xref: /openbmc/linux/net/mac80211/tx.c (revision cd5d5810)
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, shift = 0;
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 	struct ieee80211_chanctx_conf *chanctx_conf;
50 	u32 rate_flags = 0;
51 
52 	rcu_read_lock();
53 	chanctx_conf = rcu_dereference(tx->sdata->vif.chanctx_conf);
54 	if (chanctx_conf) {
55 		shift = ieee80211_chandef_get_shift(&chanctx_conf->def);
56 		rate_flags = ieee80211_chandef_rate_flags(&chanctx_conf->def);
57 	}
58 	rcu_read_unlock();
59 
60 	/* assume HW handles this */
61 	if (tx->rate.flags & IEEE80211_TX_RC_MCS)
62 		return 0;
63 
64 	/* uh huh? */
65 	if (WARN_ON_ONCE(tx->rate.idx < 0))
66 		return 0;
67 
68 	sband = local->hw.wiphy->bands[info->band];
69 	txrate = &sband->bitrates[tx->rate.idx];
70 
71 	erp = txrate->flags & IEEE80211_RATE_ERP_G;
72 
73 	/*
74 	 * data and mgmt (except PS Poll):
75 	 * - during CFP: 32768
76 	 * - during contention period:
77 	 *   if addr1 is group address: 0
78 	 *   if more fragments = 0 and addr1 is individual address: time to
79 	 *      transmit one ACK plus SIFS
80 	 *   if more fragments = 1 and addr1 is individual address: time to
81 	 *      transmit next fragment plus 2 x ACK plus 3 x SIFS
82 	 *
83 	 * IEEE 802.11, 9.6:
84 	 * - control response frame (CTS or ACK) shall be transmitted using the
85 	 *   same rate as the immediately previous frame in the frame exchange
86 	 *   sequence, if this rate belongs to the PHY mandatory rates, or else
87 	 *   at the highest possible rate belonging to the PHY rates in the
88 	 *   BSSBasicRateSet
89 	 */
90 	hdr = (struct ieee80211_hdr *)skb->data;
91 	if (ieee80211_is_ctl(hdr->frame_control)) {
92 		/* TODO: These control frames are not currently sent by
93 		 * mac80211, but should they be implemented, this function
94 		 * needs to be updated to support duration field calculation.
95 		 *
96 		 * RTS: time needed to transmit pending data/mgmt frame plus
97 		 *    one CTS frame plus one ACK frame plus 3 x SIFS
98 		 * CTS: duration of immediately previous RTS minus time
99 		 *    required to transmit CTS and its SIFS
100 		 * ACK: 0 if immediately previous directed data/mgmt had
101 		 *    more=0, with more=1 duration in ACK frame is duration
102 		 *    from previous frame minus time needed to transmit ACK
103 		 *    and its SIFS
104 		 * PS Poll: BIT(15) | BIT(14) | aid
105 		 */
106 		return 0;
107 	}
108 
109 	/* data/mgmt */
110 	if (0 /* FIX: data/mgmt during CFP */)
111 		return cpu_to_le16(32768);
112 
113 	if (group_addr) /* Group address as the destination - no ACK */
114 		return 0;
115 
116 	/* Individual destination address:
117 	 * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
118 	 * CTS and ACK frames shall be transmitted using the highest rate in
119 	 * basic rate set that is less than or equal to the rate of the
120 	 * immediately previous frame and that is using the same modulation
121 	 * (CCK or OFDM). If no basic rate set matches with these requirements,
122 	 * the highest mandatory rate of the PHY that is less than or equal to
123 	 * the rate of the previous frame is used.
124 	 * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
125 	 */
126 	rate = -1;
127 	/* use lowest available if everything fails */
128 	mrate = sband->bitrates[0].bitrate;
129 	for (i = 0; i < sband->n_bitrates; i++) {
130 		struct ieee80211_rate *r = &sband->bitrates[i];
131 
132 		if (r->bitrate > txrate->bitrate)
133 			break;
134 
135 		if ((rate_flags & r->flags) != rate_flags)
136 			continue;
137 
138 		if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
139 			rate = DIV_ROUND_UP(r->bitrate, 1 << shift);
140 
141 		switch (sband->band) {
142 		case IEEE80211_BAND_2GHZ: {
143 			u32 flag;
144 			if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
145 				flag = IEEE80211_RATE_MANDATORY_G;
146 			else
147 				flag = IEEE80211_RATE_MANDATORY_B;
148 			if (r->flags & flag)
149 				mrate = r->bitrate;
150 			break;
151 		}
152 		case IEEE80211_BAND_5GHZ:
153 			if (r->flags & IEEE80211_RATE_MANDATORY_A)
154 				mrate = r->bitrate;
155 			break;
156 		case IEEE80211_BAND_60GHZ:
157 			/* TODO, for now fall through */
158 		case IEEE80211_NUM_BANDS:
159 			WARN_ON(1);
160 			break;
161 		}
162 	}
163 	if (rate == -1) {
164 		/* No matching basic rate found; use highest suitable mandatory
165 		 * PHY rate */
166 		rate = DIV_ROUND_UP(mrate, 1 << shift);
167 	}
168 
169 	/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
170 	if (ieee80211_is_data_qos(hdr->frame_control) &&
171 	    *(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
172 		dur = 0;
173 	else
174 		/* Time needed to transmit ACK
175 		 * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
176 		 * to closest integer */
177 		dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
178 				tx->sdata->vif.bss_conf.use_short_preamble,
179 				shift);
180 
181 	if (next_frag_len) {
182 		/* Frame is fragmented: duration increases with time needed to
183 		 * transmit next fragment plus ACK and 2 x SIFS. */
184 		dur *= 2; /* ACK + SIFS */
185 		/* next fragment */
186 		dur += ieee80211_frame_duration(sband->band, next_frag_len,
187 				txrate->bitrate, erp,
188 				tx->sdata->vif.bss_conf.use_short_preamble,
189 				shift);
190 	}
191 
192 	return cpu_to_le16(dur);
193 }
194 
195 /* tx handlers */
196 static ieee80211_tx_result debug_noinline
197 ieee80211_tx_h_dynamic_ps(struct ieee80211_tx_data *tx)
198 {
199 	struct ieee80211_local *local = tx->local;
200 	struct ieee80211_if_managed *ifmgd;
201 
202 	/* driver doesn't support power save */
203 	if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_PS))
204 		return TX_CONTINUE;
205 
206 	/* hardware does dynamic power save */
207 	if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
208 		return TX_CONTINUE;
209 
210 	/* dynamic power save disabled */
211 	if (local->hw.conf.dynamic_ps_timeout <= 0)
212 		return TX_CONTINUE;
213 
214 	/* we are scanning, don't enable power save */
215 	if (local->scanning)
216 		return TX_CONTINUE;
217 
218 	if (!local->ps_sdata)
219 		return TX_CONTINUE;
220 
221 	/* No point if we're going to suspend */
222 	if (local->quiescing)
223 		return TX_CONTINUE;
224 
225 	/* dynamic ps is supported only in managed mode */
226 	if (tx->sdata->vif.type != NL80211_IFTYPE_STATION)
227 		return TX_CONTINUE;
228 
229 	ifmgd = &tx->sdata->u.mgd;
230 
231 	/*
232 	 * Don't wakeup from power save if u-apsd is enabled, voip ac has
233 	 * u-apsd enabled and the frame is in voip class. This effectively
234 	 * means that even if all access categories have u-apsd enabled, in
235 	 * practise u-apsd is only used with the voip ac. This is a
236 	 * workaround for the case when received voip class packets do not
237 	 * have correct qos tag for some reason, due the network or the
238 	 * peer application.
239 	 *
240 	 * Note: ifmgd->uapsd_queues access is racy here. If the value is
241 	 * changed via debugfs, user needs to reassociate manually to have
242 	 * everything in sync.
243 	 */
244 	if ((ifmgd->flags & IEEE80211_STA_UAPSD_ENABLED) &&
245 	    (ifmgd->uapsd_queues & IEEE80211_WMM_IE_STA_QOSINFO_AC_VO) &&
246 	    skb_get_queue_mapping(tx->skb) == IEEE80211_AC_VO)
247 		return TX_CONTINUE;
248 
249 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
250 		ieee80211_stop_queues_by_reason(&local->hw,
251 						IEEE80211_MAX_QUEUE_MAP,
252 						IEEE80211_QUEUE_STOP_REASON_PS);
253 		ifmgd->flags &= ~IEEE80211_STA_NULLFUNC_ACKED;
254 		ieee80211_queue_work(&local->hw,
255 				     &local->dynamic_ps_disable_work);
256 	}
257 
258 	/* Don't restart the timer if we're not disassociated */
259 	if (!ifmgd->associated)
260 		return TX_CONTINUE;
261 
262 	mod_timer(&local->dynamic_ps_timer, jiffies +
263 		  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
264 
265 	return TX_CONTINUE;
266 }
267 
268 static ieee80211_tx_result debug_noinline
269 ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
270 {
271 
272 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
273 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
274 	bool assoc = false;
275 
276 	if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
277 		return TX_CONTINUE;
278 
279 	if (unlikely(test_bit(SCAN_SW_SCANNING, &tx->local->scanning)) &&
280 	    test_bit(SDATA_STATE_OFFCHANNEL, &tx->sdata->state) &&
281 	    !ieee80211_is_probe_req(hdr->frame_control) &&
282 	    !ieee80211_is_nullfunc(hdr->frame_control))
283 		/*
284 		 * When software scanning only nullfunc frames (to notify
285 		 * the sleep state to the AP) and probe requests (for the
286 		 * active scan) are allowed, all other frames should not be
287 		 * sent and we should not get here, but if we do
288 		 * nonetheless, drop them to avoid sending them
289 		 * off-channel. See the link below and
290 		 * ieee80211_start_scan() for more.
291 		 *
292 		 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
293 		 */
294 		return TX_DROP;
295 
296 	if (tx->sdata->vif.type == NL80211_IFTYPE_WDS)
297 		return TX_CONTINUE;
298 
299 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
300 		return TX_CONTINUE;
301 
302 	if (tx->flags & IEEE80211_TX_PS_BUFFERED)
303 		return TX_CONTINUE;
304 
305 	if (tx->sta)
306 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
307 
308 	if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
309 		if (unlikely(!assoc &&
310 			     ieee80211_is_data(hdr->frame_control))) {
311 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
312 			sdata_info(tx->sdata,
313 				   "dropped data frame to not associated station %pM\n",
314 				   hdr->addr1);
315 #endif
316 			I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
317 			return TX_DROP;
318 		}
319 	} else if (unlikely(tx->sdata->vif.type == NL80211_IFTYPE_AP &&
320 			    ieee80211_is_data(hdr->frame_control) &&
321 			    !atomic_read(&tx->sdata->u.ap.num_mcast_sta))) {
322 		/*
323 		 * No associated STAs - no need to send multicast
324 		 * frames.
325 		 */
326 		return TX_DROP;
327 	}
328 
329 	return TX_CONTINUE;
330 }
331 
332 /* This function is called whenever the AP is about to exceed the maximum limit
333  * of buffered frames for power saving STAs. This situation should not really
334  * happen often during normal operation, so dropping the oldest buffered packet
335  * from each queue should be OK to make some room for new frames. */
336 static void purge_old_ps_buffers(struct ieee80211_local *local)
337 {
338 	int total = 0, purged = 0;
339 	struct sk_buff *skb;
340 	struct ieee80211_sub_if_data *sdata;
341 	struct sta_info *sta;
342 
343 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
344 		struct ps_data *ps;
345 
346 		if (sdata->vif.type == NL80211_IFTYPE_AP)
347 			ps = &sdata->u.ap.ps;
348 		else if (ieee80211_vif_is_mesh(&sdata->vif))
349 			ps = &sdata->u.mesh.ps;
350 		else
351 			continue;
352 
353 		skb = skb_dequeue(&ps->bc_buf);
354 		if (skb) {
355 			purged++;
356 			dev_kfree_skb(skb);
357 		}
358 		total += skb_queue_len(&ps->bc_buf);
359 	}
360 
361 	/*
362 	 * Drop one frame from each station from the lowest-priority
363 	 * AC that has frames at all.
364 	 */
365 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
366 		int ac;
367 
368 		for (ac = IEEE80211_AC_BK; ac >= IEEE80211_AC_VO; ac--) {
369 			skb = skb_dequeue(&sta->ps_tx_buf[ac]);
370 			total += skb_queue_len(&sta->ps_tx_buf[ac]);
371 			if (skb) {
372 				purged++;
373 				ieee80211_free_txskb(&local->hw, skb);
374 				break;
375 			}
376 		}
377 	}
378 
379 	local->total_ps_buffered = total;
380 	ps_dbg_hw(&local->hw, "PS buffers full - purged %d frames\n", purged);
381 }
382 
383 static ieee80211_tx_result
384 ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
385 {
386 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
387 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
388 	struct ps_data *ps;
389 
390 	/*
391 	 * broadcast/multicast frame
392 	 *
393 	 * If any of the associated/peer stations is in power save mode,
394 	 * the frame is buffered to be sent after DTIM beacon frame.
395 	 * This is done either by the hardware or us.
396 	 */
397 
398 	/* powersaving STAs currently only in AP/VLAN/mesh mode */
399 	if (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
400 	    tx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
401 		if (!tx->sdata->bss)
402 			return TX_CONTINUE;
403 
404 		ps = &tx->sdata->bss->ps;
405 	} else if (ieee80211_vif_is_mesh(&tx->sdata->vif)) {
406 		ps = &tx->sdata->u.mesh.ps;
407 	} else {
408 		return TX_CONTINUE;
409 	}
410 
411 
412 	/* no buffering for ordered frames */
413 	if (ieee80211_has_order(hdr->frame_control))
414 		return TX_CONTINUE;
415 
416 	if (tx->local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
417 		info->hw_queue = tx->sdata->vif.cab_queue;
418 
419 	/* no stations in PS mode */
420 	if (!atomic_read(&ps->num_sta_ps))
421 		return TX_CONTINUE;
422 
423 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
424 
425 	/* device releases frame after DTIM beacon */
426 	if (!(tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING))
427 		return TX_CONTINUE;
428 
429 	/* buffered in mac80211 */
430 	if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
431 		purge_old_ps_buffers(tx->local);
432 
433 	if (skb_queue_len(&ps->bc_buf) >= AP_MAX_BC_BUFFER) {
434 		ps_dbg(tx->sdata,
435 		       "BC TX buffer full - dropping the oldest frame\n");
436 		dev_kfree_skb(skb_dequeue(&ps->bc_buf));
437 	} else
438 		tx->local->total_ps_buffered++;
439 
440 	skb_queue_tail(&ps->bc_buf, tx->skb);
441 
442 	return TX_QUEUED;
443 }
444 
445 static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
446 			     struct sk_buff *skb)
447 {
448 	if (!ieee80211_is_mgmt(fc))
449 		return 0;
450 
451 	if (sta == NULL || !test_sta_flag(sta, WLAN_STA_MFP))
452 		return 0;
453 
454 	if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
455 					    skb->data))
456 		return 0;
457 
458 	return 1;
459 }
460 
461 static ieee80211_tx_result
462 ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
463 {
464 	struct sta_info *sta = tx->sta;
465 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
466 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
467 	struct ieee80211_local *local = tx->local;
468 
469 	if (unlikely(!sta))
470 		return TX_CONTINUE;
471 
472 	if (unlikely((test_sta_flag(sta, WLAN_STA_PS_STA) ||
473 		      test_sta_flag(sta, WLAN_STA_PS_DRIVER)) &&
474 		     !(info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER))) {
475 		int ac = skb_get_queue_mapping(tx->skb);
476 
477 		/* only deauth, disassoc and action are bufferable MMPDUs */
478 		if (ieee80211_is_mgmt(hdr->frame_control) &&
479 		    !ieee80211_is_deauth(hdr->frame_control) &&
480 		    !ieee80211_is_disassoc(hdr->frame_control) &&
481 		    !ieee80211_is_action(hdr->frame_control)) {
482 			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
483 			return TX_CONTINUE;
484 		}
485 
486 		ps_dbg(sta->sdata, "STA %pM aid %d: PS buffer for AC %d\n",
487 		       sta->sta.addr, sta->sta.aid, ac);
488 		if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
489 			purge_old_ps_buffers(tx->local);
490 		if (skb_queue_len(&sta->ps_tx_buf[ac]) >= STA_MAX_TX_BUFFER) {
491 			struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf[ac]);
492 			ps_dbg(tx->sdata,
493 			       "STA %pM TX buffer for AC %d full - dropping oldest frame\n",
494 			       sta->sta.addr, ac);
495 			ieee80211_free_txskb(&local->hw, old);
496 		} else
497 			tx->local->total_ps_buffered++;
498 
499 		info->control.jiffies = jiffies;
500 		info->control.vif = &tx->sdata->vif;
501 		info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
502 		skb_queue_tail(&sta->ps_tx_buf[ac], tx->skb);
503 
504 		if (!timer_pending(&local->sta_cleanup))
505 			mod_timer(&local->sta_cleanup,
506 				  round_jiffies(jiffies +
507 						STA_INFO_CLEANUP_INTERVAL));
508 
509 		/*
510 		 * We queued up some frames, so the TIM bit might
511 		 * need to be set, recalculate it.
512 		 */
513 		sta_info_recalc_tim(sta);
514 
515 		return TX_QUEUED;
516 	} else if (unlikely(test_sta_flag(sta, WLAN_STA_PS_STA))) {
517 		ps_dbg(tx->sdata,
518 		       "STA %pM in PS mode, but polling/in SP -> send frame\n",
519 		       sta->sta.addr);
520 	}
521 
522 	return TX_CONTINUE;
523 }
524 
525 static ieee80211_tx_result debug_noinline
526 ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
527 {
528 	if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
529 		return TX_CONTINUE;
530 
531 	if (tx->flags & IEEE80211_TX_UNICAST)
532 		return ieee80211_tx_h_unicast_ps_buf(tx);
533 	else
534 		return ieee80211_tx_h_multicast_ps_buf(tx);
535 }
536 
537 static ieee80211_tx_result debug_noinline
538 ieee80211_tx_h_check_control_port_protocol(struct ieee80211_tx_data *tx)
539 {
540 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
541 
542 	if (unlikely(tx->sdata->control_port_protocol == tx->skb->protocol)) {
543 		if (tx->sdata->control_port_no_encrypt)
544 			info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
545 		info->control.flags |= IEEE80211_TX_CTRL_PORT_CTRL_PROTO;
546 	}
547 
548 	return TX_CONTINUE;
549 }
550 
551 static ieee80211_tx_result debug_noinline
552 ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
553 {
554 	struct ieee80211_key *key;
555 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
556 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
557 
558 	if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
559 		tx->key = NULL;
560 	else if (tx->sta && (key = rcu_dereference(tx->sta->ptk)))
561 		tx->key = key;
562 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
563 		 is_multicast_ether_addr(hdr->addr1) &&
564 		 ieee80211_is_robust_mgmt_frame(hdr) &&
565 		 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
566 		tx->key = key;
567 	else if (is_multicast_ether_addr(hdr->addr1) &&
568 		 (key = rcu_dereference(tx->sdata->default_multicast_key)))
569 		tx->key = key;
570 	else if (!is_multicast_ether_addr(hdr->addr1) &&
571 		 (key = rcu_dereference(tx->sdata->default_unicast_key)))
572 		tx->key = key;
573 	else if (info->flags & IEEE80211_TX_CTL_INJECTED)
574 		tx->key = NULL;
575 	else if (!tx->sdata->drop_unencrypted)
576 		tx->key = NULL;
577 	else if (tx->skb->protocol == tx->sdata->control_port_protocol)
578 		tx->key = NULL;
579 	else if (ieee80211_is_robust_mgmt_frame(hdr) &&
580 		 !(ieee80211_is_action(hdr->frame_control) &&
581 		   tx->sta && test_sta_flag(tx->sta, WLAN_STA_MFP)))
582 		tx->key = NULL;
583 	else if (ieee80211_is_mgmt(hdr->frame_control) &&
584 		 !ieee80211_is_robust_mgmt_frame(hdr))
585 		tx->key = NULL;
586 	else {
587 		I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
588 		return TX_DROP;
589 	}
590 
591 	if (tx->key) {
592 		bool skip_hw = false;
593 
594 		tx->key->tx_rx_count++;
595 		/* TODO: add threshold stuff again */
596 
597 		switch (tx->key->conf.cipher) {
598 		case WLAN_CIPHER_SUITE_WEP40:
599 		case WLAN_CIPHER_SUITE_WEP104:
600 		case WLAN_CIPHER_SUITE_TKIP:
601 			if (!ieee80211_is_data_present(hdr->frame_control))
602 				tx->key = NULL;
603 			break;
604 		case WLAN_CIPHER_SUITE_CCMP:
605 			if (!ieee80211_is_data_present(hdr->frame_control) &&
606 			    !ieee80211_use_mfp(hdr->frame_control, tx->sta,
607 					       tx->skb))
608 				tx->key = NULL;
609 			else
610 				skip_hw = (tx->key->conf.flags &
611 					   IEEE80211_KEY_FLAG_SW_MGMT_TX) &&
612 					ieee80211_is_mgmt(hdr->frame_control);
613 			break;
614 		case WLAN_CIPHER_SUITE_AES_CMAC:
615 			if (!ieee80211_is_mgmt(hdr->frame_control))
616 				tx->key = NULL;
617 			break;
618 		}
619 
620 		if (unlikely(tx->key && tx->key->flags & KEY_FLAG_TAINTED &&
621 			     !ieee80211_is_deauth(hdr->frame_control)))
622 			return TX_DROP;
623 
624 		if (!skip_hw && tx->key &&
625 		    tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
626 			info->control.hw_key = &tx->key->conf;
627 	}
628 
629 	return TX_CONTINUE;
630 }
631 
632 static ieee80211_tx_result debug_noinline
633 ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
634 {
635 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
636 	struct ieee80211_hdr *hdr = (void *)tx->skb->data;
637 	struct ieee80211_supported_band *sband;
638 	u32 len;
639 	struct ieee80211_tx_rate_control txrc;
640 	struct ieee80211_sta_rates *ratetbl = NULL;
641 	bool assoc = false;
642 
643 	memset(&txrc, 0, sizeof(txrc));
644 
645 	sband = tx->local->hw.wiphy->bands[info->band];
646 
647 	len = min_t(u32, tx->skb->len + FCS_LEN,
648 			 tx->local->hw.wiphy->frag_threshold);
649 
650 	/* set up the tx rate control struct we give the RC algo */
651 	txrc.hw = &tx->local->hw;
652 	txrc.sband = sband;
653 	txrc.bss_conf = &tx->sdata->vif.bss_conf;
654 	txrc.skb = tx->skb;
655 	txrc.reported_rate.idx = -1;
656 	txrc.rate_idx_mask = tx->sdata->rc_rateidx_mask[info->band];
657 	if (txrc.rate_idx_mask == (1 << sband->n_bitrates) - 1)
658 		txrc.max_rate_idx = -1;
659 	else
660 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
661 
662 	if (tx->sdata->rc_has_mcs_mask[info->band])
663 		txrc.rate_idx_mcs_mask =
664 			tx->sdata->rc_rateidx_mcs_mask[info->band];
665 
666 	txrc.bss = (tx->sdata->vif.type == NL80211_IFTYPE_AP ||
667 		    tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
668 		    tx->sdata->vif.type == NL80211_IFTYPE_ADHOC);
669 
670 	/* set up RTS protection if desired */
671 	if (len > tx->local->hw.wiphy->rts_threshold) {
672 		txrc.rts = true;
673 	}
674 
675 	info->control.use_rts = txrc.rts;
676 	info->control.use_cts_prot = tx->sdata->vif.bss_conf.use_cts_prot;
677 
678 	/*
679 	 * Use short preamble if the BSS can handle it, but not for
680 	 * management frames unless we know the receiver can handle
681 	 * that -- the management frame might be to a station that
682 	 * just wants a probe response.
683 	 */
684 	if (tx->sdata->vif.bss_conf.use_short_preamble &&
685 	    (ieee80211_is_data(hdr->frame_control) ||
686 	     (tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
687 		txrc.short_preamble = true;
688 
689 	info->control.short_preamble = txrc.short_preamble;
690 
691 	if (tx->sta)
692 		assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
693 
694 	/*
695 	 * Lets not bother rate control if we're associated and cannot
696 	 * talk to the sta. This should not happen.
697 	 */
698 	if (WARN(test_bit(SCAN_SW_SCANNING, &tx->local->scanning) && assoc &&
699 		 !rate_usable_index_exists(sband, &tx->sta->sta),
700 		 "%s: Dropped data frame as no usable bitrate found while "
701 		 "scanning and associated. Target station: "
702 		 "%pM on %d GHz band\n",
703 		 tx->sdata->name, hdr->addr1,
704 		 info->band ? 5 : 2))
705 		return TX_DROP;
706 
707 	/*
708 	 * If we're associated with the sta at this point we know we can at
709 	 * least send the frame at the lowest bit rate.
710 	 */
711 	rate_control_get_rate(tx->sdata, tx->sta, &txrc);
712 
713 	if (tx->sta && !info->control.skip_table)
714 		ratetbl = rcu_dereference(tx->sta->sta.rates);
715 
716 	if (unlikely(info->control.rates[0].idx < 0)) {
717 		if (ratetbl) {
718 			struct ieee80211_tx_rate rate = {
719 				.idx = ratetbl->rate[0].idx,
720 				.flags = ratetbl->rate[0].flags,
721 				.count = ratetbl->rate[0].count
722 			};
723 
724 			if (ratetbl->rate[0].idx < 0)
725 				return TX_DROP;
726 
727 			tx->rate = rate;
728 		} else {
729 			return TX_DROP;
730 		}
731 	} else {
732 		tx->rate = info->control.rates[0];
733 	}
734 
735 	if (txrc.reported_rate.idx < 0) {
736 		txrc.reported_rate = tx->rate;
737 		if (tx->sta && ieee80211_is_data(hdr->frame_control))
738 			tx->sta->last_tx_rate = txrc.reported_rate;
739 	} else if (tx->sta)
740 		tx->sta->last_tx_rate = txrc.reported_rate;
741 
742 	if (ratetbl)
743 		return TX_CONTINUE;
744 
745 	if (unlikely(!info->control.rates[0].count))
746 		info->control.rates[0].count = 1;
747 
748 	if (WARN_ON_ONCE((info->control.rates[0].count > 1) &&
749 			 (info->flags & IEEE80211_TX_CTL_NO_ACK)))
750 		info->control.rates[0].count = 1;
751 
752 	return TX_CONTINUE;
753 }
754 
755 static ieee80211_tx_result debug_noinline
756 ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
757 {
758 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
759 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
760 	u16 *seq;
761 	u8 *qc;
762 	int tid;
763 
764 	/*
765 	 * Packet injection may want to control the sequence
766 	 * number, if we have no matching interface then we
767 	 * neither assign one ourselves nor ask the driver to.
768 	 */
769 	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
770 		return TX_CONTINUE;
771 
772 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
773 		return TX_CONTINUE;
774 
775 	if (ieee80211_hdrlen(hdr->frame_control) < 24)
776 		return TX_CONTINUE;
777 
778 	if (ieee80211_is_qos_nullfunc(hdr->frame_control))
779 		return TX_CONTINUE;
780 
781 	/*
782 	 * Anything but QoS data that has a sequence number field
783 	 * (is long enough) gets a sequence number from the global
784 	 * counter.  QoS data frames with a multicast destination
785 	 * also use the global counter (802.11-2012 9.3.2.10).
786 	 */
787 	if (!ieee80211_is_data_qos(hdr->frame_control) ||
788 	    is_multicast_ether_addr(hdr->addr1)) {
789 		/* driver should assign sequence number */
790 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
791 		/* for pure STA mode without beacons, we can do it */
792 		hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
793 		tx->sdata->sequence_number += 0x10;
794 		return TX_CONTINUE;
795 	}
796 
797 	/*
798 	 * This should be true for injected/management frames only, for
799 	 * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
800 	 * above since they are not QoS-data frames.
801 	 */
802 	if (!tx->sta)
803 		return TX_CONTINUE;
804 
805 	/* include per-STA, per-TID sequence counter */
806 
807 	qc = ieee80211_get_qos_ctl(hdr);
808 	tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
809 	seq = &tx->sta->tid_seq[tid];
810 
811 	hdr->seq_ctrl = cpu_to_le16(*seq);
812 
813 	/* Increase the sequence number. */
814 	*seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
815 
816 	return TX_CONTINUE;
817 }
818 
819 static int ieee80211_fragment(struct ieee80211_tx_data *tx,
820 			      struct sk_buff *skb, int hdrlen,
821 			      int frag_threshold)
822 {
823 	struct ieee80211_local *local = tx->local;
824 	struct ieee80211_tx_info *info;
825 	struct sk_buff *tmp;
826 	int per_fragm = frag_threshold - hdrlen - FCS_LEN;
827 	int pos = hdrlen + per_fragm;
828 	int rem = skb->len - hdrlen - per_fragm;
829 
830 	if (WARN_ON(rem < 0))
831 		return -EINVAL;
832 
833 	/* first fragment was already added to queue by caller */
834 
835 	while (rem) {
836 		int fraglen = per_fragm;
837 
838 		if (fraglen > rem)
839 			fraglen = rem;
840 		rem -= fraglen;
841 		tmp = dev_alloc_skb(local->tx_headroom +
842 				    frag_threshold +
843 				    IEEE80211_ENCRYPT_HEADROOM +
844 				    IEEE80211_ENCRYPT_TAILROOM);
845 		if (!tmp)
846 			return -ENOMEM;
847 
848 		__skb_queue_tail(&tx->skbs, tmp);
849 
850 		skb_reserve(tmp, local->tx_headroom +
851 				 IEEE80211_ENCRYPT_HEADROOM);
852 		/* copy control information */
853 		memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
854 
855 		info = IEEE80211_SKB_CB(tmp);
856 		info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
857 				 IEEE80211_TX_CTL_FIRST_FRAGMENT);
858 
859 		if (rem)
860 			info->flags |= IEEE80211_TX_CTL_MORE_FRAMES;
861 
862 		skb_copy_queue_mapping(tmp, skb);
863 		tmp->priority = skb->priority;
864 		tmp->dev = skb->dev;
865 
866 		/* copy header and data */
867 		memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
868 		memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
869 
870 		pos += fraglen;
871 	}
872 
873 	/* adjust first fragment's length */
874 	skb->len = hdrlen + per_fragm;
875 	return 0;
876 }
877 
878 static ieee80211_tx_result debug_noinline
879 ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
880 {
881 	struct sk_buff *skb = tx->skb;
882 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
883 	struct ieee80211_hdr *hdr = (void *)skb->data;
884 	int frag_threshold = tx->local->hw.wiphy->frag_threshold;
885 	int hdrlen;
886 	int fragnum;
887 
888 	/* no matter what happens, tx->skb moves to tx->skbs */
889 	__skb_queue_tail(&tx->skbs, skb);
890 	tx->skb = NULL;
891 
892 	if (info->flags & IEEE80211_TX_CTL_DONTFRAG)
893 		return TX_CONTINUE;
894 
895 	if (tx->local->ops->set_frag_threshold)
896 		return TX_CONTINUE;
897 
898 	/*
899 	 * Warn when submitting a fragmented A-MPDU frame and drop it.
900 	 * This scenario is handled in ieee80211_tx_prepare but extra
901 	 * caution taken here as fragmented ampdu may cause Tx stop.
902 	 */
903 	if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
904 		return TX_DROP;
905 
906 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
907 
908 	/* internal error, why isn't DONTFRAG set? */
909 	if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
910 		return TX_DROP;
911 
912 	/*
913 	 * Now fragment the frame. This will allocate all the fragments and
914 	 * chain them (using skb as the first fragment) to skb->next.
915 	 * During transmission, we will remove the successfully transmitted
916 	 * fragments from this list. When the low-level driver rejects one
917 	 * of the fragments then we will simply pretend to accept the skb
918 	 * but store it away as pending.
919 	 */
920 	if (ieee80211_fragment(tx, skb, hdrlen, frag_threshold))
921 		return TX_DROP;
922 
923 	/* update duration/seq/flags of fragments */
924 	fragnum = 0;
925 
926 	skb_queue_walk(&tx->skbs, skb) {
927 		const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
928 
929 		hdr = (void *)skb->data;
930 		info = IEEE80211_SKB_CB(skb);
931 
932 		if (!skb_queue_is_last(&tx->skbs, skb)) {
933 			hdr->frame_control |= morefrags;
934 			/*
935 			 * No multi-rate retries for fragmented frames, that
936 			 * would completely throw off the NAV at other STAs.
937 			 */
938 			info->control.rates[1].idx = -1;
939 			info->control.rates[2].idx = -1;
940 			info->control.rates[3].idx = -1;
941 			BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 4);
942 			info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
943 		} else {
944 			hdr->frame_control &= ~morefrags;
945 		}
946 		hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
947 		fragnum++;
948 	}
949 
950 	return TX_CONTINUE;
951 }
952 
953 static ieee80211_tx_result debug_noinline
954 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
955 {
956 	struct sk_buff *skb;
957 	int ac = -1;
958 
959 	if (!tx->sta)
960 		return TX_CONTINUE;
961 
962 	skb_queue_walk(&tx->skbs, skb) {
963 		ac = skb_get_queue_mapping(skb);
964 		tx->sta->tx_fragments++;
965 		tx->sta->tx_bytes[ac] += skb->len;
966 	}
967 	if (ac >= 0)
968 		tx->sta->tx_packets[ac]++;
969 
970 	return TX_CONTINUE;
971 }
972 
973 static ieee80211_tx_result debug_noinline
974 ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
975 {
976 	if (!tx->key)
977 		return TX_CONTINUE;
978 
979 	switch (tx->key->conf.cipher) {
980 	case WLAN_CIPHER_SUITE_WEP40:
981 	case WLAN_CIPHER_SUITE_WEP104:
982 		return ieee80211_crypto_wep_encrypt(tx);
983 	case WLAN_CIPHER_SUITE_TKIP:
984 		return ieee80211_crypto_tkip_encrypt(tx);
985 	case WLAN_CIPHER_SUITE_CCMP:
986 		return ieee80211_crypto_ccmp_encrypt(tx);
987 	case WLAN_CIPHER_SUITE_AES_CMAC:
988 		return ieee80211_crypto_aes_cmac_encrypt(tx);
989 	default:
990 		return ieee80211_crypto_hw_encrypt(tx);
991 	}
992 
993 	return TX_DROP;
994 }
995 
996 static ieee80211_tx_result debug_noinline
997 ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
998 {
999 	struct sk_buff *skb;
1000 	struct ieee80211_hdr *hdr;
1001 	int next_len;
1002 	bool group_addr;
1003 
1004 	skb_queue_walk(&tx->skbs, skb) {
1005 		hdr = (void *) skb->data;
1006 		if (unlikely(ieee80211_is_pspoll(hdr->frame_control)))
1007 			break; /* must not overwrite AID */
1008 		if (!skb_queue_is_last(&tx->skbs, skb)) {
1009 			struct sk_buff *next = skb_queue_next(&tx->skbs, skb);
1010 			next_len = next->len;
1011 		} else
1012 			next_len = 0;
1013 		group_addr = is_multicast_ether_addr(hdr->addr1);
1014 
1015 		hdr->duration_id =
1016 			ieee80211_duration(tx, skb, group_addr, next_len);
1017 	}
1018 
1019 	return TX_CONTINUE;
1020 }
1021 
1022 /* actual transmit path */
1023 
1024 static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
1025 				  struct sk_buff *skb,
1026 				  struct ieee80211_tx_info *info,
1027 				  struct tid_ampdu_tx *tid_tx,
1028 				  int tid)
1029 {
1030 	bool queued = false;
1031 	bool reset_agg_timer = false;
1032 	struct sk_buff *purge_skb = NULL;
1033 
1034 	if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1035 		info->flags |= IEEE80211_TX_CTL_AMPDU;
1036 		reset_agg_timer = true;
1037 	} else if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
1038 		/*
1039 		 * nothing -- this aggregation session is being started
1040 		 * but that might still fail with the driver
1041 		 */
1042 	} else {
1043 		spin_lock(&tx->sta->lock);
1044 		/*
1045 		 * Need to re-check now, because we may get here
1046 		 *
1047 		 *  1) in the window during which the setup is actually
1048 		 *     already done, but not marked yet because not all
1049 		 *     packets are spliced over to the driver pending
1050 		 *     queue yet -- if this happened we acquire the lock
1051 		 *     either before or after the splice happens, but
1052 		 *     need to recheck which of these cases happened.
1053 		 *
1054 		 *  2) during session teardown, if the OPERATIONAL bit
1055 		 *     was cleared due to the teardown but the pointer
1056 		 *     hasn't been assigned NULL yet (or we loaded it
1057 		 *     before it was assigned) -- in this case it may
1058 		 *     now be NULL which means we should just let the
1059 		 *     packet pass through because splicing the frames
1060 		 *     back is already done.
1061 		 */
1062 		tid_tx = rcu_dereference_protected_tid_tx(tx->sta, tid);
1063 
1064 		if (!tid_tx) {
1065 			/* do nothing, let packet pass through */
1066 		} else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
1067 			info->flags |= IEEE80211_TX_CTL_AMPDU;
1068 			reset_agg_timer = true;
1069 		} else {
1070 			queued = true;
1071 			info->control.vif = &tx->sdata->vif;
1072 			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1073 			__skb_queue_tail(&tid_tx->pending, skb);
1074 			if (skb_queue_len(&tid_tx->pending) > STA_MAX_TX_BUFFER)
1075 				purge_skb = __skb_dequeue(&tid_tx->pending);
1076 		}
1077 		spin_unlock(&tx->sta->lock);
1078 
1079 		if (purge_skb)
1080 			ieee80211_free_txskb(&tx->local->hw, purge_skb);
1081 	}
1082 
1083 	/* reset session timer */
1084 	if (reset_agg_timer && tid_tx->timeout)
1085 		tid_tx->last_tx = jiffies;
1086 
1087 	return queued;
1088 }
1089 
1090 /*
1091  * initialises @tx
1092  */
1093 static ieee80211_tx_result
1094 ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
1095 		     struct ieee80211_tx_data *tx,
1096 		     struct sk_buff *skb)
1097 {
1098 	struct ieee80211_local *local = sdata->local;
1099 	struct ieee80211_hdr *hdr;
1100 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1101 	int tid;
1102 	u8 *qc;
1103 
1104 	memset(tx, 0, sizeof(*tx));
1105 	tx->skb = skb;
1106 	tx->local = local;
1107 	tx->sdata = sdata;
1108 	__skb_queue_head_init(&tx->skbs);
1109 
1110 	/*
1111 	 * If this flag is set to true anywhere, and we get here,
1112 	 * we are doing the needed processing, so remove the flag
1113 	 * now.
1114 	 */
1115 	info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1116 
1117 	hdr = (struct ieee80211_hdr *) skb->data;
1118 
1119 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
1120 		tx->sta = rcu_dereference(sdata->u.vlan.sta);
1121 		if (!tx->sta && sdata->dev->ieee80211_ptr->use_4addr)
1122 			return TX_DROP;
1123 	} else if (info->flags & (IEEE80211_TX_CTL_INJECTED |
1124 				  IEEE80211_TX_INTFL_NL80211_FRAME_TX) ||
1125 		   tx->sdata->control_port_protocol == tx->skb->protocol) {
1126 		tx->sta = sta_info_get_bss(sdata, hdr->addr1);
1127 	}
1128 	if (!tx->sta)
1129 		tx->sta = sta_info_get(sdata, hdr->addr1);
1130 
1131 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1132 	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
1133 	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
1134 	    !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
1135 		struct tid_ampdu_tx *tid_tx;
1136 
1137 		qc = ieee80211_get_qos_ctl(hdr);
1138 		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1139 
1140 		tid_tx = rcu_dereference(tx->sta->ampdu_mlme.tid_tx[tid]);
1141 		if (tid_tx) {
1142 			bool queued;
1143 
1144 			queued = ieee80211_tx_prep_agg(tx, skb, info,
1145 						       tid_tx, tid);
1146 
1147 			if (unlikely(queued))
1148 				return TX_QUEUED;
1149 		}
1150 	}
1151 
1152 	if (is_multicast_ether_addr(hdr->addr1)) {
1153 		tx->flags &= ~IEEE80211_TX_UNICAST;
1154 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
1155 	} else
1156 		tx->flags |= IEEE80211_TX_UNICAST;
1157 
1158 	if (!(info->flags & IEEE80211_TX_CTL_DONTFRAG)) {
1159 		if (!(tx->flags & IEEE80211_TX_UNICAST) ||
1160 		    skb->len + FCS_LEN <= local->hw.wiphy->frag_threshold ||
1161 		    info->flags & IEEE80211_TX_CTL_AMPDU)
1162 			info->flags |= IEEE80211_TX_CTL_DONTFRAG;
1163 	}
1164 
1165 	if (!tx->sta)
1166 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1167 	else if (test_and_clear_sta_flag(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1168 		info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1169 
1170 	info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1171 
1172 	return TX_CONTINUE;
1173 }
1174 
1175 static bool ieee80211_tx_frags(struct ieee80211_local *local,
1176 			       struct ieee80211_vif *vif,
1177 			       struct ieee80211_sta *sta,
1178 			       struct sk_buff_head *skbs,
1179 			       bool txpending)
1180 {
1181 	struct ieee80211_tx_control control;
1182 	struct sk_buff *skb, *tmp;
1183 	unsigned long flags;
1184 
1185 	skb_queue_walk_safe(skbs, skb, tmp) {
1186 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1187 		int q = info->hw_queue;
1188 
1189 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1190 		if (WARN_ON_ONCE(q >= local->hw.queues)) {
1191 			__skb_unlink(skb, skbs);
1192 			ieee80211_free_txskb(&local->hw, skb);
1193 			continue;
1194 		}
1195 #endif
1196 
1197 		spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1198 		if (local->queue_stop_reasons[q] ||
1199 		    (!txpending && !skb_queue_empty(&local->pending[q]))) {
1200 			if (unlikely(info->flags &
1201 				     IEEE80211_TX_INTFL_OFFCHAN_TX_OK)) {
1202 				if (local->queue_stop_reasons[q] &
1203 				    ~BIT(IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL)) {
1204 					/*
1205 					 * Drop off-channel frames if queues
1206 					 * are stopped for any reason other
1207 					 * than off-channel operation. Never
1208 					 * queue them.
1209 					 */
1210 					spin_unlock_irqrestore(
1211 						&local->queue_stop_reason_lock,
1212 						flags);
1213 					ieee80211_purge_tx_queue(&local->hw,
1214 								 skbs);
1215 					return true;
1216 				}
1217 			} else {
1218 
1219 				/*
1220 				 * Since queue is stopped, queue up frames for
1221 				 * later transmission from the tx-pending
1222 				 * tasklet when the queue is woken again.
1223 				 */
1224 				if (txpending)
1225 					skb_queue_splice_init(skbs,
1226 							      &local->pending[q]);
1227 				else
1228 					skb_queue_splice_tail_init(skbs,
1229 								   &local->pending[q]);
1230 
1231 				spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1232 						       flags);
1233 				return false;
1234 			}
1235 		}
1236 		spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1237 
1238 		info->control.vif = vif;
1239 		control.sta = sta;
1240 
1241 		__skb_unlink(skb, skbs);
1242 		drv_tx(local, &control, skb);
1243 	}
1244 
1245 	return true;
1246 }
1247 
1248 /*
1249  * Returns false if the frame couldn't be transmitted but was queued instead.
1250  */
1251 static bool __ieee80211_tx(struct ieee80211_local *local,
1252 			   struct sk_buff_head *skbs, int led_len,
1253 			   struct sta_info *sta, bool txpending)
1254 {
1255 	struct ieee80211_tx_info *info;
1256 	struct ieee80211_sub_if_data *sdata;
1257 	struct ieee80211_vif *vif;
1258 	struct ieee80211_sta *pubsta;
1259 	struct sk_buff *skb;
1260 	bool result = true;
1261 	__le16 fc;
1262 
1263 	if (WARN_ON(skb_queue_empty(skbs)))
1264 		return true;
1265 
1266 	skb = skb_peek(skbs);
1267 	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
1268 	info = IEEE80211_SKB_CB(skb);
1269 	sdata = vif_to_sdata(info->control.vif);
1270 	if (sta && !sta->uploaded)
1271 		sta = NULL;
1272 
1273 	if (sta)
1274 		pubsta = &sta->sta;
1275 	else
1276 		pubsta = NULL;
1277 
1278 	switch (sdata->vif.type) {
1279 	case NL80211_IFTYPE_MONITOR:
1280 		if (sdata->u.mntr_flags & MONITOR_FLAG_ACTIVE) {
1281 			vif = &sdata->vif;
1282 			break;
1283 		}
1284 		sdata = rcu_dereference(local->monitor_sdata);
1285 		if (sdata) {
1286 			vif = &sdata->vif;
1287 			info->hw_queue =
1288 				vif->hw_queue[skb_get_queue_mapping(skb)];
1289 		} else if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL) {
1290 			dev_kfree_skb(skb);
1291 			return true;
1292 		} else
1293 			vif = NULL;
1294 		break;
1295 	case NL80211_IFTYPE_AP_VLAN:
1296 		sdata = container_of(sdata->bss,
1297 				     struct ieee80211_sub_if_data, u.ap);
1298 		/* fall through */
1299 	default:
1300 		vif = &sdata->vif;
1301 		break;
1302 	}
1303 
1304 	result = ieee80211_tx_frags(local, vif, pubsta, skbs,
1305 				    txpending);
1306 
1307 	ieee80211_tpt_led_trig_tx(local, fc, led_len);
1308 
1309 	WARN_ON_ONCE(!skb_queue_empty(skbs));
1310 
1311 	return result;
1312 }
1313 
1314 /*
1315  * Invoke TX handlers, return 0 on success and non-zero if the
1316  * frame was dropped or queued.
1317  */
1318 static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1319 {
1320 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
1321 	ieee80211_tx_result res = TX_DROP;
1322 
1323 #define CALL_TXH(txh) \
1324 	do {				\
1325 		res = txh(tx);		\
1326 		if (res != TX_CONTINUE)	\
1327 			goto txh_done;	\
1328 	} while (0)
1329 
1330 	CALL_TXH(ieee80211_tx_h_dynamic_ps);
1331 	CALL_TXH(ieee80211_tx_h_check_assoc);
1332 	CALL_TXH(ieee80211_tx_h_ps_buf);
1333 	CALL_TXH(ieee80211_tx_h_check_control_port_protocol);
1334 	CALL_TXH(ieee80211_tx_h_select_key);
1335 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1336 		CALL_TXH(ieee80211_tx_h_rate_ctrl);
1337 
1338 	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
1339 		__skb_queue_tail(&tx->skbs, tx->skb);
1340 		tx->skb = NULL;
1341 		goto txh_done;
1342 	}
1343 
1344 	CALL_TXH(ieee80211_tx_h_michael_mic_add);
1345 	CALL_TXH(ieee80211_tx_h_sequence);
1346 	CALL_TXH(ieee80211_tx_h_fragment);
1347 	/* handlers after fragment must be aware of tx info fragmentation! */
1348 	CALL_TXH(ieee80211_tx_h_stats);
1349 	CALL_TXH(ieee80211_tx_h_encrypt);
1350 	if (!(tx->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL))
1351 		CALL_TXH(ieee80211_tx_h_calculate_duration);
1352 #undef CALL_TXH
1353 
1354  txh_done:
1355 	if (unlikely(res == TX_DROP)) {
1356 		I802_DEBUG_INC(tx->local->tx_handlers_drop);
1357 		if (tx->skb)
1358 			ieee80211_free_txskb(&tx->local->hw, tx->skb);
1359 		else
1360 			ieee80211_purge_tx_queue(&tx->local->hw, &tx->skbs);
1361 		return -1;
1362 	} else if (unlikely(res == TX_QUEUED)) {
1363 		I802_DEBUG_INC(tx->local->tx_handlers_queued);
1364 		return -1;
1365 	}
1366 
1367 	return 0;
1368 }
1369 
1370 /*
1371  * Returns false if the frame couldn't be transmitted but was queued instead.
1372  */
1373 static bool ieee80211_tx(struct ieee80211_sub_if_data *sdata,
1374 			 struct sk_buff *skb, bool txpending,
1375 			 enum ieee80211_band band)
1376 {
1377 	struct ieee80211_local *local = sdata->local;
1378 	struct ieee80211_tx_data tx;
1379 	ieee80211_tx_result res_prepare;
1380 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1381 	bool result = true;
1382 	int led_len;
1383 
1384 	if (unlikely(skb->len < 10)) {
1385 		dev_kfree_skb(skb);
1386 		return true;
1387 	}
1388 
1389 	/* initialises tx */
1390 	led_len = skb->len;
1391 	res_prepare = ieee80211_tx_prepare(sdata, &tx, skb);
1392 
1393 	if (unlikely(res_prepare == TX_DROP)) {
1394 		ieee80211_free_txskb(&local->hw, skb);
1395 		return true;
1396 	} else if (unlikely(res_prepare == TX_QUEUED)) {
1397 		return true;
1398 	}
1399 
1400 	info->band = band;
1401 
1402 	/* set up hw_queue value early */
1403 	if (!(info->flags & IEEE80211_TX_CTL_TX_OFFCHAN) ||
1404 	    !(local->hw.flags & IEEE80211_HW_QUEUE_CONTROL))
1405 		info->hw_queue =
1406 			sdata->vif.hw_queue[skb_get_queue_mapping(skb)];
1407 
1408 	if (!invoke_tx_handlers(&tx))
1409 		result = __ieee80211_tx(local, &tx.skbs, led_len,
1410 					tx.sta, txpending);
1411 
1412 	return result;
1413 }
1414 
1415 /* device xmit handlers */
1416 
1417 static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
1418 				struct sk_buff *skb,
1419 				int head_need, bool may_encrypt)
1420 {
1421 	struct ieee80211_local *local = sdata->local;
1422 	int tail_need = 0;
1423 
1424 	if (may_encrypt && sdata->crypto_tx_tailroom_needed_cnt) {
1425 		tail_need = IEEE80211_ENCRYPT_TAILROOM;
1426 		tail_need -= skb_tailroom(skb);
1427 		tail_need = max_t(int, tail_need, 0);
1428 	}
1429 
1430 	if (skb_cloned(skb))
1431 		I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1432 	else if (head_need || tail_need)
1433 		I802_DEBUG_INC(local->tx_expand_skb_head);
1434 	else
1435 		return 0;
1436 
1437 	if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1438 		wiphy_debug(local->hw.wiphy,
1439 			    "failed to reallocate TX buffer\n");
1440 		return -ENOMEM;
1441 	}
1442 
1443 	return 0;
1444 }
1445 
1446 void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
1447 		    enum ieee80211_band band)
1448 {
1449 	struct ieee80211_local *local = sdata->local;
1450 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1451 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1452 	int headroom;
1453 	bool may_encrypt;
1454 
1455 	may_encrypt = !(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT);
1456 
1457 	headroom = local->tx_headroom;
1458 	if (may_encrypt)
1459 		headroom += IEEE80211_ENCRYPT_HEADROOM;
1460 	headroom -= skb_headroom(skb);
1461 	headroom = max_t(int, 0, headroom);
1462 
1463 	if (ieee80211_skb_resize(sdata, skb, headroom, may_encrypt)) {
1464 		ieee80211_free_txskb(&local->hw, skb);
1465 		return;
1466 	}
1467 
1468 	hdr = (struct ieee80211_hdr *) skb->data;
1469 	info->control.vif = &sdata->vif;
1470 
1471 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
1472 		if (ieee80211_is_data(hdr->frame_control) &&
1473 		    is_unicast_ether_addr(hdr->addr1)) {
1474 			if (mesh_nexthop_resolve(sdata, skb))
1475 				return; /* skb queued: don't free */
1476 		} else {
1477 			ieee80211_mps_set_frame_flags(sdata, NULL, hdr);
1478 		}
1479 	}
1480 
1481 	ieee80211_set_qos_hdr(sdata, skb);
1482 	ieee80211_tx(sdata, skb, false, band);
1483 }
1484 
1485 static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
1486 {
1487 	struct ieee80211_radiotap_iterator iterator;
1488 	struct ieee80211_radiotap_header *rthdr =
1489 		(struct ieee80211_radiotap_header *) skb->data;
1490 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1491 	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
1492 						   NULL);
1493 	u16 txflags;
1494 
1495 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
1496 		       IEEE80211_TX_CTL_DONTFRAG;
1497 
1498 	/*
1499 	 * for every radiotap entry that is present
1500 	 * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
1501 	 * entries present, or -EINVAL on error)
1502 	 */
1503 
1504 	while (!ret) {
1505 		ret = ieee80211_radiotap_iterator_next(&iterator);
1506 
1507 		if (ret)
1508 			continue;
1509 
1510 		/* see if this argument is something we can use */
1511 		switch (iterator.this_arg_index) {
1512 		/*
1513 		 * You must take care when dereferencing iterator.this_arg
1514 		 * for multibyte types... the pointer is not aligned.  Use
1515 		 * get_unaligned((type *)iterator.this_arg) to dereference
1516 		 * iterator.this_arg for type "type" safely on all arches.
1517 		*/
1518 		case IEEE80211_RADIOTAP_FLAGS:
1519 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
1520 				/*
1521 				 * this indicates that the skb we have been
1522 				 * handed has the 32-bit FCS CRC at the end...
1523 				 * we should react to that by snipping it off
1524 				 * because it will be recomputed and added
1525 				 * on transmission
1526 				 */
1527 				if (skb->len < (iterator._max_length + FCS_LEN))
1528 					return false;
1529 
1530 				skb_trim(skb, skb->len - FCS_LEN);
1531 			}
1532 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
1533 				info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
1534 			if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
1535 				info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
1536 			break;
1537 
1538 		case IEEE80211_RADIOTAP_TX_FLAGS:
1539 			txflags = get_unaligned_le16(iterator.this_arg);
1540 			if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
1541 				info->flags |= IEEE80211_TX_CTL_NO_ACK;
1542 			break;
1543 
1544 		/*
1545 		 * Please update the file
1546 		 * Documentation/networking/mac80211-injection.txt
1547 		 * when parsing new fields here.
1548 		 */
1549 
1550 		default:
1551 			break;
1552 		}
1553 	}
1554 
1555 	if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
1556 		return false;
1557 
1558 	/*
1559 	 * remove the radiotap header
1560 	 * iterator->_max_length was sanity-checked against
1561 	 * skb->len by iterator init
1562 	 */
1563 	skb_pull(skb, iterator._max_length);
1564 
1565 	return true;
1566 }
1567 
1568 netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
1569 					 struct net_device *dev)
1570 {
1571 	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1572 	struct ieee80211_chanctx_conf *chanctx_conf;
1573 	struct ieee80211_channel *chan;
1574 	struct ieee80211_radiotap_header *prthdr =
1575 		(struct ieee80211_radiotap_header *)skb->data;
1576 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1577 	struct ieee80211_hdr *hdr;
1578 	struct ieee80211_sub_if_data *tmp_sdata, *sdata;
1579 	u16 len_rthdr;
1580 	int hdrlen;
1581 
1582 	/* check for not even having the fixed radiotap header part */
1583 	if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1584 		goto fail; /* too short to be possibly valid */
1585 
1586 	/* is it a header version we can trust to find length from? */
1587 	if (unlikely(prthdr->it_version))
1588 		goto fail; /* only version 0 is supported */
1589 
1590 	/* then there must be a radiotap header with a length we can use */
1591 	len_rthdr = ieee80211_get_radiotap_len(skb->data);
1592 
1593 	/* does the skb contain enough to deliver on the alleged length? */
1594 	if (unlikely(skb->len < len_rthdr))
1595 		goto fail; /* skb too short for claimed rt header extent */
1596 
1597 	/*
1598 	 * fix up the pointers accounting for the radiotap
1599 	 * header still being in there.  We are being given
1600 	 * a precooked IEEE80211 header so no need for
1601 	 * normal processing
1602 	 */
1603 	skb_set_mac_header(skb, len_rthdr);
1604 	/*
1605 	 * these are just fixed to the end of the rt area since we
1606 	 * don't have any better information and at this point, nobody cares
1607 	 */
1608 	skb_set_network_header(skb, len_rthdr);
1609 	skb_set_transport_header(skb, len_rthdr);
1610 
1611 	if (skb->len < len_rthdr + 2)
1612 		goto fail;
1613 
1614 	hdr = (struct ieee80211_hdr *)(skb->data + len_rthdr);
1615 	hdrlen = ieee80211_hdrlen(hdr->frame_control);
1616 
1617 	if (skb->len < len_rthdr + hdrlen)
1618 		goto fail;
1619 
1620 	/*
1621 	 * Initialize skb->protocol if the injected frame is a data frame
1622 	 * carrying a rfc1042 header
1623 	 */
1624 	if (ieee80211_is_data(hdr->frame_control) &&
1625 	    skb->len >= len_rthdr + hdrlen + sizeof(rfc1042_header) + 2) {
1626 		u8 *payload = (u8 *)hdr + hdrlen;
1627 
1628 		if (ether_addr_equal(payload, rfc1042_header))
1629 			skb->protocol = cpu_to_be16((payload[6] << 8) |
1630 						    payload[7]);
1631 	}
1632 
1633 	memset(info, 0, sizeof(*info));
1634 
1635 	info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
1636 		      IEEE80211_TX_CTL_INJECTED;
1637 
1638 	/* process and remove the injection radiotap header */
1639 	if (!ieee80211_parse_tx_radiotap(skb))
1640 		goto fail;
1641 
1642 	rcu_read_lock();
1643 
1644 	/*
1645 	 * We process outgoing injected frames that have a local address
1646 	 * we handle as though they are non-injected frames.
1647 	 * This code here isn't entirely correct, the local MAC address
1648 	 * isn't always enough to find the interface to use; for proper
1649 	 * VLAN/WDS support we will need a different mechanism (which
1650 	 * likely isn't going to be monitor interfaces).
1651 	 */
1652 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1653 
1654 	list_for_each_entry_rcu(tmp_sdata, &local->interfaces, list) {
1655 		if (!ieee80211_sdata_running(tmp_sdata))
1656 			continue;
1657 		if (tmp_sdata->vif.type == NL80211_IFTYPE_MONITOR ||
1658 		    tmp_sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
1659 		    tmp_sdata->vif.type == NL80211_IFTYPE_WDS)
1660 			continue;
1661 		if (ether_addr_equal(tmp_sdata->vif.addr, hdr->addr2)) {
1662 			sdata = tmp_sdata;
1663 			break;
1664 		}
1665 	}
1666 
1667 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1668 	if (!chanctx_conf) {
1669 		tmp_sdata = rcu_dereference(local->monitor_sdata);
1670 		if (tmp_sdata)
1671 			chanctx_conf =
1672 				rcu_dereference(tmp_sdata->vif.chanctx_conf);
1673 	}
1674 
1675 	if (chanctx_conf)
1676 		chan = chanctx_conf->def.chan;
1677 	else if (!local->use_chanctx)
1678 		chan = local->_oper_chandef.chan;
1679 	else
1680 		goto fail_rcu;
1681 
1682 	/*
1683 	 * Frame injection is not allowed if beaconing is not allowed
1684 	 * or if we need radar detection. Beaconing is usually not allowed when
1685 	 * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1686 	 * Passive scan is also used in world regulatory domains where
1687 	 * your country is not known and as such it should be treated as
1688 	 * NO TX unless the channel is explicitly allowed in which case
1689 	 * your current regulatory domain would not have the passive scan
1690 	 * flag.
1691 	 *
1692 	 * Since AP mode uses monitor interfaces to inject/TX management
1693 	 * frames we can make AP mode the exception to this rule once it
1694 	 * supports radar detection as its implementation can deal with
1695 	 * radar detection by itself. We can do that later by adding a
1696 	 * monitor flag interfaces used for AP support.
1697 	 */
1698 	if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1699 			    IEEE80211_CHAN_PASSIVE_SCAN)))
1700 		goto fail_rcu;
1701 
1702 	ieee80211_xmit(sdata, skb, chan->band);
1703 	rcu_read_unlock();
1704 
1705 	return NETDEV_TX_OK;
1706 
1707 fail_rcu:
1708 	rcu_read_unlock();
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 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 	struct ieee80211_chanctx_conf *chanctx_conf;
1751 	struct ieee80211_sub_if_data *ap_sdata;
1752 	enum ieee80211_band band;
1753 
1754 	if (unlikely(skb->len < ETH_HLEN))
1755 		goto fail;
1756 
1757 	/* convert Ethernet header to proper 802.11 header (based on
1758 	 * operation mode) */
1759 	ethertype = (skb->data[12] << 8) | skb->data[13];
1760 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1761 
1762 	rcu_read_lock();
1763 
1764 	switch (sdata->vif.type) {
1765 	case NL80211_IFTYPE_AP_VLAN:
1766 		sta = rcu_dereference(sdata->u.vlan.sta);
1767 		if (sta) {
1768 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1769 			/* RA TA DA SA */
1770 			memcpy(hdr.addr1, sta->sta.addr, ETH_ALEN);
1771 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1772 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1773 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1774 			hdrlen = 30;
1775 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1776 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1777 		}
1778 		ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
1779 					u.ap);
1780 		chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);
1781 		if (!chanctx_conf)
1782 			goto fail_rcu;
1783 		band = chanctx_conf->def.chan->band;
1784 		if (sta)
1785 			break;
1786 		/* fall through */
1787 	case NL80211_IFTYPE_AP:
1788 		if (sdata->vif.type == NL80211_IFTYPE_AP)
1789 			chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1790 		if (!chanctx_conf)
1791 			goto fail_rcu;
1792 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1793 		/* DA BSSID SA */
1794 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1795 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1796 		memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1797 		hdrlen = 24;
1798 		band = chanctx_conf->def.chan->band;
1799 		break;
1800 	case NL80211_IFTYPE_WDS:
1801 		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1802 		/* RA TA DA SA */
1803 		memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1804 		memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1805 		memcpy(hdr.addr3, skb->data, ETH_ALEN);
1806 		memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1807 		hdrlen = 30;
1808 		/*
1809 		 * This is the exception! WDS style interfaces are prohibited
1810 		 * when channel contexts are in used so this must be valid
1811 		 */
1812 		band = local->hw.conf.chandef.chan->band;
1813 		break;
1814 #ifdef CONFIG_MAC80211_MESH
1815 	case NL80211_IFTYPE_MESH_POINT:
1816 		if (!is_multicast_ether_addr(skb->data)) {
1817 			struct sta_info *next_hop;
1818 			bool mpp_lookup = true;
1819 
1820 			mpath = mesh_path_lookup(sdata, skb->data);
1821 			if (mpath) {
1822 				mpp_lookup = false;
1823 				next_hop = rcu_dereference(mpath->next_hop);
1824 				if (!next_hop ||
1825 				    !(mpath->flags & (MESH_PATH_ACTIVE |
1826 						      MESH_PATH_RESOLVING)))
1827 					mpp_lookup = true;
1828 			}
1829 
1830 			if (mpp_lookup)
1831 				mppath = mpp_path_lookup(sdata, skb->data);
1832 
1833 			if (mppath && mpath)
1834 				mesh_path_del(mpath->sdata, mpath->dst);
1835 		}
1836 
1837 		/*
1838 		 * Use address extension if it is a packet from
1839 		 * another interface or if we know the destination
1840 		 * is being proxied by a portal (i.e. portal address
1841 		 * differs from proxied address)
1842 		 */
1843 		if (ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN) &&
1844 		    !(mppath && !ether_addr_equal(mppath->mpp, skb->data))) {
1845 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1846 					skb->data, skb->data + ETH_ALEN);
1847 			meshhdrlen = ieee80211_new_mesh_header(sdata, &mesh_hdr,
1848 							       NULL, NULL);
1849 		} else {
1850 			/* DS -> MBSS (802.11-2012 13.11.3.3).
1851 			 * For unicast with unknown forwarding information,
1852 			 * destination might be in the MBSS or if that fails
1853 			 * forwarded to another mesh gate. In either case
1854 			 * resolution will be handled in ieee80211_xmit(), so
1855 			 * leave the original DA. This also works for mcast */
1856 			const u8 *mesh_da = skb->data;
1857 
1858 			if (mppath)
1859 				mesh_da = mppath->mpp;
1860 			else if (mpath)
1861 				mesh_da = mpath->dst;
1862 
1863 			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,
1864 					mesh_da, sdata->vif.addr);
1865 			if (is_multicast_ether_addr(mesh_da))
1866 				/* DA TA mSA AE:SA */
1867 				meshhdrlen = ieee80211_new_mesh_header(
1868 						sdata, &mesh_hdr,
1869 						skb->data + ETH_ALEN, NULL);
1870 			else
1871 				/* RA TA mDA mSA AE:DA SA */
1872 				meshhdrlen = ieee80211_new_mesh_header(
1873 						sdata, &mesh_hdr, skb->data,
1874 						skb->data + ETH_ALEN);
1875 
1876 		}
1877 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1878 		if (!chanctx_conf)
1879 			goto fail_rcu;
1880 		band = chanctx_conf->def.chan->band;
1881 		break;
1882 #endif
1883 	case NL80211_IFTYPE_STATION:
1884 		if (sdata->wdev.wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS) {
1885 			bool tdls_peer = false;
1886 
1887 			sta = sta_info_get(sdata, skb->data);
1888 			if (sta) {
1889 				authorized = test_sta_flag(sta,
1890 							WLAN_STA_AUTHORIZED);
1891 				wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1892 				tdls_peer = test_sta_flag(sta,
1893 							 WLAN_STA_TDLS_PEER);
1894 				tdls_auth = test_sta_flag(sta,
1895 						WLAN_STA_TDLS_PEER_AUTH);
1896 			}
1897 
1898 			/*
1899 			 * If the TDLS link is enabled, send everything
1900 			 * directly. Otherwise, allow TDLS setup frames
1901 			 * to be transmitted indirectly.
1902 			 */
1903 			tdls_direct = tdls_peer && (tdls_auth ||
1904 				 !(ethertype == ETH_P_TDLS && skb->len > 14 &&
1905 				   skb->data[14] == WLAN_TDLS_SNAP_RFTYPE));
1906 		}
1907 
1908 		if (tdls_direct) {
1909 			/* link during setup - throw out frames to peer */
1910 			if (!tdls_auth)
1911 				goto fail_rcu;
1912 
1913 			/* DA SA BSSID */
1914 			memcpy(hdr.addr1, skb->data, ETH_ALEN);
1915 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1916 			memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
1917 			hdrlen = 24;
1918 		}  else if (sdata->u.mgd.use_4addr &&
1919 			    cpu_to_be16(ethertype) != sdata->control_port_protocol) {
1920 			fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
1921 					  IEEE80211_FCTL_TODS);
1922 			/* RA TA DA SA */
1923 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1924 			memcpy(hdr.addr2, sdata->vif.addr, ETH_ALEN);
1925 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1926 			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1927 			hdrlen = 30;
1928 		} else {
1929 			fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1930 			/* BSSID SA DA */
1931 			memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1932 			memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1933 			memcpy(hdr.addr3, skb->data, ETH_ALEN);
1934 			hdrlen = 24;
1935 		}
1936 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1937 		if (!chanctx_conf)
1938 			goto fail_rcu;
1939 		band = chanctx_conf->def.chan->band;
1940 		break;
1941 	case NL80211_IFTYPE_ADHOC:
1942 		/* DA SA BSSID */
1943 		memcpy(hdr.addr1, skb->data, ETH_ALEN);
1944 		memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1945 		memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1946 		hdrlen = 24;
1947 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1948 		if (!chanctx_conf)
1949 			goto fail_rcu;
1950 		band = chanctx_conf->def.chan->band;
1951 		break;
1952 	default:
1953 		goto fail_rcu;
1954 	}
1955 
1956 	/*
1957 	 * There's no need to try to look up the destination
1958 	 * if it is a multicast address (which can only happen
1959 	 * in AP mode)
1960 	 */
1961 	multicast = is_multicast_ether_addr(hdr.addr1);
1962 	if (!multicast) {
1963 		sta = sta_info_get(sdata, hdr.addr1);
1964 		if (sta) {
1965 			authorized = test_sta_flag(sta, WLAN_STA_AUTHORIZED);
1966 			wme_sta = test_sta_flag(sta, WLAN_STA_WME);
1967 		}
1968 	}
1969 
1970 	/* For mesh, the use of the QoS header is mandatory */
1971 	if (ieee80211_vif_is_mesh(&sdata->vif))
1972 		wme_sta = true;
1973 
1974 	/* receiver and we are QoS enabled, use a QoS type frame */
1975 	if (wme_sta && local->hw.queues >= IEEE80211_NUM_ACS) {
1976 		fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1977 		hdrlen += 2;
1978 	}
1979 
1980 	/*
1981 	 * Drop unicast frames to unauthorised stations unless they are
1982 	 * EAPOL frames from the local station.
1983 	 */
1984 	if (unlikely(!ieee80211_vif_is_mesh(&sdata->vif) &&
1985 		     !is_multicast_ether_addr(hdr.addr1) && !authorized &&
1986 		     (cpu_to_be16(ethertype) != sdata->control_port_protocol ||
1987 		      !ether_addr_equal(sdata->vif.addr, skb->data + ETH_ALEN)))) {
1988 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1989 		net_info_ratelimited("%s: dropped frame to %pM (unauthorized port)\n",
1990 				    dev->name, hdr.addr1);
1991 #endif
1992 
1993 		I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1994 
1995 		goto fail_rcu;
1996 	}
1997 
1998 	if (unlikely(!multicast && skb->sk &&
1999 		     skb_shinfo(skb)->tx_flags & SKBTX_WIFI_STATUS)) {
2000 		struct sk_buff *orig_skb = skb;
2001 
2002 		skb = skb_clone(skb, GFP_ATOMIC);
2003 		if (skb) {
2004 			unsigned long flags;
2005 			int id;
2006 
2007 			spin_lock_irqsave(&local->ack_status_lock, flags);
2008 			id = idr_alloc(&local->ack_status_frames, orig_skb,
2009 				       1, 0x10000, GFP_ATOMIC);
2010 			spin_unlock_irqrestore(&local->ack_status_lock, flags);
2011 
2012 			if (id >= 0) {
2013 				info_id = id;
2014 				info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
2015 			} else if (skb_shared(skb)) {
2016 				kfree_skb(orig_skb);
2017 			} else {
2018 				kfree_skb(skb);
2019 				skb = orig_skb;
2020 			}
2021 		} else {
2022 			/* couldn't clone -- lose tx status ... */
2023 			skb = orig_skb;
2024 		}
2025 	}
2026 
2027 	/*
2028 	 * If the skb is shared we need to obtain our own copy.
2029 	 */
2030 	if (skb_shared(skb)) {
2031 		struct sk_buff *tmp_skb = skb;
2032 
2033 		/* can't happen -- skb is a clone if info_id != 0 */
2034 		WARN_ON(info_id);
2035 
2036 		skb = skb_clone(skb, GFP_ATOMIC);
2037 		kfree_skb(tmp_skb);
2038 
2039 		if (!skb)
2040 			goto fail_rcu;
2041 	}
2042 
2043 	hdr.frame_control = fc;
2044 	hdr.duration_id = 0;
2045 	hdr.seq_ctrl = 0;
2046 
2047 	skip_header_bytes = ETH_HLEN;
2048 	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
2049 		encaps_data = bridge_tunnel_header;
2050 		encaps_len = sizeof(bridge_tunnel_header);
2051 		skip_header_bytes -= 2;
2052 	} else if (ethertype >= ETH_P_802_3_MIN) {
2053 		encaps_data = rfc1042_header;
2054 		encaps_len = sizeof(rfc1042_header);
2055 		skip_header_bytes -= 2;
2056 	} else {
2057 		encaps_data = NULL;
2058 		encaps_len = 0;
2059 	}
2060 
2061 	nh_pos = skb_network_header(skb) - skb->data;
2062 	h_pos = skb_transport_header(skb) - skb->data;
2063 
2064 	skb_pull(skb, skip_header_bytes);
2065 	nh_pos -= skip_header_bytes;
2066 	h_pos -= skip_header_bytes;
2067 
2068 	head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
2069 
2070 	/*
2071 	 * So we need to modify the skb header and hence need a copy of
2072 	 * that. The head_need variable above doesn't, so far, include
2073 	 * the needed header space that we don't need right away. If we
2074 	 * can, then we don't reallocate right now but only after the
2075 	 * frame arrives at the master device (if it does...)
2076 	 *
2077 	 * If we cannot, however, then we will reallocate to include all
2078 	 * the ever needed space. Also, if we need to reallocate it anyway,
2079 	 * make it big enough for everything we may ever need.
2080 	 */
2081 
2082 	if (head_need > 0 || skb_cloned(skb)) {
2083 		head_need += IEEE80211_ENCRYPT_HEADROOM;
2084 		head_need += local->tx_headroom;
2085 		head_need = max_t(int, 0, head_need);
2086 		if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
2087 			ieee80211_free_txskb(&local->hw, skb);
2088 			skb = NULL;
2089 			goto fail_rcu;
2090 		}
2091 	}
2092 
2093 	if (encaps_data) {
2094 		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
2095 		nh_pos += encaps_len;
2096 		h_pos += encaps_len;
2097 	}
2098 
2099 #ifdef CONFIG_MAC80211_MESH
2100 	if (meshhdrlen > 0) {
2101 		memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
2102 		nh_pos += meshhdrlen;
2103 		h_pos += meshhdrlen;
2104 	}
2105 #endif
2106 
2107 	if (ieee80211_is_data_qos(fc)) {
2108 		__le16 *qos_control;
2109 
2110 		qos_control = (__le16*) skb_push(skb, 2);
2111 		memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
2112 		/*
2113 		 * Maybe we could actually set some fields here, for now just
2114 		 * initialise to zero to indicate no special operation.
2115 		 */
2116 		*qos_control = 0;
2117 	} else
2118 		memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
2119 
2120 	nh_pos += hdrlen;
2121 	h_pos += hdrlen;
2122 
2123 	dev->stats.tx_packets++;
2124 	dev->stats.tx_bytes += skb->len;
2125 
2126 	/* Update skb pointers to various headers since this modified frame
2127 	 * is going to go through Linux networking code that may potentially
2128 	 * need things like pointer to IP header. */
2129 	skb_set_mac_header(skb, 0);
2130 	skb_set_network_header(skb, nh_pos);
2131 	skb_set_transport_header(skb, h_pos);
2132 
2133 	info = IEEE80211_SKB_CB(skb);
2134 	memset(info, 0, sizeof(*info));
2135 
2136 	dev->trans_start = jiffies;
2137 
2138 	info->flags = info_flags;
2139 	info->ack_frame_id = info_id;
2140 
2141 	ieee80211_xmit(sdata, skb, band);
2142 	rcu_read_unlock();
2143 
2144 	return NETDEV_TX_OK;
2145 
2146  fail_rcu:
2147 	rcu_read_unlock();
2148  fail:
2149 	dev_kfree_skb(skb);
2150 	return NETDEV_TX_OK;
2151 }
2152 
2153 
2154 /*
2155  * ieee80211_clear_tx_pending may not be called in a context where
2156  * it is possible that it packets could come in again.
2157  */
2158 void ieee80211_clear_tx_pending(struct ieee80211_local *local)
2159 {
2160 	struct sk_buff *skb;
2161 	int i;
2162 
2163 	for (i = 0; i < local->hw.queues; i++) {
2164 		while ((skb = skb_dequeue(&local->pending[i])) != NULL)
2165 			ieee80211_free_txskb(&local->hw, skb);
2166 	}
2167 }
2168 
2169 /*
2170  * Returns false if the frame couldn't be transmitted but was queued instead,
2171  * which in this case means re-queued -- take as an indication to stop sending
2172  * more pending frames.
2173  */
2174 static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
2175 				     struct sk_buff *skb)
2176 {
2177 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2178 	struct ieee80211_sub_if_data *sdata;
2179 	struct sta_info *sta;
2180 	struct ieee80211_hdr *hdr;
2181 	bool result;
2182 	struct ieee80211_chanctx_conf *chanctx_conf;
2183 
2184 	sdata = vif_to_sdata(info->control.vif);
2185 
2186 	if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
2187 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2188 		if (unlikely(!chanctx_conf)) {
2189 			dev_kfree_skb(skb);
2190 			return true;
2191 		}
2192 		result = ieee80211_tx(sdata, skb, true,
2193 				      chanctx_conf->def.chan->band);
2194 	} else {
2195 		struct sk_buff_head skbs;
2196 
2197 		__skb_queue_head_init(&skbs);
2198 		__skb_queue_tail(&skbs, skb);
2199 
2200 		hdr = (struct ieee80211_hdr *)skb->data;
2201 		sta = sta_info_get(sdata, hdr->addr1);
2202 
2203 		result = __ieee80211_tx(local, &skbs, skb->len, sta, true);
2204 	}
2205 
2206 	return result;
2207 }
2208 
2209 /*
2210  * Transmit all pending packets. Called from tasklet.
2211  */
2212 void ieee80211_tx_pending(unsigned long data)
2213 {
2214 	struct ieee80211_local *local = (struct ieee80211_local *)data;
2215 	unsigned long flags;
2216 	int i;
2217 	bool txok;
2218 
2219 	rcu_read_lock();
2220 
2221 	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
2222 	for (i = 0; i < local->hw.queues; i++) {
2223 		/*
2224 		 * If queue is stopped by something other than due to pending
2225 		 * frames, or we have no pending frames, proceed to next queue.
2226 		 */
2227 		if (local->queue_stop_reasons[i] ||
2228 		    skb_queue_empty(&local->pending[i]))
2229 			continue;
2230 
2231 		while (!skb_queue_empty(&local->pending[i])) {
2232 			struct sk_buff *skb = __skb_dequeue(&local->pending[i]);
2233 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2234 
2235 			if (WARN_ON(!info->control.vif)) {
2236 				ieee80211_free_txskb(&local->hw, skb);
2237 				continue;
2238 			}
2239 
2240 			spin_unlock_irqrestore(&local->queue_stop_reason_lock,
2241 						flags);
2242 
2243 			txok = ieee80211_tx_pending_skb(local, skb);
2244 			spin_lock_irqsave(&local->queue_stop_reason_lock,
2245 					  flags);
2246 			if (!txok)
2247 				break;
2248 		}
2249 
2250 		if (skb_queue_empty(&local->pending[i]))
2251 			ieee80211_propagate_queue_wake(local, i);
2252 	}
2253 	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
2254 
2255 	rcu_read_unlock();
2256 }
2257 
2258 /* functions for drivers to get certain frames */
2259 
2260 static void __ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2261 				       struct ps_data *ps, struct sk_buff *skb)
2262 {
2263 	u8 *pos, *tim;
2264 	int aid0 = 0;
2265 	int i, have_bits = 0, n1, n2;
2266 
2267 	/* Generate bitmap for TIM only if there are any STAs in power save
2268 	 * mode. */
2269 	if (atomic_read(&ps->num_sta_ps) > 0)
2270 		/* in the hope that this is faster than
2271 		 * checking byte-for-byte */
2272 		have_bits = !bitmap_empty((unsigned long*)ps->tim,
2273 					  IEEE80211_MAX_AID+1);
2274 
2275 	if (ps->dtim_count == 0)
2276 		ps->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
2277 	else
2278 		ps->dtim_count--;
2279 
2280 	tim = pos = (u8 *) skb_put(skb, 6);
2281 	*pos++ = WLAN_EID_TIM;
2282 	*pos++ = 4;
2283 	*pos++ = ps->dtim_count;
2284 	*pos++ = sdata->vif.bss_conf.dtim_period;
2285 
2286 	if (ps->dtim_count == 0 && !skb_queue_empty(&ps->bc_buf))
2287 		aid0 = 1;
2288 
2289 	ps->dtim_bc_mc = aid0 == 1;
2290 
2291 	if (have_bits) {
2292 		/* Find largest even number N1 so that bits numbered 1 through
2293 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
2294 		 * (N2 + 1) x 8 through 2007 are 0. */
2295 		n1 = 0;
2296 		for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2297 			if (ps->tim[i]) {
2298 				n1 = i & 0xfe;
2299 				break;
2300 			}
2301 		}
2302 		n2 = n1;
2303 		for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2304 			if (ps->tim[i]) {
2305 				n2 = i;
2306 				break;
2307 			}
2308 		}
2309 
2310 		/* Bitmap control */
2311 		*pos++ = n1 | aid0;
2312 		/* Part Virt Bitmap */
2313 		skb_put(skb, n2 - n1);
2314 		memcpy(pos, ps->tim + n1, n2 - n1 + 1);
2315 
2316 		tim[1] = n2 - n1 + 4;
2317 	} else {
2318 		*pos++ = aid0; /* Bitmap control */
2319 		*pos++ = 0; /* Part Virt Bitmap */
2320 	}
2321 }
2322 
2323 static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
2324 				    struct ps_data *ps, struct sk_buff *skb)
2325 {
2326 	struct ieee80211_local *local = sdata->local;
2327 
2328 	/*
2329 	 * Not very nice, but we want to allow the driver to call
2330 	 * ieee80211_beacon_get() as a response to the set_tim()
2331 	 * callback. That, however, is already invoked under the
2332 	 * sta_lock to guarantee consistent and race-free update
2333 	 * of the tim bitmap in mac80211 and the driver.
2334 	 */
2335 	if (local->tim_in_locked_section) {
2336 		__ieee80211_beacon_add_tim(sdata, ps, skb);
2337 	} else {
2338 		spin_lock_bh(&local->tim_lock);
2339 		__ieee80211_beacon_add_tim(sdata, ps, skb);
2340 		spin_unlock_bh(&local->tim_lock);
2341 	}
2342 
2343 	return 0;
2344 }
2345 
2346 void ieee80211_csa_finish(struct ieee80211_vif *vif)
2347 {
2348 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2349 
2350 	ieee80211_queue_work(&sdata->local->hw,
2351 			     &sdata->csa_finalize_work);
2352 }
2353 EXPORT_SYMBOL(ieee80211_csa_finish);
2354 
2355 static void ieee80211_update_csa(struct ieee80211_sub_if_data *sdata,
2356 				 struct beacon_data *beacon)
2357 {
2358 	struct probe_resp *resp;
2359 	int counter_offset_beacon = sdata->csa_counter_offset_beacon;
2360 	int counter_offset_presp = sdata->csa_counter_offset_presp;
2361 
2362 	/* warn if the driver did not check for/react to csa completeness */
2363 	if (WARN_ON(((u8 *)beacon->tail)[counter_offset_beacon] == 0))
2364 		return;
2365 
2366 	((u8 *)beacon->tail)[counter_offset_beacon]--;
2367 
2368 	if (sdata->vif.type == NL80211_IFTYPE_AP &&
2369 	    counter_offset_presp) {
2370 		rcu_read_lock();
2371 		resp = rcu_dereference(sdata->u.ap.probe_resp);
2372 
2373 		/* if nl80211 accepted the offset, this should not happen. */
2374 		if (WARN_ON(!resp)) {
2375 			rcu_read_unlock();
2376 			return;
2377 		}
2378 		resp->data[counter_offset_presp]--;
2379 		rcu_read_unlock();
2380 	}
2381 }
2382 
2383 bool ieee80211_csa_is_complete(struct ieee80211_vif *vif)
2384 {
2385 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2386 	struct beacon_data *beacon = NULL;
2387 	u8 *beacon_data;
2388 	size_t beacon_data_len;
2389 	int counter_beacon = sdata->csa_counter_offset_beacon;
2390 	int ret = false;
2391 
2392 	if (!ieee80211_sdata_running(sdata))
2393 		return false;
2394 
2395 	rcu_read_lock();
2396 	if (vif->type == NL80211_IFTYPE_AP) {
2397 		struct ieee80211_if_ap *ap = &sdata->u.ap;
2398 
2399 		beacon = rcu_dereference(ap->beacon);
2400 		if (WARN_ON(!beacon || !beacon->tail))
2401 			goto out;
2402 		beacon_data = beacon->tail;
2403 		beacon_data_len = beacon->tail_len;
2404 	} else {
2405 		WARN_ON(1);
2406 		goto out;
2407 	}
2408 
2409 	if (WARN_ON(counter_beacon > beacon_data_len))
2410 		goto out;
2411 
2412 	if (beacon_data[counter_beacon] == 0)
2413 		ret = true;
2414  out:
2415 	rcu_read_unlock();
2416 
2417 	return ret;
2418 }
2419 EXPORT_SYMBOL(ieee80211_csa_is_complete);
2420 
2421 struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
2422 					 struct ieee80211_vif *vif,
2423 					 u16 *tim_offset, u16 *tim_length)
2424 {
2425 	struct ieee80211_local *local = hw_to_local(hw);
2426 	struct sk_buff *skb = NULL;
2427 	struct ieee80211_tx_info *info;
2428 	struct ieee80211_sub_if_data *sdata = NULL;
2429 	enum ieee80211_band band;
2430 	struct ieee80211_tx_rate_control txrc;
2431 	struct ieee80211_chanctx_conf *chanctx_conf;
2432 
2433 	rcu_read_lock();
2434 
2435 	sdata = vif_to_sdata(vif);
2436 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2437 
2438 	if (!ieee80211_sdata_running(sdata) || !chanctx_conf)
2439 		goto out;
2440 
2441 	if (tim_offset)
2442 		*tim_offset = 0;
2443 	if (tim_length)
2444 		*tim_length = 0;
2445 
2446 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2447 		struct ieee80211_if_ap *ap = &sdata->u.ap;
2448 		struct beacon_data *beacon = rcu_dereference(ap->beacon);
2449 
2450 		if (beacon) {
2451 			if (sdata->vif.csa_active)
2452 				ieee80211_update_csa(sdata, beacon);
2453 
2454 			/*
2455 			 * headroom, head length,
2456 			 * tail length and maximum TIM length
2457 			 */
2458 			skb = dev_alloc_skb(local->tx_headroom +
2459 					    beacon->head_len +
2460 					    beacon->tail_len + 256);
2461 			if (!skb)
2462 				goto out;
2463 
2464 			skb_reserve(skb, local->tx_headroom);
2465 			memcpy(skb_put(skb, beacon->head_len), beacon->head,
2466 			       beacon->head_len);
2467 
2468 			ieee80211_beacon_add_tim(sdata, &ap->ps, skb);
2469 
2470 			if (tim_offset)
2471 				*tim_offset = beacon->head_len;
2472 			if (tim_length)
2473 				*tim_length = skb->len - beacon->head_len;
2474 
2475 			if (beacon->tail)
2476 				memcpy(skb_put(skb, beacon->tail_len),
2477 				       beacon->tail, beacon->tail_len);
2478 		} else
2479 			goto out;
2480 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2481 		struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2482 		struct ieee80211_hdr *hdr;
2483 		struct beacon_data *presp = rcu_dereference(ifibss->presp);
2484 
2485 		if (!presp)
2486 			goto out;
2487 
2488 		skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
2489 		if (!skb)
2490 			goto out;
2491 		skb_reserve(skb, local->tx_headroom);
2492 		memcpy(skb_put(skb, presp->head_len), presp->head,
2493 		       presp->head_len);
2494 
2495 		hdr = (struct ieee80211_hdr *) skb->data;
2496 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2497 						 IEEE80211_STYPE_BEACON);
2498 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2499 		struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
2500 		struct beacon_data *bcn = rcu_dereference(ifmsh->beacon);
2501 
2502 		if (!bcn)
2503 			goto out;
2504 
2505 		if (ifmsh->sync_ops)
2506 			ifmsh->sync_ops->adjust_tbtt(
2507 						sdata);
2508 
2509 		skb = dev_alloc_skb(local->tx_headroom +
2510 				    bcn->head_len +
2511 				    256 + /* TIM IE */
2512 				    bcn->tail_len);
2513 		if (!skb)
2514 			goto out;
2515 		skb_reserve(skb, local->tx_headroom);
2516 		memcpy(skb_put(skb, bcn->head_len), bcn->head, bcn->head_len);
2517 		ieee80211_beacon_add_tim(sdata, &ifmsh->ps, skb);
2518 		memcpy(skb_put(skb, bcn->tail_len), bcn->tail, bcn->tail_len);
2519 	} else {
2520 		WARN_ON(1);
2521 		goto out;
2522 	}
2523 
2524 	band = chanctx_conf->def.chan->band;
2525 
2526 	info = IEEE80211_SKB_CB(skb);
2527 
2528 	info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
2529 	info->flags |= IEEE80211_TX_CTL_NO_ACK;
2530 	info->band = band;
2531 
2532 	memset(&txrc, 0, sizeof(txrc));
2533 	txrc.hw = hw;
2534 	txrc.sband = local->hw.wiphy->bands[band];
2535 	txrc.bss_conf = &sdata->vif.bss_conf;
2536 	txrc.skb = skb;
2537 	txrc.reported_rate.idx = -1;
2538 	txrc.rate_idx_mask = sdata->rc_rateidx_mask[band];
2539 	if (txrc.rate_idx_mask == (1 << txrc.sband->n_bitrates) - 1)
2540 		txrc.max_rate_idx = -1;
2541 	else
2542 		txrc.max_rate_idx = fls(txrc.rate_idx_mask) - 1;
2543 	txrc.bss = true;
2544 	rate_control_get_rate(sdata, NULL, &txrc);
2545 
2546 	info->control.vif = vif;
2547 
2548 	info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT |
2549 			IEEE80211_TX_CTL_ASSIGN_SEQ |
2550 			IEEE80211_TX_CTL_FIRST_FRAGMENT;
2551  out:
2552 	rcu_read_unlock();
2553 	return skb;
2554 }
2555 EXPORT_SYMBOL(ieee80211_beacon_get_tim);
2556 
2557 struct sk_buff *ieee80211_proberesp_get(struct ieee80211_hw *hw,
2558 					struct ieee80211_vif *vif)
2559 {
2560 	struct ieee80211_if_ap *ap = NULL;
2561 	struct sk_buff *skb = NULL;
2562 	struct probe_resp *presp = NULL;
2563 	struct ieee80211_hdr *hdr;
2564 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
2565 
2566 	if (sdata->vif.type != NL80211_IFTYPE_AP)
2567 		return NULL;
2568 
2569 	rcu_read_lock();
2570 
2571 	ap = &sdata->u.ap;
2572 	presp = rcu_dereference(ap->probe_resp);
2573 	if (!presp)
2574 		goto out;
2575 
2576 	skb = dev_alloc_skb(presp->len);
2577 	if (!skb)
2578 		goto out;
2579 
2580 	memcpy(skb_put(skb, presp->len), presp->data, presp->len);
2581 
2582 	hdr = (struct ieee80211_hdr *) skb->data;
2583 	memset(hdr->addr1, 0, sizeof(hdr->addr1));
2584 
2585 out:
2586 	rcu_read_unlock();
2587 	return skb;
2588 }
2589 EXPORT_SYMBOL(ieee80211_proberesp_get);
2590 
2591 struct sk_buff *ieee80211_pspoll_get(struct ieee80211_hw *hw,
2592 				     struct ieee80211_vif *vif)
2593 {
2594 	struct ieee80211_sub_if_data *sdata;
2595 	struct ieee80211_if_managed *ifmgd;
2596 	struct ieee80211_pspoll *pspoll;
2597 	struct ieee80211_local *local;
2598 	struct sk_buff *skb;
2599 
2600 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2601 		return NULL;
2602 
2603 	sdata = vif_to_sdata(vif);
2604 	ifmgd = &sdata->u.mgd;
2605 	local = sdata->local;
2606 
2607 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*pspoll));
2608 	if (!skb)
2609 		return NULL;
2610 
2611 	skb_reserve(skb, local->hw.extra_tx_headroom);
2612 
2613 	pspoll = (struct ieee80211_pspoll *) skb_put(skb, sizeof(*pspoll));
2614 	memset(pspoll, 0, sizeof(*pspoll));
2615 	pspoll->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
2616 					    IEEE80211_STYPE_PSPOLL);
2617 	pspoll->aid = cpu_to_le16(ifmgd->aid);
2618 
2619 	/* aid in PS-Poll has its two MSBs each set to 1 */
2620 	pspoll->aid |= cpu_to_le16(1 << 15 | 1 << 14);
2621 
2622 	memcpy(pspoll->bssid, ifmgd->bssid, ETH_ALEN);
2623 	memcpy(pspoll->ta, vif->addr, ETH_ALEN);
2624 
2625 	return skb;
2626 }
2627 EXPORT_SYMBOL(ieee80211_pspoll_get);
2628 
2629 struct sk_buff *ieee80211_nullfunc_get(struct ieee80211_hw *hw,
2630 				       struct ieee80211_vif *vif)
2631 {
2632 	struct ieee80211_hdr_3addr *nullfunc;
2633 	struct ieee80211_sub_if_data *sdata;
2634 	struct ieee80211_if_managed *ifmgd;
2635 	struct ieee80211_local *local;
2636 	struct sk_buff *skb;
2637 
2638 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
2639 		return NULL;
2640 
2641 	sdata = vif_to_sdata(vif);
2642 	ifmgd = &sdata->u.mgd;
2643 	local = sdata->local;
2644 
2645 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*nullfunc));
2646 	if (!skb)
2647 		return NULL;
2648 
2649 	skb_reserve(skb, local->hw.extra_tx_headroom);
2650 
2651 	nullfunc = (struct ieee80211_hdr_3addr *) skb_put(skb,
2652 							  sizeof(*nullfunc));
2653 	memset(nullfunc, 0, sizeof(*nullfunc));
2654 	nullfunc->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
2655 					      IEEE80211_STYPE_NULLFUNC |
2656 					      IEEE80211_FCTL_TODS);
2657 	memcpy(nullfunc->addr1, ifmgd->bssid, ETH_ALEN);
2658 	memcpy(nullfunc->addr2, vif->addr, ETH_ALEN);
2659 	memcpy(nullfunc->addr3, ifmgd->bssid, ETH_ALEN);
2660 
2661 	return skb;
2662 }
2663 EXPORT_SYMBOL(ieee80211_nullfunc_get);
2664 
2665 struct sk_buff *ieee80211_probereq_get(struct ieee80211_hw *hw,
2666 				       struct ieee80211_vif *vif,
2667 				       const u8 *ssid, size_t ssid_len,
2668 				       size_t tailroom)
2669 {
2670 	struct ieee80211_sub_if_data *sdata;
2671 	struct ieee80211_local *local;
2672 	struct ieee80211_hdr_3addr *hdr;
2673 	struct sk_buff *skb;
2674 	size_t ie_ssid_len;
2675 	u8 *pos;
2676 
2677 	sdata = vif_to_sdata(vif);
2678 	local = sdata->local;
2679 	ie_ssid_len = 2 + ssid_len;
2680 
2681 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*hdr) +
2682 			    ie_ssid_len + tailroom);
2683 	if (!skb)
2684 		return NULL;
2685 
2686 	skb_reserve(skb, local->hw.extra_tx_headroom);
2687 
2688 	hdr = (struct ieee80211_hdr_3addr *) skb_put(skb, sizeof(*hdr));
2689 	memset(hdr, 0, sizeof(*hdr));
2690 	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2691 					 IEEE80211_STYPE_PROBE_REQ);
2692 	eth_broadcast_addr(hdr->addr1);
2693 	memcpy(hdr->addr2, vif->addr, ETH_ALEN);
2694 	eth_broadcast_addr(hdr->addr3);
2695 
2696 	pos = skb_put(skb, ie_ssid_len);
2697 	*pos++ = WLAN_EID_SSID;
2698 	*pos++ = ssid_len;
2699 	if (ssid_len)
2700 		memcpy(pos, ssid, ssid_len);
2701 	pos += ssid_len;
2702 
2703 	return skb;
2704 }
2705 EXPORT_SYMBOL(ieee80211_probereq_get);
2706 
2707 void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2708 		       const void *frame, size_t frame_len,
2709 		       const struct ieee80211_tx_info *frame_txctl,
2710 		       struct ieee80211_rts *rts)
2711 {
2712 	const struct ieee80211_hdr *hdr = frame;
2713 
2714 	rts->frame_control =
2715 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2716 	rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2717 					       frame_txctl);
2718 	memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2719 	memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2720 }
2721 EXPORT_SYMBOL(ieee80211_rts_get);
2722 
2723 void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2724 			     const void *frame, size_t frame_len,
2725 			     const struct ieee80211_tx_info *frame_txctl,
2726 			     struct ieee80211_cts *cts)
2727 {
2728 	const struct ieee80211_hdr *hdr = frame;
2729 
2730 	cts->frame_control =
2731 	    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2732 	cts->duration = ieee80211_ctstoself_duration(hw, vif,
2733 						     frame_len, frame_txctl);
2734 	memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2735 }
2736 EXPORT_SYMBOL(ieee80211_ctstoself_get);
2737 
2738 struct sk_buff *
2739 ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2740 			  struct ieee80211_vif *vif)
2741 {
2742 	struct ieee80211_local *local = hw_to_local(hw);
2743 	struct sk_buff *skb = NULL;
2744 	struct ieee80211_tx_data tx;
2745 	struct ieee80211_sub_if_data *sdata;
2746 	struct ps_data *ps;
2747 	struct ieee80211_tx_info *info;
2748 	struct ieee80211_chanctx_conf *chanctx_conf;
2749 
2750 	sdata = vif_to_sdata(vif);
2751 
2752 	rcu_read_lock();
2753 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
2754 
2755 	if (!chanctx_conf)
2756 		goto out;
2757 
2758 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
2759 		struct beacon_data *beacon =
2760 				rcu_dereference(sdata->u.ap.beacon);
2761 
2762 		if (!beacon || !beacon->head)
2763 			goto out;
2764 
2765 		ps = &sdata->u.ap.ps;
2766 	} else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2767 		ps = &sdata->u.mesh.ps;
2768 	} else {
2769 		goto out;
2770 	}
2771 
2772 	if (ps->dtim_count != 0 || !ps->dtim_bc_mc)
2773 		goto out; /* send buffered bc/mc only after DTIM beacon */
2774 
2775 	while (1) {
2776 		skb = skb_dequeue(&ps->bc_buf);
2777 		if (!skb)
2778 			goto out;
2779 		local->total_ps_buffered--;
2780 
2781 		if (!skb_queue_empty(&ps->bc_buf) && skb->len >= 2) {
2782 			struct ieee80211_hdr *hdr =
2783 				(struct ieee80211_hdr *) skb->data;
2784 			/* more buffered multicast/broadcast frames ==> set
2785 			 * MoreData flag in IEEE 802.11 header to inform PS
2786 			 * STAs */
2787 			hdr->frame_control |=
2788 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2789 		}
2790 
2791 		if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
2792 			sdata = IEEE80211_DEV_TO_SUB_IF(skb->dev);
2793 		if (!ieee80211_tx_prepare(sdata, &tx, skb))
2794 			break;
2795 		dev_kfree_skb_any(skb);
2796 	}
2797 
2798 	info = IEEE80211_SKB_CB(skb);
2799 
2800 	tx.flags |= IEEE80211_TX_PS_BUFFERED;
2801 	info->band = chanctx_conf->def.chan->band;
2802 
2803 	if (invoke_tx_handlers(&tx))
2804 		skb = NULL;
2805  out:
2806 	rcu_read_unlock();
2807 
2808 	return skb;
2809 }
2810 EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2811 
2812 void __ieee80211_tx_skb_tid_band(struct ieee80211_sub_if_data *sdata,
2813 				 struct sk_buff *skb, int tid,
2814 				 enum ieee80211_band band)
2815 {
2816 	int ac = ieee802_1d_to_ac[tid & 7];
2817 
2818 	skb_set_mac_header(skb, 0);
2819 	skb_set_network_header(skb, 0);
2820 	skb_set_transport_header(skb, 0);
2821 
2822 	skb_set_queue_mapping(skb, ac);
2823 	skb->priority = tid;
2824 
2825 	skb->dev = sdata->dev;
2826 
2827 	/*
2828 	 * The other path calling ieee80211_xmit is from the tasklet,
2829 	 * and while we can handle concurrent transmissions locking
2830 	 * requirements are that we do not come into tx with bhs on.
2831 	 */
2832 	local_bh_disable();
2833 	ieee80211_xmit(sdata, skb, band);
2834 	local_bh_enable();
2835 }
2836