xref: /openbmc/linux/net/mac80211/agg-rx.c (revision b593bce5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * HT handling
4  *
5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6  * Copyright 2002-2005, Instant802 Networks, Inc.
7  * Copyright 2005-2006, Devicescape Software, Inc.
8  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10  * Copyright 2007-2010, Intel Corporation
11  * Copyright(c) 2015-2017 Intel Deutschland GmbH
12  * Copyright (C) 2018        Intel Corporation
13  */
14 
15 /**
16  * DOC: RX A-MPDU aggregation
17  *
18  * Aggregation on the RX side requires only implementing the
19  * @ampdu_action callback that is invoked to start/stop any
20  * block-ack sessions for RX aggregation.
21  *
22  * When RX aggregation is started by the peer, the driver is
23  * notified via @ampdu_action function, with the
24  * %IEEE80211_AMPDU_RX_START action, and may reject the request
25  * in which case a negative response is sent to the peer, if it
26  * accepts it a positive response is sent.
27  *
28  * While the session is active, the device/driver are required
29  * to de-aggregate frames and pass them up one by one to mac80211,
30  * which will handle the reorder buffer.
31  *
32  * When the aggregation session is stopped again by the peer or
33  * ourselves, the driver's @ampdu_action function will be called
34  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
35  * call must not fail.
36  */
37 
38 #include <linux/ieee80211.h>
39 #include <linux/slab.h>
40 #include <linux/export.h>
41 #include <net/mac80211.h>
42 #include "ieee80211_i.h"
43 #include "driver-ops.h"
44 
45 static void ieee80211_free_tid_rx(struct rcu_head *h)
46 {
47 	struct tid_ampdu_rx *tid_rx =
48 		container_of(h, struct tid_ampdu_rx, rcu_head);
49 	int i;
50 
51 	for (i = 0; i < tid_rx->buf_size; i++)
52 		__skb_queue_purge(&tid_rx->reorder_buf[i]);
53 	kfree(tid_rx->reorder_buf);
54 	kfree(tid_rx->reorder_time);
55 	kfree(tid_rx);
56 }
57 
58 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
59 				     u16 initiator, u16 reason, bool tx)
60 {
61 	struct ieee80211_local *local = sta->local;
62 	struct tid_ampdu_rx *tid_rx;
63 	struct ieee80211_ampdu_params params = {
64 		.sta = &sta->sta,
65 		.action = IEEE80211_AMPDU_RX_STOP,
66 		.tid = tid,
67 		.amsdu = false,
68 		.timeout = 0,
69 		.ssn = 0,
70 	};
71 
72 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
73 
74 	tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
75 					lockdep_is_held(&sta->ampdu_mlme.mtx));
76 
77 	if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
78 		return;
79 
80 	RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
81 	__clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
82 
83 	ht_dbg(sta->sdata,
84 	       "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
85 	       sta->sta.addr, tid,
86 	       initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
87 	       (int)reason);
88 
89 	if (drv_ampdu_action(local, sta->sdata, &params))
90 		sdata_info(sta->sdata,
91 			   "HW problem - can not stop rx aggregation for %pM tid %d\n",
92 			   sta->sta.addr, tid);
93 
94 	/* check if this is a self generated aggregation halt */
95 	if (initiator == WLAN_BACK_RECIPIENT && tx)
96 		ieee80211_send_delba(sta->sdata, sta->sta.addr,
97 				     tid, WLAN_BACK_RECIPIENT, reason);
98 
99 	/*
100 	 * return here in case tid_rx is not assigned - which will happen if
101 	 * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
102 	 */
103 	if (!tid_rx)
104 		return;
105 
106 	del_timer_sync(&tid_rx->session_timer);
107 
108 	/* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
109 	spin_lock_bh(&tid_rx->reorder_lock);
110 	tid_rx->removed = true;
111 	spin_unlock_bh(&tid_rx->reorder_lock);
112 	del_timer_sync(&tid_rx->reorder_timer);
113 
114 	call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
115 }
116 
117 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
118 				    u16 initiator, u16 reason, bool tx)
119 {
120 	mutex_lock(&sta->ampdu_mlme.mtx);
121 	___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
122 	mutex_unlock(&sta->ampdu_mlme.mtx);
123 }
124 
125 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
126 				  const u8 *addr)
127 {
128 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
129 	struct sta_info *sta;
130 	int i;
131 
132 	rcu_read_lock();
133 	sta = sta_info_get_bss(sdata, addr);
134 	if (!sta) {
135 		rcu_read_unlock();
136 		return;
137 	}
138 
139 	for (i = 0; i < IEEE80211_NUM_TIDS; i++)
140 		if (ba_rx_bitmap & BIT(i))
141 			set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
142 
143 	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
144 	rcu_read_unlock();
145 }
146 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
147 
148 /*
149  * After accepting the AddBA Request we activated a timer,
150  * resetting it after each frame that arrives from the originator.
151  */
152 static void sta_rx_agg_session_timer_expired(struct timer_list *t)
153 {
154 	struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, session_timer);
155 	struct sta_info *sta = tid_rx->sta;
156 	u8 tid = tid_rx->tid;
157 	unsigned long timeout;
158 
159 	timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
160 	if (time_is_after_jiffies(timeout)) {
161 		mod_timer(&tid_rx->session_timer, timeout);
162 		return;
163 	}
164 
165 	ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
166 	       sta->sta.addr, tid);
167 
168 	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
169 	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
170 }
171 
172 static void sta_rx_agg_reorder_timer_expired(struct timer_list *t)
173 {
174 	struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, reorder_timer);
175 
176 	rcu_read_lock();
177 	ieee80211_release_reorder_timeout(tid_rx->sta, tid_rx->tid);
178 	rcu_read_unlock();
179 }
180 
181 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
182 				      u8 dialog_token, u16 status, u16 policy,
183 				      u16 buf_size, u16 timeout)
184 {
185 	struct ieee80211_local *local = sdata->local;
186 	struct sk_buff *skb;
187 	struct ieee80211_mgmt *mgmt;
188 	bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
189 	u16 capab;
190 
191 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
192 	if (!skb)
193 		return;
194 
195 	skb_reserve(skb, local->hw.extra_tx_headroom);
196 	mgmt = skb_put_zero(skb, 24);
197 	memcpy(mgmt->da, da, ETH_ALEN);
198 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
199 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
200 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
201 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
202 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
203 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
204 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
205 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
206 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
207 
208 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
209 					  IEEE80211_STYPE_ACTION);
210 
211 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
212 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
213 	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
214 	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
215 
216 	capab = (u16)(amsdu << 0);	/* bit 0 A-MSDU support */
217 	capab |= (u16)(policy << 1);	/* bit 1 aggregation policy */
218 	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
219 	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */
220 
221 	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
222 	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
223 	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
224 
225 	ieee80211_tx_skb(sdata, skb);
226 }
227 
228 void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
229 				      u8 dialog_token, u16 timeout,
230 				      u16 start_seq_num, u16 ba_policy, u16 tid,
231 				      u16 buf_size, bool tx, bool auto_seq)
232 {
233 	struct ieee80211_local *local = sta->sdata->local;
234 	struct tid_ampdu_rx *tid_agg_rx;
235 	struct ieee80211_ampdu_params params = {
236 		.sta = &sta->sta,
237 		.action = IEEE80211_AMPDU_RX_START,
238 		.tid = tid,
239 		.amsdu = false,
240 		.timeout = timeout,
241 		.ssn = start_seq_num,
242 	};
243 	int i, ret = -EOPNOTSUPP;
244 	u16 status = WLAN_STATUS_REQUEST_DECLINED;
245 	u16 max_buf_size;
246 
247 	if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
248 		ht_dbg(sta->sdata,
249 		       "STA %pM requests BA session on unsupported tid %d\n",
250 		       sta->sta.addr, tid);
251 		goto end;
252 	}
253 
254 	if (!sta->sta.ht_cap.ht_supported) {
255 		ht_dbg(sta->sdata,
256 		       "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
257 		       sta->sta.addr, tid);
258 		/* send a response anyway, it's an error case if we get here */
259 		goto end;
260 	}
261 
262 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
263 		ht_dbg(sta->sdata,
264 		       "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
265 		       sta->sta.addr, tid);
266 		goto end;
267 	}
268 
269 	if (sta->sta.he_cap.has_he)
270 		max_buf_size = IEEE80211_MAX_AMPDU_BUF;
271 	else
272 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
273 
274 	/* sanity check for incoming parameters:
275 	 * check if configuration can support the BA policy
276 	 * and if buffer size does not exceeds max value */
277 	/* XXX: check own ht delayed BA capability?? */
278 	if (((ba_policy != 1) &&
279 	     (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
280 	    (buf_size > max_buf_size)) {
281 		status = WLAN_STATUS_INVALID_QOS_PARAM;
282 		ht_dbg_ratelimited(sta->sdata,
283 				   "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
284 				   sta->sta.addr, tid, ba_policy, buf_size);
285 		goto end;
286 	}
287 	/* determine default buffer size */
288 	if (buf_size == 0)
289 		buf_size = max_buf_size;
290 
291 	/* make sure the size doesn't exceed the maximum supported by the hw */
292 	if (buf_size > sta->sta.max_rx_aggregation_subframes)
293 		buf_size = sta->sta.max_rx_aggregation_subframes;
294 	params.buf_size = buf_size;
295 
296 	ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
297 	       buf_size, sta->sta.addr);
298 
299 	/* examine state machine */
300 	lockdep_assert_held(&sta->ampdu_mlme.mtx);
301 
302 	if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
303 		if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
304 			struct tid_ampdu_rx *tid_rx;
305 
306 			ht_dbg_ratelimited(sta->sdata,
307 					   "updated AddBA Req from %pM on tid %u\n",
308 					   sta->sta.addr, tid);
309 			/* We have no API to update the timeout value in the
310 			 * driver so reject the timeout update if the timeout
311 			 * changed. If if did not change, i.e., no real update,
312 			 * just reply with success.
313 			 */
314 			rcu_read_lock();
315 			tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
316 			if (tid_rx && tid_rx->timeout == timeout)
317 				status = WLAN_STATUS_SUCCESS;
318 			else
319 				status = WLAN_STATUS_REQUEST_DECLINED;
320 			rcu_read_unlock();
321 			goto end;
322 		}
323 
324 		ht_dbg_ratelimited(sta->sdata,
325 				   "unexpected AddBA Req from %pM on tid %u\n",
326 				   sta->sta.addr, tid);
327 
328 		/* delete existing Rx BA session on the same tid */
329 		___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
330 						WLAN_STATUS_UNSPECIFIED_QOS,
331 						false);
332 	}
333 
334 	if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
335 		ret = drv_ampdu_action(local, sta->sdata, &params);
336 		ht_dbg(sta->sdata,
337 		       "Rx A-MPDU request on %pM tid %d result %d\n",
338 		       sta->sta.addr, tid, ret);
339 		if (!ret)
340 			status = WLAN_STATUS_SUCCESS;
341 		goto end;
342 	}
343 
344 	/* prepare A-MPDU MLME for Rx aggregation */
345 	tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
346 	if (!tid_agg_rx)
347 		goto end;
348 
349 	spin_lock_init(&tid_agg_rx->reorder_lock);
350 
351 	/* rx timer */
352 	timer_setup(&tid_agg_rx->session_timer,
353 		    sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
354 
355 	/* rx reorder timer */
356 	timer_setup(&tid_agg_rx->reorder_timer,
357 		    sta_rx_agg_reorder_timer_expired, 0);
358 
359 	/* prepare reordering buffer */
360 	tid_agg_rx->reorder_buf =
361 		kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
362 	tid_agg_rx->reorder_time =
363 		kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
364 	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
365 		kfree(tid_agg_rx->reorder_buf);
366 		kfree(tid_agg_rx->reorder_time);
367 		kfree(tid_agg_rx);
368 		goto end;
369 	}
370 
371 	for (i = 0; i < buf_size; i++)
372 		__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
373 
374 	ret = drv_ampdu_action(local, sta->sdata, &params);
375 	ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
376 	       sta->sta.addr, tid, ret);
377 	if (ret) {
378 		kfree(tid_agg_rx->reorder_buf);
379 		kfree(tid_agg_rx->reorder_time);
380 		kfree(tid_agg_rx);
381 		goto end;
382 	}
383 
384 	/* update data */
385 	tid_agg_rx->ssn = start_seq_num;
386 	tid_agg_rx->head_seq_num = start_seq_num;
387 	tid_agg_rx->buf_size = buf_size;
388 	tid_agg_rx->timeout = timeout;
389 	tid_agg_rx->stored_mpdu_num = 0;
390 	tid_agg_rx->auto_seq = auto_seq;
391 	tid_agg_rx->started = false;
392 	tid_agg_rx->reorder_buf_filtered = 0;
393 	tid_agg_rx->tid = tid;
394 	tid_agg_rx->sta = sta;
395 	status = WLAN_STATUS_SUCCESS;
396 
397 	/* activate it for RX */
398 	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
399 
400 	if (timeout) {
401 		mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
402 		tid_agg_rx->last_rx = jiffies;
403 	}
404 
405 end:
406 	if (status == WLAN_STATUS_SUCCESS) {
407 		__set_bit(tid, sta->ampdu_mlme.agg_session_valid);
408 		__clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
409 		sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
410 	}
411 
412 	if (tx)
413 		ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
414 					  dialog_token, status, 1, buf_size,
415 					  timeout);
416 }
417 
418 static void __ieee80211_start_rx_ba_session(struct sta_info *sta,
419 					    u8 dialog_token, u16 timeout,
420 					    u16 start_seq_num, u16 ba_policy,
421 					    u16 tid, u16 buf_size, bool tx,
422 					    bool auto_seq)
423 {
424 	mutex_lock(&sta->ampdu_mlme.mtx);
425 	___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
426 					 start_seq_num, ba_policy, tid,
427 					 buf_size, tx, auto_seq);
428 	mutex_unlock(&sta->ampdu_mlme.mtx);
429 }
430 
431 void ieee80211_process_addba_request(struct ieee80211_local *local,
432 				     struct sta_info *sta,
433 				     struct ieee80211_mgmt *mgmt,
434 				     size_t len)
435 {
436 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
437 	u8 dialog_token;
438 
439 	/* extract session parameters from addba request frame */
440 	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
441 	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
442 	start_seq_num =
443 		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
444 
445 	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
446 	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
447 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
448 	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
449 
450 	__ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
451 					start_seq_num, ba_policy, tid,
452 					buf_size, true, false);
453 }
454 
455 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
456 				 const u8 *addr, unsigned int tid)
457 {
458 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
459 	struct ieee80211_local *local = sdata->local;
460 	struct sta_info *sta;
461 
462 	rcu_read_lock();
463 	sta = sta_info_get_bss(sdata, addr);
464 	if (!sta)
465 		goto unlock;
466 
467 	set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
468 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
469  unlock:
470 	rcu_read_unlock();
471 }
472 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
473 
474 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
475 				   const u8 *addr, unsigned int tid)
476 {
477 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
478 	struct ieee80211_local *local = sdata->local;
479 	struct sta_info *sta;
480 
481 	rcu_read_lock();
482 	sta = sta_info_get_bss(sdata, addr);
483 	if (!sta)
484 		goto unlock;
485 
486 	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
487 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
488 
489  unlock:
490 	rcu_read_unlock();
491 }
492 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);
493