1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OCB mode implementation
4 *
5 * Copyright: (c) 2014 Czech Technical University in Prague
6 *            (c) 2014 Volkswagen Group Research
7 * Copyright (C) 2022 - 2023 Intel Corporation
8 * Author:    Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
9 * Funded by: Volkswagen Group Research
10 */
11
12#include <linux/delay.h>
13#include <linux/if_ether.h>
14#include <linux/skbuff.h>
15#include <linux/if_arp.h>
16#include <linux/etherdevice.h>
17#include <linux/rtnetlink.h>
18#include <net/mac80211.h>
19#include <asm/unaligned.h>
20
21#include "ieee80211_i.h"
22#include "driver-ops.h"
23#include "rate.h"
24
25#define IEEE80211_OCB_HOUSEKEEPING_INTERVAL		(60 * HZ)
26#define IEEE80211_OCB_PEER_INACTIVITY_LIMIT		(240 * HZ)
27#define IEEE80211_OCB_MAX_STA_ENTRIES			128
28
29/**
30 * enum ocb_deferred_task_flags - mac80211 OCB deferred tasks
31 * @OCB_WORK_HOUSEKEEPING: run the periodic OCB housekeeping tasks
32 *
33 * These flags are used in @wrkq_flags field of &struct ieee80211_if_ocb
34 */
35enum ocb_deferred_task_flags {
36	OCB_WORK_HOUSEKEEPING,
37};
38
39void ieee80211_ocb_rx_no_sta(struct ieee80211_sub_if_data *sdata,
40			     const u8 *bssid, const u8 *addr,
41			     u32 supp_rates)
42{
43	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
44	struct ieee80211_local *local = sdata->local;
45	struct ieee80211_chanctx_conf *chanctx_conf;
46	struct ieee80211_supported_band *sband;
47	struct sta_info *sta;
48	int band;
49
50	/* XXX: Consider removing the least recently used entry and
51	 *      allow new one to be added.
52	 */
53	if (local->num_sta >= IEEE80211_OCB_MAX_STA_ENTRIES) {
54		net_info_ratelimited("%s: No room for a new OCB STA entry %pM\n",
55				     sdata->name, addr);
56		return;
57	}
58
59	ocb_dbg(sdata, "Adding new OCB station %pM\n", addr);
60
61	rcu_read_lock();
62	chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
63	if (WARN_ON_ONCE(!chanctx_conf)) {
64		rcu_read_unlock();
65		return;
66	}
67	band = chanctx_conf->def.chan->band;
68	rcu_read_unlock();
69
70	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
71	if (!sta)
72		return;
73
74	/* Add only mandatory rates for now */
75	sband = local->hw.wiphy->bands[band];
76	sta->sta.deflink.supp_rates[band] = ieee80211_mandatory_rates(sband);
77
78	spin_lock(&ifocb->incomplete_lock);
79	list_add(&sta->list, &ifocb->incomplete_stations);
80	spin_unlock(&ifocb->incomplete_lock);
81	wiphy_work_queue(local->hw.wiphy, &sdata->work);
82}
83
84static struct sta_info *ieee80211_ocb_finish_sta(struct sta_info *sta)
85	__acquires(RCU)
86{
87	struct ieee80211_sub_if_data *sdata = sta->sdata;
88	u8 addr[ETH_ALEN];
89
90	memcpy(addr, sta->sta.addr, ETH_ALEN);
91
92	ocb_dbg(sdata, "Adding new IBSS station %pM (dev=%s)\n",
93		addr, sdata->name);
94
95	sta_info_move_state(sta, IEEE80211_STA_AUTH);
96	sta_info_move_state(sta, IEEE80211_STA_ASSOC);
97	sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
98
99	rate_control_rate_init(sta);
100
101	/* If it fails, maybe we raced another insertion? */
102	if (sta_info_insert_rcu(sta))
103		return sta_info_get(sdata, addr);
104	return sta;
105}
106
107static void ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data *sdata)
108{
109	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
110
111	ocb_dbg(sdata, "Running ocb housekeeping\n");
112
113	ieee80211_sta_expire(sdata, IEEE80211_OCB_PEER_INACTIVITY_LIMIT);
114
115	mod_timer(&ifocb->housekeeping_timer,
116		  round_jiffies(jiffies + IEEE80211_OCB_HOUSEKEEPING_INTERVAL));
117}
118
119void ieee80211_ocb_work(struct ieee80211_sub_if_data *sdata)
120{
121	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
122	struct sta_info *sta;
123
124	lockdep_assert_wiphy(sdata->local->hw.wiphy);
125
126	if (ifocb->joined != true)
127		return;
128
129	spin_lock_bh(&ifocb->incomplete_lock);
130	while (!list_empty(&ifocb->incomplete_stations)) {
131		sta = list_first_entry(&ifocb->incomplete_stations,
132				       struct sta_info, list);
133		list_del(&sta->list);
134		spin_unlock_bh(&ifocb->incomplete_lock);
135
136		ieee80211_ocb_finish_sta(sta);
137		rcu_read_unlock();
138		spin_lock_bh(&ifocb->incomplete_lock);
139	}
140	spin_unlock_bh(&ifocb->incomplete_lock);
141
142	if (test_and_clear_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags))
143		ieee80211_ocb_housekeeping(sdata);
144}
145
146static void ieee80211_ocb_housekeeping_timer(struct timer_list *t)
147{
148	struct ieee80211_sub_if_data *sdata =
149		from_timer(sdata, t, u.ocb.housekeeping_timer);
150	struct ieee80211_local *local = sdata->local;
151	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
152
153	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
154
155	wiphy_work_queue(local->hw.wiphy, &sdata->work);
156}
157
158void ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data *sdata)
159{
160	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
161
162	timer_setup(&ifocb->housekeeping_timer,
163		    ieee80211_ocb_housekeeping_timer, 0);
164	INIT_LIST_HEAD(&ifocb->incomplete_stations);
165	spin_lock_init(&ifocb->incomplete_lock);
166}
167
168int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
169		       struct ocb_setup *setup)
170{
171	struct ieee80211_chan_req chanreq = { .oper = setup->chandef };
172	struct ieee80211_local *local = sdata->local;
173	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
174	u64 changed = BSS_CHANGED_OCB | BSS_CHANGED_BSSID;
175	int err;
176
177	lockdep_assert_wiphy(sdata->local->hw.wiphy);
178
179	if (ifocb->joined == true)
180		return -EINVAL;
181
182	sdata->deflink.operating_11g_mode = true;
183	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
184	sdata->deflink.needed_rx_chains = sdata->local->rx_chains;
185
186	err = ieee80211_link_use_channel(&sdata->deflink, &chanreq,
187					 IEEE80211_CHANCTX_SHARED);
188	if (err)
189		return err;
190
191	ieee80211_bss_info_change_notify(sdata, changed);
192
193	ifocb->joined = true;
194
195	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
196	wiphy_work_queue(local->hw.wiphy, &sdata->work);
197
198	netif_carrier_on(sdata->dev);
199	return 0;
200}
201
202int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
203{
204	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
205	struct ieee80211_local *local = sdata->local;
206	struct sta_info *sta;
207
208	lockdep_assert_wiphy(sdata->local->hw.wiphy);
209
210	ifocb->joined = false;
211	sta_info_flush(sdata, -1);
212
213	spin_lock_bh(&ifocb->incomplete_lock);
214	while (!list_empty(&ifocb->incomplete_stations)) {
215		sta = list_first_entry(&ifocb->incomplete_stations,
216				       struct sta_info, list);
217		list_del(&sta->list);
218		spin_unlock_bh(&ifocb->incomplete_lock);
219
220		sta_info_free(local, sta);
221		spin_lock_bh(&ifocb->incomplete_lock);
222	}
223	spin_unlock_bh(&ifocb->incomplete_lock);
224
225	netif_carrier_off(sdata->dev);
226	clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
227	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_OCB);
228
229	ieee80211_link_release_channel(&sdata->deflink);
230
231	skb_queue_purge(&sdata->skb_queue);
232
233	del_timer_sync(&sdata->u.ocb.housekeeping_timer);
234	/* If the timer fired while we waited for it, it will have
235	 * requeued the work. Now the work will be running again
236	 * but will not rearm the timer again because it checks
237	 * whether we are connected to the network or not -- at this
238	 * point we shouldn't be anymore.
239	 */
240
241	return 0;
242}
243