xref: /openbmc/linux/net/mac80211/agg-rx.c (revision 8ee90c5c)
1 /*
2  * HT handling
3  *
4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5  * Copyright 2002-2005, Instant802 Networks, Inc.
6  * Copyright 2005-2006, Devicescape Software, Inc.
7  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9  * Copyright 2007-2010, Intel Corporation
10  * Copyright(c) 2015-2017 Intel Deutschland GmbH
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16 
17 /**
18  * DOC: RX A-MPDU aggregation
19  *
20  * Aggregation on the RX side requires only implementing the
21  * @ampdu_action callback that is invoked to start/stop any
22  * block-ack sessions for RX aggregation.
23  *
24  * When RX aggregation is started by the peer, the driver is
25  * notified via @ampdu_action function, with the
26  * %IEEE80211_AMPDU_RX_START action, and may reject the request
27  * in which case a negative response is sent to the peer, if it
28  * accepts it a positive response is sent.
29  *
30  * While the session is active, the device/driver are required
31  * to de-aggregate frames and pass them up one by one to mac80211,
32  * which will handle the reorder buffer.
33  *
34  * When the aggregation session is stopped again by the peer or
35  * ourselves, the driver's @ampdu_action function will be called
36  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
37  * call must not fail.
38  */
39 
40 #include <linux/ieee80211.h>
41 #include <linux/slab.h>
42 #include <linux/export.h>
43 #include <net/mac80211.h>
44 #include "ieee80211_i.h"
45 #include "driver-ops.h"
46 
47 static void ieee80211_free_tid_rx(struct rcu_head *h)
48 {
49 	struct tid_ampdu_rx *tid_rx =
50 		container_of(h, struct tid_ampdu_rx, rcu_head);
51 	int i;
52 
53 	for (i = 0; i < tid_rx->buf_size; i++)
54 		__skb_queue_purge(&tid_rx->reorder_buf[i]);
55 	kfree(tid_rx->reorder_buf);
56 	kfree(tid_rx->reorder_time);
57 	kfree(tid_rx);
58 }
59 
60 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
61 				     u16 initiator, u16 reason, bool tx)
62 {
63 	struct ieee80211_local *local = sta->local;
64 	struct tid_ampdu_rx *tid_rx;
65 	struct ieee80211_ampdu_params params = {
66 		.sta = &sta->sta,
67 		.action = IEEE80211_AMPDU_RX_STOP,
68 		.tid = tid,
69 		.amsdu = false,
70 		.timeout = 0,
71 		.ssn = 0,
72 	};
73 
74 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
75 
76 	tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
77 					lockdep_is_held(&sta->ampdu_mlme.mtx));
78 
79 	if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
80 		return;
81 
82 	RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
83 	__clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
84 
85 	ht_dbg(sta->sdata,
86 	       "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
87 	       sta->sta.addr, tid,
88 	       initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
89 	       (int)reason);
90 
91 	if (drv_ampdu_action(local, sta->sdata, &params))
92 		sdata_info(sta->sdata,
93 			   "HW problem - can not stop rx aggregation for %pM tid %d\n",
94 			   sta->sta.addr, tid);
95 
96 	/* check if this is a self generated aggregation halt */
97 	if (initiator == WLAN_BACK_RECIPIENT && tx)
98 		ieee80211_send_delba(sta->sdata, sta->sta.addr,
99 				     tid, WLAN_BACK_RECIPIENT, reason);
100 
101 	/*
102 	 * return here in case tid_rx is not assigned - which will happen if
103 	 * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
104 	 */
105 	if (!tid_rx)
106 		return;
107 
108 	del_timer_sync(&tid_rx->session_timer);
109 
110 	/* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
111 	spin_lock_bh(&tid_rx->reorder_lock);
112 	tid_rx->removed = true;
113 	spin_unlock_bh(&tid_rx->reorder_lock);
114 	del_timer_sync(&tid_rx->reorder_timer);
115 
116 	call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
117 }
118 
119 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
120 				    u16 initiator, u16 reason, bool tx)
121 {
122 	mutex_lock(&sta->ampdu_mlme.mtx);
123 	___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
124 	mutex_unlock(&sta->ampdu_mlme.mtx);
125 }
126 
127 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
128 				  const u8 *addr)
129 {
130 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
131 	struct sta_info *sta;
132 	int i;
133 
134 	rcu_read_lock();
135 	sta = sta_info_get_bss(sdata, addr);
136 	if (!sta) {
137 		rcu_read_unlock();
138 		return;
139 	}
140 
141 	for (i = 0; i < IEEE80211_NUM_TIDS; i++)
142 		if (ba_rx_bitmap & BIT(i))
143 			set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
144 
145 	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
146 	rcu_read_unlock();
147 }
148 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
149 
150 /*
151  * After accepting the AddBA Request we activated a timer,
152  * resetting it after each frame that arrives from the originator.
153  */
154 static void sta_rx_agg_session_timer_expired(unsigned long data)
155 {
156 	/* not an elegant detour, but there is no choice as the timer passes
157 	 * only one argument, and various sta_info are needed here, so init
158 	 * flow in sta_info_create gives the TID as data, while the timer_to_id
159 	 * array gives the sta through container_of */
160 	u8 *ptid = (u8 *)data;
161 	u8 *timer_to_id = ptid - *ptid;
162 	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
163 					 timer_to_tid[0]);
164 	struct tid_ampdu_rx *tid_rx;
165 	unsigned long timeout;
166 
167 	rcu_read_lock();
168 	tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
169 	if (!tid_rx) {
170 		rcu_read_unlock();
171 		return;
172 	}
173 
174 	timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
175 	if (time_is_after_jiffies(timeout)) {
176 		mod_timer(&tid_rx->session_timer, timeout);
177 		rcu_read_unlock();
178 		return;
179 	}
180 	rcu_read_unlock();
181 
182 	ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
183 	       sta->sta.addr, (u16)*ptid);
184 
185 	set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
186 	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
187 }
188 
189 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
190 {
191 	u8 *ptid = (u8 *)data;
192 	u8 *timer_to_id = ptid - *ptid;
193 	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
194 			timer_to_tid[0]);
195 
196 	rcu_read_lock();
197 	ieee80211_release_reorder_timeout(sta, *ptid);
198 	rcu_read_unlock();
199 }
200 
201 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
202 				      u8 dialog_token, u16 status, u16 policy,
203 				      u16 buf_size, u16 timeout)
204 {
205 	struct ieee80211_local *local = sdata->local;
206 	struct sk_buff *skb;
207 	struct ieee80211_mgmt *mgmt;
208 	bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
209 	u16 capab;
210 
211 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
212 	if (!skb)
213 		return;
214 
215 	skb_reserve(skb, local->hw.extra_tx_headroom);
216 	mgmt = skb_put_zero(skb, 24);
217 	memcpy(mgmt->da, da, ETH_ALEN);
218 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
219 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
220 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
221 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
222 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
223 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
224 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
225 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
226 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
227 
228 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
229 					  IEEE80211_STYPE_ACTION);
230 
231 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
232 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
233 	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
234 	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
235 
236 	capab = (u16)(amsdu << 0);	/* bit 0 A-MSDU support */
237 	capab |= (u16)(policy << 1);	/* bit 1 aggregation policy */
238 	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
239 	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */
240 
241 	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
242 	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
243 	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
244 
245 	ieee80211_tx_skb(sdata, skb);
246 }
247 
248 void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
249 				      u8 dialog_token, u16 timeout,
250 				      u16 start_seq_num, u16 ba_policy, u16 tid,
251 				      u16 buf_size, bool tx, bool auto_seq)
252 {
253 	struct ieee80211_local *local = sta->sdata->local;
254 	struct tid_ampdu_rx *tid_agg_rx;
255 	struct ieee80211_ampdu_params params = {
256 		.sta = &sta->sta,
257 		.action = IEEE80211_AMPDU_RX_START,
258 		.tid = tid,
259 		.amsdu = false,
260 		.timeout = timeout,
261 		.ssn = start_seq_num,
262 	};
263 	int i, ret = -EOPNOTSUPP;
264 	u16 status = WLAN_STATUS_REQUEST_DECLINED;
265 
266 	if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
267 		ht_dbg(sta->sdata,
268 		       "STA %pM requests BA session on unsupported tid %d\n",
269 		       sta->sta.addr, tid);
270 		goto end;
271 	}
272 
273 	if (!sta->sta.ht_cap.ht_supported) {
274 		ht_dbg(sta->sdata,
275 		       "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
276 		       sta->sta.addr, tid);
277 		/* send a response anyway, it's an error case if we get here */
278 		goto end;
279 	}
280 
281 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
282 		ht_dbg(sta->sdata,
283 		       "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
284 		       sta->sta.addr, tid);
285 		goto end;
286 	}
287 
288 	/* sanity check for incoming parameters:
289 	 * check if configuration can support the BA policy
290 	 * and if buffer size does not exceeds max value */
291 	/* XXX: check own ht delayed BA capability?? */
292 	if (((ba_policy != 1) &&
293 	     (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
294 	    (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
295 		status = WLAN_STATUS_INVALID_QOS_PARAM;
296 		ht_dbg_ratelimited(sta->sdata,
297 				   "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
298 				   sta->sta.addr, tid, ba_policy, buf_size);
299 		goto end;
300 	}
301 	/* determine default buffer size */
302 	if (buf_size == 0)
303 		buf_size = IEEE80211_MAX_AMPDU_BUF;
304 
305 	/* make sure the size doesn't exceed the maximum supported by the hw */
306 	if (buf_size > sta->sta.max_rx_aggregation_subframes)
307 		buf_size = sta->sta.max_rx_aggregation_subframes;
308 	params.buf_size = buf_size;
309 
310 	ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
311 	       buf_size, sta->sta.addr);
312 
313 	/* examine state machine */
314 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
315 
316 	if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
317 		if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
318 			ht_dbg_ratelimited(sta->sdata,
319 					   "updated AddBA Req from %pM on tid %u\n",
320 					   sta->sta.addr, tid);
321 			/* We have no API to update the timeout value in the
322 			 * driver so reject the timeout update.
323 			 */
324 			status = WLAN_STATUS_REQUEST_DECLINED;
325 			ieee80211_send_addba_resp(sta->sdata, sta->sta.addr,
326 						  tid, dialog_token, status,
327 						  1, buf_size, timeout);
328 			goto end;
329 		}
330 
331 		ht_dbg_ratelimited(sta->sdata,
332 				   "unexpected AddBA Req from %pM on tid %u\n",
333 				   sta->sta.addr, tid);
334 
335 		/* delete existing Rx BA session on the same tid */
336 		___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
337 						WLAN_STATUS_UNSPECIFIED_QOS,
338 						false);
339 	}
340 
341 	if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
342 		ret = drv_ampdu_action(local, sta->sdata, &params);
343 		ht_dbg(sta->sdata,
344 		       "Rx A-MPDU request on %pM tid %d result %d\n",
345 		       sta->sta.addr, tid, ret);
346 		if (!ret)
347 			status = WLAN_STATUS_SUCCESS;
348 		goto end;
349 	}
350 
351 	/* prepare A-MPDU MLME for Rx aggregation */
352 	tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
353 	if (!tid_agg_rx)
354 		goto end;
355 
356 	spin_lock_init(&tid_agg_rx->reorder_lock);
357 
358 	/* rx timer */
359 	setup_deferrable_timer(&tid_agg_rx->session_timer,
360 			       sta_rx_agg_session_timer_expired,
361 			       (unsigned long)&sta->timer_to_tid[tid]);
362 
363 	/* rx reorder timer */
364 	setup_timer(&tid_agg_rx->reorder_timer,
365 		    sta_rx_agg_reorder_timer_expired,
366 		    (unsigned long)&sta->timer_to_tid[tid]);
367 
368 	/* prepare reordering buffer */
369 	tid_agg_rx->reorder_buf =
370 		kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
371 	tid_agg_rx->reorder_time =
372 		kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
373 	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
374 		kfree(tid_agg_rx->reorder_buf);
375 		kfree(tid_agg_rx->reorder_time);
376 		kfree(tid_agg_rx);
377 		goto end;
378 	}
379 
380 	for (i = 0; i < buf_size; i++)
381 		__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
382 
383 	ret = drv_ampdu_action(local, sta->sdata, &params);
384 	ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
385 	       sta->sta.addr, tid, ret);
386 	if (ret) {
387 		kfree(tid_agg_rx->reorder_buf);
388 		kfree(tid_agg_rx->reorder_time);
389 		kfree(tid_agg_rx);
390 		goto end;
391 	}
392 
393 	/* update data */
394 	tid_agg_rx->ssn = start_seq_num;
395 	tid_agg_rx->head_seq_num = start_seq_num;
396 	tid_agg_rx->buf_size = buf_size;
397 	tid_agg_rx->timeout = timeout;
398 	tid_agg_rx->stored_mpdu_num = 0;
399 	tid_agg_rx->auto_seq = auto_seq;
400 	tid_agg_rx->started = false;
401 	tid_agg_rx->reorder_buf_filtered = 0;
402 	status = WLAN_STATUS_SUCCESS;
403 
404 	/* activate it for RX */
405 	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
406 
407 	if (timeout) {
408 		mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
409 		tid_agg_rx->last_rx = jiffies;
410 	}
411 
412 end:
413 	if (status == WLAN_STATUS_SUCCESS) {
414 		__set_bit(tid, sta->ampdu_mlme.agg_session_valid);
415 		__clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
416 		sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
417 	}
418 
419 	if (tx)
420 		ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
421 					  dialog_token, status, 1, buf_size,
422 					  timeout);
423 }
424 
425 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
426 				     u8 dialog_token, u16 timeout,
427 				     u16 start_seq_num, u16 ba_policy, u16 tid,
428 				     u16 buf_size, bool tx, bool auto_seq)
429 {
430 	mutex_lock(&sta->ampdu_mlme.mtx);
431 	___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
432 					 start_seq_num, ba_policy, tid,
433 					 buf_size, tx, auto_seq);
434 	mutex_unlock(&sta->ampdu_mlme.mtx);
435 }
436 
437 void ieee80211_process_addba_request(struct ieee80211_local *local,
438 				     struct sta_info *sta,
439 				     struct ieee80211_mgmt *mgmt,
440 				     size_t len)
441 {
442 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
443 	u8 dialog_token;
444 
445 	/* extract session parameters from addba request frame */
446 	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
447 	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
448 	start_seq_num =
449 		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
450 
451 	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
452 	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
453 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
454 	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
455 
456 	__ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
457 					start_seq_num, ba_policy, tid,
458 					buf_size, true, false);
459 }
460 
461 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
462 				 const u8 *addr, unsigned int bit)
463 {
464 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
465 	struct ieee80211_local *local = sdata->local;
466 	struct sta_info *sta;
467 
468 	rcu_read_lock();
469 	sta = sta_info_get_bss(sdata, addr);
470 	if (!sta)
471 		goto unlock;
472 
473 	set_bit(bit, sta->ampdu_mlme.tid_rx_manage_offl);
474 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
475  unlock:
476 	rcu_read_unlock();
477 }
478 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
479 
480 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
481 				   const u8 *addr, unsigned int tid)
482 {
483 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
484 	struct ieee80211_local *local = sdata->local;
485 	struct sta_info *sta;
486 
487 	rcu_read_lock();
488 	sta = sta_info_get_bss(sdata, addr);
489 	if (!sta)
490 		goto unlock;
491 
492 	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
493 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
494 
495  unlock:
496 	rcu_read_unlock();
497 }
498 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);
499