xref: /linux/net/mac80211/agg-rx.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 = ieee80211_mgmt_ba(skb, da, sdata);
211 
212 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
213 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
214 	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
215 	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
216 
217 	capab = u16_encode_bits(amsdu, IEEE80211_ADDBA_PARAM_AMSDU_MASK);
218 	capab |= u16_encode_bits(policy, IEEE80211_ADDBA_PARAM_POLICY_MASK);
219 	capab |= u16_encode_bits(tid, IEEE80211_ADDBA_PARAM_TID_MASK);
220 	capab |= u16_encode_bits(buf_size, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
221 
222 	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
223 	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
224 	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
225 
226 	if (sta->sta.deflink.he_cap.has_he && addbaext)
227 		ieee80211_add_addbaext(sdata, skb, addbaext, buf_size);
228 
229 	ieee80211_tx_skb(sdata, skb);
230 }
231 
232 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
233 				     u8 dialog_token, u16 timeout,
234 				     u16 start_seq_num, u16 ba_policy, u16 tid,
235 				     u16 buf_size, bool tx, bool auto_seq,
236 				     const struct ieee80211_addba_ext_ie *addbaext)
237 {
238 	struct ieee80211_local *local = sta->sdata->local;
239 	struct tid_ampdu_rx *tid_agg_rx;
240 	struct ieee80211_ampdu_params params = {
241 		.sta = &sta->sta,
242 		.action = IEEE80211_AMPDU_RX_START,
243 		.tid = tid,
244 		.amsdu = false,
245 		.timeout = timeout,
246 		.ssn = start_seq_num,
247 	};
248 	int i, ret = -EOPNOTSUPP;
249 	u16 status = WLAN_STATUS_REQUEST_DECLINED;
250 	u16 max_buf_size;
251 
252 	lockdep_assert_wiphy(sta->local->hw.wiphy);
253 
254 	if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
255 		ht_dbg(sta->sdata,
256 		       "STA %pM requests BA session on unsupported tid %d\n",
257 		       sta->sta.addr, tid);
258 		goto end;
259 	}
260 
261 	if (!sta->sta.deflink.ht_cap.ht_supported &&
262 	    !sta->sta.deflink.he_cap.has_he) {
263 		ht_dbg(sta->sdata,
264 		       "STA %pM erroneously requests BA session on tid %d w/o HT\n",
265 		       sta->sta.addr, tid);
266 		/* send a response anyway, it's an error case if we get here */
267 		goto end;
268 	}
269 
270 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
271 		ht_dbg(sta->sdata,
272 		       "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
273 		       sta->sta.addr, tid);
274 		goto end;
275 	}
276 
277 	if (sta->sta.deflink.eht_cap.has_eht)
278 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_EHT;
279 	else if (sta->sta.deflink.he_cap.has_he)
280 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_HE;
281 	else
282 		max_buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
283 
284 	/* sanity check for incoming parameters:
285 	 * check if configuration can support the BA policy
286 	 * and if buffer size does not exceeds max value */
287 	/* XXX: check own ht delayed BA capability?? */
288 	if (((ba_policy != 1) &&
289 	     (!(sta->sta.deflink.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
290 	    (buf_size > max_buf_size)) {
291 		status = WLAN_STATUS_INVALID_QOS_PARAM;
292 		ht_dbg_ratelimited(sta->sdata,
293 				   "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
294 				   sta->sta.addr, tid, ba_policy, buf_size);
295 		goto end;
296 	}
297 	/* determine default buffer size */
298 	if (buf_size == 0)
299 		buf_size = max_buf_size;
300 
301 	/* make sure the size doesn't exceed the maximum supported by the hw */
302 	if (buf_size > sta->sta.max_rx_aggregation_subframes)
303 		buf_size = sta->sta.max_rx_aggregation_subframes;
304 	params.buf_size = buf_size;
305 
306 	ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
307 	       buf_size, sta->sta.addr);
308 
309 	if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
310 		if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
311 			struct tid_ampdu_rx *tid_rx;
312 
313 			ht_dbg_ratelimited(sta->sdata,
314 					   "updated AddBA Req from %pM on tid %u\n",
315 					   sta->sta.addr, tid);
316 			/* We have no API to update the timeout value in the
317 			 * driver so reject the timeout update if the timeout
318 			 * changed. If it did not change, i.e., no real update,
319 			 * just reply with success.
320 			 */
321 			rcu_read_lock();
322 			tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
323 			if (tid_rx && tid_rx->timeout == timeout)
324 				status = WLAN_STATUS_SUCCESS;
325 			else
326 				status = WLAN_STATUS_REQUEST_DECLINED;
327 			rcu_read_unlock();
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 	timer_setup(&tid_agg_rx->session_timer,
360 		    sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
361 
362 	/* rx reorder timer */
363 	timer_setup(&tid_agg_rx->reorder_timer,
364 		    sta_rx_agg_reorder_timer_expired, 0);
365 
366 	/* prepare reordering buffer */
367 	tid_agg_rx->reorder_buf =
368 		kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
369 	tid_agg_rx->reorder_time =
370 		kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
371 	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
372 		kfree(tid_agg_rx->reorder_buf);
373 		kfree(tid_agg_rx->reorder_time);
374 		kfree(tid_agg_rx);
375 		goto end;
376 	}
377 
378 	for (i = 0; i < buf_size; i++)
379 		__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
380 
381 	ret = drv_ampdu_action(local, sta->sdata, &params);
382 	ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
383 	       sta->sta.addr, tid, ret);
384 	if (ret) {
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 	/* update data */
392 	tid_agg_rx->ssn = start_seq_num;
393 	tid_agg_rx->head_seq_num = start_seq_num;
394 	tid_agg_rx->buf_size = buf_size;
395 	tid_agg_rx->timeout = timeout;
396 	tid_agg_rx->stored_mpdu_num = 0;
397 	tid_agg_rx->auto_seq = auto_seq;
398 	tid_agg_rx->started = false;
399 	tid_agg_rx->reorder_buf_filtered = 0;
400 	tid_agg_rx->tid = tid;
401 	tid_agg_rx->sta = sta;
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, sta->sta.addr, tid,
421 					  dialog_token, status, 1, buf_size,
422 					  timeout, addbaext);
423 }
424 
425 void ieee80211_process_addba_request(struct ieee80211_local *local,
426 				     struct sta_info *sta,
427 				     struct ieee80211_mgmt *mgmt,
428 				     size_t len)
429 {
430 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
431 	struct ieee802_11_elems *elems = NULL;
432 	u8 dialog_token;
433 	int ies_len;
434 
435 	/* extract session parameters from addba request frame */
436 	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
437 	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
438 	start_seq_num =
439 		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
440 
441 	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
442 	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
443 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
444 	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
445 
446 	ies_len = len - offsetof(struct ieee80211_mgmt,
447 				 u.action.u.addba_req.variable);
448 	if (ies_len) {
449 		elems = ieee802_11_parse_elems(mgmt->u.action.u.addba_req.variable,
450 					       ies_len, true, NULL);
451 		if (!elems || elems->parse_error)
452 			goto free;
453 	}
454 
455 	if (sta->sta.deflink.eht_cap.has_eht && elems && elems->addba_ext_ie) {
456 		u8 buf_size_1k = u8_get_bits(elems->addba_ext_ie->data,
457 					     IEEE80211_ADDBA_EXT_BUF_SIZE_MASK);
458 
459 		buf_size |= buf_size_1k << IEEE80211_ADDBA_EXT_BUF_SIZE_SHIFT;
460 	}
461 
462 	__ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
463 					start_seq_num, ba_policy, tid,
464 					buf_size, true, false,
465 					elems ? elems->addba_ext_ie : NULL);
466 free:
467 	kfree(elems);
468 }
469 
470 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
471 				 const u8 *addr, unsigned int tid)
472 {
473 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
474 	struct sta_info *sta;
475 
476 	rcu_read_lock();
477 	sta = sta_info_get_bss(sdata, addr);
478 	if (!sta)
479 		goto unlock;
480 
481 	set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
482 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
483  unlock:
484 	rcu_read_unlock();
485 }
486 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
487 
488 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
489 				   const u8 *addr, unsigned int tid)
490 {
491 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
492 	struct sta_info *sta;
493 
494 	rcu_read_lock();
495 	sta = sta_info_get_bss(sdata, addr);
496 	if (!sta)
497 		goto unlock;
498 
499 	set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
500 	wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
501 
502  unlock:
503 	rcu_read_unlock();
504 }
505 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);
506