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
45static 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
58void __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
117void 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}
138EXPORT_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 */
144static 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
164static 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
173static 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
191static 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
245void __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
425end:
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
438void 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);
479free:
480	kfree(elems);
481}
482
483void 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}
499EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
500
501void 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}
518EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);
519