xref: /openbmc/linux/net/mac80211/main.c (revision e8e0929d)
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  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <net/mac80211.h>
12 #include <net/ieee80211_radiotap.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/netdevice.h>
16 #include <linux/types.h>
17 #include <linux/slab.h>
18 #include <linux/skbuff.h>
19 #include <linux/etherdevice.h>
20 #include <linux/if_arp.h>
21 #include <linux/wireless.h>
22 #include <linux/rtnetlink.h>
23 #include <linux/bitmap.h>
24 #include <linux/pm_qos_params.h>
25 #include <net/net_namespace.h>
26 #include <net/cfg80211.h>
27 
28 #include "ieee80211_i.h"
29 #include "driver-ops.h"
30 #include "rate.h"
31 #include "mesh.h"
32 #include "wep.h"
33 #include "wme.h"
34 #include "aes_ccm.h"
35 #include "led.h"
36 #include "cfg.h"
37 #include "debugfs.h"
38 #include "debugfs_netdev.h"
39 
40 /*
41  * For seeing transmitted packets on monitor interfaces
42  * we have a radiotap header too.
43  */
44 struct ieee80211_tx_status_rtap_hdr {
45 	struct ieee80211_radiotap_header hdr;
46 	u8 rate;
47 	u8 padding_for_rate;
48 	__le16 tx_flags;
49 	u8 data_retries;
50 } __attribute__ ((packed));
51 
52 
53 void ieee80211_configure_filter(struct ieee80211_local *local)
54 {
55 	u64 mc;
56 	unsigned int changed_flags;
57 	unsigned int new_flags = 0;
58 
59 	if (atomic_read(&local->iff_promiscs))
60 		new_flags |= FIF_PROMISC_IN_BSS;
61 
62 	if (atomic_read(&local->iff_allmultis))
63 		new_flags |= FIF_ALLMULTI;
64 
65 	if (local->monitors || local->scanning)
66 		new_flags |= FIF_BCN_PRBRESP_PROMISC;
67 
68 	if (local->fif_fcsfail)
69 		new_flags |= FIF_FCSFAIL;
70 
71 	if (local->fif_plcpfail)
72 		new_flags |= FIF_PLCPFAIL;
73 
74 	if (local->fif_control)
75 		new_flags |= FIF_CONTROL;
76 
77 	if (local->fif_other_bss)
78 		new_flags |= FIF_OTHER_BSS;
79 
80 	if (local->fif_pspoll)
81 		new_flags |= FIF_PSPOLL;
82 
83 	spin_lock_bh(&local->filter_lock);
84 	changed_flags = local->filter_flags ^ new_flags;
85 
86 	mc = drv_prepare_multicast(local, local->mc_count, local->mc_list);
87 	spin_unlock_bh(&local->filter_lock);
88 
89 	/* be a bit nasty */
90 	new_flags |= (1<<31);
91 
92 	drv_configure_filter(local, changed_flags, &new_flags, mc);
93 
94 	WARN_ON(new_flags & (1<<31));
95 
96 	local->filter_flags = new_flags & ~(1<<31);
97 }
98 
99 static void ieee80211_reconfig_filter(struct work_struct *work)
100 {
101 	struct ieee80211_local *local =
102 		container_of(work, struct ieee80211_local, reconfig_filter);
103 
104 	ieee80211_configure_filter(local);
105 }
106 
107 int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
108 {
109 	struct ieee80211_channel *chan, *scan_chan;
110 	int ret = 0;
111 	int power;
112 	enum nl80211_channel_type channel_type;
113 
114 	might_sleep();
115 
116 	scan_chan = local->scan_channel;
117 
118 	if (scan_chan) {
119 		chan = scan_chan;
120 		channel_type = NL80211_CHAN_NO_HT;
121 	} else {
122 		chan = local->oper_channel;
123 		channel_type = local->oper_channel_type;
124 	}
125 
126 	if (chan != local->hw.conf.channel ||
127 	    channel_type != local->hw.conf.channel_type) {
128 		local->hw.conf.channel = chan;
129 		local->hw.conf.channel_type = channel_type;
130 		changed |= IEEE80211_CONF_CHANGE_CHANNEL;
131 	}
132 
133 	if (scan_chan)
134 		power = chan->max_power;
135 	else
136 		power = local->power_constr_level ?
137 			(chan->max_power - local->power_constr_level) :
138 			chan->max_power;
139 
140 	if (local->user_power_level >= 0)
141 		power = min(power, local->user_power_level);
142 
143 	if (local->hw.conf.power_level != power) {
144 		changed |= IEEE80211_CONF_CHANGE_POWER;
145 		local->hw.conf.power_level = power;
146 	}
147 
148 	if (changed && local->open_count) {
149 		ret = drv_config(local, changed);
150 		/*
151 		 * Goal:
152 		 * HW reconfiguration should never fail, the driver has told
153 		 * us what it can support so it should live up to that promise.
154 		 *
155 		 * Current status:
156 		 * rfkill is not integrated with mac80211 and a
157 		 * configuration command can thus fail if hardware rfkill
158 		 * is enabled
159 		 *
160 		 * FIXME: integrate rfkill with mac80211 and then add this
161 		 * WARN_ON() back
162 		 *
163 		 */
164 		/* WARN_ON(ret); */
165 	}
166 
167 	return ret;
168 }
169 
170 void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata,
171 				      u32 changed)
172 {
173 	struct ieee80211_local *local = sdata->local;
174 	static const u8 zero[ETH_ALEN] = { 0 };
175 
176 	if (!changed)
177 		return;
178 
179 	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
180 		/*
181 		 * While not associated, claim a BSSID of all-zeroes
182 		 * so that drivers don't do any weird things with the
183 		 * BSSID at that time.
184 		 */
185 		if (sdata->vif.bss_conf.assoc)
186 			sdata->vif.bss_conf.bssid = sdata->u.mgd.bssid;
187 		else
188 			sdata->vif.bss_conf.bssid = zero;
189 	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
190 		sdata->vif.bss_conf.bssid = sdata->u.ibss.bssid;
191 	else if (sdata->vif.type == NL80211_IFTYPE_AP)
192 		sdata->vif.bss_conf.bssid = sdata->dev->dev_addr;
193 	else if (ieee80211_vif_is_mesh(&sdata->vif)) {
194 		sdata->vif.bss_conf.bssid = zero;
195 	} else {
196 		WARN_ON(1);
197 		return;
198 	}
199 
200 	switch (sdata->vif.type) {
201 	case NL80211_IFTYPE_AP:
202 	case NL80211_IFTYPE_ADHOC:
203 	case NL80211_IFTYPE_MESH_POINT:
204 		break;
205 	default:
206 		/* do not warn to simplify caller in scan.c */
207 		changed &= ~BSS_CHANGED_BEACON_ENABLED;
208 		if (WARN_ON(changed & BSS_CHANGED_BEACON))
209 			return;
210 		break;
211 	}
212 
213 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
214 		if (local->quiescing || !netif_running(sdata->dev) ||
215 		    test_bit(SCAN_SW_SCANNING, &local->scanning)) {
216 			sdata->vif.bss_conf.enable_beacon = false;
217 		} else {
218 			/*
219 			 * Beacon should be enabled, but AP mode must
220 			 * check whether there is a beacon configured.
221 			 */
222 			switch (sdata->vif.type) {
223 			case NL80211_IFTYPE_AP:
224 				sdata->vif.bss_conf.enable_beacon =
225 					!!rcu_dereference(sdata->u.ap.beacon);
226 				break;
227 			case NL80211_IFTYPE_ADHOC:
228 				sdata->vif.bss_conf.enable_beacon =
229 					!!rcu_dereference(sdata->u.ibss.presp);
230 				break;
231 			case NL80211_IFTYPE_MESH_POINT:
232 				sdata->vif.bss_conf.enable_beacon = true;
233 				break;
234 			default:
235 				/* not reached */
236 				WARN_ON(1);
237 				break;
238 			}
239 		}
240 	}
241 
242 	drv_bss_info_changed(local, &sdata->vif,
243 			     &sdata->vif.bss_conf, changed);
244 }
245 
246 u32 ieee80211_reset_erp_info(struct ieee80211_sub_if_data *sdata)
247 {
248 	sdata->vif.bss_conf.use_cts_prot = false;
249 	sdata->vif.bss_conf.use_short_preamble = false;
250 	sdata->vif.bss_conf.use_short_slot = false;
251 	return BSS_CHANGED_ERP_CTS_PROT |
252 	       BSS_CHANGED_ERP_PREAMBLE |
253 	       BSS_CHANGED_ERP_SLOT;
254 }
255 
256 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
257 				 struct sk_buff *skb)
258 {
259 	struct ieee80211_local *local = hw_to_local(hw);
260 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
261 	int tmp;
262 
263 	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
264 	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
265 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
266 	tmp = skb_queue_len(&local->skb_queue) +
267 		skb_queue_len(&local->skb_queue_unreliable);
268 	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
269 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
270 		dev_kfree_skb_irq(skb);
271 		tmp--;
272 		I802_DEBUG_INC(local->tx_status_drop);
273 	}
274 	tasklet_schedule(&local->tasklet);
275 }
276 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
277 
278 static void ieee80211_tasklet_handler(unsigned long data)
279 {
280 	struct ieee80211_local *local = (struct ieee80211_local *) data;
281 	struct sk_buff *skb;
282 	struct ieee80211_ra_tid *ra_tid;
283 
284 	while ((skb = skb_dequeue(&local->skb_queue)) ||
285 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
286 		switch (skb->pkt_type) {
287 		case IEEE80211_RX_MSG:
288 			/* Clear skb->pkt_type in order to not confuse kernel
289 			 * netstack. */
290 			skb->pkt_type = 0;
291 			ieee80211_rx(local_to_hw(local), skb);
292 			break;
293 		case IEEE80211_TX_STATUS_MSG:
294 			skb->pkt_type = 0;
295 			ieee80211_tx_status(local_to_hw(local), skb);
296 			break;
297 		case IEEE80211_DELBA_MSG:
298 			ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
299 			ieee80211_stop_tx_ba_cb(local_to_hw(local),
300 						ra_tid->ra, ra_tid->tid);
301 			dev_kfree_skb(skb);
302 			break;
303 		case IEEE80211_ADDBA_MSG:
304 			ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
305 			ieee80211_start_tx_ba_cb(local_to_hw(local),
306 						 ra_tid->ra, ra_tid->tid);
307 			dev_kfree_skb(skb);
308 			break ;
309 		default:
310 			WARN(1, "mac80211: Packet is of unknown type %d\n",
311 			     skb->pkt_type);
312 			dev_kfree_skb(skb);
313 			break;
314 		}
315 	}
316 }
317 
318 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
319 					    struct sta_info *sta,
320 					    struct sk_buff *skb)
321 {
322 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
323 
324 	/*
325 	 * XXX: This is temporary!
326 	 *
327 	 *	The problem here is that when we get here, the driver will
328 	 *	quite likely have pretty much overwritten info->control by
329 	 *	using info->driver_data or info->rate_driver_data. Thus,
330 	 *	when passing out the frame to the driver again, we would be
331 	 *	passing completely bogus data since the driver would then
332 	 *	expect a properly filled info->control. In mac80211 itself
333 	 *	the same problem occurs, since we need info->control.vif
334 	 *	internally.
335 	 *
336 	 *	To fix this, we should send the frame through TX processing
337 	 *	again. However, it's not that simple, since the frame will
338 	 *	have been software-encrypted (if applicable) already, and
339 	 *	encrypting it again doesn't do much good. So to properly do
340 	 *	that, we not only have to skip the actual 'raw' encryption
341 	 *	(key selection etc. still has to be done!) but also the
342 	 *	sequence number assignment since that impacts the crypto
343 	 *	encapsulation, of course.
344 	 *
345 	 *	Hence, for now, fix the bug by just dropping the frame.
346 	 */
347 	goto drop;
348 
349 	sta->tx_filtered_count++;
350 
351 	/*
352 	 * Clear the TX filter mask for this STA when sending the next
353 	 * packet. If the STA went to power save mode, this will happen
354 	 * when it wakes up for the next time.
355 	 */
356 	set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT);
357 
358 	/*
359 	 * This code races in the following way:
360 	 *
361 	 *  (1) STA sends frame indicating it will go to sleep and does so
362 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
363 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
364 	 *  (4) we get TX status before having processed the frame and
365 	 *	knowing that the STA has gone to sleep.
366 	 *
367 	 * This is actually quite unlikely even when both those events are
368 	 * processed from interrupts coming in quickly after one another or
369 	 * even at the same time because we queue both TX status events and
370 	 * RX frames to be processed by a tasklet and process them in the
371 	 * same order that they were received or TX status last. Hence, there
372 	 * is no race as long as the frame RX is processed before the next TX
373 	 * status, which drivers can ensure, see below.
374 	 *
375 	 * Note that this can only happen if the hardware or firmware can
376 	 * actually add STAs to the filter list, if this is done by the
377 	 * driver in response to set_tim() (which will only reduce the race
378 	 * this whole filtering tries to solve, not completely solve it)
379 	 * this situation cannot happen.
380 	 *
381 	 * To completely solve this race drivers need to make sure that they
382 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
383 	 *	functions and
384 	 *  (b) always process RX events before TX status events if ordering
385 	 *      can be unknown, for example with different interrupt status
386 	 *	bits.
387 	 */
388 	if (test_sta_flags(sta, WLAN_STA_PS) &&
389 	    skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
390 		skb_queue_tail(&sta->tx_filtered, skb);
391 		return;
392 	}
393 
394 	if (!test_sta_flags(sta, WLAN_STA_PS) &&
395 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
396 		/* Software retry the packet once */
397 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
398 		ieee80211_add_pending_skb(local, skb);
399 		return;
400 	}
401 
402  drop:
403 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
404 	if (net_ratelimit())
405 		printk(KERN_DEBUG "%s: dropped TX filtered frame, "
406 		       "queue_len=%d PS=%d @%lu\n",
407 		       wiphy_name(local->hw.wiphy),
408 		       skb_queue_len(&sta->tx_filtered),
409 		       !!test_sta_flags(sta, WLAN_STA_PS), jiffies);
410 #endif
411 	dev_kfree_skb(skb);
412 }
413 
414 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
415 {
416 	struct sk_buff *skb2;
417 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
418 	struct ieee80211_local *local = hw_to_local(hw);
419 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
420 	u16 frag, type;
421 	__le16 fc;
422 	struct ieee80211_supported_band *sband;
423 	struct ieee80211_tx_status_rtap_hdr *rthdr;
424 	struct ieee80211_sub_if_data *sdata;
425 	struct net_device *prev_dev = NULL;
426 	struct sta_info *sta;
427 	int retry_count = -1, i;
428 
429 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
430 		/* the HW cannot have attempted that rate */
431 		if (i >= hw->max_rates) {
432 			info->status.rates[i].idx = -1;
433 			info->status.rates[i].count = 0;
434 		}
435 
436 		retry_count += info->status.rates[i].count;
437 	}
438 	if (retry_count < 0)
439 		retry_count = 0;
440 
441 	rcu_read_lock();
442 
443 	sband = local->hw.wiphy->bands[info->band];
444 
445 	sta = sta_info_get(local, hdr->addr1);
446 
447 	if (sta) {
448 		if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
449 		    test_sta_flags(sta, WLAN_STA_PS)) {
450 			/*
451 			 * The STA is in power save mode, so assume
452 			 * that this TX packet failed because of that.
453 			 */
454 			ieee80211_handle_filtered_frame(local, sta, skb);
455 			rcu_read_unlock();
456 			return;
457 		}
458 
459 		fc = hdr->frame_control;
460 
461 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
462 		    (ieee80211_is_data_qos(fc))) {
463 			u16 tid, ssn;
464 			u8 *qc;
465 
466 			qc = ieee80211_get_qos_ctl(hdr);
467 			tid = qc[0] & 0xf;
468 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
469 						& IEEE80211_SCTL_SEQ);
470 			ieee80211_send_bar(sta->sdata, hdr->addr1,
471 					   tid, ssn);
472 		}
473 
474 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
475 			ieee80211_handle_filtered_frame(local, sta, skb);
476 			rcu_read_unlock();
477 			return;
478 		} else {
479 			if (!(info->flags & IEEE80211_TX_STAT_ACK))
480 				sta->tx_retry_failed++;
481 			sta->tx_retry_count += retry_count;
482 		}
483 
484 		rate_control_tx_status(local, sband, sta, skb);
485 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
486 			ieee80211s_update_metric(local, sta, skb);
487 	}
488 
489 	rcu_read_unlock();
490 
491 	ieee80211_led_tx(local, 0);
492 
493 	/* SNMP counters
494 	 * Fragments are passed to low-level drivers as separate skbs, so these
495 	 * are actually fragments, not frames. Update frame counters only for
496 	 * the first fragment of the frame. */
497 
498 	frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
499 	type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;
500 
501 	if (info->flags & IEEE80211_TX_STAT_ACK) {
502 		if (frag == 0) {
503 			local->dot11TransmittedFrameCount++;
504 			if (is_multicast_ether_addr(hdr->addr1))
505 				local->dot11MulticastTransmittedFrameCount++;
506 			if (retry_count > 0)
507 				local->dot11RetryCount++;
508 			if (retry_count > 1)
509 				local->dot11MultipleRetryCount++;
510 		}
511 
512 		/* This counter shall be incremented for an acknowledged MPDU
513 		 * with an individual address in the address 1 field or an MPDU
514 		 * with a multicast address in the address 1 field of type Data
515 		 * or Management. */
516 		if (!is_multicast_ether_addr(hdr->addr1) ||
517 		    type == IEEE80211_FTYPE_DATA ||
518 		    type == IEEE80211_FTYPE_MGMT)
519 			local->dot11TransmittedFragmentCount++;
520 	} else {
521 		if (frag == 0)
522 			local->dot11FailedCount++;
523 	}
524 
525 	/* this was a transmitted frame, but now we want to reuse it */
526 	skb_orphan(skb);
527 
528 	/*
529 	 * This is a bit racy but we can avoid a lot of work
530 	 * with this test...
531 	 */
532 	if (!local->monitors && !local->cooked_mntrs) {
533 		dev_kfree_skb(skb);
534 		return;
535 	}
536 
537 	/* send frame to monitor interfaces now */
538 
539 	if (skb_headroom(skb) < sizeof(*rthdr)) {
540 		printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
541 		dev_kfree_skb(skb);
542 		return;
543 	}
544 
545 	rthdr = (struct ieee80211_tx_status_rtap_hdr *)
546 				skb_push(skb, sizeof(*rthdr));
547 
548 	memset(rthdr, 0, sizeof(*rthdr));
549 	rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
550 	rthdr->hdr.it_present =
551 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
552 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES) |
553 			    (1 << IEEE80211_RADIOTAP_RATE));
554 
555 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
556 	    !is_multicast_ether_addr(hdr->addr1))
557 		rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL);
558 
559 	/*
560 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
561 	 *	extensions proposal contains, we can actually report
562 	 *	the whole set of tries we did.
563 	 */
564 	if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
565 	    (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
566 		rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS);
567 	else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
568 		rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS);
569 	if (info->status.rates[0].idx >= 0 &&
570 	    !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
571 		rthdr->rate = sband->bitrates[
572 				info->status.rates[0].idx].bitrate / 5;
573 
574 	/* for now report the total retry_count */
575 	rthdr->data_retries = retry_count;
576 
577 	/* XXX: is this sufficient for BPF? */
578 	skb_set_mac_header(skb, 0);
579 	skb->ip_summed = CHECKSUM_UNNECESSARY;
580 	skb->pkt_type = PACKET_OTHERHOST;
581 	skb->protocol = htons(ETH_P_802_2);
582 	memset(skb->cb, 0, sizeof(skb->cb));
583 
584 	rcu_read_lock();
585 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
586 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
587 			if (!netif_running(sdata->dev))
588 				continue;
589 
590 			if (prev_dev) {
591 				skb2 = skb_clone(skb, GFP_ATOMIC);
592 				if (skb2) {
593 					skb2->dev = prev_dev;
594 					netif_rx(skb2);
595 				}
596 			}
597 
598 			prev_dev = sdata->dev;
599 		}
600 	}
601 	if (prev_dev) {
602 		skb->dev = prev_dev;
603 		netif_rx(skb);
604 		skb = NULL;
605 	}
606 	rcu_read_unlock();
607 	dev_kfree_skb(skb);
608 }
609 EXPORT_SYMBOL(ieee80211_tx_status);
610 
611 static void ieee80211_restart_work(struct work_struct *work)
612 {
613 	struct ieee80211_local *local =
614 		container_of(work, struct ieee80211_local, restart_work);
615 
616 	rtnl_lock();
617 	ieee80211_reconfig(local);
618 	rtnl_unlock();
619 }
620 
621 void ieee80211_restart_hw(struct ieee80211_hw *hw)
622 {
623 	struct ieee80211_local *local = hw_to_local(hw);
624 
625 	/* use this reason, __ieee80211_resume will unblock it */
626 	ieee80211_stop_queues_by_reason(hw,
627 		IEEE80211_QUEUE_STOP_REASON_SUSPEND);
628 
629 	schedule_work(&local->restart_work);
630 }
631 EXPORT_SYMBOL(ieee80211_restart_hw);
632 
633 struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
634 					const struct ieee80211_ops *ops)
635 {
636 	struct ieee80211_local *local;
637 	int priv_size, i;
638 	struct wiphy *wiphy;
639 
640 	/* Ensure 32-byte alignment of our private data and hw private data.
641 	 * We use the wiphy priv data for both our ieee80211_local and for
642 	 * the driver's private data
643 	 *
644 	 * In memory it'll be like this:
645 	 *
646 	 * +-------------------------+
647 	 * | struct wiphy	    |
648 	 * +-------------------------+
649 	 * | struct ieee80211_local  |
650 	 * +-------------------------+
651 	 * | driver's private data   |
652 	 * +-------------------------+
653 	 *
654 	 */
655 	priv_size = ALIGN(sizeof(*local), NETDEV_ALIGN) + priv_data_len;
656 
657 	wiphy = wiphy_new(&mac80211_config_ops, priv_size);
658 
659 	if (!wiphy)
660 		return NULL;
661 
662 	wiphy->netnsok = true;
663 	wiphy->privid = mac80211_wiphy_privid;
664 
665 	/* Yes, putting cfg80211_bss into ieee80211_bss is a hack */
666 	wiphy->bss_priv_size = sizeof(struct ieee80211_bss) -
667 			       sizeof(struct cfg80211_bss);
668 
669 	local = wiphy_priv(wiphy);
670 
671 	local->hw.wiphy = wiphy;
672 
673 	local->hw.priv = (char *)local + ALIGN(sizeof(*local), NETDEV_ALIGN);
674 
675 	BUG_ON(!ops->tx);
676 	BUG_ON(!ops->start);
677 	BUG_ON(!ops->stop);
678 	BUG_ON(!ops->config);
679 	BUG_ON(!ops->add_interface);
680 	BUG_ON(!ops->remove_interface);
681 	BUG_ON(!ops->configure_filter);
682 	local->ops = ops;
683 
684 	/* set up some defaults */
685 	local->hw.queues = 1;
686 	local->hw.max_rates = 1;
687 	local->hw.conf.long_frame_max_tx_count = wiphy->retry_long;
688 	local->hw.conf.short_frame_max_tx_count = wiphy->retry_short;
689 	local->user_power_level = -1;
690 
691 	INIT_LIST_HEAD(&local->interfaces);
692 	mutex_init(&local->iflist_mtx);
693 	mutex_init(&local->scan_mtx);
694 
695 	spin_lock_init(&local->key_lock);
696 	spin_lock_init(&local->filter_lock);
697 	spin_lock_init(&local->queue_stop_reason_lock);
698 
699 	INIT_DELAYED_WORK(&local->scan_work, ieee80211_scan_work);
700 
701 	INIT_WORK(&local->restart_work, ieee80211_restart_work);
702 
703 	INIT_WORK(&local->reconfig_filter, ieee80211_reconfig_filter);
704 
705 	INIT_WORK(&local->dynamic_ps_enable_work,
706 		  ieee80211_dynamic_ps_enable_work);
707 	INIT_WORK(&local->dynamic_ps_disable_work,
708 		  ieee80211_dynamic_ps_disable_work);
709 	setup_timer(&local->dynamic_ps_timer,
710 		    ieee80211_dynamic_ps_timer, (unsigned long) local);
711 
712 	sta_info_init(local);
713 
714 	for (i = 0; i < IEEE80211_MAX_QUEUES; i++)
715 		skb_queue_head_init(&local->pending[i]);
716 	tasklet_init(&local->tx_pending_tasklet, ieee80211_tx_pending,
717 		     (unsigned long)local);
718 
719 	tasklet_init(&local->tasklet,
720 		     ieee80211_tasklet_handler,
721 		     (unsigned long) local);
722 
723 	skb_queue_head_init(&local->skb_queue);
724 	skb_queue_head_init(&local->skb_queue_unreliable);
725 
726 	spin_lock_init(&local->ampdu_lock);
727 
728 	return local_to_hw(local);
729 }
730 EXPORT_SYMBOL(ieee80211_alloc_hw);
731 
732 int ieee80211_register_hw(struct ieee80211_hw *hw)
733 {
734 	struct ieee80211_local *local = hw_to_local(hw);
735 	int result;
736 	enum ieee80211_band band;
737 	int channels, i, j, max_bitrates;
738 	bool supp_ht;
739 	static const u32 cipher_suites[] = {
740 		WLAN_CIPHER_SUITE_WEP40,
741 		WLAN_CIPHER_SUITE_WEP104,
742 		WLAN_CIPHER_SUITE_TKIP,
743 		WLAN_CIPHER_SUITE_CCMP,
744 
745 		/* keep last -- depends on hw flags! */
746 		WLAN_CIPHER_SUITE_AES_CMAC
747 	};
748 
749 	/*
750 	 * generic code guarantees at least one band,
751 	 * set this very early because much code assumes
752 	 * that hw.conf.channel is assigned
753 	 */
754 	channels = 0;
755 	max_bitrates = 0;
756 	supp_ht = false;
757 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
758 		struct ieee80211_supported_band *sband;
759 
760 		sband = local->hw.wiphy->bands[band];
761 		if (!sband)
762 			continue;
763 		if (!local->oper_channel) {
764 			/* init channel we're on */
765 			local->hw.conf.channel =
766 			local->oper_channel = &sband->channels[0];
767 			local->hw.conf.channel_type = NL80211_CHAN_NO_HT;
768 		}
769 		channels += sband->n_channels;
770 
771 		if (max_bitrates < sband->n_bitrates)
772 			max_bitrates = sband->n_bitrates;
773 		supp_ht = supp_ht || sband->ht_cap.ht_supported;
774 	}
775 
776 	local->int_scan_req = kzalloc(sizeof(*local->int_scan_req) +
777 				      sizeof(void *) * channels, GFP_KERNEL);
778 	if (!local->int_scan_req)
779 		return -ENOMEM;
780 
781 	/* if low-level driver supports AP, we also support VLAN */
782 	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_AP))
783 		local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_AP_VLAN);
784 
785 	/* mac80211 always supports monitor */
786 	local->hw.wiphy->interface_modes |= BIT(NL80211_IFTYPE_MONITOR);
787 
788 	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
789 		local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_MBM;
790 	else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
791 		local->hw.wiphy->signal_type = CFG80211_SIGNAL_TYPE_UNSPEC;
792 
793 	/*
794 	 * Calculate scan IE length -- we need this to alloc
795 	 * memory and to subtract from the driver limit. It
796 	 * includes the (extended) supported rates and HT
797 	 * information -- SSID is the driver's responsibility.
798 	 */
799 	local->scan_ies_len = 4 + max_bitrates; /* (ext) supp rates */
800 	if (supp_ht)
801 		local->scan_ies_len += 2 + sizeof(struct ieee80211_ht_cap);
802 
803 	if (!local->ops->hw_scan) {
804 		/* For hw_scan, driver needs to set these up. */
805 		local->hw.wiphy->max_scan_ssids = 4;
806 		local->hw.wiphy->max_scan_ie_len = IEEE80211_MAX_DATA_LEN;
807 	}
808 
809 	/*
810 	 * If the driver supports any scan IEs, then assume the
811 	 * limit includes the IEs mac80211 will add, otherwise
812 	 * leave it at zero and let the driver sort it out; we
813 	 * still pass our IEs to the driver but userspace will
814 	 * not be allowed to in that case.
815 	 */
816 	if (local->hw.wiphy->max_scan_ie_len)
817 		local->hw.wiphy->max_scan_ie_len -= local->scan_ies_len;
818 
819 	local->hw.wiphy->cipher_suites = cipher_suites;
820 	local->hw.wiphy->n_cipher_suites = ARRAY_SIZE(cipher_suites);
821 	if (!(local->hw.flags & IEEE80211_HW_MFP_CAPABLE))
822 		local->hw.wiphy->n_cipher_suites--;
823 
824 	result = wiphy_register(local->hw.wiphy);
825 	if (result < 0)
826 		goto fail_wiphy_register;
827 
828 	/*
829 	 * We use the number of queues for feature tests (QoS, HT) internally
830 	 * so restrict them appropriately.
831 	 */
832 	if (hw->queues > IEEE80211_MAX_QUEUES)
833 		hw->queues = IEEE80211_MAX_QUEUES;
834 
835 	local->workqueue =
836 		create_singlethread_workqueue(wiphy_name(local->hw.wiphy));
837 	if (!local->workqueue) {
838 		result = -ENOMEM;
839 		goto fail_workqueue;
840 	}
841 
842 	/*
843 	 * The hardware needs headroom for sending the frame,
844 	 * and we need some headroom for passing the frame to monitor
845 	 * interfaces, but never both at the same time.
846 	 */
847 	local->tx_headroom = max_t(unsigned int , local->hw.extra_tx_headroom,
848 				   sizeof(struct ieee80211_tx_status_rtap_hdr));
849 
850 	debugfs_hw_add(local);
851 
852 	if (local->hw.max_listen_interval == 0)
853 		local->hw.max_listen_interval = 1;
854 
855 	local->hw.conf.listen_interval = local->hw.max_listen_interval;
856 
857 	result = sta_info_start(local);
858 	if (result < 0)
859 		goto fail_sta_info;
860 
861 	result = ieee80211_wep_init(local);
862 	if (result < 0) {
863 		printk(KERN_DEBUG "%s: Failed to initialize wep: %d\n",
864 		       wiphy_name(local->hw.wiphy), result);
865 		goto fail_wep;
866 	}
867 
868 	rtnl_lock();
869 
870 	result = ieee80211_init_rate_ctrl_alg(local,
871 					      hw->rate_control_algorithm);
872 	if (result < 0) {
873 		printk(KERN_DEBUG "%s: Failed to initialize rate control "
874 		       "algorithm\n", wiphy_name(local->hw.wiphy));
875 		goto fail_rate;
876 	}
877 
878 	/* add one default STA interface if supported */
879 	if (local->hw.wiphy->interface_modes & BIT(NL80211_IFTYPE_STATION)) {
880 		result = ieee80211_if_add(local, "wlan%d", NULL,
881 					  NL80211_IFTYPE_STATION, NULL);
882 		if (result)
883 			printk(KERN_WARNING "%s: Failed to add default virtual iface\n",
884 			       wiphy_name(local->hw.wiphy));
885 	}
886 
887 	rtnl_unlock();
888 
889 	ieee80211_led_init(local);
890 
891 	/* alloc internal scan request */
892 	i = 0;
893 	local->int_scan_req->ssids = &local->scan_ssid;
894 	local->int_scan_req->n_ssids = 1;
895 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
896 		if (!hw->wiphy->bands[band])
897 			continue;
898 		for (j = 0; j < hw->wiphy->bands[band]->n_channels; j++) {
899 			local->int_scan_req->channels[i] =
900 				&hw->wiphy->bands[band]->channels[j];
901 			i++;
902 		}
903 	}
904 
905 	local->network_latency_notifier.notifier_call =
906 		ieee80211_max_network_latency;
907 	result = pm_qos_add_notifier(PM_QOS_NETWORK_LATENCY,
908 				     &local->network_latency_notifier);
909 
910 	if (result) {
911 		rtnl_lock();
912 		goto fail_pm_qos;
913 	}
914 
915 	return 0;
916 
917  fail_pm_qos:
918 	ieee80211_led_exit(local);
919 	ieee80211_remove_interfaces(local);
920  fail_rate:
921 	rtnl_unlock();
922 	ieee80211_wep_free(local);
923  fail_wep:
924 	sta_info_stop(local);
925  fail_sta_info:
926 	debugfs_hw_del(local);
927 	destroy_workqueue(local->workqueue);
928  fail_workqueue:
929 	wiphy_unregister(local->hw.wiphy);
930  fail_wiphy_register:
931 	kfree(local->int_scan_req);
932 	return result;
933 }
934 EXPORT_SYMBOL(ieee80211_register_hw);
935 
936 void ieee80211_unregister_hw(struct ieee80211_hw *hw)
937 {
938 	struct ieee80211_local *local = hw_to_local(hw);
939 
940 	tasklet_kill(&local->tx_pending_tasklet);
941 	tasklet_kill(&local->tasklet);
942 
943 	pm_qos_remove_notifier(PM_QOS_NETWORK_LATENCY,
944 			       &local->network_latency_notifier);
945 
946 	rtnl_lock();
947 
948 	/*
949 	 * At this point, interface list manipulations are fine
950 	 * because the driver cannot be handing us frames any
951 	 * more and the tasklet is killed.
952 	 */
953 	ieee80211_remove_interfaces(local);
954 
955 	rtnl_unlock();
956 
957 	cancel_work_sync(&local->reconfig_filter);
958 
959 	ieee80211_clear_tx_pending(local);
960 	sta_info_stop(local);
961 	rate_control_deinitialize(local);
962 	debugfs_hw_del(local);
963 
964 	if (skb_queue_len(&local->skb_queue)
965 			|| skb_queue_len(&local->skb_queue_unreliable))
966 		printk(KERN_WARNING "%s: skb_queue not empty\n",
967 		       wiphy_name(local->hw.wiphy));
968 	skb_queue_purge(&local->skb_queue);
969 	skb_queue_purge(&local->skb_queue_unreliable);
970 
971 	destroy_workqueue(local->workqueue);
972 	wiphy_unregister(local->hw.wiphy);
973 	ieee80211_wep_free(local);
974 	ieee80211_led_exit(local);
975 	kfree(local->int_scan_req);
976 }
977 EXPORT_SYMBOL(ieee80211_unregister_hw);
978 
979 void ieee80211_free_hw(struct ieee80211_hw *hw)
980 {
981 	struct ieee80211_local *local = hw_to_local(hw);
982 
983 	mutex_destroy(&local->iflist_mtx);
984 	mutex_destroy(&local->scan_mtx);
985 
986 	wiphy_free(local->hw.wiphy);
987 }
988 EXPORT_SYMBOL(ieee80211_free_hw);
989 
990 static int __init ieee80211_init(void)
991 {
992 	struct sk_buff *skb;
993 	int ret;
994 
995 	BUILD_BUG_ON(sizeof(struct ieee80211_tx_info) > sizeof(skb->cb));
996 	BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, driver_data) +
997 		     IEEE80211_TX_INFO_DRIVER_DATA_SIZE > sizeof(skb->cb));
998 
999 	ret = rc80211_minstrel_init();
1000 	if (ret)
1001 		return ret;
1002 
1003 	ret = rc80211_pid_init();
1004 	if (ret)
1005 		return ret;
1006 
1007 	ieee80211_debugfs_netdev_init();
1008 
1009 	return 0;
1010 }
1011 
1012 static void __exit ieee80211_exit(void)
1013 {
1014 	rc80211_pid_exit();
1015 	rc80211_minstrel_exit();
1016 
1017 	/*
1018 	 * For key todo, it'll be empty by now but the work
1019 	 * might still be scheduled.
1020 	 */
1021 	flush_scheduled_work();
1022 
1023 	if (mesh_allocated)
1024 		ieee80211s_stop();
1025 
1026 	ieee80211_debugfs_netdev_exit();
1027 }
1028 
1029 
1030 subsys_initcall(ieee80211_init);
1031 module_exit(ieee80211_exit);
1032 
1033 MODULE_DESCRIPTION("IEEE 802.11 subsystem");
1034 MODULE_LICENSE("GPL");
1035