xref: /linux/net/mac80211/agg-rx.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
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 static void ieee80211_add_addbaext(struct ieee80211_sub_if_data *sdata,
174 				   struct sk_buff *skb,
175 				   const struct ieee80211_addba_ext_ie *req,
176 				   u16 buf_size)
177 {
178 	struct ieee80211_addba_ext_ie *resp;
179 	u8 *pos;
180 
181 	pos = skb_put_zero(skb, 2 + sizeof(struct ieee80211_addba_ext_ie));
182 	*pos++ = WLAN_EID_ADDBA_EXT;
183 	*pos++ = sizeof(struct ieee80211_addba_ext_ie);
184 	resp = (struct ieee80211_addba_ext_ie *)pos;
185 	resp->data = req->data & IEEE80211_ADDBA_EXT_NO_FRAG;
186 
187 	resp->data |= u8_encode_bits(buf_size >> IEEE80211_ADDBA_EXT_BUF_SIZE_SHIFT,
188 				     IEEE80211_ADDBA_EXT_BUF_SIZE_MASK);
189 }
190 
191 static void ieee80211_send_addba_resp(struct sta_info *sta, u8 *da, u16 tid,
192 				      u8 dialog_token, u16 status, u16 policy,
193 				      u16 buf_size, u16 timeout,
194 				      const struct ieee80211_addba_ext_ie *addbaext)
195 {
196 	struct ieee80211_sub_if_data *sdata = sta->sdata;
197 	struct ieee80211_local *local = sdata->local;
198 	struct sk_buff *skb;
199 	struct ieee80211_mgmt *mgmt;
200 	bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
201 	u16 capab;
202 
203 	skb = dev_alloc_skb(sizeof(*mgmt) +
204 		    2 + sizeof(struct ieee80211_addba_ext_ie) +
205 		    local->hw.extra_tx_headroom);
206 	if (!skb)
207 		return;
208 
209 	skb_reserve(skb, local->hw.extra_tx_headroom);
210 	mgmt = skb_put_zero(skb, 24);
211 	memcpy(mgmt->da, da, ETH_ALEN);
212 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
213 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
214 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
215 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
216 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
217 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
218 		memcpy(mgmt->bssid, sdata->vif.cfg.ap_addr, ETH_ALEN);
219 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
220 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
221 
222 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
223 					  IEEE80211_STYPE_ACTION);
224 
225 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
226 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
227 	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
228 	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
229 
230 	capab = u16_encode_bits(amsdu, IEEE80211_ADDBA_PARAM_AMSDU_MASK);
231 	capab |= u16_encode_bits(policy, IEEE80211_ADDBA_PARAM_POLICY_MASK);
232 	capab |= u16_encode_bits(tid, IEEE80211_ADDBA_PARAM_TID_MASK);
233 	capab |= u16_encode_bits(buf_size, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
234 
235 	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
236 	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
237 	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
238 
239 	if (sta->sta.deflink.he_cap.has_he && addbaext)
240 		ieee80211_add_addbaext(sdata, skb, addbaext, buf_size);
241 
242 	ieee80211_tx_skb(sdata, skb);
243 }
244 
245 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
246 				     u8 dialog_token, u16 timeout,
247 				     u16 start_seq_num, u16 ba_policy, u16 tid,
248 				     u16 buf_size, bool tx, bool auto_seq,
249 				     const struct ieee80211_addba_ext_ie *addbaext)
250 {
251 	struct ieee80211_local *local = sta->sdata->local;
252 	struct tid_ampdu_rx *tid_agg_rx;
253 	struct ieee80211_ampdu_params params = {
254 		.sta = &sta->sta,
255 		.action = IEEE80211_AMPDU_RX_START,
256 		.tid = tid,
257 		.amsdu = false,
258 		.timeout = timeout,
259 		.ssn = start_seq_num,
260 	};
261 	int i, ret = -EOPNOTSUPP;
262 	u16 status = WLAN_STATUS_REQUEST_DECLINED;
263 	u16 max_buf_size;
264 
265 	lockdep_assert_wiphy(sta->local->hw.wiphy);
266 
267 	if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
268 		ht_dbg(sta->sdata,
269 		       "STA %pM requests BA session on unsupported tid %d\n",
270 		       sta->sta.addr, tid);
271 		goto end;
272 	}
273 
274 	if (!sta->sta.deflink.ht_cap.ht_supported &&
275 	    !sta->sta.deflink.he_cap.has_he) {
276 		ht_dbg(sta->sdata,
277 		       "STA %pM erroneously requests BA session on tid %d w/o HT\n",
278 		       sta->sta.addr, tid);
279 		/* send a response anyway, it's an error case if we get here */
280 		goto end;
281 	}
282 
283 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
284 		ht_dbg(sta->sdata,
285 		       "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
286 		       sta->sta.addr, tid);
287 		goto end;
288 	}
289 
290 	if (sta->sta.deflink.eht_cap.has_eht)
291 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_EHT;
292 	else if (sta->sta.deflink.he_cap.has_he)
293 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_HE;
294 	else
295 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
296 
297 	/* sanity check for incoming parameters:
298 	 * check if configuration can support the BA policy
299 	 * and if buffer size does not exceeds max value */
300 	/* XXX: check own ht delayed BA capability?? */
301 	if (((ba_policy != 1) &&
302 	     (!(sta->sta.deflink.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
303 	    (buf_size > max_buf_size)) {
304 		status = WLAN_STATUS_INVALID_QOS_PARAM;
305 		ht_dbg_ratelimited(sta->sdata,
306 				   "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
307 				   sta->sta.addr, tid, ba_policy, buf_size);
308 		goto end;
309 	}
310 	/* determine default buffer size */
311 	if (buf_size == 0)
312 		buf_size = max_buf_size;
313 
314 	/* make sure the size doesn't exceed the maximum supported by the hw */
315 	if (buf_size > sta->sta.max_rx_aggregation_subframes)
316 		buf_size = sta->sta.max_rx_aggregation_subframes;
317 	params.buf_size = buf_size;
318 
319 	ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
320 	       buf_size, sta->sta.addr);
321 
322 	if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
323 		if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
324 			struct tid_ampdu_rx *tid_rx;
325 
326 			ht_dbg_ratelimited(sta->sdata,
327 					   "updated AddBA Req from %pM on tid %u\n",
328 					   sta->sta.addr, tid);
329 			/* We have no API to update the timeout value in the
330 			 * driver so reject the timeout update if the timeout
331 			 * changed. If it did not change, i.e., no real update,
332 			 * just reply with success.
333 			 */
334 			rcu_read_lock();
335 			tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
336 			if (tid_rx && tid_rx->timeout == timeout)
337 				status = WLAN_STATUS_SUCCESS;
338 			else
339 				status = WLAN_STATUS_REQUEST_DECLINED;
340 			rcu_read_unlock();
341 			goto end;
342 		}
343 
344 		ht_dbg_ratelimited(sta->sdata,
345 				   "unexpected AddBA Req from %pM on tid %u\n",
346 				   sta->sta.addr, tid);
347 
348 		/* delete existing Rx BA session on the same tid */
349 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
350 					       WLAN_STATUS_UNSPECIFIED_QOS,
351 					       false);
352 	}
353 
354 	if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
355 		ret = drv_ampdu_action(local, sta->sdata, &params);
356 		ht_dbg(sta->sdata,
357 		       "Rx A-MPDU request on %pM tid %d result %d\n",
358 		       sta->sta.addr, tid, ret);
359 		if (!ret)
360 			status = WLAN_STATUS_SUCCESS;
361 		goto end;
362 	}
363 
364 	/* prepare A-MPDU MLME for Rx aggregation */
365 	tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
366 	if (!tid_agg_rx)
367 		goto end;
368 
369 	spin_lock_init(&tid_agg_rx->reorder_lock);
370 
371 	/* rx timer */
372 	timer_setup(&tid_agg_rx->session_timer,
373 		    sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
374 
375 	/* rx reorder timer */
376 	timer_setup(&tid_agg_rx->reorder_timer,
377 		    sta_rx_agg_reorder_timer_expired, 0);
378 
379 	/* prepare reordering buffer */
380 	tid_agg_rx->reorder_buf =
381 		kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
382 	tid_agg_rx->reorder_time =
383 		kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
384 	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
385 		kfree(tid_agg_rx->reorder_buf);
386 		kfree(tid_agg_rx->reorder_time);
387 		kfree(tid_agg_rx);
388 		goto end;
389 	}
390 
391 	for (i = 0; i < buf_size; i++)
392 		__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
393 
394 	ret = drv_ampdu_action(local, sta->sdata, &params);
395 	ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
396 	       sta->sta.addr, tid, ret);
397 	if (ret) {
398 		kfree(tid_agg_rx->reorder_buf);
399 		kfree(tid_agg_rx->reorder_time);
400 		kfree(tid_agg_rx);
401 		goto end;
402 	}
403 
404 	/* update data */
405 	tid_agg_rx->ssn = start_seq_num;
406 	tid_agg_rx->head_seq_num = start_seq_num;
407 	tid_agg_rx->buf_size = buf_size;
408 	tid_agg_rx->timeout = timeout;
409 	tid_agg_rx->stored_mpdu_num = 0;
410 	tid_agg_rx->auto_seq = auto_seq;
411 	tid_agg_rx->started = false;
412 	tid_agg_rx->reorder_buf_filtered = 0;
413 	tid_agg_rx->tid = tid;
414 	tid_agg_rx->sta = sta;
415 	status = WLAN_STATUS_SUCCESS;
416 
417 	/* activate it for RX */
418 	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
419 
420 	if (timeout) {
421 		mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
422 		tid_agg_rx->last_rx = jiffies;
423 	}
424 
425 end:
426 	if (status == WLAN_STATUS_SUCCESS) {
427 		__set_bit(tid, sta->ampdu_mlme.agg_session_valid);
428 		__clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
429 		sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
430 	}
431 
432 	if (tx)
433 		ieee80211_send_addba_resp(sta, sta->sta.addr, tid,
434 					  dialog_token, status, 1, buf_size,
435 					  timeout, addbaext);
436 }
437 
438 void ieee80211_process_addba_request(struct ieee80211_local *local,
439 				     struct sta_info *sta,
440 				     struct ieee80211_mgmt *mgmt,
441 				     size_t len)
442 {
443 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
444 	struct ieee802_11_elems *elems = NULL;
445 	u8 dialog_token;
446 	int ies_len;
447 
448 	/* extract session parameters from addba request frame */
449 	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
450 	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
451 	start_seq_num =
452 		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
453 
454 	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
455 	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
456 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
457 	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
458 
459 	ies_len = len - offsetof(struct ieee80211_mgmt,
460 				 u.action.u.addba_req.variable);
461 	if (ies_len) {
462 		elems = ieee802_11_parse_elems(mgmt->u.action.u.addba_req.variable,
463 					       ies_len, true, NULL);
464 		if (!elems || elems->parse_error)
465 			goto free;
466 	}
467 
468 	if (sta->sta.deflink.eht_cap.has_eht && elems && elems->addba_ext_ie) {
469 		u8 buf_size_1k = u8_get_bits(elems->addba_ext_ie->data,
470 					     IEEE80211_ADDBA_EXT_BUF_SIZE_MASK);
471 
472 		buf_size |= buf_size_1k << IEEE80211_ADDBA_EXT_BUF_SIZE_SHIFT;
473 	}
474 
475 	__ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
476 					start_seq_num, ba_policy, tid,
477 					buf_size, true, false,
478 					elems ? elems->addba_ext_ie : NULL);
479 free:
480 	kfree(elems);
481 }
482 
483 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
484 				 const u8 *addr, unsigned int tid)
485 {
486 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
487 	struct sta_info *sta;
488 
489 	rcu_read_lock();
490 	sta = sta_info_get_bss(sdata, addr);
491 	if (!sta)
492 		goto unlock;
493 
494 	set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
495 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
496  unlock:
497 	rcu_read_unlock();
498 }
499 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
500 
501 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
502 				   const u8 *addr, unsigned int tid)
503 {
504 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
505 	struct sta_info *sta;
506 
507 	rcu_read_lock();
508 	sta = sta_info_get_bss(sdata, addr);
509 	if (!sta)
510 		goto unlock;
511 
512 	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
513 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
514 
515  unlock:
516 	rcu_read_unlock();
517 }
518 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);
519