678 	 * radar detection by itself. We can do that later by adding a
1679 	 * monitor flag interfaces used for AP support.
1680 	 */
1681 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1682 	     IEEE80211_CHAN_PASSIVE_SCAN)))
1683 		goto fail;
1684 
1685 	/* check for not even having the fixed radiotap header part */
1686 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1687 		goto fail; /* too short to be possibly valid */
1688 
1689 	/* is it a header version we can trust to find length from? */
1690 	if (unlikely(prthdr->it_version))
1691 		goto fail; /* only version 0 is supported */
1692 
1693 	/* then there must be a radiotap header with a length we can use */
1694 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1695 
1696 	/* does the skb contain enough to deliver on the alleged length? */
1697 	if (unlikely(skb->len < len_rthdr))
1698 		goto fail; /* skb too short for claimed rt header extent */
1699 
1700 	/*
1701 	 * fix up the pointers accounting for the radiotap
1702 	 * header still being in there.  We are being given
1703 	 * a precooked IEEE80211 header so no need for
1704 	 * normal processing
1705 	 */
1706 	skb_set_mac_header(skb, len_rthdr);
1707 	/*
1708 	 * these are just fixed to the end of the rt area since we
1709 	 * don't have any better information and at this point, nobody cares
1710 	 */
1711 	skb_set_network_header(skb, len_rthdr);
1712 	skb_set_transport_header(skb, len_rthdr);
1713 
1714 	memset(info, 0, sizeof(*info));
1715 
1716 	info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1717 
1718 	/* pass the radiotap header up to xmit */
1719 	ieee80211_xmit(IEEE80211_DEV_TO_SUB_IF(dev), skb);
1720 	return NETDEV_TX_OK;
1721 
1722 fail:
1723 	dev_kfree_skb(skb);
1724 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1725 }
1726 
1727 /**
1728  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1729  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1730  * @skb: packet to be sent
1731  * @dev: incoming interface
1732  *
1733  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1734  * not be freed, and caller is responsible for either retrying later or freeing
1735  * skb).
1736  *
1737  * This function takes in an Ethernet header and encapsulates it with suitable
1738  * IEEE 802.11 header based on which interface the packet is coming in. The
1739  * encapsulated packet will then be passed to master interface, wlan#.11, for
1740  * transmission (through low-level driver).
1741  */
1742 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1743 				    struct net_device *dev)
1744 {
1745 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1746 	struct ieee80211_local *local = sdata->local;
1747 	struct ieee80211_tx_info *info;
1748 	int ret = NETDEV_TX_BUSY, head_need;
1749 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1750 	__le16 fc;
1751 	struct ieee80211_hdr hdr;
1752 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1753 	struct mesh_path *mppath = NULL;
1754 	const u8 *encaps_data;
1755 	int encaps_len, skip_header_bytes;
1756 	int nh_pos, h_pos;
1757 	struct sta_info *sta = NULL;
1758 	u32 sta_flags = 0;
1759 	struct sk_buff *tmp_skb;
1760 
1761 	if (unlikely(skb->len < ETH_HLEN)) {
1762 		ret = NETDEV_TX_OK;
1763 		goto fail;
1764 	}
1765 
1766 	/* convert Ethernet header to proper 802.11 header (based on
1767 	 * operation mode) */
1768 	ethertype = (skb->data[12] << 8) | skb->data[13];
1769 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1770 
1771 	switch (sdata->vif.type) {
1772 	case NL80211_IFTYPE_AP_VLAN:
1773 		rcu_read_lock();
1774 		sta = rcu_dereference(sdata->u.vlan.sta);
1775 		if (sta) {
1776 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1777 			/* RA TA DA SA */
1778 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1779 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1780 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1781 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1782 			hdrlen = 30;
1783 			sta_flags = get_sta_flags(sta);
1784 		}
1785 		rcu_read_unlock();
1786 		if (sta)
1787 			break;
1788 		/* fall through */
1789 	case NL80211_IFTYPE_AP:
1790 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1791 		/* DA BSSID SA */
1792 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1793 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1794 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1795 		hdrlen = 24;
1796 		break;
1797 	case NL80211_IFTYPE_WDS:
1798 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1799 		/* RA TA DA SA */
1800 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1801 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1802 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1803 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1804 		hdrlen = 30;
1805 		break;
1806 #ifdef CONFIG_MAC80211_MESH
1807 	case NL80211_IFTYPE_MESH_POINT:
1808 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1809 			/* Do not send frames with mesh_ttl == 0 */
1810 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1811 			ret = NETDEV_TX_OK;
1812 			goto fail;
1813 		}
1814 		if (!is_multicast_ether_addr(skb->data))
1815 			mppath = mpp_path_lookup(skb->data, sdata);
1816 
1817 		/*
1818 		 * Do not use address extension, if it is a packet from
1819 		 * the same interface and the destination is not being
1820 		 * proxied by any other mest point.
1821 		 */
1822 		if (compare_ether_addr(sdata->vif.addr,
1823 				       skb->data + ETH_ALEN) == 0 &&
1824 		    (!mppath || !compare_ether_addr(mppath->mpp, skb->data))) {
1825 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1826 					skb->data, skb->data + ETH_ALEN);
1827 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1828 					sdata, NULL, NULL);
1829 		} else {
1830 			/* packet from other interface */
1831 			int is_mesh_mcast = 1;
1832 			const u8 *mesh_da;
1833 
1834 			rcu_read_lock();
1835 			if (is_multicast_ether_addr(skb->data))
1836 				/* DA TA mSA AE:SA */
1837 				mesh_da = skb->data;
1838 			else {
1839 				static const u8 bcast[ETH_ALEN] =
1840 					{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1841 				if (mppath) {
1842 					/* RA TA mDA mSA AE:DA SA */
1843 					mesh_da = mppath->mpp;
1844 					is_mesh_mcast = 0;
1845 				} else {
1846 					/* DA TA mSA AE:SA */
1847 					mesh_da = bcast;
1848 				}
1849 			}
1850 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1851 					mesh_da, sdata->vif.addr);
1852 			rcu_read_unlock();
1853 			if (is_mesh_mcast)
1854 				meshhdrlen =
1855 					ieee80211_new_mesh_header(&mesh_hdr,
1856 							sdata,
1857 							skb->data + ETH_ALEN,
1858 							NULL);
1859 			else
1860 				meshhdrlen =
1861 					ieee80211_new_mesh_header(&mesh_hdr,
1862 							sdata,
1863 							skb->data,
1864 							skb->data + ETH_ALEN);
1865 
1866 		}
1867 		break;
1868 #endif
1869 	case NL80211_IFTYPE_STATION:
1870 		memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1871 		if (sdata->u.mgd.use_4addr &&
1872 		    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1873 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1874 			/* RA TA DA SA */
1875 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1876 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1877 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1878 			hdrlen = 30;
1879 		} else {
1880 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1881 			/* BSSID SA DA */
1882 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1883 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1884 			hdrlen = 24;
1885 		}
1886 		break;
1887 	case NL80211_IFTYPE_ADHOC:
1888 		/* DA SA BSSID */
1889 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1890 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1891 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1892 		hdrlen = 24;
1893 		break;
1894 	default:
1895 		ret = NETDEV_TX_OK;
1896 		goto fail;
1897 	}
1898 
1899 	/*
1900 	 * There's no need to try to look up the destination
1901 	 * if it is a multicast address (which can only happen
1902 	 * in AP mode)
1903 	 */
1904 	if (!is_multicast_ether_addr(hdr.addr1)) {
1905 		rcu_read_lock();
1906 		sta = sta_info_get(sdata, hdr.addr1);
1907 		if (sta)
1908 			sta_flags = get_sta_flags(sta);
1909 		rcu_read_unlock();
1910 	}
1911 
1912 	/* receiver and we are QoS enabled, use a QoS type frame */
1913 	if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1914 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1915 		hdrlen += 2;
1916 	}
1917 
1918 	/*
1919 	 * Drop unicast frames to unauthorised stations unless they are
1920 	 * EAPOL frames from the local station.
1921 	 */
1922 	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
1923 		unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1924 		      !(sta_flags & WLAN_STA_AUTHORIZED) &&
1925 		      !(cpu_to_be16(ethertype) == sdata->control_port_protocol &&
1926 		       compare_ether_addr(sdata->vif.addr,
1927 					  skb->data + ETH_ALEN) == 0))) {
1928 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1929 		if (net_ratelimit())
1930 			printk(KERN_DEBUG "%s: dropped frame to %pM"
1931 			       " (unauthorized port)\n", dev->name,
1932 			       hdr.addr1);
1933 #endif
1934 
1935 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1936 
1937 		ret = NETDEV_TX_OK;
1938 		goto fail;
1939 	}
1940 
1941 	/*
1942 	 * If the skb is shared we need to obtain our own copy.
1943 	 */
1944 	if (skb_shared(skb)) {
1945 		tmp_skb = skb;
1946 		skb = skb_clone(skb, GFP_ATOMIC);
1947 		kfree_skb(tmp_skb);
1948 
1949 		if (!skb) {
1950 			ret = NETDEV_TX_OK;
1951 			goto fail;
1952 		}
1953 	}
1954 
1955 	hdr.frame_control = fc;
1956 	hdr.duration_id = 0;
1957 	hdr.seq_ctrl = 0;
1958 
1959 	skip_header_bytes = ETH_HLEN;
1960 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
1961 		encaps_data = bridge_tunnel_header;
1962 		encaps_len = sizeof(bridge_tunnel_header);
1963 		skip_header_bytes -= 2;
1964 	} else if (ethertype >= 0x600) {
1965 		encaps_data = rfc1042_header;
1966 		encaps_len = sizeof(rfc1042_header);
1967 		skip_header_bytes -= 2;
1968 	} else {
1969 		encaps_data = NULL;
1970 		encaps_len = 0;
1971 	}
1972 
1973 	nh_pos = skb_network_header(skb) - skb->data;
1974 	h_pos = skb_transport_header(skb) - skb->data;
1975 
1976 	skb_pull(skb, skip_header_bytes);
1977 	nh_pos -= skip_header_bytes;
1978 	h_pos -= skip_header_bytes;
1979 
1980 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1981 
1982 	/*
1983 	 * So we need to modify the skb header and hence need a copy of
1984 	 * that. The head_need variable above doesn't, so far, include
1985 	 * the needed header space that we don't need right away. If we
1986 	 * can, then we don't reallocate right now but only after the
1987 	 * frame arrives at the master device (if it does...)
1988 	 *
1989 	 * If we cannot, however, then we will reallocate to include all
1990 	 * the ever needed space. Also, if we need to reallocate it anyway,
1991 	 * make it big enough for everything we may ever need.
1992 	 */
1993 
1994 	if (head_need > 0 || skb_cloned(skb)) {
1995 		head_need += IEEE80211_ENCRYPT_HEADROOM;
1996 		head_need += local->tx_headroom;
1997 		head_need = max_t(int, 0, head_need);
1998 		if (ieee80211_skb_resize(local, skb, head_need, true))
1999 			goto fail;
2000 	}
2001 
2002 	if (encaps_data) {
2003 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2004 		nh_pos += encaps_len;
2005 		h_pos += encaps_len;
2006 	}
2007 
2008 #ifdef CONFIG_MAC80211_MESH
2009 	if (meshhdrlen > 0) {
2010 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2011 		nh_pos += meshhdrlen;
2012 		h_pos += meshhdrlen;
2013 	}
2014 #endif
2015 
2016 	if (ieee80211_is_data_qos(fc)) {
2017 		__le16 *qos_control;
2018 
2019 		qos_control = (__le16*) skb_push(skb, 2);
2020 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2021 		/*
2022 		 * Maybe we could actually set some fields here, for now just
2023 		 * initialise to zero to indicate no special operation.
2024 		 */
2025 		*qos_control = 0;
2026 	} else
2027 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2028 
2029 	nh_pos += hdrlen;
2030 	h_pos += hdrlen;
2031 
2032 	dev->stats.tx_packets++;
2033 	dev->stats.tx_bytes += skb->len;
2034 
2035 	/* Update skb pointers to various headers since this modified frame
2036 	 * is going to go through Linux networking code that may potentially
2037 	 * need things like pointer to IP header. */
2038 	skb_set_mac_header(skb, 0);
2039 	skb_set_network_header(skb, nh_pos);
2040 	skb_set_transport_header(skb, h_pos);
2041 
2042 	info = IEEE80211_SKB_CB(skb);
2043 	memset(info, 0, sizeof(*info));
2044 
2045 	dev->trans_start = jiffies;
2046 	ieee80211_xmit(sdata, skb);
2047 
2048 	return NETDEV_TX_OK;
2049 
2050  fail:
2051 	if (ret == NETDEV_TX_OK)
2052 		dev_kfree_skb(skb);
2053 
2054 	return ret;
2055 }
2056 
2057 
2058 /*
2059  * ieee80211_clear_tx_pending may not be called in a context where
2060  * it is possible that it packets could come in again.
2061  */
2062 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2063 {
2064 	int i;
2065 
2066 	for (i = 0; i < local->hw.queues; i++)
2067 		skb_queue_purge(&local->pending[i]);
2068 }
2069 
2070 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2071 				     struct sk_buff *skb)
2072 {
2073 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2074 	struct ieee80211_sub_if_data *sdata;
2075 	struct sta_info *sta;
2076 	struct ieee80211_hdr *hdr;
2077 	int ret;
2078 	bool result = true;
2079 
2080 	sdata = vif_to_sdata(info->control.vif);
2081 
2082 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2083 		ieee80211_tx(sdata, skb, true);
2084 	} else {
2085 		hdr = (struct ieee80211_hdr *)skb->data;
2086 		sta = sta_info_get(sdata, hdr->addr1);
2087 
2088 		ret = __ieee80211_tx(local, &skb, sta, true);
2089 		if (ret != IEEE80211_TX_OK)
2090 			result = false;
2091 	}
2092 
2093 	return result;
2094 }
2095 
2096 /*
2097  * Transmit all pending packets. Called from tasklet.
2098  */
2099 void ieee80211_tx_pending(unsigned long data)
2100 {
2101 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2102 	struct ieee80211_sub_if_data *sdata;
2103 	unsigned long flags;
2104 	int i;
2105 	bool txok;
2106 
2107 	rcu_read_lock();
2108 
2109 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2110 	for (i = 0; i < local->hw.queues; i++) {
2111 		/*
2112 		 * If queue is stopped by something other than due to pending
2113 		 * frames, or we have no pending frames, proceed to next queue.
2114 		 */
2115 		if (local->queue_stop_reasons[i] ||
2116 		    skb_queue_empty(&local->pending[i]))
2117 			continue;
2118 
2119 		while (!skb_queue_empty(&local->pending[i])) {
2120 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2121 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2122 
2123 			if (WARN_ON(!info->control.vif)) {
2124 				kfree_skb(skb);
2125 				continue;
2126 			}
2127 
2128 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2129 						flags);
2130 
2131 			txok = ieee80211_tx_pending_skb(local, skb);
2132 			if (!txok)
2133 				__skb_queue_head(&local->pending[i], skb);
2134 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2135 					  flags);
2136 			if (!txok)
2137 				break;
2138 		}
2139 
2140 		if (skb_queue_empty(&local->pending[i]))
2141 			list_for_each_entry_rcu(sdata, &local->interfaces, list)
2142 				netif_wake_subqueue(sdata->dev, i);
2143 	}
2144 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2145 
2146 	rcu_read_unlock();
2147 }
2148 
2149 /* functions for drivers to get certain frames */
2150 
2151 static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
2152 				     struct sk_buff *skb,
2153 				     struct beacon_data *beacon)
2154 {
2155 	u8 *pos, *tim;
2156 	int aid0 = 0;
2157 	int i, have_bits = 0, n1, n2;
2158 
2159 	/* Generate bitmap for TIM only if there are any STAs in power save
2160 	 * mode. */
2161 	if (atomic_read(&bss->num_sta_ps) > 0)
2162 		/* in the hope that this is faster than
2163 		 * checking byte-for-byte */
2164 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2165 					  IEEE80211_MAX_AID+1);
2166 
2167 	if (bss->dtim_count == 0)
2168 		bss->dtim_count = beacon->dtim_period - 1;
2169 	else
2170 		bss->dtim_count--;
2171 
2172 	tim = pos = (u8 *) skb_put(skb, 6);
2173 	*pos++ = WLAN_EID_TIM;
2174 	*pos++ = 4;
2175 	*pos++ = bss->dtim_count;
2176 	*pos++ = beacon->dtim_period;
2177 
2178 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2179 		aid0 = 1;
2180 
2181 	if (have_bits) {
2182 		/* Find largest even number N1 so that bits numbered 1 through
2183 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2184 		 * (N2 + 1) x 8 through 2007 are 0. */
2185 		n1 = 0;
2186 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2187 			if (bss->tim[i]) {
2188 				n1 = i & 0xfe;
2189 				break;
2190 			}
2191 		}
2192 		n2 = n1;
2193 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2194 			if (bss->tim[i]) {
2195 				n2 = i;
2196 				break;
2197 			}
2198 		}
2199 
2200 		/* Bitmap control */
2201 		*pos++ = n1 | aid0;
2202 		/* Part Virt Bitmap */
2203 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2204 
2205 		tim[1] = n2 - n1 + 4;
2206 		skb_put(skb, n2 - n1);
2207 	} else {
2208 		*pos++ = aid0; /* Bitmap control */
2209 		*pos++ = 0; /* Part Virt Bitmap */
2210 	}
2211 }
2212 
2213 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2214 					 struct ieee80211_vif *vif,
2215 					 u16 *tim_offset, u16 *tim_length)
2216 {
2217 	struct ieee80211_local *local = hw_to_local(hw);
2218 	struct sk_buff *skb = NULL;
2219 	struct ieee80211_tx_info *info;
2220 	struct ieee80211_sub_if_data *sdata = NULL;
2221 	struct ieee80211_if_ap *ap = NULL;
2222 	struct beacon_data *beacon;
2223 	struct ieee80211_supported_band *sband;
2224 	enum ieee80211_band band = local->hw.conf.channel->band;
2225 	struct ieee80211_tx_rate_control txrc;
2226 
2227 	sband = local->hw.wiphy->bands[band];
2228 
2229 	rcu_read_lock();
2230 
2231 	sdata = vif_to_sdata(vif);
2232 
2233 	if (tim_offset)
2234 		*tim_offset = 0;
2235 	if (tim_length)
2236 		*tim_length = 0;
2237 
2238 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2239 		ap = &sdata->u.ap;
2240 		beacon = rcu_dereference(ap->beacon);
2241 		if (ap && beacon) {
2242 			/*
2243 			 * headroom, head length,
2244 			 * tail length and maximum TIM length
2245 			 */
2246 			skb = dev_alloc_skb(local->tx_headroom +
2247 					    beacon->head_len +
2248 					    beacon->tail_len + 256);
2249 			if (!skb)
2250 				goto out;
2251 
2252 			skb_reserve(skb, local->tx_headroom);
2253 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2254 			       beacon->head_len);
2255 
2256 			/*
2257 			 * Not very nice, but we want to allow the driver to call
2258 			 * ieee80211_beacon_get() as a response to the set_tim()
2259 			 * callback. That, however, is already invoked under the
2260 			 * sta_lock to guarantee consistent and race-free update
2261 			 * of the tim bitmap in mac80211 and the driver.
2262 			 */
2263 			if (local->tim_in_locked_section) {
2264 				ieee80211_beacon_add_tim(ap, skb, beacon);
2265 			} else {
2266 				unsigned long flags;
2267 
2268 				spin_lock_irqsave(&local->sta_lock, flags);
2269 				ieee80211_beacon_add_tim(ap, skb, beacon);
2270 				spin_unlock_irqrestore(&local->sta_lock, flags);
2271 			}
2272 
2273 			if (tim_offset)
2274 				*tim_offset = beacon->head_len;
2275 			if (tim_length)
2276 				*tim_length = skb->len - beacon->head_len;
2277 
2278 			if (beacon->tail)
2279 				memcpy(skb_put(skb, beacon->tail_len),
2280 				       beacon->tail, beacon->tail_len);
2281 		} else
2282 			goto out;
2283 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2284 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2285 		struct ieee80211_hdr *hdr;
2286 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2287 
2288 		if (!presp)
2289 			goto out;
2290 
2291 		skb = skb_copy(presp, GFP_ATOMIC);
2292 		if (!skb)
2293 			goto out;
2294 
2295 		hdr = (struct ieee80211_hdr *) skb->data;
2296 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2297 						 IEEE80211_STYPE_BEACON);
2298 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2299 		struct ieee80211_mgmt *mgmt;
2300 		u8 *pos;
2301 
2302 		/* headroom, head length, tail length and maximum TIM length */
2303 		skb = dev_alloc_skb(local->tx_headroom + 400 +
2304 				sdata->u.mesh.vendor_ie_len);
2305 		if (!skb)
2306 			goto out;
2307 
2308 		skb_reserve(skb, local->hw.extra_tx_headroom);
2309 		mgmt = (struct ieee80211_mgmt *)
2310 			skb_put(skb, 24 + sizeof(mgmt->u.beacon));
2311 		memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2312 		mgmt->frame_control =
2313 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2314 		memset(mgmt->da, 0xff, ETH_ALEN);
2315 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2316 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2317 		mgmt->u.beacon.beacon_int =
2318 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2319 		mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
2320 
2321 		pos = skb_put(skb, 2);
2322 		*pos++ = WLAN_EID_SSID;
2323 		*pos++ = 0x0;
2324 
2325 		mesh_mgmt_ies_add(skb, sdata);
2326 	} else {
2327 		WARN_ON(1);
2328 		goto out;
2329 	}
2330 
2331 	info = IEEE80211_SKB_CB(skb);
2332 
2333 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2334 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2335 	info->band = band;
2336 
2337 	memset(&txrc, 0, sizeof(txrc));
2338 	txrc.hw = hw;
2339 	txrc.sband = sband;
2340 	txrc.bss_conf = &sdata->vif.bss_conf;
2341 	txrc.skb = skb;
2342 	txrc.reported_rate.idx = -1;
2343 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2344 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2345 		txrc.max_rate_idx = -1;
2346 	else
2347 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2348 	txrc.bss = true;
2349 	rate_control_get_rate(sdata, NULL, &txrc);
2350 
2351 	info->control.vif = vif;
2352 
2353 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2354 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2355 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2356  out:
2357 	rcu_read_unlock();
2358 	return skb;
2359 }
2360 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2361 
2362 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2363 				     struct ieee80211_vif *vif)
2364 {
2365 	struct ieee80211_sub_if_data *sdata;
2366 	struct ieee80211_if_managed *ifmgd;
2367 	struct ieee80211_pspoll *pspoll;
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(*pspoll));
2379 	if (!skb) {
2380 		printk(KERN_DEBUG "%s: failed to allocate buffer for "
2381 		       "pspoll template\n", sdata->name);
2382 		return NULL;
2383 	}
2384 	skb_reserve(skb, local->hw.extra_tx_headroom);
2385 
2386 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2387 	memset(pspoll, 0, sizeof(*pspoll));
2388 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2389 					    IEEE80211_STYPE_PSPOLL);
2390 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2391 
2392 	/* aid in PS-Poll has its two MSBs each set to 1 */
2393 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2394 
2395 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2396 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2397 
2398 	return skb;
2399 }
2400 EXPORT_SYMBOL(ieee80211_pspoll_get);
2401 
2402 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2403 				       struct ieee80211_vif *vif)
2404 {
2405 	struct ieee80211_hdr_3addr *nullfunc;
2406 	struct ieee80211_sub_if_data *sdata;
2407 	struct ieee80211_if_managed *ifmgd;
2408 	struct ieee80211_local *local;
2409 	struct sk_buff *skb;
2410 
2411 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2412 		return NULL;
2413 
2414 	sdata = vif_to_sdata(vif);
2415 	ifmgd = &sdata->u.mgd;
2416 	local = sdata->local;
2417 
2418 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2419 	if (!skb) {
2420 		printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc "
2421 		       "template\n", sdata->name);
2422 		return NULL;
2423 	}
2424 	skb_reserve(skb, local->hw.extra_tx_headroom);
2425 
2426 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2427 							  sizeof(*nullfunc));
2428 	memset(nullfunc, 0, sizeof(*nullfunc));
2429 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2430 					      IEEE80211_STYPE_NULLFUNC |
2431 					      IEEE80211_FCTL_TODS);
2432 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2433 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2434 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2435 
2436 	return skb;
2437 }
2438 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2439 
2440 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2441 				       struct ieee80211_vif *vif,
2442 				       const u8 *ssid, size_t ssid_len,
2443 				       const u8 *ie, size_t ie_len)
2444 {
2445 	struct ieee80211_sub_if_data *sdata;
2446 	struct ieee80211_local *local;
2447 	struct ieee80211_hdr_3addr *hdr;
2448 	struct sk_buff *skb;
2449 	size_t ie_ssid_len;
2450 	u8 *pos;
2451 
2452 	sdata = vif_to_sdata(vif);
2453 	local = sdata->local;
2454 	ie_ssid_len = 2 + ssid_len;
2455 
2456 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2457 			    ie_ssid_len + ie_len);
2458 	if (!skb) {
2459 		printk(KERN_DEBUG "%s: failed to allocate buffer for probe "
2460 		       "request template\n", sdata->name);
2461 		return NULL;
2462 	}
2463 
2464 	skb_reserve(skb, local->hw.extra_tx_headroom);
2465 
2466 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2467 	memset(hdr, 0, sizeof(*hdr));
2468 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2469 					 IEEE80211_STYPE_PROBE_REQ);
2470 	memset(hdr->addr1, 0xff, ETH_ALEN);
2471 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2472 	memset(hdr->addr3, 0xff, ETH_ALEN);
2473 
2474 	pos = skb_put(skb, ie_ssid_len);
2475 	*pos++ = WLAN_EID_SSID;
2476 	*pos++ = ssid_len;
2477 	if (ssid)
2478 		memcpy(pos, ssid, ssid_len);
2479 	pos += ssid_len;
2480 
2481 	if (ie) {
2482 		pos = skb_put(skb, ie_len);
2483 		memcpy(pos, ie, ie_len);
2484 	}
2485 
2486 	return skb;
2487 }
2488 EXPORT_SYMBOL(ieee80211_probereq_get);
2489 
2490 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2491 		       const void *frame, size_t frame_len,
2492 		       const struct ieee80211_tx_info *frame_txctl,
2493 		       struct ieee80211_rts *rts)
2494 {
2495 	const struct ieee80211_hdr *hdr = frame;
2496 
2497 	rts->frame_control =
2498 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2499 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2500 					       frame_txctl);
2501 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2502 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2503 }
2504 EXPORT_SYMBOL(ieee80211_rts_get);
2505 
2506 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2507 			     const void *frame, size_t frame_len,
2508 			     const struct ieee80211_tx_info *frame_txctl,
2509 			     struct ieee80211_cts *cts)
2510 {
2511 	const struct ieee80211_hdr *hdr = frame;
2512 
2513 	cts->frame_control =
2514 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2515 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2516 						     frame_len, frame_txctl);
2517 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2518 }
2519 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2520 
2521 struct sk_buff *
2522 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2523 			  struct ieee80211_vif *vif)
2524 {
2525 	struct ieee80211_local *local = hw_to_local(hw);
2526 	struct sk_buff *skb = NULL;
2527 	struct sta_info *sta;
2528 	struct ieee80211_tx_data tx;
2529 	struct ieee80211_sub_if_data *sdata;
2530 	struct ieee80211_if_ap *bss = NULL;
2531 	struct beacon_data *beacon;
2532 	struct ieee80211_tx_info *info;
2533 
2534 	sdata = vif_to_sdata(vif);
2535 	bss = &sdata->u.ap;
2536 
2537 	rcu_read_lock();
2538 	beacon = rcu_dereference(bss->beacon);
2539 
2540 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2541 		goto out;
2542 
2543 	if (bss->dtim_count != 0)
2544 		goto out; /* send buffered bc/mc only after DTIM beacon */
2545 
2546 	while (1) {
2547 		skb = skb_dequeue(&bss->ps_bc_buf);
2548 		if (!skb)
2549 			goto out;
2550 		local->total_ps_buffered--;
2551 
2552 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2553 			struct ieee80211_hdr *hdr =
2554 				(struct ieee80211_hdr *) skb->data;
2555 			/* more buffered multicast/broadcast frames ==> set
2556 			 * MoreData flag in IEEE 802.11 header to inform PS
2557 			 * STAs */
2558 			hdr->frame_control |=
2559 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2560 		}
2561 
2562 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2563 			break;
2564 		dev_kfree_skb_any(skb);
2565 	}
2566 
2567 	info = IEEE80211_SKB_CB(skb);
2568 
2569 	sta = tx.sta;
2570 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2571 	tx.channel = local->hw.conf.channel;
2572 	info->band = tx.channel->band;
2573 
2574 	if (invoke_tx_handlers(&tx))
2575 		skb = NULL;
2576  out:
2577 	rcu_read_unlock();
2578 
2579 	return skb;
2580 }
2581 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2582 
2583 void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
2584 {
2585 	skb_set_mac_header(skb, 0);
2586 	skb_set_network_header(skb, 0);
2587 	skb_set_transport_header(skb, 0);
2588 
2589 	/* send all internal mgmt frames on VO */
2590 	skb_set_queue_mapping(skb, 0);
2591 
2592 	/*
2593 	 * The other path calling ieee80211_xmit is from the tasklet,
2594 	 * and while we can handle concurrent transmissions locking
2595 	 * requirements are that we do not come into tx with bhs on.
2596 	 */
2597 	local_bh_disable();
2598 	ieee80211_xmit(sdata, skb);
2599 	local_bh_enable();
2600 }
2601