xref: /linux/net/mac80211/tx.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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 <linux/export.h>
22 #include <net/net_namespace.h>
23 #include <net/ieee80211_radiotap.h>
24 #include <net/cfg80211.h>
25 #include <net/mac80211.h>
26 #include <asm/unaligned.h>
27 
28 #include "ieee80211_i.h"
29 #include "driver-ops.h"
30 #include "led.h"
31 #include "mesh.h"
32 #include "wep.h"
33 #include "wpa.h"
34 #include "wme.h"
35 #include "rate.h"
36 
37 /* misc utils */
38 
39 static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
40 				 struct sk_buff *skb, int group_addr,
41 				 int next_frag_len)
42 {
43 	int rate, mrate, erp, dur, i;
44 	struct ieee80211_rate *txrate;
45 	struct ieee80211_local *local = tx->local;
46 	struct ieee80211_supported_band *sband;
47 	struct ieee80211_hdr *hdr;
48 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
49 
50 	/* assume HW handles this */
51 	if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
52 		return 0;
53 
54 	/* uh huh? */
55 	if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
56 		return 0;
57 
58 	sband = local->hw.wiphy->bands[tx->channel->band];
59 	txrate = &sband->bitrates[info->control.rates[0].idx];
60 
61 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
62 
63 	/*
64 	 * data and mgmt (except PS Poll):
65 	 * - during CFP: 32768
66 	 * - during contention period:
67 	 *   if addr1 is group address: 0
68 	 *   if more fragments = 0 and addr1 is individual address: time to
69 	 *      transmit one ACK plus SIFS
70 	 *   if more fragments = 1 and addr1 is individual address: time to
71 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
72 	 *
73 	 * IEEE 802.11, 9.6:
74 	 * - control response frame (CTS or ACK) shall be transmitted using the
75 	 *   same rate as the immediately previous frame in the frame exchange
76 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
77 	 *   at the highest possible rate belonging to the PHY rates in the
78 	 *   BSSBasicRateSet
79 	 */
80 	hdr = (struct ieee80211_hdr *)skb->data;
81 	if (ieee80211_is_ctl(hdr->frame_control)) {
82 		/* TODO: These control frames are not currently sent by
83 		 * mac80211, but should they be implemented, this function
84 		 * needs to be updated to support duration field calculation.
85 		 *
86 		 * RTS: time needed to transmit pending data/mgmt frame plus
87 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
88 		 * CTS: duration of immediately previous RTS minus time
89 		 *    required to transmit CTS and its SIFS
90 		 * ACK: 0 if immediately previous directed data/mgmt had
91 		 *    more=0, with more=1 duration in ACK frame is duration
92 		 *    from previous frame minus time needed to transmit ACK
93 		 *    and its SIFS
94 		 * PS Poll: BIT(15) | BIT(14) | aid
95 		 */
96 		return 0;
97 	}
98 
99 	/* data/mgmt */
100 	if (0 /* FIX: data/mgmt during CFP */)
101 		return cpu_to_le16(32768);
102 
103 	if (group_addr) /* Group address as the destination - no ACK */
104 		return 0;
105 
106 	/* Individual destination address:
107 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
108 	 * CTS and ACK frames shall be transmitted using the highest rate in
109 	 * basic rate set that is less than or equal to the rate of the
110 	 * immediately previous frame and that is using the same modulation
111 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
112 	 * the highest mandatory rate of the PHY that is less than or equal to
113 	 * the rate of the previous frame is used.
114 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
115 	 */
116 	rate = -1;
117 	/* use lowest available if everything fails */
118 	mrate = sband->bitrates[0].bitrate;
119 	for (i = 0; i < sband->n_bitrates; i++) {
120 		struct ieee80211_rate *r = &sband->bitrates[i];
121 
122 		if (r->bitrate > txrate->bitrate)
123 			break;
124 
125 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
126 			rate = r->bitrate;
127 
128 		switch (sband->band) {
129 		case IEEE80211_BAND_2GHZ: {
130 			u32 flag;
131 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
132 				flag = IEEE80211_RATE_MANDATORY_G;
133 			else
134 				flag = IEEE80211_RATE_MANDATORY_B;
135 			if (r->flags & flag)
136 				mrate = r->bitrate;
137 			break;
138 		}
139 		case IEEE80211_BAND_5GHZ:
140 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
141 				mrate = r->bitrate;
142 			break;
143 		case IEEE80211_NUM_BANDS:
144 			WARN_ON(1);
145 			break;
146 		}
147 	}
148 	if (rate == -1) {
149 		/* No matching basic rate found; use highest suitable mandatory
150 		 * PHY rate */
151 		rate = mrate;
152 	}
153 
154 	/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
155 	if (ieee80211_is_data_qos(hdr->frame_control) &&
156 	    *(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
157 		dur = 0;
158 	else
159 		/* Time needed to transmit ACK
160 		 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
161 		 * to closest integer */
162 		dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
163 				tx->sdata->vif.bss_conf.use_short_preamble);
164 
165 	if (next_frag_len) {
166 		/* Frame is fragmented: duration increases with time needed to
167 		 * transmit next fragment plus ACK and 2 x SIFS. */
168 		dur *= 2; /* ACK + SIFS */
169 		/* next fragment */
170 		dur += ieee80211_frame_duration(sband->band, next_frag_len,
171 				txrate->bitrate, erp,
172 				tx->sdata->vif.bss_conf.use_short_preamble);
173 	}
174 
175 	return cpu_to_le16(dur);
176 }
177 
178 static inline int is_ieee80211_device(struct ieee80211_local *local,
179 				      struct net_device *dev)
180 {
181 	return local == wdev_priv(dev->ieee80211_ptr);
182 }
183 
184 /* tx handlers */
185 static ieee80211_tx_result debug_noinline
186 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
187 {
188 	struct ieee80211_local *local = tx->local;
189 	struct ieee80211_if_managed *ifmgd;
190 
191 	/* driver doesn't support power save */
192 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
193 		return TX_CONTINUE;
194 
195 	/* hardware does dynamic power save */
196 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
197 		return TX_CONTINUE;
198 
199 	/* dynamic power save disabled */
200 	if (local->hw.conf.dynamic_ps_timeout <= 0)
201 		return TX_CONTINUE;
202 
203 	/* we are scanning, don't enable power save */
204 	if (local->scanning)
205 		return TX_CONTINUE;
206 
207 	if (!local->ps_sdata)
208 		return TX_CONTINUE;
209 
210 	/* No point if we're going to suspend */
211 	if (local->quiescing)
212 		return TX_CONTINUE;
213 
214 	/* dynamic ps is supported only in managed mode */
215 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
216 		return TX_CONTINUE;
217 
218 	ifmgd = &tx->sdata->u.mgd;
219 
220 	/*
221 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
222 	 * u-apsd enabled and the frame is in voip class. This effectively
223 	 * means that even if all access categories have u-apsd enabled, in
224 	 * practise u-apsd is only used with the voip ac. This is a
225 	 * workaround for the case when received voip class packets do not
226 	 * have correct qos tag for some reason, due the network or the
227 	 * peer application.
228 	 *
229 	 * Note: ifmgd->uapsd_queues access is racy here. If the value is
230 	 * changed via debugfs, user needs to reassociate manually to have
231 	 * everything in sync.
232 	 */
233 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED) &&
234 	    (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO) &&
235 	    skb_get_queue_mapping(tx->skb) == IEEE80211_AC_VO)
236 		return TX_CONTINUE;
237 
238 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
239 		ieee80211_stop_queues_by_reason(&local->hw,
240 						IEEE80211_QUEUE_STOP_REASON_PS);
241 		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
242 		ieee80211_queue_work(&local->hw,
243 				     &local->dynamic_ps_disable_work);
244 	}
245 
246 	/* Don't restart the timer if we're not disassociated */
247 	if (!ifmgd->associated)
248 		return TX_CONTINUE;
249 
250 	mod_timer(&local->dynamic_ps_timer, jiffies +
251 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
252 
253 	return TX_CONTINUE;
254 }
255 
256 static ieee80211_tx_result debug_noinline
257 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
258 {
259 
260 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
261 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
262 	bool assoc = false;
263 
264 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
265 		return TX_CONTINUE;
266 
267 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
268 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
269 	    !ieee80211_is_probe_req(hdr->frame_control) &&
270 	    !ieee80211_is_nullfunc(hdr->frame_control))
271 		/*
272 		 * When software scanning only nullfunc frames (to notify
273 		 * the sleep state to the AP) and probe requests (for the
274 		 * active scan) are allowed, all other frames should not be
275 		 * sent and we should not get here, but if we do
276 		 * nonetheless, drop them to avoid sending them
277 		 * off-channel. See the link below and
278 		 * ieee80211_start_scan() for more.
279 		 *
280 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
281 		 */
282 		return TX_DROP;
283 
284 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
285 		return TX_CONTINUE;
286 
287 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
288 		return TX_CONTINUE;
289 
290 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
291 		return TX_CONTINUE;
292 
293 	if (tx->sta)
294 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
295 
296 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
297 		if (unlikely(!assoc &&
298 			     ieee80211_is_data(hdr->frame_control))) {
299 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
300 			printk(KERN_DEBUG "%s: dropped data frame to not "
301 			       "associated station %pM\n",
302 			       tx->sdata->name, hdr->addr1);
303 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
304 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
305 			return TX_DROP;
306 		}
307 	} else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
308 			    ieee80211_is_data(hdr->frame_control) &&
309 			    !atomic_read(&tx->sdata->u.ap.num_mcast_sta))) {
310 		/*
311 		 * No associated STAs - no need to send multicast
312 		 * frames.
313 		 */
314 		return TX_DROP;
315 	}
316 
317 	return TX_CONTINUE;
318 }
319 
320 /* This function is called whenever the AP is about to exceed the maximum limit
321  * of buffered frames for power saving STAs. This situation should not really
322  * happen often during normal operation, so dropping the oldest buffered packet
323  * from each queue should be OK to make some room for new frames. */
324 static void purge_old_ps_buffers(struct ieee80211_local *local)
325 {
326 	int total = 0, purged = 0;
327 	struct sk_buff *skb;
328 	struct ieee80211_sub_if_data *sdata;
329 	struct sta_info *sta;
330 
331 	/*
332 	 * virtual interfaces are protected by RCU
333 	 */
334 	rcu_read_lock();
335 
336 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
337 		struct ieee80211_if_ap *ap;
338 		if (sdata->vif.type != NL80211_IFTYPE_AP)
339 			continue;
340 		ap = &sdata->u.ap;
341 		skb = skb_dequeue(&ap->ps_bc_buf);
342 		if (skb) {
343 			purged++;
344 			dev_kfree_skb(skb);
345 		}
346 		total += skb_queue_len(&ap->ps_bc_buf);
347 	}
348 
349 	/*
350 	 * Drop one frame from each station from the lowest-priority
351 	 * AC that has frames at all.
352 	 */
353 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
354 		int ac;
355 
356 		for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
357 			skb = skb_dequeue(&sta->ps_tx_buf[ac]);
358 			total += skb_queue_len(&sta->ps_tx_buf[ac]);
359 			if (skb) {
360 				purged++;
361 				dev_kfree_skb(skb);
362 				break;
363 			}
364 		}
365 	}
366 
367 	rcu_read_unlock();
368 
369 	local->total_ps_buffered = total;
370 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
371 	wiphy_debug(local->hw.wiphy, "PS buffers full - purged %d frames\n",
372 		    purged);
373 #endif
374 }
375 
376 static ieee80211_tx_result
377 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
378 {
379 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
380 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
381 
382 	/*
383 	 * broadcast/multicast frame
384 	 *
385 	 * If any of the associated stations is in power save mode,
386 	 * the frame is buffered to be sent after DTIM beacon frame.
387 	 * This is done either by the hardware or us.
388 	 */
389 
390 	/* powersaving STAs only in AP/VLAN mode */
391 	if (!tx->sdata->bss)
392 		return TX_CONTINUE;
393 
394 	/* no buffering for ordered frames */
395 	if (ieee80211_has_order(hdr->frame_control))
396 		return TX_CONTINUE;
397 
398 	/* no stations in PS mode */
399 	if (!atomic_read(&tx->sdata->bss->num_sta_ps))
400 		return TX_CONTINUE;
401 
402 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
403 	if (tx->local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
404 		info->hw_queue = tx->sdata->vif.cab_queue;
405 
406 	/* device releases frame after DTIM beacon */
407 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
408 		return TX_CONTINUE;
409 
410 	/* buffered in mac80211 */
411 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
412 		purge_old_ps_buffers(tx->local);
413 
414 	if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >= AP_MAX_BC_BUFFER) {
415 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
416 		net_dbg_ratelimited("%s: BC TX buffer full - dropping the oldest frame\n",
417 				    tx->sdata->name);
418 #endif
419 		dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
420 	} else
421 		tx->local->total_ps_buffered++;
422 
423 	skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
424 
425 	return TX_QUEUED;
426 }
427 
428 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
429 			     struct sk_buff *skb)
430 {
431 	if (!ieee80211_is_mgmt(fc))
432 		return 0;
433 
434 	if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
435 		return 0;
436 
437 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
438 					    skb->data))
439 		return 0;
440 
441 	return 1;
442 }
443 
444 static ieee80211_tx_result
445 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
446 {
447 	struct sta_info *sta = tx->sta;
448 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
449 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
450 	struct ieee80211_local *local = tx->local;
451 
452 	if (unlikely(!sta))
453 		return TX_CONTINUE;
454 
455 	if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
456 		      test_sta_flag(sta, WLAN_STA_PS_DRIVER)) &&
457 		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
458 		int ac = skb_get_queue_mapping(tx->skb);
459 
460 		/* only deauth, disassoc and action are bufferable MMPDUs */
461 		if (ieee80211_is_mgmt(hdr->frame_control) &&
462 		    !ieee80211_is_deauth(hdr->frame_control) &&
463 		    !ieee80211_is_disassoc(hdr->frame_control) &&
464 		    !ieee80211_is_action(hdr->frame_control)) {
465 			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
466 			return TX_CONTINUE;
467 		}
468 
469 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
470 		printk(KERN_DEBUG "STA %pM aid %d: PS buffer for AC %d\n",
471 		       sta->sta.addr, sta->sta.aid, ac);
472 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
473 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
474 			purge_old_ps_buffers(tx->local);
475 		if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
476 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
477 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
478 			net_dbg_ratelimited("%s: STA %pM TX buffer for AC %d full - dropping oldest frame\n",
479 					    tx->sdata->name, sta->sta.addr, ac);
480 #endif
481 			dev_kfree_skb(old);
482 		} else
483 			tx->local->total_ps_buffered++;
484 
485 		info->control.jiffies = jiffies;
486 		info->control.vif = &tx->sdata->vif;
487 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
488 		skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
489 
490 		if (!timer_pending(&local->sta_cleanup))
491 			mod_timer(&local->sta_cleanup,
492 				  round_jiffies(jiffies +
493 						STA_INFO_CLEANUP_INTERVAL));
494 
495 		/*
496 		 * We queued up some frames, so the TIM bit might
497 		 * need to be set, recalculate it.
498 		 */
499 		sta_info_recalc_tim(sta);
500 
501 		return TX_QUEUED;
502 	}
503 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
504 	else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
505 		printk(KERN_DEBUG
506 		       "%s: STA %pM in PS mode, but polling/in SP -> send frame\n",
507 		       tx->sdata->name, sta->sta.addr);
508 	}
509 #endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
510 
511 	return TX_CONTINUE;
512 }
513 
514 static ieee80211_tx_result debug_noinline
515 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
516 {
517 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
518 		return TX_CONTINUE;
519 
520 	if (tx->flags & IEEE80211_TX_UNICAST)
521 		return ieee80211_tx_h_unicast_ps_buf(tx);
522 	else
523 		return ieee80211_tx_h_multicast_ps_buf(tx);
524 }
525 
526 static ieee80211_tx_result debug_noinline
527 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
528 {
529 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
530 
531 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol &&
532 		     tx->sdata->control_port_no_encrypt))
533 		info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
534 
535 	return TX_CONTINUE;
536 }
537 
538 static ieee80211_tx_result debug_noinline
539 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
540 {
541 	struct ieee80211_key *key = NULL;
542 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
543 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
544 
545 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
546 		tx->key = NULL;
547 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
548 		tx->key = key;
549 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
550 		 is_multicast_ether_addr(hdr->addr1) &&
551 		 ieee80211_is_robust_mgmt_frame(hdr) &&
552 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
553 		tx->key = key;
554 	else if (is_multicast_ether_addr(hdr->addr1) &&
555 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
556 		tx->key = key;
557 	else if (!is_multicast_ether_addr(hdr->addr1) &&
558 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
559 		tx->key = key;
560 	else if (tx->sdata->drop_unencrypted &&
561 		 (tx->skb->protocol != tx->sdata->control_port_protocol) &&
562 		 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
563 		 (!ieee80211_is_robust_mgmt_frame(hdr) ||
564 		  (ieee80211_is_action(hdr->frame_control) &&
565 		   tx->sta && test_sta_flag(tx->sta, WLAN_STA_MFP)))) {
566 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
567 		return TX_DROP;
568 	} else
569 		tx->key = NULL;
570 
571 	if (tx->key) {
572 		bool skip_hw = false;
573 
574 		tx->key->tx_rx_count++;
575 		/* TODO: add threshold stuff again */
576 
577 		switch (tx->key->conf.cipher) {
578 		case WLAN_CIPHER_SUITE_WEP40:
579 		case WLAN_CIPHER_SUITE_WEP104:
580 		case WLAN_CIPHER_SUITE_TKIP:
581 			if (!ieee80211_is_data_present(hdr->frame_control))
582 				tx->key = NULL;
583 			break;
584 		case WLAN_CIPHER_SUITE_CCMP:
585 			if (!ieee80211_is_data_present(hdr->frame_control) &&
586 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
587 					       tx->skb))
588 				tx->key = NULL;
589 			else
590 				skip_hw = (tx->key->conf.flags &
591 					   IEEE80211_KEY_FLAG_SW_MGMT) &&
592 					ieee80211_is_mgmt(hdr->frame_control);
593 			break;
594 		case WLAN_CIPHER_SUITE_AES_CMAC:
595 			if (!ieee80211_is_mgmt(hdr->frame_control))
596 				tx->key = NULL;
597 			break;
598 		}
599 
600 		if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED))
601 			return TX_DROP;
602 
603 		if (!skip_hw && tx->key &&
604 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
605 			info->control.hw_key = &tx->key->conf;
606 	}
607 
608 	return TX_CONTINUE;
609 }
610 
611 static ieee80211_tx_result debug_noinline
612 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
613 {
614 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
615 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
616 	struct ieee80211_supported_band *sband;
617 	struct ieee80211_rate *rate;
618 	int i;
619 	u32 len;
620 	bool inval = false, rts = false, short_preamble = false;
621 	struct ieee80211_tx_rate_control txrc;
622 	bool assoc = false;
623 
624 	memset(&txrc, 0, sizeof(txrc));
625 
626 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
627 
628 	len = min_t(u32, tx->skb->len + FCS_LEN,
629 			 tx->local->hw.wiphy->frag_threshold);
630 
631 	/* set up the tx rate control struct we give the RC algo */
632 	txrc.hw = &tx->local->hw;
633 	txrc.sband = sband;
634 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
635 	txrc.skb = tx->skb;
636 	txrc.reported_rate.idx = -1;
637 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[tx->channel->band];
638 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
639 		txrc.max_rate_idx = -1;
640 	else
641 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
642 	memcpy(txrc.rate_idx_mcs_mask,
643 	       tx->sdata->rc_rateidx_mcs_mask[tx->channel->band],
644 	       sizeof(txrc.rate_idx_mcs_mask));
645 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
646 		    tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
647 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
648 
649 	/* set up RTS protection if desired */
650 	if (len > tx->local->hw.wiphy->rts_threshold) {
651 		txrc.rts = rts = true;
652 	}
653 
654 	/*
655 	 * Use short preamble if the BSS can handle it, but not for
656 	 * management frames unless we know the receiver can handle
657 	 * that -- the management frame might be to a station that
658 	 * just wants a probe response.
659 	 */
660 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
661 	    (ieee80211_is_data(hdr->frame_control) ||
662 	     (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
663 		txrc.short_preamble = short_preamble = true;
664 
665 	if (tx->sta)
666 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
667 
668 	/*
669 	 * Lets not bother rate control if we're associated and cannot
670 	 * talk to the sta. This should not happen.
671 	 */
672 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
673 		 !rate_usable_index_exists(sband, &tx->sta->sta),
674 		 "%s: Dropped data frame as no usable bitrate found while "
675 		 "scanning and associated. Target station: "
676 		 "%pM on %d GHz band\n",
677 		 tx->sdata->name, hdr->addr1,
678 		 tx->channel->band ? 5 : 2))
679 		return TX_DROP;
680 
681 	/*
682 	 * If we're associated with the sta at this point we know we can at
683 	 * least send the frame at the lowest bit rate.
684 	 */
685 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
686 
687 	if (unlikely(info->control.rates[0].idx < 0))
688 		return TX_DROP;
689 
690 	if (txrc.reported_rate.idx < 0) {
691 		txrc.reported_rate = info->control.rates[0];
692 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
693 			tx->sta->last_tx_rate = txrc.reported_rate;
694 	} else if (tx->sta)
695 		tx->sta->last_tx_rate = txrc.reported_rate;
696 
697 	if (unlikely(!info->control.rates[0].count))
698 		info->control.rates[0].count = 1;
699 
700 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
701 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
702 		info->control.rates[0].count = 1;
703 
704 	if (is_multicast_ether_addr(hdr->addr1)) {
705 		/*
706 		 * XXX: verify the rate is in the basic rateset
707 		 */
708 		return TX_CONTINUE;
709 	}
710 
711 	/*
712 	 * set up the RTS/CTS rate as the fastest basic rate
713 	 * that is not faster than the data rate
714 	 *
715 	 * XXX: Should this check all retry rates?
716 	 */
717 	if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
718 		s8 baserate = 0;
719 
720 		rate = &sband->bitrates[info->control.rates[0].idx];
721 
722 		for (i = 0; i < sband->n_bitrates; i++) {
723 			/* must be a basic rate */
724 			if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
725 				continue;
726 			/* must not be faster than the data rate */
727 			if (sband->bitrates[i].bitrate > rate->bitrate)
728 				continue;
729 			/* maximum */
730 			if (sband->bitrates[baserate].bitrate <
731 			     sband->bitrates[i].bitrate)
732 				baserate = i;
733 		}
734 
735 		info->control.rts_cts_rate_idx = baserate;
736 	}
737 
738 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
739 		/*
740 		 * make sure there's no valid rate following
741 		 * an invalid one, just in case drivers don't
742 		 * take the API seriously to stop at -1.
743 		 */
744 		if (inval) {
745 			info->control.rates[i].idx = -1;
746 			continue;
747 		}
748 		if (info->control.rates[i].idx < 0) {
749 			inval = true;
750 			continue;
751 		}
752 
753 		/*
754 		 * For now assume MCS is already set up correctly, this
755 		 * needs to be fixed.
756 		 */
757 		if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
758 			WARN_ON(info->control.rates[i].idx > 76);
759 			continue;
760 		}
761 
762 		/* set up RTS protection if desired */
763 		if (rts)
764 			info->control.rates[i].flags |=
765 				IEEE80211_TX_RC_USE_RTS_CTS;
766 
767 		/* RC is busted */
768 		if (WARN_ON_ONCE(info->control.rates[i].idx >=
769 				 sband->n_bitrates)) {
770 			info->control.rates[i].idx = -1;
771 			continue;
772 		}
773 
774 		rate = &sband->bitrates[info->control.rates[i].idx];
775 
776 		/* set up short preamble */
777 		if (short_preamble &&
778 		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
779 			info->control.rates[i].flags |=
780 				IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
781 
782 		/* set up G protection */
783 		if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
784 		    rate->flags & IEEE80211_RATE_ERP_G)
785 			info->control.rates[i].flags |=
786 				IEEE80211_TX_RC_USE_CTS_PROTECT;
787 	}
788 
789 	return TX_CONTINUE;
790 }
791 
792 static ieee80211_tx_result debug_noinline
793 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
794 {
795 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
796 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
797 	u16 *seq;
798 	u8 *qc;
799 	int tid;
800 
801 	/*
802 	 * Packet injection may want to control the sequence
803 	 * number, if we have no matching interface then we
804 	 * neither assign one ourselves nor ask the driver to.
805 	 */
806 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
807 		return TX_CONTINUE;
808 
809 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
810 		return TX_CONTINUE;
811 
812 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
813 		return TX_CONTINUE;
814 
815 	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
816 		return TX_CONTINUE;
817 
818 	/*
819 	 * Anything but QoS data that has a sequence number field
820 	 * (is long enough) gets a sequence number from the global
821 	 * counter.
822 	 */
823 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
824 		/* driver should assign sequence number */
825 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
826 		/* for pure STA mode without beacons, we can do it */
827 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
828 		tx->sdata->sequence_number += 0x10;
829 		return TX_CONTINUE;
830 	}
831 
832 	/*
833 	 * This should be true for injected/management frames only, for
834 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
835 	 * above since they are not QoS-data frames.
836 	 */
837 	if (!tx->sta)
838 		return TX_CONTINUE;
839 
840 	/* include per-STA, per-TID sequence counter */
841 
842 	qc = ieee80211_get_qos_ctl(hdr);
843 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
844 	seq = &tx->sta->tid_seq[tid];
845 
846 	hdr->seq_ctrl = cpu_to_le16(*seq);
847 
848 	/* Increase the sequence number. */
849 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
850 
851 	return TX_CONTINUE;
852 }
853 
854 static int ieee80211_fragment(struct ieee80211_tx_data *tx,
855 			      struct sk_buff *skb, int hdrlen,
856 			      int frag_threshold)
857 {
858 	struct ieee80211_local *local = tx->local;
859 	struct ieee80211_tx_info *info;
860 	struct sk_buff *tmp;
861 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
862 	int pos = hdrlen + per_fragm;
863 	int rem = skb->len - hdrlen - per_fragm;
864 
865 	if (WARN_ON(rem < 0))
866 		return -EINVAL;
867 
868 	/* first fragment was already added to queue by caller */
869 
870 	while (rem) {
871 		int fraglen = per_fragm;
872 
873 		if (fraglen > rem)
874 			fraglen = rem;
875 		rem -= fraglen;
876 		tmp = dev_alloc_skb(local->tx_headroom +
877 				    frag_threshold +
878 				    IEEE80211_ENCRYPT_HEADROOM +
879 				    IEEE80211_ENCRYPT_TAILROOM);
880 		if (!tmp)
881 			return -ENOMEM;
882 
883 		__skb_queue_tail(&tx->skbs, tmp);
884 
885 		skb_reserve(tmp, local->tx_headroom +
886 				 IEEE80211_ENCRYPT_HEADROOM);
887 		/* copy control information */
888 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
889 
890 		info = IEEE80211_SKB_CB(tmp);
891 		info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
892 				 IEEE80211_TX_CTL_FIRST_FRAGMENT);
893 
894 		if (rem)
895 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
896 
897 		skb_copy_queue_mapping(tmp, skb);
898 		tmp->priority = skb->priority;
899 		tmp->dev = skb->dev;
900 
901 		/* copy header and data */
902 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
903 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
904 
905 		pos += fraglen;
906 	}
907 
908 	/* adjust first fragment's length */
909 	skb->len = hdrlen + per_fragm;
910 	return 0;
911 }
912 
913 static ieee80211_tx_result debug_noinline
914 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
915 {
916 	struct sk_buff *skb = tx->skb;
917 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
918 	struct ieee80211_hdr *hdr = (void *)skb->data;
919 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
920 	int hdrlen;
921 	int fragnum;
922 
923 	/* no matter what happens, tx->skb moves to tx->skbs */
924 	__skb_queue_tail(&tx->skbs, skb);
925 	tx->skb = NULL;
926 
927 	if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
928 		return TX_CONTINUE;
929 
930 	if (tx->local->ops->set_frag_threshold)
931 		return TX_CONTINUE;
932 
933 	/*
934 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
935 	 * This scenario is handled in ieee80211_tx_prepare but extra
936 	 * caution taken here as fragmented ampdu may cause Tx stop.
937 	 */
938 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
939 		return TX_DROP;
940 
941 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
942 
943 	/* internal error, why isn't DONTFRAG set? */
944 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
945 		return TX_DROP;
946 
947 	/*
948 	 * Now fragment the frame. This will allocate all the fragments and
949 	 * chain them (using skb as the first fragment) to skb->next.
950 	 * During transmission, we will remove the successfully transmitted
951 	 * fragments from this list. When the low-level driver rejects one
952 	 * of the fragments then we will simply pretend to accept the skb
953 	 * but store it away as pending.
954 	 */
955 	if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
956 		return TX_DROP;
957 
958 	/* update duration/seq/flags of fragments */
959 	fragnum = 0;
960 
961 	skb_queue_walk(&tx->skbs, skb) {
962 		int next_len;
963 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
964 
965 		hdr = (void *)skb->data;
966 		info = IEEE80211_SKB_CB(skb);
967 
968 		if (!skb_queue_is_last(&tx->skbs, skb)) {
969 			hdr->frame_control |= morefrags;
970 			/*
971 			 * No multi-rate retries for fragmented frames, that
972 			 * would completely throw off the NAV at other STAs.
973 			 */
974 			info->control.rates[1].idx = -1;
975 			info->control.rates[2].idx = -1;
976 			info->control.rates[3].idx = -1;
977 			info->control.rates[4].idx = -1;
978 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
979 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
980 		} else {
981 			hdr->frame_control &= ~morefrags;
982 			next_len = 0;
983 		}
984 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
985 		fragnum++;
986 	}
987 
988 	return TX_CONTINUE;
989 }
990 
991 static ieee80211_tx_result debug_noinline
992 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
993 {
994 	struct sk_buff *skb;
995 
996 	if (!tx->sta)
997 		return TX_CONTINUE;
998 
999 	tx->sta->tx_packets++;
1000 	skb_queue_walk(&tx->skbs, skb) {
1001 		tx->sta->tx_fragments++;
1002 		tx->sta->tx_bytes += skb->len;
1003 	}
1004 
1005 	return TX_CONTINUE;
1006 }
1007 
1008 static ieee80211_tx_result debug_noinline
1009 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
1010 {
1011 	if (!tx->key)
1012 		return TX_CONTINUE;
1013 
1014 	switch (tx->key->conf.cipher) {
1015 	case WLAN_CIPHER_SUITE_WEP40:
1016 	case WLAN_CIPHER_SUITE_WEP104:
1017 		return ieee80211_crypto_wep_encrypt(tx);
1018 	case WLAN_CIPHER_SUITE_TKIP:
1019 		return ieee80211_crypto_tkip_encrypt(tx);
1020 	case WLAN_CIPHER_SUITE_CCMP:
1021 		return ieee80211_crypto_ccmp_encrypt(tx);
1022 	case WLAN_CIPHER_SUITE_AES_CMAC:
1023 		return ieee80211_crypto_aes_cmac_encrypt(tx);
1024 	default:
1025 		return ieee80211_crypto_hw_encrypt(tx);
1026 	}
1027 
1028 	return TX_DROP;
1029 }
1030 
1031 static ieee80211_tx_result debug_noinline
1032 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
1033 {
1034 	struct sk_buff *skb;
1035 	struct ieee80211_hdr *hdr;
1036 	int next_len;
1037 	bool group_addr;
1038 
1039 	skb_queue_walk(&tx->skbs, skb) {
1040 		hdr = (void *) skb->data;
1041 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1042 			break; /* must not overwrite AID */
1043 		if (!skb_queue_is_last(&tx->skbs, skb)) {
1044 			struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
1045 			next_len = next->len;
1046 		} else
1047 			next_len = 0;
1048 		group_addr = is_multicast_ether_addr(hdr->addr1);
1049 
1050 		hdr->duration_id =
1051 			ieee80211_duration(tx, skb, group_addr, next_len);
1052 	}
1053 
1054 	return TX_CONTINUE;
1055 }
1056 
1057 /* actual transmit path */
1058 
1059 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1060 				  struct sk_buff *skb,
1061 				  struct ieee80211_tx_info *info,
1062 				  struct tid_ampdu_tx *tid_tx,
1063 				  int tid)
1064 {
1065 	bool queued = false;
1066 	bool reset_agg_timer = false;
1067 	struct sk_buff *purge_skb = NULL;
1068 
1069 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1070 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1071 		reset_agg_timer = true;
1072 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1073 		/*
1074 		 * nothing -- this aggregation session is being started
1075 		 * but that might still fail with the driver
1076 		 */
1077 	} else {
1078 		spin_lock(&tx->sta->lock);
1079 		/*
1080 		 * Need to re-check now, because we may get here
1081 		 *
1082 		 *  1) in the window during which the setup is actually
1083 		 *     already done, but not marked yet because not all
1084 		 *     packets are spliced over to the driver pending
1085 		 *     queue yet -- if this happened we acquire the lock
1086 		 *     either before or after the splice happens, but
1087 		 *     need to recheck which of these cases happened.
1088 		 *
1089 		 *  2) during session teardown, if the OPERATIONAL bit
1090 		 *     was cleared due to the teardown but the pointer
1091 		 *     hasn't been assigned NULL yet (or we loaded it
1092 		 *     before it was assigned) -- in this case it may
1093 		 *     now be NULL which means we should just let the
1094 		 *     packet pass through because splicing the frames
1095 		 *     back is already done.
1096 		 */
1097 		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1098 
1099 		if (!tid_tx) {
1100 			/* do nothing, let packet pass through */
1101 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1102 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1103 			reset_agg_timer = true;
1104 		} else {
1105 			queued = true;
1106 			info->control.vif = &tx->sdata->vif;
1107 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1108 			__skb_queue_tail(&tid_tx->pending, skb);
1109 			if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
1110 				purge_skb = __skb_dequeue(&tid_tx->pending);
1111 		}
1112 		spin_unlock(&tx->sta->lock);
1113 
1114 		if (purge_skb)
1115 			dev_kfree_skb(purge_skb);
1116 	}
1117 
1118 	/* reset session timer */
1119 	if (reset_agg_timer && tid_tx->timeout)
1120 		tid_tx->last_tx = jiffies;
1121 
1122 	return queued;
1123 }
1124 
1125 /*
1126  * initialises @tx
1127  */
1128 static ieee80211_tx_result
1129 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1130 		     struct ieee80211_tx_data *tx,
1131 		     struct sk_buff *skb)
1132 {
1133 	struct ieee80211_local *local = sdata->local;
1134 	struct ieee80211_hdr *hdr;
1135 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1136 	int tid;
1137 	u8 *qc;
1138 
1139 	memset(tx, 0, sizeof(*tx));
1140 	tx->skb = skb;
1141 	tx->local = local;
1142 	tx->sdata = sdata;
1143 	tx->channel = local->hw.conf.channel;
1144 	__skb_queue_head_init(&tx->skbs);
1145 
1146 	/*
1147 	 * If this flag is set to true anywhere, and we get here,
1148 	 * we are doing the needed processing, so remove the flag
1149 	 * now.
1150 	 */
1151 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1152 
1153 	hdr = (struct ieee80211_hdr *) skb->data;
1154 
1155 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1156 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1157 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1158 			return TX_DROP;
1159 	} else if (info->flags & IEEE80211_TX_CTL_INJECTED ||
1160 		   tx->sdata->control_port_protocol == tx->skb->protocol) {
1161 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1162 	}
1163 	if (!tx->sta)
1164 		tx->sta = sta_info_get(sdata, hdr->addr1);
1165 
1166 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1167 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1168 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
1169 	    !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
1170 		struct tid_ampdu_tx *tid_tx;
1171 
1172 		qc = ieee80211_get_qos_ctl(hdr);
1173 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1174 
1175 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1176 		if (tid_tx) {
1177 			bool queued;
1178 
1179 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1180 						       tid_tx, tid);
1181 
1182 			if (unlikely(queued))
1183 				return TX_QUEUED;
1184 		}
1185 	}
1186 
1187 	if (is_multicast_ether_addr(hdr->addr1)) {
1188 		tx->flags &= ~IEEE80211_TX_UNICAST;
1189 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1190 	} else
1191 		tx->flags |= IEEE80211_TX_UNICAST;
1192 
1193 	if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
1194 		if (!(tx->flags & IEEE80211_TX_UNICAST) ||
1195 		    skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
1196 		    info->flags & IEEE80211_TX_CTL_AMPDU)
1197 			info->flags |= IEEE80211_TX_CTL_DONTFRAG;
1198 	}
1199 
1200 	if (!tx->sta)
1201 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1202 	else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1203 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1204 
1205 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1206 
1207 	return TX_CONTINUE;
1208 }
1209 
1210 static bool ieee80211_tx_frags(struct ieee80211_local *local,
1211 			       struct ieee80211_vif *vif,
1212 			       struct ieee80211_sta *sta,
1213 			       struct sk_buff_head *skbs,
1214 			       bool txpending)
1215 {
1216 	struct sk_buff *skb, *tmp;
1217 	unsigned long flags;
1218 
1219 	skb_queue_walk_safe(skbs, skb, tmp) {
1220 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1221 		int q = info->hw_queue;
1222 
1223 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1224 		if (WARN_ON_ONCE(q >= local->hw.queues)) {
1225 			__skb_unlink(skb, skbs);
1226 			dev_kfree_skb(skb);
1227 			continue;
1228 		}
1229 #endif
1230 
1231 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1232 		if (local->queue_stop_reasons[q] ||
1233 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1234 			/*
1235 			 * Since queue is stopped, queue up frames for later
1236 			 * transmission from the tx-pending tasklet when the
1237 			 * queue is woken again.
1238 			 */
1239 			if (txpending)
1240 				skb_queue_splice_init(skbs, &local->pending[q]);
1241 			else
1242 				skb_queue_splice_tail_init(skbs,
1243 							   &local->pending[q]);
1244 
1245 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1246 					       flags);
1247 			return false;
1248 		}
1249 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1250 
1251 		info->control.vif = vif;
1252 		info->control.sta = sta;
1253 
1254 		__skb_unlink(skb, skbs);
1255 		drv_tx(local, skb);
1256 	}
1257 
1258 	return true;
1259 }
1260 
1261 /*
1262  * Returns false if the frame couldn't be transmitted but was queued instead.
1263  */
1264 static bool __ieee80211_tx(struct ieee80211_local *local,
1265 			   struct sk_buff_head *skbs, int led_len,
1266 			   struct sta_info *sta, bool txpending)
1267 {
1268 	struct ieee80211_tx_info *info;
1269 	struct ieee80211_sub_if_data *sdata;
1270 	struct ieee80211_vif *vif;
1271 	struct ieee80211_sta *pubsta;
1272 	struct sk_buff *skb;
1273 	bool result = true;
1274 	__le16 fc;
1275 
1276 	if (WARN_ON(skb_queue_empty(skbs)))
1277 		return true;
1278 
1279 	skb = skb_peek(skbs);
1280 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1281 	info = IEEE80211_SKB_CB(skb);
1282 	sdata = vif_to_sdata(info->control.vif);
1283 	if (sta && !sta->uploaded)
1284 		sta = NULL;
1285 
1286 	if (sta)
1287 		pubsta = &sta->sta;
1288 	else
1289 		pubsta = NULL;
1290 
1291 	switch (sdata->vif.type) {
1292 	case NL80211_IFTYPE_MONITOR:
1293 		sdata = rcu_dereference(local->monitor_sdata);
1294 		if (sdata) {
1295 			vif = &sdata->vif;
1296 			info->hw_queue =
1297 				vif->hw_queue[skb_get_queue_mapping(skb)];
1298 		} else if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL) {
1299 			dev_kfree_skb(skb);
1300 			return true;
1301 		} else
1302 			vif = NULL;
1303 		break;
1304 	case NL80211_IFTYPE_AP_VLAN:
1305 		sdata = container_of(sdata->bss,
1306 				     struct ieee80211_sub_if_data, u.ap);
1307 		/* fall through */
1308 	default:
1309 		vif = &sdata->vif;
1310 		break;
1311 	}
1312 
1313 	if (local->ops->tx_frags)
1314 		drv_tx_frags(local, vif, pubsta, skbs);
1315 	else
1316 		result = ieee80211_tx_frags(local, vif, pubsta, skbs,
1317 					    txpending);
1318 
1319 	ieee80211_tpt_led_trig_tx(local, fc, led_len);
1320 	ieee80211_led_tx(local, 1);
1321 
1322 	WARN_ON_ONCE(!skb_queue_empty(skbs));
1323 
1324 	return result;
1325 }
1326 
1327 /*
1328  * Invoke TX handlers, return 0 on success and non-zero if the
1329  * frame was dropped or queued.
1330  */
1331 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1332 {
1333 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
1334 	ieee80211_tx_result res = TX_DROP;
1335 
1336 #define CALL_TXH(txh) \
1337 	do {				\
1338 		res = txh(tx);		\
1339 		if (res != TX_CONTINUE)	\
1340 			goto txh_done;	\
1341 	} while (0)
1342 
1343 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1344 	CALL_TXH(ieee80211_tx_h_check_assoc);
1345 	CALL_TXH(ieee80211_tx_h_ps_buf);
1346 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1347 	CALL_TXH(ieee80211_tx_h_select_key);
1348 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1349 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1350 
1351 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
1352 		__skb_queue_tail(&tx->skbs, tx->skb);
1353 		tx->skb = NULL;
1354 		goto txh_done;
1355 	}
1356 
1357 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1358 	CALL_TXH(ieee80211_tx_h_sequence);
1359 	CALL_TXH(ieee80211_tx_h_fragment);
1360 	/* handlers after fragment must be aware of tx info fragmentation! */
1361 	CALL_TXH(ieee80211_tx_h_stats);
1362 	CALL_TXH(ieee80211_tx_h_encrypt);
1363 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1364 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1365 #undef CALL_TXH
1366 
1367  txh_done:
1368 	if (unlikely(res == TX_DROP)) {
1369 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1370 		if (tx->skb)
1371 			dev_kfree_skb(tx->skb);
1372 		else
1373 			__skb_queue_purge(&tx->skbs);
1374 		return -1;
1375 	} else if (unlikely(res == TX_QUEUED)) {
1376 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1377 		return -1;
1378 	}
1379 
1380 	return 0;
1381 }
1382 
1383 /*
1384  * Returns false if the frame couldn't be transmitted but was queued instead.
1385  */
1386 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1387 			 struct sk_buff *skb, bool txpending)
1388 {
1389 	struct ieee80211_local *local = sdata->local;
1390 	struct ieee80211_tx_data tx;
1391 	ieee80211_tx_result res_prepare;
1392 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1393 	bool result = true;
1394 	int led_len;
1395 
1396 	if (unlikely(skb->len < 10)) {
1397 		dev_kfree_skb(skb);
1398 		return true;
1399 	}
1400 
1401 	rcu_read_lock();
1402 
1403 	/* initialises tx */
1404 	led_len = skb->len;
1405 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1406 
1407 	if (unlikely(res_prepare == TX_DROP)) {
1408 		dev_kfree_skb(skb);
1409 		goto out;
1410 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1411 		goto out;
1412 	}
1413 
1414 	tx.channel = local->hw.conf.channel;
1415 	info->band = tx.channel->band;
1416 
1417 	/* set up hw_queue value early */
1418 	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
1419 	    !(local->hw.flags & IEEE80211_HW_QUEUE_CONTROL))
1420 		info->hw_queue =
1421 			sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
1422 
1423 	if (!invoke_tx_handlers(&tx))
1424 		result = __ieee80211_tx(local, &tx.skbs, led_len,
1425 					tx.sta, txpending);
1426  out:
1427 	rcu_read_unlock();
1428 	return result;
1429 }
1430 
1431 /* device xmit handlers */
1432 
1433 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
1434 				struct sk_buff *skb,
1435 				int head_need, bool may_encrypt)
1436 {
1437 	struct ieee80211_local *local = sdata->local;
1438 	int tail_need = 0;
1439 
1440 	if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
1441 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1442 		tail_need -= skb_tailroom(skb);
1443 		tail_need = max_t(int, tail_need, 0);
1444 	}
1445 
1446 	if (skb_cloned(skb))
1447 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1448 	else if (head_need || tail_need)
1449 		I802_DEBUG_INC(local->tx_expand_skb_head);
1450 	else
1451 		return 0;
1452 
1453 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1454 		wiphy_debug(local->hw.wiphy,
1455 			    "failed to reallocate TX buffer\n");
1456 		return -ENOMEM;
1457 	}
1458 
1459 	return 0;
1460 }
1461 
1462 void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
1463 {
1464 	struct ieee80211_local *local = sdata->local;
1465 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1466 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1467 	int headroom;
1468 	bool may_encrypt;
1469 
1470 	rcu_read_lock();
1471 
1472 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1473 
1474 	headroom = local->tx_headroom;
1475 	if (may_encrypt)
1476 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1477 	headroom -= skb_headroom(skb);
1478 	headroom = max_t(int, 0, headroom);
1479 
1480 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
1481 		dev_kfree_skb(skb);
1482 		rcu_read_unlock();
1483 		return;
1484 	}
1485 
1486 	hdr = (struct ieee80211_hdr *) skb->data;
1487 	info->control.vif = &sdata->vif;
1488 
1489 	if (ieee80211_vif_is_mesh(&sdata->vif) &&
1490 	    ieee80211_is_data(hdr->frame_control) &&
1491 	    !is_multicast_ether_addr(hdr->addr1) &&
1492 	    mesh_nexthop_resolve(skb, sdata)) {
1493 		/* skb queued: don't free */
1494 		rcu_read_unlock();
1495 		return;
1496 	}
1497 
1498 	ieee80211_set_qos_hdr(sdata, skb);
1499 	ieee80211_tx(sdata, skb, false);
1500 	rcu_read_unlock();
1501 }
1502 
1503 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
1504 {
1505 	struct ieee80211_radiotap_iterator iterator;
1506 	struct ieee80211_radiotap_header *rthdr =
1507 		(struct ieee80211_radiotap_header *) skb->data;
1508 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1509 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1510 						   NULL);
1511 	u16 txflags;
1512 
1513 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
1514 		       IEEE80211_TX_CTL_DONTFRAG;
1515 
1516 	/*
1517 	 * for every radiotap entry that is present
1518 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1519 	 * entries present, or -EINVAL on error)
1520 	 */
1521 
1522 	while (!ret) {
1523 		ret = ieee80211_radiotap_iterator_next(&iterator);
1524 
1525 		if (ret)
1526 			continue;
1527 
1528 		/* see if this argument is something we can use */
1529 		switch (iterator.this_arg_index) {
1530 		/*
1531 		 * You must take care when dereferencing iterator.this_arg
1532 		 * for multibyte types... the pointer is not aligned.  Use
1533 		 * get_unaligned((type *)iterator.this_arg) to dereference
1534 		 * iterator.this_arg for type "type" safely on all arches.
1535 		*/
1536 		case IEEE80211_RADIOTAP_FLAGS:
1537 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1538 				/*
1539 				 * this indicates that the skb we have been
1540 				 * handed has the 32-bit FCS CRC at the end...
1541 				 * we should react to that by snipping it off
1542 				 * because it will be recomputed and added
1543 				 * on transmission
1544 				 */
1545 				if (skb->len < (iterator._max_length + FCS_LEN))
1546 					return false;
1547 
1548 				skb_trim(skb, skb->len - FCS_LEN);
1549 			}
1550 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1551 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1552 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1553 				info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
1554 			break;
1555 
1556 		case IEEE80211_RADIOTAP_TX_FLAGS:
1557 			txflags = get_unaligned_le16(iterator.this_arg);
1558 			if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
1559 				info->flags |= IEEE80211_TX_CTL_NO_ACK;
1560 			break;
1561 
1562 		/*
1563 		 * Please update the file
1564 		 * Documentation/networking/mac80211-injection.txt
1565 		 * when parsing new fields here.
1566 		 */
1567 
1568 		default:
1569 			break;
1570 		}
1571 	}
1572 
1573 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1574 		return false;
1575 
1576 	/*
1577 	 * remove the radiotap header
1578 	 * iterator->_max_length was sanity-checked against
1579 	 * skb->len by iterator init
1580 	 */
1581 	skb_pull(skb, iterator._max_length);
1582 
1583 	return true;
1584 }
1585 
1586 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1587 					 struct net_device *dev)
1588 {
1589 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1590 	struct ieee80211_channel *chan = local->hw.conf.channel;
1591 	struct ieee80211_radiotap_header *prthdr =
1592 		(struct ieee80211_radiotap_header *)skb->data;
1593 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1594 	struct ieee80211_hdr *hdr;
1595 	struct ieee80211_sub_if_data *tmp_sdata, *sdata;
1596 	u16 len_rthdr;
1597 	int hdrlen;
1598 
1599 	/*
1600 	 * Frame injection is not allowed if beaconing is not allowed
1601 	 * or if we need radar detection. Beaconing is usually not allowed when
1602 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1603 	 * Passive scan is also used in world regulatory domains where
1604 	 * your country is not known and as such it should be treated as
1605 	 * NO TX unless the channel is explicitly allowed in which case
1606 	 * your current regulatory domain would not have the passive scan
1607 	 * flag.
1608 	 *
1609 	 * Since AP mode uses monitor interfaces to inject/TX management
1610 	 * frames we can make AP mode the exception to this rule once it
1611 	 * supports radar detection as its implementation can deal with
1612 	 * radar detection by itself. We can do that later by adding a
1613 	 * monitor flag interfaces used for AP support.
1614 	 */
1615 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1616 	     IEEE80211_CHAN_PASSIVE_SCAN)))
1617 		goto fail;
1618 
1619 	/* check for not even having the fixed radiotap header part */
1620 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1621 		goto fail; /* too short to be possibly valid */
1622 
1623 	/* is it a header version we can trust to find length from? */
1624 	if (unlikely(prthdr->it_version))
1625 		goto fail; /* only version 0 is supported */
1626 
1627 	/* then there must be a radiotap header with a length we can use */
1628 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1629 
1630 	/* does the skb contain enough to deliver on the alleged length? */
1631 	if (unlikely(skb->len < len_rthdr))
1632 		goto fail; /* skb too short for claimed rt header extent */
1633 
1634 	/*
1635 	 * fix up the pointers accounting for the radiotap
1636 	 * header still being in there.  We are being given
1637 	 * a precooked IEEE80211 header so no need for
1638 	 * normal processing
1639 	 */
1640 	skb_set_mac_header(skb, len_rthdr);
1641 	/*
1642 	 * these are just fixed to the end of the rt area since we
1643 	 * don't have any better information and at this point, nobody cares
1644 	 */
1645 	skb_set_network_header(skb, len_rthdr);
1646 	skb_set_transport_header(skb, len_rthdr);
1647 
1648 	if (skb->len < len_rthdr + 2)
1649 		goto fail;
1650 
1651 	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1652 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1653 
1654 	if (skb->len < len_rthdr + hdrlen)
1655 		goto fail;
1656 
1657 	/*
1658 	 * Initialize skb->protocol if the injected frame is a data frame
1659 	 * carrying a rfc1042 header
1660 	 */
1661 	if (ieee80211_is_data(hdr->frame_control) &&
1662 	    skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
1663 		u8 *payload = (u8 *)hdr + hdrlen;
1664 
1665 		if (ether_addr_equal(payload, rfc1042_header))
1666 			skb->protocol = cpu_to_be16((payload[6] << 8) |
1667 						    payload[7]);
1668 	}
1669 
1670 	memset(info, 0, sizeof(*info));
1671 
1672 	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
1673 		      IEEE80211_TX_CTL_INJECTED;
1674 
1675 	/* process and remove the injection radiotap header */
1676 	if (!ieee80211_parse_tx_radiotap(skb))
1677 		goto fail;
1678 
1679 	rcu_read_lock();
1680 
1681 	/*
1682 	 * We process outgoing injected frames that have a local address
1683 	 * we handle as though they are non-injected frames.
1684 	 * This code here isn't entirely correct, the local MAC address
1685 	 * isn't always enough to find the interface to use; for proper
1686 	 * VLAN/WDS support we will need a different mechanism (which
1687 	 * likely isn't going to be monitor interfaces).
1688 	 */
1689 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1690 
1691 	list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
1692 		if (!ieee80211_sdata_running(tmp_sdata))
1693 			continue;
1694 		if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
1695 		    tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
1696 		    tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
1697 			continue;
1698 		if (ether_addr_equal(tmp_sdata->vif.addr, hdr->addr2)) {
1699 			sdata = tmp_sdata;
1700 			break;
1701 		}
1702 	}
1703 
1704 	ieee80211_xmit(sdata, skb);
1705 	rcu_read_unlock();
1706 
1707 	return NETDEV_TX_OK;
1708 
1709 fail:
1710 	dev_kfree_skb(skb);
1711 	return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1712 }
1713 
1714 /**
1715  * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1716  * subinterfaces (wlan#, WDS, and VLAN interfaces)
1717  * @skb: packet to be sent
1718  * @dev: incoming interface
1719  *
1720  * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1721  * not be freed, and caller is responsible for either retrying later or freeing
1722  * skb).
1723  *
1724  * This function takes in an Ethernet header and encapsulates it with suitable
1725  * IEEE 802.11 header based on which interface the packet is coming in. The
1726  * encapsulated packet will then be passed to master interface, wlan#.11, for
1727  * transmission (through low-level driver).
1728  */
1729 netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
1730 				    struct net_device *dev)
1731 {
1732 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1733 	struct ieee80211_local *local = sdata->local;
1734 	struct ieee80211_tx_info *info;
1735 	int ret = NETDEV_TX_BUSY, head_need;
1736 	u16 ethertype, hdrlen,  meshhdrlen = 0;
1737 	__le16 fc;
1738 	struct ieee80211_hdr hdr;
1739 	struct ieee80211s_hdr mesh_hdr __maybe_unused;
1740 	struct mesh_path __maybe_unused *mppath = NULL, *mpath = NULL;
1741 	const u8 *encaps_data;
1742 	int encaps_len, skip_header_bytes;
1743 	int nh_pos, h_pos;
1744 	struct sta_info *sta = NULL;
1745 	bool wme_sta = false, authorized = false, tdls_auth = false;
1746 	bool tdls_direct = false;
1747 	bool multicast;
1748 	u32 info_flags = 0;
1749 	u16 info_id = 0;
1750 
1751 	if (unlikely(skb->len < ETH_HLEN)) {
1752 		ret = NETDEV_TX_OK;
1753 		goto fail;
1754 	}
1755 
1756 	/* convert Ethernet header to proper 802.11 header (based on
1757 	 * operation mode) */
1758 	ethertype = (skb->data[12] << 8) | skb->data[13];
1759 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1760 
1761 	switch (sdata->vif.type) {
1762 	case NL80211_IFTYPE_AP_VLAN:
1763 		rcu_read_lock();
1764 		sta = rcu_dereference(sdata->u.vlan.sta);
1765 		if (sta) {
1766 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1767 			/* RA TA DA SA */
1768 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1769 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1770 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1771 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1772 			hdrlen = 30;
1773 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1774 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1775 		}
1776 		rcu_read_unlock();
1777 		if (sta)
1778 			break;
1779 		/* fall through */
1780 	case NL80211_IFTYPE_AP:
1781 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1782 		/* DA BSSID SA */
1783 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1784 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1785 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1786 		hdrlen = 24;
1787 		break;
1788 	case NL80211_IFTYPE_WDS:
1789 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1790 		/* RA TA DA SA */
1791 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1792 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1793 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1794 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1795 		hdrlen = 30;
1796 		break;
1797 #ifdef CONFIG_MAC80211_MESH
1798 	case NL80211_IFTYPE_MESH_POINT:
1799 		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1800 			/* Do not send frames with mesh_ttl == 0 */
1801 			sdata->u.mesh.mshstats.dropped_frames_ttl++;
1802 			ret = NETDEV_TX_OK;
1803 			goto fail;
1804 		}
1805 		rcu_read_lock();
1806 		if (!is_multicast_ether_addr(skb->data)) {
1807 			mpath = mesh_path_lookup(skb->data, sdata);
1808 			if (!mpath)
1809 				mppath = mpp_path_lookup(skb->data, sdata);
1810 		}
1811 
1812 		/*
1813 		 * Use address extension if it is a packet from
1814 		 * another interface or if we know the destination
1815 		 * is being proxied by a portal (i.e. portal address
1816 		 * differs from proxied address)
1817 		 */
1818 		if (ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN) &&
1819 		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
1820 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1821 					skb->data, skb->data + ETH_ALEN);
1822 			rcu_read_unlock();
1823 			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
1824 					sdata, NULL, NULL);
1825 		} else {
1826 			int is_mesh_mcast = 1;
1827 			const u8 *mesh_da;
1828 
1829 			if (is_multicast_ether_addr(skb->data))
1830 				/* DA TA mSA AE:SA */
1831 				mesh_da = skb->data;
1832 			else {
1833 				static const u8 bcast[ETH_ALEN] =
1834 					{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1835 				if (mppath) {
1836 					/* RA TA mDA mSA AE:DA SA */
1837 					mesh_da = mppath->mpp;
1838 					is_mesh_mcast = 0;
1839 				} else {
1840 					/* DA TA mSA AE:SA */
1841 					mesh_da = bcast;
1842 				}
1843 			}
1844 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1845 					mesh_da, sdata->vif.addr);
1846 			rcu_read_unlock();
1847 			if (is_mesh_mcast)
1848 				meshhdrlen =
1849 					ieee80211_new_mesh_header(&mesh_hdr,
1850 							sdata,
1851 							skb->data + ETH_ALEN,
1852 							NULL);
1853 			else
1854 				meshhdrlen =
1855 					ieee80211_new_mesh_header(&mesh_hdr,
1856 							sdata,
1857 							skb->data,
1858 							skb->data + ETH_ALEN);
1859 
1860 		}
1861 		break;
1862 #endif
1863 	case NL80211_IFTYPE_STATION:
1864 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
1865 			bool tdls_peer = false;
1866 
1867 			rcu_read_lock();
1868 			sta = sta_info_get(sdata, skb->data);
1869 			if (sta) {
1870 				authorized = test_sta_flag(sta,
1871 							WLAN_STA_AUTHORIZED);
1872 				wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1873 				tdls_peer = test_sta_flag(sta,
1874 							 WLAN_STA_TDLS_PEER);
1875 				tdls_auth = test_sta_flag(sta,
1876 						WLAN_STA_TDLS_PEER_AUTH);
1877 			}
1878 			rcu_read_unlock();
1879 
1880 			/*
1881 			 * If the TDLS link is enabled, send everything
1882 			 * directly. Otherwise, allow TDLS setup frames
1883 			 * to be transmitted indirectly.
1884 			 */
1885 			tdls_direct = tdls_peer && (tdls_auth ||
1886 				 !(ethertype == ETH_P_TDLS && skb->len > 14 &&
1887 				   skb->data[14] == WLAN_TDLS_SNAP_RFTYPE));
1888 		}
1889 
1890 		if (tdls_direct) {
1891 			/* link during setup - throw out frames to peer */
1892 			if (!tdls_auth) {
1893 				ret = NETDEV_TX_OK;
1894 				goto fail;
1895 			}
1896 
1897 			/* DA SA BSSID */
1898 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
1899 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1900 			memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
1901 			hdrlen = 24;
1902 		}  else if (sdata->u.mgd.use_4addr &&
1903 			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1904 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
1905 					  IEEE80211_FCTL_TODS);
1906 			/* RA TA DA SA */
1907 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1908 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1909 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1910 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1911 			hdrlen = 30;
1912 		} else {
1913 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1914 			/* BSSID SA DA */
1915 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1916 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1917 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1918 			hdrlen = 24;
1919 		}
1920 		break;
1921 	case NL80211_IFTYPE_ADHOC:
1922 		/* DA SA BSSID */
1923 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1924 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1925 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1926 		hdrlen = 24;
1927 		break;
1928 	default:
1929 		ret = NETDEV_TX_OK;
1930 		goto fail;
1931 	}
1932 
1933 	/*
1934 	 * There's no need to try to look up the destination
1935 	 * if it is a multicast address (which can only happen
1936 	 * in AP mode)
1937 	 */
1938 	multicast = is_multicast_ether_addr(hdr.addr1);
1939 	if (!multicast) {
1940 		rcu_read_lock();
1941 		sta = sta_info_get(sdata, hdr.addr1);
1942 		if (sta) {
1943 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1944 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1945 		}
1946 		rcu_read_unlock();
1947 	}
1948 
1949 	/* For mesh, the use of the QoS header is mandatory */
1950 	if (ieee80211_vif_is_mesh(&sdata->vif))
1951 		wme_sta = true;
1952 
1953 	/* receiver and we are QoS enabled, use a QoS type frame */
1954 	if (wme_sta && local->hw.queues >= IEEE80211_NUM_ACS) {
1955 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1956 		hdrlen += 2;
1957 	}
1958 
1959 	/*
1960 	 * Drop unicast frames to unauthorised stations unless they are
1961 	 * EAPOL frames from the local station.
1962 	 */
1963 	if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
1964 		     !is_multicast_ether_addr(hdr.addr1) && !authorized &&
1965 		     (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
1966 		      !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {
1967 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1968 		net_dbg_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",
1969 				    dev->name, hdr.addr1);
1970 #endif
1971 
1972 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1973 
1974 		ret = NETDEV_TX_OK;
1975 		goto fail;
1976 	}
1977 
1978 	if (unlikely(!multicast && skb->sk &&
1979 		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
1980 		struct sk_buff *orig_skb = skb;
1981 
1982 		skb = skb_clone(skb, GFP_ATOMIC);
1983 		if (skb) {
1984 			unsigned long flags;
1985 			int id, r;
1986 
1987 			spin_lock_irqsave(&local->ack_status_lock, flags);
1988 			r = idr_get_new_above(&local->ack_status_frames,
1989 					      orig_skb, 1, &id);
1990 			if (r == -EAGAIN) {
1991 				idr_pre_get(&local->ack_status_frames,
1992 					    GFP_ATOMIC);
1993 				r = idr_get_new_above(&local->ack_status_frames,
1994 						      orig_skb, 1, &id);
1995 			}
1996 			if (WARN_ON(!id) || id > 0xffff) {
1997 				idr_remove(&local->ack_status_frames, id);
1998 				r = -ERANGE;
1999 			}
2000 			spin_unlock_irqrestore(&local->ack_status_lock, flags);
2001 
2002 			if (!r) {
2003 				info_id = id;
2004 				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
2005 			} else if (skb_shared(skb)) {
2006 				kfree_skb(orig_skb);
2007 			} else {
2008 				kfree_skb(skb);
2009 				skb = orig_skb;
2010 			}
2011 		} else {
2012 			/* couldn't clone -- lose tx status ... */
2013 			skb = orig_skb;
2014 		}
2015 	}
2016 
2017 	/*
2018 	 * If the skb is shared we need to obtain our own copy.
2019 	 */
2020 	if (skb_shared(skb)) {
2021 		struct sk_buff *tmp_skb = skb;
2022 
2023 		/* can't happen -- skb is a clone if info_id != 0 */
2024 		WARN_ON(info_id);
2025 
2026 		skb = skb_clone(skb, GFP_ATOMIC);
2027 		kfree_skb(tmp_skb);
2028 
2029 		if (!skb) {
2030 			ret = NETDEV_TX_OK;
2031 			goto fail;
2032 		}
2033 	}
2034 
2035 	hdr.frame_control = fc;
2036 	hdr.duration_id = 0;
2037 	hdr.seq_ctrl = 0;
2038 
2039 	skip_header_bytes = ETH_HLEN;
2040 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
2041 		encaps_data = bridge_tunnel_header;
2042 		encaps_len = sizeof(bridge_tunnel_header);
2043 		skip_header_bytes -= 2;
2044 	} else if (ethertype >= 0x600) {
2045 		encaps_data = rfc1042_header;
2046 		encaps_len = sizeof(rfc1042_header);
2047 		skip_header_bytes -= 2;
2048 	} else {
2049 		encaps_data = NULL;
2050 		encaps_len = 0;
2051 	}
2052 
2053 	nh_pos = skb_network_header(skb) - skb->data;
2054 	h_pos = skb_transport_header(skb) - skb->data;
2055 
2056 	skb_pull(skb, skip_header_bytes);
2057 	nh_pos -= skip_header_bytes;
2058 	h_pos -= skip_header_bytes;
2059 
2060 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
2061 
2062 	/*
2063 	 * So we need to modify the skb header and hence need a copy of
2064 	 * that. The head_need variable above doesn't, so far, include
2065 	 * the needed header space that we don't need right away. If we
2066 	 * can, then we don't reallocate right now but only after the
2067 	 * frame arrives at the master device (if it does...)
2068 	 *
2069 	 * If we cannot, however, then we will reallocate to include all
2070 	 * the ever needed space. Also, if we need to reallocate it anyway,
2071 	 * make it big enough for everything we may ever need.
2072 	 */
2073 
2074 	if (head_need > 0 || skb_cloned(skb)) {
2075 		head_need += IEEE80211_ENCRYPT_HEADROOM;
2076 		head_need += local->tx_headroom;
2077 		head_need = max_t(int, 0, head_need);
2078 		if (ieee80211_skb_resize(sdata, skb, head_need, true))
2079 			goto fail;
2080 	}
2081 
2082 	if (encaps_data) {
2083 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2084 		nh_pos += encaps_len;
2085 		h_pos += encaps_len;
2086 	}
2087 
2088 #ifdef CONFIG_MAC80211_MESH
2089 	if (meshhdrlen > 0) {
2090 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2091 		nh_pos += meshhdrlen;
2092 		h_pos += meshhdrlen;
2093 	}
2094 #endif
2095 
2096 	if (ieee80211_is_data_qos(fc)) {
2097 		__le16 *qos_control;
2098 
2099 		qos_control = (__le16*) skb_push(skb, 2);
2100 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2101 		/*
2102 		 * Maybe we could actually set some fields here, for now just
2103 		 * initialise to zero to indicate no special operation.
2104 		 */
2105 		*qos_control = 0;
2106 	} else
2107 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2108 
2109 	nh_pos += hdrlen;
2110 	h_pos += hdrlen;
2111 
2112 	dev->stats.tx_packets++;
2113 	dev->stats.tx_bytes += skb->len;
2114 
2115 	/* Update skb pointers to various headers since this modified frame
2116 	 * is going to go through Linux networking code that may potentially
2117 	 * need things like pointer to IP header. */
2118 	skb_set_mac_header(skb, 0);
2119 	skb_set_network_header(skb, nh_pos);
2120 	skb_set_transport_header(skb, h_pos);
2121 
2122 	info = IEEE80211_SKB_CB(skb);
2123 	memset(info, 0, sizeof(*info));
2124 
2125 	dev->trans_start = jiffies;
2126 
2127 	info->flags = info_flags;
2128 	info->ack_frame_id = info_id;
2129 
2130 	ieee80211_xmit(sdata, skb);
2131 
2132 	return NETDEV_TX_OK;
2133 
2134  fail:
2135 	if (ret == NETDEV_TX_OK)
2136 		dev_kfree_skb(skb);
2137 
2138 	return ret;
2139 }
2140 
2141 
2142 /*
2143  * ieee80211_clear_tx_pending may not be called in a context where
2144  * it is possible that it packets could come in again.
2145  */
2146 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2147 {
2148 	int i;
2149 
2150 	for (i = 0; i < local->hw.queues; i++)
2151 		skb_queue_purge(&local->pending[i]);
2152 }
2153 
2154 /*
2155  * Returns false if the frame couldn't be transmitted but was queued instead,
2156  * which in this case means re-queued -- take as an indication to stop sending
2157  * more pending frames.
2158  */
2159 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2160 				     struct sk_buff *skb)
2161 {
2162 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2163 	struct ieee80211_sub_if_data *sdata;
2164 	struct sta_info *sta;
2165 	struct ieee80211_hdr *hdr;
2166 	bool result;
2167 
2168 	sdata = vif_to_sdata(info->control.vif);
2169 
2170 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2171 		result = ieee80211_tx(sdata, skb, true);
2172 	} else {
2173 		struct sk_buff_head skbs;
2174 
2175 		__skb_queue_head_init(&skbs);
2176 		__skb_queue_tail(&skbs, skb);
2177 
2178 		hdr = (struct ieee80211_hdr *)skb->data;
2179 		sta = sta_info_get(sdata, hdr->addr1);
2180 
2181 		result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
2182 	}
2183 
2184 	return result;
2185 }
2186 
2187 /*
2188  * Transmit all pending packets. Called from tasklet.
2189  */
2190 void ieee80211_tx_pending(unsigned long data)
2191 {
2192 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2193 	unsigned long flags;
2194 	int i;
2195 	bool txok;
2196 
2197 	rcu_read_lock();
2198 
2199 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2200 	for (i = 0; i < local->hw.queues; i++) {
2201 		/*
2202 		 * If queue is stopped by something other than due to pending
2203 		 * frames, or we have no pending frames, proceed to next queue.
2204 		 */
2205 		if (local->queue_stop_reasons[i] ||
2206 		    skb_queue_empty(&local->pending[i]))
2207 			continue;
2208 
2209 		while (!skb_queue_empty(&local->pending[i])) {
2210 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2211 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2212 
2213 			if (WARN_ON(!info->control.vif)) {
2214 				kfree_skb(skb);
2215 				continue;
2216 			}
2217 
2218 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2219 						flags);
2220 
2221 			txok = ieee80211_tx_pending_skb(local, skb);
2222 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2223 					  flags);
2224 			if (!txok)
2225 				break;
2226 		}
2227 
2228 		if (skb_queue_empty(&local->pending[i]))
2229 			ieee80211_propagate_queue_wake(local, i);
2230 	}
2231 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2232 
2233 	rcu_read_unlock();
2234 }
2235 
2236 /* functions for drivers to get certain frames */
2237 
2238 static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2239 				     struct ieee80211_if_ap *bss,
2240 				     struct sk_buff *skb,
2241 				     struct beacon_data *beacon)
2242 {
2243 	u8 *pos, *tim;
2244 	int aid0 = 0;
2245 	int i, have_bits = 0, n1, n2;
2246 
2247 	/* Generate bitmap for TIM only if there are any STAs in power save
2248 	 * mode. */
2249 	if (atomic_read(&bss->num_sta_ps) > 0)
2250 		/* in the hope that this is faster than
2251 		 * checking byte-for-byte */
2252 		have_bits = !bitmap_empty((unsigned long*)bss->tim,
2253 					  IEEE80211_MAX_AID+1);
2254 
2255 	if (bss->dtim_count == 0)
2256 		bss->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
2257 	else
2258 		bss->dtim_count--;
2259 
2260 	tim = pos = (u8 *) skb_put(skb, 6);
2261 	*pos++ = WLAN_EID_TIM;
2262 	*pos++ = 4;
2263 	*pos++ = bss->dtim_count;
2264 	*pos++ = sdata->vif.bss_conf.dtim_period;
2265 
2266 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
2267 		aid0 = 1;
2268 
2269 	bss->dtim_bc_mc = aid0 == 1;
2270 
2271 	if (have_bits) {
2272 		/* Find largest even number N1 so that bits numbered 1 through
2273 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2274 		 * (N2 + 1) x 8 through 2007 are 0. */
2275 		n1 = 0;
2276 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2277 			if (bss->tim[i]) {
2278 				n1 = i & 0xfe;
2279 				break;
2280 			}
2281 		}
2282 		n2 = n1;
2283 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2284 			if (bss->tim[i]) {
2285 				n2 = i;
2286 				break;
2287 			}
2288 		}
2289 
2290 		/* Bitmap control */
2291 		*pos++ = n1 | aid0;
2292 		/* Part Virt Bitmap */
2293 		skb_put(skb, n2 - n1);
2294 		memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2295 
2296 		tim[1] = n2 - n1 + 4;
2297 	} else {
2298 		*pos++ = aid0; /* Bitmap control */
2299 		*pos++ = 0; /* Part Virt Bitmap */
2300 	}
2301 }
2302 
2303 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2304 					 struct ieee80211_vif *vif,
2305 					 u16 *tim_offset, u16 *tim_length)
2306 {
2307 	struct ieee80211_local *local = hw_to_local(hw);
2308 	struct sk_buff *skb = NULL;
2309 	struct ieee80211_tx_info *info;
2310 	struct ieee80211_sub_if_data *sdata = NULL;
2311 	struct ieee80211_if_ap *ap = NULL;
2312 	struct beacon_data *beacon;
2313 	struct ieee80211_supported_band *sband;
2314 	enum ieee80211_band band = local->hw.conf.channel->band;
2315 	struct ieee80211_tx_rate_control txrc;
2316 
2317 	sband = local->hw.wiphy->bands[band];
2318 
2319 	rcu_read_lock();
2320 
2321 	sdata = vif_to_sdata(vif);
2322 
2323 	if (!ieee80211_sdata_running(sdata))
2324 		goto out;
2325 
2326 	if (tim_offset)
2327 		*tim_offset = 0;
2328 	if (tim_length)
2329 		*tim_length = 0;
2330 
2331 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2332 		ap = &sdata->u.ap;
2333 		beacon = rcu_dereference(ap->beacon);
2334 		if (beacon) {
2335 			/*
2336 			 * headroom, head length,
2337 			 * tail length and maximum TIM length
2338 			 */
2339 			skb = dev_alloc_skb(local->tx_headroom +
2340 					    beacon->head_len +
2341 					    beacon->tail_len + 256);
2342 			if (!skb)
2343 				goto out;
2344 
2345 			skb_reserve(skb, local->tx_headroom);
2346 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2347 			       beacon->head_len);
2348 
2349 			/*
2350 			 * Not very nice, but we want to allow the driver to call
2351 			 * ieee80211_beacon_get() as a response to the set_tim()
2352 			 * callback. That, however, is already invoked under the
2353 			 * sta_lock to guarantee consistent and race-free update
2354 			 * of the tim bitmap in mac80211 and the driver.
2355 			 */
2356 			if (local->tim_in_locked_section) {
2357 				ieee80211_beacon_add_tim(sdata, ap, skb,
2358 							 beacon);
2359 			} else {
2360 				unsigned long flags;
2361 
2362 				spin_lock_irqsave(&local->tim_lock, flags);
2363 				ieee80211_beacon_add_tim(sdata, ap, skb,
2364 							 beacon);
2365 				spin_unlock_irqrestore(&local->tim_lock, flags);
2366 			}
2367 
2368 			if (tim_offset)
2369 				*tim_offset = beacon->head_len;
2370 			if (tim_length)
2371 				*tim_length = skb->len - beacon->head_len;
2372 
2373 			if (beacon->tail)
2374 				memcpy(skb_put(skb, beacon->tail_len),
2375 				       beacon->tail, beacon->tail_len);
2376 		} else
2377 			goto out;
2378 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2379 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2380 		struct ieee80211_hdr *hdr;
2381 		struct sk_buff *presp = rcu_dereference(ifibss->presp);
2382 
2383 		if (!presp)
2384 			goto out;
2385 
2386 		skb = skb_copy(presp, GFP_ATOMIC);
2387 		if (!skb)
2388 			goto out;
2389 
2390 		hdr = (struct ieee80211_hdr *) skb->data;
2391 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2392 						 IEEE80211_STYPE_BEACON);
2393 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2394 		struct ieee80211_mgmt *mgmt;
2395 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2396 		u8 *pos;
2397 		int hdr_len = offsetof(struct ieee80211_mgmt, u.beacon) +
2398 			      sizeof(mgmt->u.beacon);
2399 
2400 #ifdef CONFIG_MAC80211_MESH
2401 		if (!sdata->u.mesh.mesh_id_len)
2402 			goto out;
2403 #endif
2404 
2405 		if (ifmsh->sync_ops)
2406 			ifmsh->sync_ops->adjust_tbtt(
2407 						sdata);
2408 
2409 		skb = dev_alloc_skb(local->tx_headroom +
2410 				    hdr_len +
2411 				    2 + /* NULL SSID */
2412 				    2 + 8 + /* supported rates */
2413 				    2 + 3 + /* DS params */
2414 				    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
2415 				    2 + sizeof(struct ieee80211_ht_cap) +
2416 				    2 + sizeof(struct ieee80211_ht_operation) +
2417 				    2 + sdata->u.mesh.mesh_id_len +
2418 				    2 + sizeof(struct ieee80211_meshconf_ie) +
2419 				    sdata->u.mesh.ie_len);
2420 		if (!skb)
2421 			goto out;
2422 
2423 		skb_reserve(skb, local->hw.extra_tx_headroom);
2424 		mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
2425 		memset(mgmt, 0, hdr_len);
2426 		mgmt->frame_control =
2427 		    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2428 		memset(mgmt->da, 0xff, ETH_ALEN);
2429 		memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
2430 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
2431 		mgmt->u.beacon.beacon_int =
2432 			cpu_to_le16(sdata->vif.bss_conf.beacon_int);
2433 		mgmt->u.beacon.capab_info |= cpu_to_le16(
2434 			sdata->u.mesh.security ? WLAN_CAPABILITY_PRIVACY : 0);
2435 
2436 		pos = skb_put(skb, 2);
2437 		*pos++ = WLAN_EID_SSID;
2438 		*pos++ = 0x0;
2439 
2440 		if (ieee80211_add_srates_ie(&sdata->vif, skb, true) ||
2441 		    mesh_add_ds_params_ie(skb, sdata) ||
2442 		    ieee80211_add_ext_srates_ie(&sdata->vif, skb, true) ||
2443 		    mesh_add_rsn_ie(skb, sdata) ||
2444 		    mesh_add_ht_cap_ie(skb, sdata) ||
2445 		    mesh_add_ht_oper_ie(skb, sdata) ||
2446 		    mesh_add_meshid_ie(skb, sdata) ||
2447 		    mesh_add_meshconf_ie(skb, sdata) ||
2448 		    mesh_add_vendor_ies(skb, sdata)) {
2449 			pr_err("o11s: couldn't add ies!\n");
2450 			goto out;
2451 		}
2452 	} else {
2453 		WARN_ON(1);
2454 		goto out;
2455 	}
2456 
2457 	info = IEEE80211_SKB_CB(skb);
2458 
2459 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2460 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2461 	info->band = band;
2462 
2463 	memset(&txrc, 0, sizeof(txrc));
2464 	txrc.hw = hw;
2465 	txrc.sband = sband;
2466 	txrc.bss_conf = &sdata->vif.bss_conf;
2467 	txrc.skb = skb;
2468 	txrc.reported_rate.idx = -1;
2469 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2470 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
2471 		txrc.max_rate_idx = -1;
2472 	else
2473 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2474 	memcpy(txrc.rate_idx_mcs_mask, sdata->rc_rateidx_mcs_mask[band],
2475 	       sizeof(txrc.rate_idx_mcs_mask));
2476 	txrc.bss = true;
2477 	rate_control_get_rate(sdata, NULL, &txrc);
2478 
2479 	info->control.vif = vif;
2480 
2481 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2482 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2483 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2484  out:
2485 	rcu_read_unlock();
2486 	return skb;
2487 }
2488 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2489 
2490 struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
2491 					struct ieee80211_vif *vif)
2492 {
2493 	struct ieee80211_if_ap *ap = NULL;
2494 	struct sk_buff *presp = NULL, *skb = NULL;
2495 	struct ieee80211_hdr *hdr;
2496 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2497 
2498 	if (sdata->vif.type != NL80211_IFTYPE_AP)
2499 		return NULL;
2500 
2501 	rcu_read_lock();
2502 
2503 	ap = &sdata->u.ap;
2504 	presp = rcu_dereference(ap->probe_resp);
2505 	if (!presp)
2506 		goto out;
2507 
2508 	skb = skb_copy(presp, GFP_ATOMIC);
2509 	if (!skb)
2510 		goto out;
2511 
2512 	hdr = (struct ieee80211_hdr *) skb->data;
2513 	memset(hdr->addr1, 0, sizeof(hdr->addr1));
2514 
2515 out:
2516 	rcu_read_unlock();
2517 	return skb;
2518 }
2519 EXPORT_SYMBOL(ieee80211_proberesp_get);
2520 
2521 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2522 				     struct ieee80211_vif *vif)
2523 {
2524 	struct ieee80211_sub_if_data *sdata;
2525 	struct ieee80211_if_managed *ifmgd;
2526 	struct ieee80211_pspoll *pspoll;
2527 	struct ieee80211_local *local;
2528 	struct sk_buff *skb;
2529 
2530 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2531 		return NULL;
2532 
2533 	sdata = vif_to_sdata(vif);
2534 	ifmgd = &sdata->u.mgd;
2535 	local = sdata->local;
2536 
2537 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2538 	if (!skb)
2539 		return NULL;
2540 
2541 	skb_reserve(skb, local->hw.extra_tx_headroom);
2542 
2543 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2544 	memset(pspoll, 0, sizeof(*pspoll));
2545 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2546 					    IEEE80211_STYPE_PSPOLL);
2547 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2548 
2549 	/* aid in PS-Poll has its two MSBs each set to 1 */
2550 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2551 
2552 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2553 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2554 
2555 	return skb;
2556 }
2557 EXPORT_SYMBOL(ieee80211_pspoll_get);
2558 
2559 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2560 				       struct ieee80211_vif *vif)
2561 {
2562 	struct ieee80211_hdr_3addr *nullfunc;
2563 	struct ieee80211_sub_if_data *sdata;
2564 	struct ieee80211_if_managed *ifmgd;
2565 	struct ieee80211_local *local;
2566 	struct sk_buff *skb;
2567 
2568 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2569 		return NULL;
2570 
2571 	sdata = vif_to_sdata(vif);
2572 	ifmgd = &sdata->u.mgd;
2573 	local = sdata->local;
2574 
2575 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2576 	if (!skb)
2577 		return NULL;
2578 
2579 	skb_reserve(skb, local->hw.extra_tx_headroom);
2580 
2581 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2582 							  sizeof(*nullfunc));
2583 	memset(nullfunc, 0, sizeof(*nullfunc));
2584 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2585 					      IEEE80211_STYPE_NULLFUNC |
2586 					      IEEE80211_FCTL_TODS);
2587 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2588 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2589 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2590 
2591 	return skb;
2592 }
2593 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2594 
2595 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2596 				       struct ieee80211_vif *vif,
2597 				       const u8 *ssid, size_t ssid_len,
2598 				       const u8 *ie, size_t ie_len)
2599 {
2600 	struct ieee80211_sub_if_data *sdata;
2601 	struct ieee80211_local *local;
2602 	struct ieee80211_hdr_3addr *hdr;
2603 	struct sk_buff *skb;
2604 	size_t ie_ssid_len;
2605 	u8 *pos;
2606 
2607 	sdata = vif_to_sdata(vif);
2608 	local = sdata->local;
2609 	ie_ssid_len = 2 + ssid_len;
2610 
2611 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2612 			    ie_ssid_len + ie_len);
2613 	if (!skb)
2614 		return NULL;
2615 
2616 	skb_reserve(skb, local->hw.extra_tx_headroom);
2617 
2618 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2619 	memset(hdr, 0, sizeof(*hdr));
2620 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2621 					 IEEE80211_STYPE_PROBE_REQ);
2622 	memset(hdr->addr1, 0xff, ETH_ALEN);
2623 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2624 	memset(hdr->addr3, 0xff, ETH_ALEN);
2625 
2626 	pos = skb_put(skb, ie_ssid_len);
2627 	*pos++ = WLAN_EID_SSID;
2628 	*pos++ = ssid_len;
2629 	if (ssid_len)
2630 		memcpy(pos, ssid, ssid_len);
2631 	pos += ssid_len;
2632 
2633 	if (ie) {
2634 		pos = skb_put(skb, ie_len);
2635 		memcpy(pos, ie, ie_len);
2636 	}
2637 
2638 	return skb;
2639 }
2640 EXPORT_SYMBOL(ieee80211_probereq_get);
2641 
2642 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2643 		       const void *frame, size_t frame_len,
2644 		       const struct ieee80211_tx_info *frame_txctl,
2645 		       struct ieee80211_rts *rts)
2646 {
2647 	const struct ieee80211_hdr *hdr = frame;
2648 
2649 	rts->frame_control =
2650 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2651 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2652 					       frame_txctl);
2653 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2654 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2655 }
2656 EXPORT_SYMBOL(ieee80211_rts_get);
2657 
2658 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2659 			     const void *frame, size_t frame_len,
2660 			     const struct ieee80211_tx_info *frame_txctl,
2661 			     struct ieee80211_cts *cts)
2662 {
2663 	const struct ieee80211_hdr *hdr = frame;
2664 
2665 	cts->frame_control =
2666 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2667 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2668 						     frame_len, frame_txctl);
2669 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2670 }
2671 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2672 
2673 struct sk_buff *
2674 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2675 			  struct ieee80211_vif *vif)
2676 {
2677 	struct ieee80211_local *local = hw_to_local(hw);
2678 	struct sk_buff *skb = NULL;
2679 	struct ieee80211_tx_data tx;
2680 	struct ieee80211_sub_if_data *sdata;
2681 	struct ieee80211_if_ap *bss = NULL;
2682 	struct beacon_data *beacon;
2683 	struct ieee80211_tx_info *info;
2684 
2685 	sdata = vif_to_sdata(vif);
2686 	bss = &sdata->u.ap;
2687 
2688 	rcu_read_lock();
2689 	beacon = rcu_dereference(bss->beacon);
2690 
2691 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2692 		goto out;
2693 
2694 	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
2695 		goto out; /* send buffered bc/mc only after DTIM beacon */
2696 
2697 	while (1) {
2698 		skb = skb_dequeue(&bss->ps_bc_buf);
2699 		if (!skb)
2700 			goto out;
2701 		local->total_ps_buffered--;
2702 
2703 		if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2704 			struct ieee80211_hdr *hdr =
2705 				(struct ieee80211_hdr *) skb->data;
2706 			/* more buffered multicast/broadcast frames ==> set
2707 			 * MoreData flag in IEEE 802.11 header to inform PS
2708 			 * STAs */
2709 			hdr->frame_control |=
2710 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2711 		}
2712 
2713 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2714 			break;
2715 		dev_kfree_skb_any(skb);
2716 	}
2717 
2718 	info = IEEE80211_SKB_CB(skb);
2719 
2720 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2721 	tx.channel = local->hw.conf.channel;
2722 	info->band = tx.channel->band;
2723 
2724 	if (invoke_tx_handlers(&tx))
2725 		skb = NULL;
2726  out:
2727 	rcu_read_unlock();
2728 
2729 	return skb;
2730 }
2731 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2732 
2733 void ieee80211_tx_skb_tid(struct ieee80211_sub_if_data *sdata,
2734 			  struct sk_buff *skb, int tid)
2735 {
2736 	int ac = ieee802_1d_to_ac[tid];
2737 
2738 	skb_set_mac_header(skb, 0);
2739 	skb_set_network_header(skb, 0);
2740 	skb_set_transport_header(skb, 0);
2741 
2742 	skb_set_queue_mapping(skb, ac);
2743 	skb->priority = tid;
2744 
2745 	/*
2746 	 * The other path calling ieee80211_xmit is from the tasklet,
2747 	 * and while we can handle concurrent transmissions locking
2748 	 * requirements are that we do not come into tx with bhs on.
2749 	 */
2750 	local_bh_disable();
2751 	ieee80211_xmit(sdata, skb);
2752 	local_bh_enable();
2753 }
2754