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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * IEEE 802.15.4 scanning management
  4 *
  5 * Copyright (C) 2021 Qorvo US, Inc
  6 * Authors:
  7 *   - David Girault <david.girault@qorvo.com>
  8 *   - Miquel Raynal <miquel.raynal@bootlin.com>
  9 */
 10
 11#include <linux/module.h>
 12#include <linux/rtnetlink.h>
 13#include <net/mac802154.h>
 14
 15#include "ieee802154_i.h"
 16#include "driver-ops.h"
 17#include "../ieee802154/nl802154.h"
 18
 19#define IEEE802154_BEACON_MHR_SZ 13
 20#define IEEE802154_BEACON_PL_SZ 4
 21#define IEEE802154_MAC_CMD_MHR_SZ 23
 22#define IEEE802154_MAC_CMD_PL_SZ 1
 23#define IEEE802154_BEACON_SKB_SZ (IEEE802154_BEACON_MHR_SZ + \
 24				  IEEE802154_BEACON_PL_SZ)
 25#define IEEE802154_MAC_CMD_SKB_SZ (IEEE802154_MAC_CMD_MHR_SZ + \
 26				   IEEE802154_MAC_CMD_PL_SZ)
 27
 28/* mac802154_scan_cleanup_locked() must be called upon scan completion or abort.
 29 * - Completions are asynchronous, not locked by the rtnl and decided by the
 30 *   scan worker.
 31 * - Aborts are decided by userspace, and locked by the rtnl.
 32 *
 33 * Concurrent modifications to the PHY, the interfaces or the hardware is in
 34 * general prevented by the rtnl. So in most cases we don't need additional
 35 * protection.
 36 *
 37 * However, the scan worker get's triggered without anybody noticing and thus we
 38 * must ensure the presence of the devices as well as data consistency:
 39 * - The sub-interface and device driver module get both their reference
 40 *   counters incremented whenever we start a scan, so they cannot disappear
 41 *   during operation.
 42 * - Data consistency is achieved by the use of rcu protected pointers.
 43 */
 44static int mac802154_scan_cleanup_locked(struct ieee802154_local *local,
 45					 struct ieee802154_sub_if_data *sdata,
 46					 bool aborted)
 47{
 48	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
 49	struct wpan_phy *wpan_phy = local->phy;
 50	struct cfg802154_scan_request *request;
 51	u8 arg;
 52
 53	/* Prevent any further use of the scan request */
 54	clear_bit(IEEE802154_IS_SCANNING, &local->ongoing);
 55	cancel_delayed_work(&local->scan_work);
 56	request = rcu_replace_pointer(local->scan_req, NULL, 1);
 57	if (!request)
 58		return 0;
 59	kvfree_rcu_mightsleep(request);
 60
 61	/* Advertize first, while we know the devices cannot be removed */
 62	if (aborted)
 63		arg = NL802154_SCAN_DONE_REASON_ABORTED;
 64	else
 65		arg = NL802154_SCAN_DONE_REASON_FINISHED;
 66	nl802154_scan_done(wpan_phy, wpan_dev, arg);
 67
 68	/* Cleanup software stack */
 69	ieee802154_mlme_op_post(local);
 70
 71	/* Set the hardware back in its original state */
 72	drv_set_channel(local, wpan_phy->current_page,
 73			wpan_phy->current_channel);
 74	ieee802154_configure_durations(wpan_phy, wpan_phy->current_page,
 75				       wpan_phy->current_channel);
 76	drv_stop(local);
 77	synchronize_net();
 78	sdata->required_filtering = sdata->iface_default_filtering;
 79	drv_start(local, sdata->required_filtering, &local->addr_filt);
 80
 81	return 0;
 82}
 83
 84int mac802154_abort_scan_locked(struct ieee802154_local *local,
 85				struct ieee802154_sub_if_data *sdata)
 86{
 87	ASSERT_RTNL();
 88
 89	if (!mac802154_is_scanning(local))
 90		return -ESRCH;
 91
 92	return mac802154_scan_cleanup_locked(local, sdata, true);
 93}
 94
 95static unsigned int mac802154_scan_get_channel_time(u8 duration_order,
 96						    u8 symbol_duration)
 97{
 98	u64 base_super_frame_duration = (u64)symbol_duration *
 99		IEEE802154_SUPERFRAME_PERIOD * IEEE802154_SLOT_PERIOD;
100
101	return usecs_to_jiffies(base_super_frame_duration *
102				(BIT(duration_order) + 1));
103}
104
105static void mac802154_flush_queued_beacons(struct ieee802154_local *local)
106{
107	struct cfg802154_mac_pkt *mac_pkt, *tmp;
108
109	list_for_each_entry_safe(mac_pkt, tmp, &local->rx_beacon_list, node) {
110		list_del(&mac_pkt->node);
111		kfree_skb(mac_pkt->skb);
112		kfree(mac_pkt);
113	}
114}
115
116static void
117mac802154_scan_get_next_channel(struct ieee802154_local *local,
118				struct cfg802154_scan_request *scan_req,
119				u8 *channel)
120{
121	(*channel)++;
122	*channel = find_next_bit((const unsigned long *)&scan_req->channels,
123				 IEEE802154_MAX_CHANNEL + 1,
124				 *channel);
125}
126
127static int mac802154_scan_find_next_chan(struct ieee802154_local *local,
128					 struct cfg802154_scan_request *scan_req,
129					 u8 page, u8 *channel)
130{
131	mac802154_scan_get_next_channel(local, scan_req, channel);
132	if (*channel > IEEE802154_MAX_CHANNEL)
133		return -EINVAL;
134
135	return 0;
136}
137
138static int mac802154_scan_prepare_beacon_req(struct ieee802154_local *local)
139{
140	memset(&local->scan_beacon_req, 0, sizeof(local->scan_beacon_req));
141	local->scan_beacon_req.mhr.fc.type = IEEE802154_FC_TYPE_MAC_CMD;
142	local->scan_beacon_req.mhr.fc.dest_addr_mode = IEEE802154_SHORT_ADDRESSING;
143	local->scan_beacon_req.mhr.fc.version = IEEE802154_2003_STD;
144	local->scan_beacon_req.mhr.fc.source_addr_mode = IEEE802154_NO_ADDRESSING;
145	local->scan_beacon_req.mhr.dest.mode = IEEE802154_ADDR_SHORT;
146	local->scan_beacon_req.mhr.dest.pan_id = cpu_to_le16(IEEE802154_PANID_BROADCAST);
147	local->scan_beacon_req.mhr.dest.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
148	local->scan_beacon_req.mac_pl.cmd_id = IEEE802154_CMD_BEACON_REQ;
149
150	return 0;
151}
152
153static int mac802154_transmit_beacon_req(struct ieee802154_local *local,
154					 struct ieee802154_sub_if_data *sdata)
155{
156	struct sk_buff *skb;
157	int ret;
158
159	skb = alloc_skb(IEEE802154_MAC_CMD_SKB_SZ, GFP_KERNEL);
160	if (!skb)
161		return -ENOBUFS;
162
163	skb->dev = sdata->dev;
164
165	ret = ieee802154_mac_cmd_push(skb, &local->scan_beacon_req, NULL, 0);
166	if (ret) {
167		kfree_skb(skb);
168		return ret;
169	}
170
171	return ieee802154_mlme_tx(local, sdata, skb);
172}
173
174void mac802154_scan_worker(struct work_struct *work)
175{
176	struct ieee802154_local *local =
177		container_of(work, struct ieee802154_local, scan_work.work);
178	struct cfg802154_scan_request *scan_req;
179	enum nl802154_scan_types scan_req_type;
180	struct ieee802154_sub_if_data *sdata;
181	unsigned int scan_duration = 0;
182	struct wpan_phy *wpan_phy;
183	u8 scan_req_duration;
184	u8 page, channel;
185	int ret;
186
187	/* Ensure the device receiver is turned off when changing channels
188	 * because there is no atomic way to change the channel and know on
189	 * which one a beacon might have been received.
190	 */
191	drv_stop(local);
192	synchronize_net();
193	mac802154_flush_queued_beacons(local);
194
195	rcu_read_lock();
196	scan_req = rcu_dereference(local->scan_req);
197	if (unlikely(!scan_req)) {
198		rcu_read_unlock();
199		return;
200	}
201
202	sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(scan_req->wpan_dev);
203
204	/* Wait an arbitrary amount of time in case we cannot use the device */
205	if (local->suspended || !ieee802154_sdata_running(sdata)) {
206		rcu_read_unlock();
207		queue_delayed_work(local->mac_wq, &local->scan_work,
208				   msecs_to_jiffies(1000));
209		return;
210	}
211
212	wpan_phy = scan_req->wpan_phy;
213	scan_req_type = scan_req->type;
214	scan_req_duration = scan_req->duration;
215
216	/* Look for the next valid chan */
217	page = local->scan_page;
218	channel = local->scan_channel;
219	do {
220		ret = mac802154_scan_find_next_chan(local, scan_req, page, &channel);
221		if (ret) {
222			rcu_read_unlock();
223			goto end_scan;
224		}
225	} while (!ieee802154_chan_is_valid(scan_req->wpan_phy, page, channel));
226
227	rcu_read_unlock();
228
229	/* Bypass the stack on purpose when changing the channel */
230	rtnl_lock();
231	ret = drv_set_channel(local, page, channel);
232	rtnl_unlock();
233	if (ret) {
234		dev_err(&sdata->dev->dev,
235			"Channel change failure during scan, aborting (%d)\n", ret);
236		goto end_scan;
237	}
238
239	local->scan_page = page;
240	local->scan_channel = channel;
241
242	rtnl_lock();
243	ret = drv_start(local, IEEE802154_FILTERING_3_SCAN, &local->addr_filt);
244	rtnl_unlock();
245	if (ret) {
246		dev_err(&sdata->dev->dev,
247			"Restarting failure after channel change, aborting (%d)\n", ret);
248		goto end_scan;
249	}
250
251	if (scan_req_type == NL802154_SCAN_ACTIVE) {
252		ret = mac802154_transmit_beacon_req(local, sdata);
253		if (ret)
254			dev_err(&sdata->dev->dev,
255				"Error when transmitting beacon request (%d)\n", ret);
256	}
257
258	ieee802154_configure_durations(wpan_phy, page, channel);
259	scan_duration = mac802154_scan_get_channel_time(scan_req_duration,
260							wpan_phy->symbol_duration);
261	dev_dbg(&sdata->dev->dev,
262		"Scan page %u channel %u for %ums\n",
263		page, channel, jiffies_to_msecs(scan_duration));
264	queue_delayed_work(local->mac_wq, &local->scan_work, scan_duration);
265	return;
266
267end_scan:
268	rtnl_lock();
269	mac802154_scan_cleanup_locked(local, sdata, false);
270	rtnl_unlock();
271}
272
273int mac802154_trigger_scan_locked(struct ieee802154_sub_if_data *sdata,
274				  struct cfg802154_scan_request *request)
275{
276	struct ieee802154_local *local = sdata->local;
277
278	ASSERT_RTNL();
279
280	if (mac802154_is_scanning(local))
281		return -EBUSY;
282
283	if (request->type != NL802154_SCAN_PASSIVE &&
284	    request->type != NL802154_SCAN_ACTIVE)
285		return -EOPNOTSUPP;
286
287	/* Store scanning parameters */
288	rcu_assign_pointer(local->scan_req, request);
289
290	/* Software scanning requires to set promiscuous mode, so we need to
291	 * pause the Tx queue during the entire operation.
292	 */
293	ieee802154_mlme_op_pre(local);
294
295	sdata->required_filtering = IEEE802154_FILTERING_3_SCAN;
296	local->scan_page = request->page;
297	local->scan_channel = -1;
298	set_bit(IEEE802154_IS_SCANNING, &local->ongoing);
299	if (request->type == NL802154_SCAN_ACTIVE)
300		mac802154_scan_prepare_beacon_req(local);
301
302	nl802154_scan_started(request->wpan_phy, request->wpan_dev);
303
304	queue_delayed_work(local->mac_wq, &local->scan_work, 0);
305
306	return 0;
307}
308
309int mac802154_process_beacon(struct ieee802154_local *local,
310			     struct sk_buff *skb,
311			     u8 page, u8 channel)
312{
313	struct ieee802154_beacon_hdr *bh = (void *)skb->data;
314	struct ieee802154_addr *src = &mac_cb(skb)->source;
315	struct cfg802154_scan_request *scan_req;
316	struct ieee802154_coord_desc desc;
317
318	if (skb->len != sizeof(*bh))
319		return -EINVAL;
320
321	if (unlikely(src->mode == IEEE802154_ADDR_NONE))
322		return -EINVAL;
323
324	dev_dbg(&skb->dev->dev,
325		"BEACON received on page %u channel %u\n",
326		page, channel);
327
328	memcpy(&desc.addr, src, sizeof(desc.addr));
329	desc.page = page;
330	desc.channel = channel;
331	desc.link_quality = mac_cb(skb)->lqi;
332	desc.superframe_spec = get_unaligned_le16(skb->data);
333	desc.gts_permit = bh->gts_permit;
334
335	trace_802154_scan_event(&desc);
336
337	rcu_read_lock();
338	scan_req = rcu_dereference(local->scan_req);
339	if (likely(scan_req))
340		nl802154_scan_event(scan_req->wpan_phy, scan_req->wpan_dev, &desc);
341	rcu_read_unlock();
342
343	return 0;
344}
345
346static int mac802154_transmit_beacon(struct ieee802154_local *local,
347				     struct wpan_dev *wpan_dev)
348{
349	struct cfg802154_beacon_request *beacon_req;
350	struct ieee802154_sub_if_data *sdata;
351	struct sk_buff *skb;
352	int ret;
353
354	/* Update the sequence number */
355	local->beacon.mhr.seq = atomic_inc_return(&wpan_dev->bsn) & 0xFF;
356
357	skb = alloc_skb(IEEE802154_BEACON_SKB_SZ, GFP_KERNEL);
358	if (!skb)
359		return -ENOBUFS;
360
361	rcu_read_lock();
362	beacon_req = rcu_dereference(local->beacon_req);
363	if (unlikely(!beacon_req)) {
364		rcu_read_unlock();
365		kfree_skb(skb);
366		return -EINVAL;
367	}
368
369	sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(beacon_req->wpan_dev);
370	skb->dev = sdata->dev;
371
372	rcu_read_unlock();
373
374	ret = ieee802154_beacon_push(skb, &local->beacon);
375	if (ret) {
376		kfree_skb(skb);
377		return ret;
378	}
379
380	/* Using the MLME transmission helper for sending beacons is a bit
381	 * overkill because we do not really care about the final outcome.
382	 *
383	 * Even though, going through the whole net stack with a regular
384	 * dev_queue_xmit() is not relevant either because we want beacons to be
385	 * sent "now" rather than go through the whole net stack scheduling
386	 * (qdisc & co).
387	 *
388	 * Finally, using ieee802154_subif_start_xmit() would only be an option
389	 * if we had a generic transmit helper which would acquire the
390	 * HARD_TX_LOCK() to prevent buffer handling conflicts with regular
391	 * packets.
392	 *
393	 * So for now we keep it simple and send beacons with our MLME helper,
394	 * even if it stops the ieee802154 queue entirely during these
395	 * transmissions, wich anyway does not have a huge impact on the
396	 * performances given the current design of the stack.
397	 */
398	return ieee802154_mlme_tx(local, sdata, skb);
399}
400
401void mac802154_beacon_worker(struct work_struct *work)
402{
403	struct ieee802154_local *local =
404		container_of(work, struct ieee802154_local, beacon_work.work);
405	struct cfg802154_beacon_request *beacon_req;
406	struct ieee802154_sub_if_data *sdata;
407	struct wpan_dev *wpan_dev;
408	u8 interval;
409	int ret;
410
411	rcu_read_lock();
412	beacon_req = rcu_dereference(local->beacon_req);
413	if (unlikely(!beacon_req)) {
414		rcu_read_unlock();
415		return;
416	}
417
418	sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(beacon_req->wpan_dev);
419
420	/* Wait an arbitrary amount of time in case we cannot use the device */
421	if (local->suspended || !ieee802154_sdata_running(sdata)) {
422		rcu_read_unlock();
423		queue_delayed_work(local->mac_wq, &local->beacon_work,
424				   msecs_to_jiffies(1000));
425		return;
426	}
427
428	wpan_dev = beacon_req->wpan_dev;
429	interval = beacon_req->interval;
430
431	rcu_read_unlock();
432
433	dev_dbg(&sdata->dev->dev, "Sending beacon\n");
434	ret = mac802154_transmit_beacon(local, wpan_dev);
435	if (ret)
436		dev_err(&sdata->dev->dev,
437			"Beacon could not be transmitted (%d)\n", ret);
438
439	if (interval < IEEE802154_ACTIVE_SCAN_DURATION)
440		queue_delayed_work(local->mac_wq, &local->beacon_work,
441				   local->beacon_interval);
442}
443
444int mac802154_stop_beacons_locked(struct ieee802154_local *local,
445				  struct ieee802154_sub_if_data *sdata)
446{
447	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
448	struct cfg802154_beacon_request *request;
449
450	ASSERT_RTNL();
451
452	if (!mac802154_is_beaconing(local))
453		return -ESRCH;
454
455	clear_bit(IEEE802154_IS_BEACONING, &local->ongoing);
456	cancel_delayed_work(&local->beacon_work);
457	request = rcu_replace_pointer(local->beacon_req, NULL, 1);
458	if (!request)
459		return 0;
460	kvfree_rcu_mightsleep(request);
461
462	nl802154_beaconing_done(wpan_dev);
463
464	return 0;
465}
466
467int mac802154_send_beacons_locked(struct ieee802154_sub_if_data *sdata,
468				  struct cfg802154_beacon_request *request)
469{
470	struct ieee802154_local *local = sdata->local;
471	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
472
473	ASSERT_RTNL();
474
475	if (mac802154_is_beaconing(local))
476		mac802154_stop_beacons_locked(local, sdata);
477
478	/* Store beaconing parameters */
479	rcu_assign_pointer(local->beacon_req, request);
480
481	set_bit(IEEE802154_IS_BEACONING, &local->ongoing);
482
483	memset(&local->beacon, 0, sizeof(local->beacon));
484	local->beacon.mhr.fc.type = IEEE802154_FC_TYPE_BEACON;
485	local->beacon.mhr.fc.security_enabled = 0;
486	local->beacon.mhr.fc.frame_pending = 0;
487	local->beacon.mhr.fc.ack_request = 0;
488	local->beacon.mhr.fc.intra_pan = 0;
489	local->beacon.mhr.fc.dest_addr_mode = IEEE802154_NO_ADDRESSING;
490	local->beacon.mhr.fc.version = IEEE802154_2003_STD;
491	local->beacon.mhr.fc.source_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
492	atomic_set(&request->wpan_dev->bsn, -1);
493	local->beacon.mhr.source.mode = IEEE802154_ADDR_LONG;
494	local->beacon.mhr.source.pan_id = request->wpan_dev->pan_id;
495	local->beacon.mhr.source.extended_addr = request->wpan_dev->extended_addr;
496	local->beacon.mac_pl.beacon_order = request->interval;
497	if (request->interval <= IEEE802154_MAX_SCAN_DURATION)
498		local->beacon.mac_pl.superframe_order = request->interval;
499	local->beacon.mac_pl.final_cap_slot = 0xf;
500	local->beacon.mac_pl.battery_life_ext = 0;
501	local->beacon.mac_pl.pan_coordinator = !wpan_dev->parent;
502	local->beacon.mac_pl.assoc_permit = 1;
503
504	if (request->interval == IEEE802154_ACTIVE_SCAN_DURATION)
505		return 0;
506
507	/* Start the beacon work */
508	local->beacon_interval =
509		mac802154_scan_get_channel_time(request->interval,
510						request->wpan_phy->symbol_duration);
511	queue_delayed_work(local->mac_wq, &local->beacon_work, 0);
512
513	return 0;
514}
515
516int mac802154_perform_association(struct ieee802154_sub_if_data *sdata,
517				  struct ieee802154_pan_device *coord,
518				  __le16 *short_addr)
519{
520	u64 ceaddr = swab64((__force u64)coord->extended_addr);
521	struct ieee802154_association_req_frame frame = {};
522	struct ieee802154_local *local = sdata->local;
523	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
524	struct sk_buff *skb;
525	int ret;
526
527	frame.mhr.fc.type = IEEE802154_FC_TYPE_MAC_CMD;
528	frame.mhr.fc.security_enabled = 0;
529	frame.mhr.fc.frame_pending = 0;
530	frame.mhr.fc.ack_request = 1; /* We always expect an ack here */
531	frame.mhr.fc.intra_pan = 0;
532	frame.mhr.fc.dest_addr_mode = (coord->mode == IEEE802154_ADDR_LONG) ?
533		IEEE802154_EXTENDED_ADDRESSING : IEEE802154_SHORT_ADDRESSING;
534	frame.mhr.fc.version = IEEE802154_2003_STD;
535	frame.mhr.fc.source_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
536	frame.mhr.source.mode = IEEE802154_ADDR_LONG;
537	frame.mhr.source.pan_id = cpu_to_le16(IEEE802154_PANID_BROADCAST);
538	frame.mhr.source.extended_addr = wpan_dev->extended_addr;
539	frame.mhr.dest.mode = coord->mode;
540	frame.mhr.dest.pan_id = coord->pan_id;
541	if (coord->mode == IEEE802154_ADDR_LONG)
542		frame.mhr.dest.extended_addr = coord->extended_addr;
543	else
544		frame.mhr.dest.short_addr = coord->short_addr;
545	frame.mhr.seq = atomic_inc_return(&wpan_dev->dsn) & 0xFF;
546	frame.mac_pl.cmd_id = IEEE802154_CMD_ASSOCIATION_REQ;
547	frame.assoc_req_pl.device_type = 1;
548	frame.assoc_req_pl.power_source = 1;
549	frame.assoc_req_pl.rx_on_when_idle = 1;
550	frame.assoc_req_pl.alloc_addr = 1;
551
552	skb = alloc_skb(IEEE802154_MAC_CMD_SKB_SZ + sizeof(frame.assoc_req_pl),
553			GFP_KERNEL);
554	if (!skb)
555		return -ENOBUFS;
556
557	skb->dev = sdata->dev;
558
559	ret = ieee802154_mac_cmd_push(skb, &frame, &frame.assoc_req_pl,
560				      sizeof(frame.assoc_req_pl));
561	if (ret) {
562		kfree_skb(skb);
563		return ret;
564	}
565
566	local->assoc_dev = coord;
567	reinit_completion(&local->assoc_done);
568	set_bit(IEEE802154_IS_ASSOCIATING, &local->ongoing);
569
570	ret = ieee802154_mlme_tx_one_locked(local, sdata, skb);
571	if (ret) {
572		if (ret > 0)
573			ret = (ret == IEEE802154_NO_ACK) ? -EREMOTEIO : -EIO;
574		dev_warn(&sdata->dev->dev,
575			 "No ASSOC REQ ACK received from %8phC\n", &ceaddr);
576		goto clear_assoc;
577	}
578
579	ret = wait_for_completion_killable_timeout(&local->assoc_done, 10 * HZ);
580	if (ret <= 0) {
581		dev_warn(&sdata->dev->dev,
582			 "No ASSOC RESP received from %8phC\n", &ceaddr);
583		ret = -ETIMEDOUT;
584		goto clear_assoc;
585	}
586
587	if (local->assoc_status != IEEE802154_ASSOCIATION_SUCCESSFUL) {
588		if (local->assoc_status == IEEE802154_PAN_AT_CAPACITY)
589			ret = -ERANGE;
590		else
591			ret = -EPERM;
592
593		dev_warn(&sdata->dev->dev,
594			 "Negative ASSOC RESP received from %8phC: %s\n", &ceaddr,
595			 local->assoc_status == IEEE802154_PAN_AT_CAPACITY ?
596			 "PAN at capacity" : "access denied");
597	}
598
599	ret = 0;
600	*short_addr = local->assoc_addr;
601
602clear_assoc:
603	clear_bit(IEEE802154_IS_ASSOCIATING, &local->ongoing);
604	local->assoc_dev = NULL;
605
606	return ret;
607}
608
609int mac802154_process_association_resp(struct ieee802154_sub_if_data *sdata,
610				       struct sk_buff *skb)
611{
612	struct ieee802154_addr *src = &mac_cb(skb)->source;
613	struct ieee802154_addr *dest = &mac_cb(skb)->dest;
614	u64 deaddr = swab64((__force u64)dest->extended_addr);
615	struct ieee802154_local *local = sdata->local;
616	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
617	struct ieee802154_assoc_resp_pl resp_pl = {};
618
619	if (skb->len != sizeof(resp_pl))
620		return -EINVAL;
621
622	if (unlikely(src->mode != IEEE802154_EXTENDED_ADDRESSING ||
623		     dest->mode != IEEE802154_EXTENDED_ADDRESSING))
624		return -EINVAL;
625
626	if (unlikely(dest->extended_addr != wpan_dev->extended_addr ||
627		     src->extended_addr != local->assoc_dev->extended_addr))
628		return -ENODEV;
629
630	memcpy(&resp_pl, skb->data, sizeof(resp_pl));
631	local->assoc_addr = resp_pl.short_addr;
632	local->assoc_status = resp_pl.status;
633
634	dev_dbg(&skb->dev->dev,
635		"ASSOC RESP 0x%x received from %8phC, getting short address %04x\n",
636		local->assoc_status, &deaddr, local->assoc_addr);
637
638	complete(&local->assoc_done);
639
640	return 0;
641}
642
643int mac802154_send_disassociation_notif(struct ieee802154_sub_if_data *sdata,
644					struct ieee802154_pan_device *target,
645					u8 reason)
646{
647	struct ieee802154_disassociation_notif_frame frame = {};
648	u64 teaddr = swab64((__force u64)target->extended_addr);
649	struct ieee802154_local *local = sdata->local;
650	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
651	struct sk_buff *skb;
652	int ret;
653
654	frame.mhr.fc.type = IEEE802154_FC_TYPE_MAC_CMD;
655	frame.mhr.fc.security_enabled = 0;
656	frame.mhr.fc.frame_pending = 0;
657	frame.mhr.fc.ack_request = 1;
658	frame.mhr.fc.intra_pan = 1;
659	frame.mhr.fc.dest_addr_mode = (target->mode == IEEE802154_ADDR_LONG) ?
660		IEEE802154_EXTENDED_ADDRESSING : IEEE802154_SHORT_ADDRESSING;
661	frame.mhr.fc.version = IEEE802154_2003_STD;
662	frame.mhr.fc.source_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
663	frame.mhr.source.mode = IEEE802154_ADDR_LONG;
664	frame.mhr.source.pan_id = wpan_dev->pan_id;
665	frame.mhr.source.extended_addr = wpan_dev->extended_addr;
666	frame.mhr.dest.mode = target->mode;
667	frame.mhr.dest.pan_id = wpan_dev->pan_id;
668	if (target->mode == IEEE802154_ADDR_LONG)
669		frame.mhr.dest.extended_addr = target->extended_addr;
670	else
671		frame.mhr.dest.short_addr = target->short_addr;
672	frame.mhr.seq = atomic_inc_return(&wpan_dev->dsn) & 0xFF;
673	frame.mac_pl.cmd_id = IEEE802154_CMD_DISASSOCIATION_NOTIFY;
674	frame.disassoc_pl = reason;
675
676	skb = alloc_skb(IEEE802154_MAC_CMD_SKB_SZ + sizeof(frame.disassoc_pl),
677			GFP_KERNEL);
678	if (!skb)
679		return -ENOBUFS;
680
681	skb->dev = sdata->dev;
682
683	ret = ieee802154_mac_cmd_push(skb, &frame, &frame.disassoc_pl,
684				      sizeof(frame.disassoc_pl));
685	if (ret) {
686		kfree_skb(skb);
687		return ret;
688	}
689
690	ret = ieee802154_mlme_tx_one_locked(local, sdata, skb);
691	if (ret) {
692		dev_warn(&sdata->dev->dev,
693			 "No DISASSOC ACK received from %8phC\n", &teaddr);
694		if (ret > 0)
695			ret = (ret == IEEE802154_NO_ACK) ? -EREMOTEIO : -EIO;
696		return ret;
697	}
698
699	dev_dbg(&sdata->dev->dev, "DISASSOC ACK received from %8phC\n", &teaddr);
700	return 0;
701}
702
703static int
704mac802154_send_association_resp_locked(struct ieee802154_sub_if_data *sdata,
705				       struct ieee802154_pan_device *target,
706				       struct ieee802154_assoc_resp_pl *assoc_resp_pl)
707{
708	u64 teaddr = swab64((__force u64)target->extended_addr);
709	struct ieee802154_association_resp_frame frame = {};
710	struct ieee802154_local *local = sdata->local;
711	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
712	struct sk_buff *skb;
713	int ret;
714
715	frame.mhr.fc.type = IEEE802154_FC_TYPE_MAC_CMD;
716	frame.mhr.fc.security_enabled = 0;
717	frame.mhr.fc.frame_pending = 0;
718	frame.mhr.fc.ack_request = 1; /* We always expect an ack here */
719	frame.mhr.fc.intra_pan = 1;
720	frame.mhr.fc.dest_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
721	frame.mhr.fc.version = IEEE802154_2003_STD;
722	frame.mhr.fc.source_addr_mode = IEEE802154_EXTENDED_ADDRESSING;
723	frame.mhr.source.mode = IEEE802154_ADDR_LONG;
724	frame.mhr.source.extended_addr = wpan_dev->extended_addr;
725	frame.mhr.dest.mode = IEEE802154_ADDR_LONG;
726	frame.mhr.dest.pan_id = wpan_dev->pan_id;
727	frame.mhr.dest.extended_addr = target->extended_addr;
728	frame.mhr.seq = atomic_inc_return(&wpan_dev->dsn) & 0xFF;
729	frame.mac_pl.cmd_id = IEEE802154_CMD_ASSOCIATION_RESP;
730
731	skb = alloc_skb(IEEE802154_MAC_CMD_SKB_SZ + sizeof(*assoc_resp_pl),
732			GFP_KERNEL);
733	if (!skb)
734		return -ENOBUFS;
735
736	skb->dev = sdata->dev;
737
738	ret = ieee802154_mac_cmd_push(skb, &frame, assoc_resp_pl,
739				      sizeof(*assoc_resp_pl));
740	if (ret) {
741		kfree_skb(skb);
742		return ret;
743	}
744
745	ret = ieee802154_mlme_tx_locked(local, sdata, skb);
746	if (ret) {
747		dev_warn(&sdata->dev->dev,
748			 "No ASSOC RESP ACK received from %8phC\n", &teaddr);
749		if (ret > 0)
750			ret = (ret == IEEE802154_NO_ACK) ? -EREMOTEIO : -EIO;
751		return ret;
752	}
753
754	return 0;
755}
756
757int mac802154_process_association_req(struct ieee802154_sub_if_data *sdata,
758				      struct sk_buff *skb)
759{
760	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
761	struct ieee802154_addr *src = &mac_cb(skb)->source;
762	struct ieee802154_addr *dest = &mac_cb(skb)->dest;
763	struct ieee802154_assoc_resp_pl assoc_resp_pl = {};
764	struct ieee802154_assoc_req_pl assoc_req_pl;
765	struct ieee802154_pan_device *child, *exchild;
766	struct ieee802154_addr tmp = {};
767	u64 ceaddr;
768	int ret;
769
770	if (skb->len != sizeof(assoc_req_pl))
771		return -EINVAL;
772
773	if (unlikely(src->mode != IEEE802154_EXTENDED_ADDRESSING))
774		return -EINVAL;
775
776	if (unlikely(dest->pan_id != wpan_dev->pan_id))
777		return -ENODEV;
778
779	if (dest->mode == IEEE802154_EXTENDED_ADDRESSING &&
780	    unlikely(dest->extended_addr != wpan_dev->extended_addr))
781		return -ENODEV;
782	else if (dest->mode == IEEE802154_SHORT_ADDRESSING &&
783		 unlikely(dest->short_addr != wpan_dev->short_addr))
784		return -ENODEV;
785
786	if (wpan_dev->parent) {
787		dev_dbg(&sdata->dev->dev,
788			"Ignoring ASSOC REQ, not the PAN coordinator\n");
789		return -ENODEV;
790	}
791
792	mutex_lock(&wpan_dev->association_lock);
793
794	memcpy(&assoc_req_pl, skb->data, sizeof(assoc_req_pl));
795	if (assoc_req_pl.assoc_type) {
796		dev_err(&skb->dev->dev, "Fast associations not supported yet\n");
797		ret = -EOPNOTSUPP;
798		goto unlock;
799	}
800
801	child = kzalloc(sizeof(*child), GFP_KERNEL);
802	if (!child) {
803		ret = -ENOMEM;
804		goto unlock;
805	}
806
807	child->extended_addr = src->extended_addr;
808	child->mode = IEEE802154_EXTENDED_ADDRESSING;
809	ceaddr = swab64((__force u64)child->extended_addr);
810
811	if (wpan_dev->nchildren >= wpan_dev->max_associations) {
812		if (!wpan_dev->max_associations)
813			assoc_resp_pl.status = IEEE802154_PAN_ACCESS_DENIED;
814		else
815			assoc_resp_pl.status = IEEE802154_PAN_AT_CAPACITY;
816		assoc_resp_pl.short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_BROADCAST);
817		dev_dbg(&sdata->dev->dev,
818			"Refusing ASSOC REQ from child %8phC, %s\n", &ceaddr,
819			assoc_resp_pl.status == IEEE802154_PAN_ACCESS_DENIED ?
820			"access denied" : "too many children");
821	} else {
822		assoc_resp_pl.status = IEEE802154_ASSOCIATION_SUCCESSFUL;
823		if (assoc_req_pl.alloc_addr) {
824			assoc_resp_pl.short_addr = cfg802154_get_free_short_addr(wpan_dev);
825			child->mode = IEEE802154_SHORT_ADDRESSING;
826		} else {
827			assoc_resp_pl.short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
828		}
829		child->short_addr = assoc_resp_pl.short_addr;
830		dev_dbg(&sdata->dev->dev,
831			"Accepting ASSOC REQ from child %8phC, providing short address 0x%04x\n",
832			&ceaddr, le16_to_cpu(child->short_addr));
833	}
834
835	ret = mac802154_send_association_resp_locked(sdata, child, &assoc_resp_pl);
836	if (ret || assoc_resp_pl.status != IEEE802154_ASSOCIATION_SUCCESSFUL) {
837		kfree(child);
838		goto unlock;
839	}
840
841	dev_dbg(&sdata->dev->dev,
842		"Successful association with new child %8phC\n", &ceaddr);
843
844	/* Ensure this child is not already associated (might happen due to
845	 * retransmissions), in this case drop the ex structure.
846	 */
847	tmp.mode = child->mode;
848	tmp.extended_addr = child->extended_addr;
849	exchild = cfg802154_device_is_child(wpan_dev, &tmp);
850	if (exchild) {
851		dev_dbg(&sdata->dev->dev,
852			"Child %8phC was already known\n", &ceaddr);
853		list_del(&exchild->node);
854	}
855
856	list_add(&child->node, &wpan_dev->children);
857	wpan_dev->nchildren++;
858
859unlock:
860	mutex_unlock(&wpan_dev->association_lock);
861	return ret;
862}
863
864int mac802154_process_disassociation_notif(struct ieee802154_sub_if_data *sdata,
865					   struct sk_buff *skb)
866{
867	struct ieee802154_addr *src = &mac_cb(skb)->source;
868	struct ieee802154_addr *dest = &mac_cb(skb)->dest;
869	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
870	struct ieee802154_pan_device *child;
871	struct ieee802154_addr target;
872	bool parent;
873	u64 teaddr;
874
875	if (skb->len != sizeof(u8))
876		return -EINVAL;
877
878	if (unlikely(src->mode != IEEE802154_EXTENDED_ADDRESSING))
879		return -EINVAL;
880
881	if (dest->mode == IEEE802154_EXTENDED_ADDRESSING &&
882	    unlikely(dest->extended_addr != wpan_dev->extended_addr))
883		return -ENODEV;
884	else if (dest->mode == IEEE802154_SHORT_ADDRESSING &&
885		 unlikely(dest->short_addr != wpan_dev->short_addr))
886		return -ENODEV;
887
888	if (dest->pan_id != wpan_dev->pan_id)
889		return -ENODEV;
890
891	target.mode = IEEE802154_EXTENDED_ADDRESSING;
892	target.extended_addr = src->extended_addr;
893	teaddr = swab64((__force u64)target.extended_addr);
894	dev_dbg(&skb->dev->dev, "Processing DISASSOC NOTIF from %8phC\n", &teaddr);
895
896	mutex_lock(&wpan_dev->association_lock);
897	parent = cfg802154_device_is_parent(wpan_dev, &target);
898	if (!parent)
899		child = cfg802154_device_is_child(wpan_dev, &target);
900	if (!parent && !child) {
901		mutex_unlock(&wpan_dev->association_lock);
902		return -EINVAL;
903	}
904
905	if (parent) {
906		kfree(wpan_dev->parent);
907		wpan_dev->parent = NULL;
908	} else {
909		list_del(&child->node);
910		kfree(child);
911		wpan_dev->nchildren--;
912	}
913
914	mutex_unlock(&wpan_dev->association_lock);
915
916	return 0;
917}