xref: /linux/net/mac80211/agg-rx.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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) 2018-2023 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_wiphy(sta->local->hw.wiphy);
73 
74 	tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
75 					lockdep_is_held(&sta->local->hw.wiphy->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 ieee80211_vif *vif, u16 ba_rx_bitmap,
118 				  const u8 *addr)
119 {
120 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
121 	struct sta_info *sta;
122 	int i;
123 
124 	rcu_read_lock();
125 	sta = sta_info_get_bss(sdata, addr);
126 	if (!sta) {
127 		rcu_read_unlock();
128 		return;
129 	}
130 
131 	for (i = 0; i < IEEE80211_NUM_TIDS; i++)
132 		if (ba_rx_bitmap & BIT(i))
133 			set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
134 
135 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
136 	rcu_read_unlock();
137 }
138 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
139 
140 /*
141  * After accepting the AddBA Request we activated a timer,
142  * resetting it after each frame that arrives from the originator.
143  */
144 static void sta_rx_agg_session_timer_expired(struct timer_list *t)
145 {
146 	struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, session_timer);
147 	struct sta_info *sta = tid_rx->sta;
148 	u8 tid = tid_rx->tid;
149 	unsigned long timeout;
150 
151 	timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
152 	if (time_is_after_jiffies(timeout)) {
153 		mod_timer(&tid_rx->session_timer, timeout);
154 		return;
155 	}
156 
157 	ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
158 	       sta->sta.addr, tid);
159 
160 	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
161 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
162 }
163 
164 static void sta_rx_agg_reorder_timer_expired(struct timer_list *t)
165 {
166 	struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, reorder_timer);
167 
168 	rcu_read_lock();
169 	ieee80211_release_reorder_timeout(tid_rx->sta, tid_rx->tid);
170 	rcu_read_unlock();
171 }
172 
173 void ieee80211_add_addbaext(struct sk_buff *skb,
174 			    const u8 req_addba_ext_data,
175 			    u16 buf_size)
176 {
177 	struct ieee80211_addba_ext_ie *addba_ext;
178 	u8 *pos;
179 
180 	pos = skb_put_zero(skb, 2 + sizeof(struct ieee80211_addba_ext_ie));
181 	*pos++ = WLAN_EID_ADDBA_EXT;
182 	*pos++ = sizeof(struct ieee80211_addba_ext_ie);
183 	addba_ext = (struct ieee80211_addba_ext_ie *)pos;
184 
185 	addba_ext->data = IEEE80211_ADDBA_EXT_NO_FRAG;
186 	if (req_addba_ext_data)
187 		addba_ext->data &= req_addba_ext_data;
188 
189 	addba_ext->data |=
190 		u8_encode_bits(buf_size >> IEEE80211_ADDBA_EXT_BUF_SIZE_SHIFT,
191 			       IEEE80211_ADDBA_EXT_BUF_SIZE_MASK);
192 }
193 
194 u8 ieee80211_retrieve_addba_ext_data(struct sta_info *sta,
195 				     const void *elem_data, ssize_t elem_len,
196 				     u16 *buf_size)
197 {
198 	struct ieee802_11_elems *elems;
199 	u8 buf_size_1k, data = 0;
200 
201 	if (!sta->sta.deflink.he_cap.has_he)
202 		return 0;
203 
204 	if (elem_len <= 0)
205 		return 0;
206 
207 	elems = ieee802_11_parse_elems(elem_data, elem_len, true, NULL);
208 
209 	if (elems && !elems->parse_error && elems->addba_ext_ie) {
210 		data = elems->addba_ext_ie->data;
211 
212 		if (!sta->sta.deflink.eht_cap.has_eht || !buf_size)
213 			goto free;
214 
215 		buf_size_1k = u8_get_bits(elems->addba_ext_ie->data,
216 					  IEEE80211_ADDBA_EXT_BUF_SIZE_MASK);
217 		*buf_size |= (u16)buf_size_1k <<
218 			     IEEE80211_ADDBA_EXT_BUF_SIZE_SHIFT;
219 	}
220 free:
221 	kfree(elems);
222 
223 	return data;
224 }
225 
226 static void ieee80211_send_addba_resp(struct sta_info *sta, u8 *da, u16 tid,
227 				      u8 dialog_token, u16 status, u16 policy,
228 				      u16 buf_size, u16 timeout,
229 				      const u8 req_addba_ext_data)
230 {
231 	struct ieee80211_sub_if_data *sdata = sta->sdata;
232 	struct ieee80211_local *local = sdata->local;
233 	struct sk_buff *skb;
234 	struct ieee80211_mgmt *mgmt;
235 	bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
236 	u16 capab;
237 
238 	skb = dev_alloc_skb(sizeof(*mgmt) +
239 		    2 + sizeof(struct ieee80211_addba_ext_ie) +
240 		    local->hw.extra_tx_headroom);
241 	if (!skb)
242 		return;
243 
244 	skb_reserve(skb, local->hw.extra_tx_headroom);
245 	mgmt = ieee80211_mgmt_ba(skb, da, sdata);
246 
247 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
248 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
249 	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
250 	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
251 
252 	capab = u16_encode_bits(amsdu, IEEE80211_ADDBA_PARAM_AMSDU_MASK);
253 	capab |= u16_encode_bits(policy, IEEE80211_ADDBA_PARAM_POLICY_MASK);
254 	capab |= u16_encode_bits(tid, IEEE80211_ADDBA_PARAM_TID_MASK);
255 	capab |= u16_encode_bits(buf_size, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
256 
257 	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
258 	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
259 	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
260 
261 	if (sta->sta.deflink.he_cap.has_he)
262 		ieee80211_add_addbaext(skb, req_addba_ext_data, buf_size);
263 
264 	ieee80211_tx_skb(sdata, skb);
265 }
266 
267 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
268 				     u8 dialog_token, u16 timeout,
269 				     u16 start_seq_num, u16 ba_policy, u16 tid,
270 				     u16 buf_size, bool tx, bool auto_seq,
271 				     const u8 addba_ext_data)
272 {
273 	struct ieee80211_local *local = sta->sdata->local;
274 	struct tid_ampdu_rx *tid_agg_rx;
275 	struct ieee80211_ampdu_params params = {
276 		.sta = &sta->sta,
277 		.action = IEEE80211_AMPDU_RX_START,
278 		.tid = tid,
279 		.amsdu = false,
280 		.timeout = timeout,
281 		.ssn = start_seq_num,
282 	};
283 	int i, ret = -EOPNOTSUPP;
284 	u16 status = WLAN_STATUS_REQUEST_DECLINED;
285 	u16 max_buf_size;
286 
287 	lockdep_assert_wiphy(sta->local->hw.wiphy);
288 
289 	if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
290 		ht_dbg(sta->sdata,
291 		       "STA %pM requests BA session on unsupported tid %d\n",
292 		       sta->sta.addr, tid);
293 		goto end;
294 	}
295 
296 	if (!sta->sta.deflink.ht_cap.ht_supported &&
297 	    !sta->sta.deflink.he_cap.has_he) {
298 		ht_dbg(sta->sdata,
299 		       "STA %pM erroneously requests BA session on tid %d w/o HT\n",
300 		       sta->sta.addr, tid);
301 		/* send a response anyway, it's an error case if we get here */
302 		goto end;
303 	}
304 
305 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
306 		ht_dbg(sta->sdata,
307 		       "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
308 		       sta->sta.addr, tid);
309 		goto end;
310 	}
311 
312 	if (sta->sta.deflink.eht_cap.has_eht)
313 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_EHT;
314 	else if (sta->sta.deflink.he_cap.has_he)
315 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_HE;
316 	else
317 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
318 
319 	/* sanity check for incoming parameters:
320 	 * check if configuration can support the BA policy
321 	 * and if buffer size does not exceeds max value */
322 	/* XXX: check own ht delayed BA capability?? */
323 	if (((ba_policy != 1) &&
324 	     (!(sta->sta.deflink.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
325 	    (buf_size > max_buf_size)) {
326 		status = WLAN_STATUS_INVALID_QOS_PARAM;
327 		ht_dbg_ratelimited(sta->sdata,
328 				   "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
329 				   sta->sta.addr, tid, ba_policy, buf_size);
330 		goto end;
331 	}
332 	/* determine default buffer size */
333 	if (buf_size == 0)
334 		buf_size = max_buf_size;
335 
336 	/* make sure the size doesn't exceed the maximum supported by the hw */
337 	if (buf_size > sta->sta.max_rx_aggregation_subframes)
338 		buf_size = sta->sta.max_rx_aggregation_subframes;
339 	params.buf_size = buf_size;
340 
341 	ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
342 	       buf_size, sta->sta.addr);
343 
344 	if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
345 		if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
346 			struct tid_ampdu_rx *tid_rx;
347 
348 			ht_dbg_ratelimited(sta->sdata,
349 					   "updated AddBA Req from %pM on tid %u\n",
350 					   sta->sta.addr, tid);
351 			/* We have no API to update the timeout value in the
352 			 * driver so reject the timeout update if the timeout
353 			 * changed. If it did not change, i.e., no real update,
354 			 * just reply with success.
355 			 */
356 			rcu_read_lock();
357 			tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
358 			if (tid_rx && tid_rx->timeout == timeout)
359 				status = WLAN_STATUS_SUCCESS;
360 			else
361 				status = WLAN_STATUS_REQUEST_DECLINED;
362 			rcu_read_unlock();
363 			goto end;
364 		}
365 
366 		ht_dbg_ratelimited(sta->sdata,
367 				   "unexpected AddBA Req from %pM on tid %u\n",
368 				   sta->sta.addr, tid);
369 
370 		/* delete existing Rx BA session on the same tid */
371 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
372 					       WLAN_STATUS_UNSPECIFIED_QOS,
373 					       false);
374 	}
375 
376 	if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
377 		ret = drv_ampdu_action(local, sta->sdata, &params);
378 		ht_dbg(sta->sdata,
379 		       "Rx A-MPDU request on %pM tid %d result %d\n",
380 		       sta->sta.addr, tid, ret);
381 		if (!ret)
382 			status = WLAN_STATUS_SUCCESS;
383 		goto end;
384 	}
385 
386 	/* prepare A-MPDU MLME for Rx aggregation */
387 	tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
388 	if (!tid_agg_rx)
389 		goto end;
390 
391 	spin_lock_init(&tid_agg_rx->reorder_lock);
392 
393 	/* rx timer */
394 	timer_setup(&tid_agg_rx->session_timer,
395 		    sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
396 
397 	/* rx reorder timer */
398 	timer_setup(&tid_agg_rx->reorder_timer,
399 		    sta_rx_agg_reorder_timer_expired, 0);
400 
401 	/* prepare reordering buffer */
402 	tid_agg_rx->reorder_buf =
403 		kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
404 	tid_agg_rx->reorder_time =
405 		kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
406 	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
407 		kfree(tid_agg_rx->reorder_buf);
408 		kfree(tid_agg_rx->reorder_time);
409 		kfree(tid_agg_rx);
410 		goto end;
411 	}
412 
413 	for (i = 0; i < buf_size; i++)
414 		__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
415 
416 	ret = drv_ampdu_action(local, sta->sdata, &params);
417 	ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
418 	       sta->sta.addr, tid, ret);
419 	if (ret) {
420 		kfree(tid_agg_rx->reorder_buf);
421 		kfree(tid_agg_rx->reorder_time);
422 		kfree(tid_agg_rx);
423 		goto end;
424 	}
425 
426 	/* update data */
427 	tid_agg_rx->ssn = start_seq_num;
428 	tid_agg_rx->head_seq_num = start_seq_num;
429 	tid_agg_rx->buf_size = buf_size;
430 	tid_agg_rx->timeout = timeout;
431 	tid_agg_rx->stored_mpdu_num = 0;
432 	tid_agg_rx->auto_seq = auto_seq;
433 	tid_agg_rx->started = false;
434 	tid_agg_rx->reorder_buf_filtered = 0;
435 	tid_agg_rx->tid = tid;
436 	tid_agg_rx->sta = sta;
437 	status = WLAN_STATUS_SUCCESS;
438 
439 	/* activate it for RX */
440 	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
441 
442 	if (timeout) {
443 		mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
444 		tid_agg_rx->last_rx = jiffies;
445 	}
446 
447 end:
448 	if (status == WLAN_STATUS_SUCCESS) {
449 		__set_bit(tid, sta->ampdu_mlme.agg_session_valid);
450 		__clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
451 		sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
452 	}
453 
454 	if (tx)
455 		ieee80211_send_addba_resp(sta, sta->sta.addr, tid,
456 					  dialog_token, status, 1, buf_size,
457 					  timeout, addba_ext_data);
458 }
459 
460 void ieee80211_process_addba_request(struct ieee80211_local *local,
461 				     struct sta_info *sta,
462 				     struct ieee80211_mgmt *mgmt,
463 				     size_t len)
464 {
465 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
466 	u8 dialog_token, addba_ext_data;
467 
468 	/* extract session parameters from addba request frame */
469 	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
470 	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
471 	start_seq_num =
472 		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
473 
474 	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
475 	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
476 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
477 	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
478 
479 	addba_ext_data =
480 		ieee80211_retrieve_addba_ext_data(sta,
481 						  mgmt->u.action.u.addba_req.variable,
482 						  len -
483 						  offsetof(typeof(*mgmt),
484 							   u.action.u.addba_req.variable),
485 						  &buf_size);
486 
487 	__ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
488 					start_seq_num, ba_policy, tid,
489 					buf_size, true, false, addba_ext_data);
490 }
491 
492 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
493 				 const u8 *addr, unsigned int tid)
494 {
495 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
496 	struct sta_info *sta;
497 
498 	rcu_read_lock();
499 	sta = sta_info_get_bss(sdata, addr);
500 	if (!sta)
501 		goto unlock;
502 
503 	set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
504 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
505  unlock:
506 	rcu_read_unlock();
507 }
508 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
509 
510 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
511 				   const u8 *addr, unsigned int tid)
512 {
513 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
514 	struct sta_info *sta;
515 
516 	rcu_read_lock();
517 	sta = sta_info_get_bss(sdata, addr);
518 	if (!sta)
519 		goto unlock;
520 
521 	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
522 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
523 
524  unlock:
525 	rcu_read_unlock();
526 }
527 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);
528