xref: /linux/net/mac80211/ocb.c (revision d603517771d8e08a2d8fc9e1f7682ce393d3973a)
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 - 2024, 2026 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 <linux/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  */
35 enum ocb_deferred_task_flags {
36 	OCB_WORK_HOUSEKEEPING,
37 };
38 
39 void 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 	if (!ifocb->joined)
51 		return;
52 
53 	/* XXX: Consider removing the least recently used entry and
54 	 *      allow new one to be added.
55 	 */
56 	if (local->num_sta >= IEEE80211_OCB_MAX_STA_ENTRIES) {
57 		net_info_ratelimited("%s: No room for a new OCB STA entry %pM\n",
58 				     sdata->name, addr);
59 		return;
60 	}
61 
62 	ocb_dbg(sdata, "Adding new OCB station %pM\n", addr);
63 
64 	rcu_read_lock();
65 	chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
66 	if (WARN_ON_ONCE(!chanctx_conf)) {
67 		rcu_read_unlock();
68 		return;
69 	}
70 	band = chanctx_conf->def.chan->band;
71 	rcu_read_unlock();
72 
73 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
74 	if (!sta)
75 		return;
76 
77 	/* Add only mandatory rates for now */
78 	sband = local->hw.wiphy->bands[band];
79 	sta->sta.deflink.supp_rates[band] = ieee80211_mandatory_rates(sband);
80 
81 	spin_lock(&ifocb->incomplete_lock);
82 	list_add(&sta->list, &ifocb->incomplete_stations);
83 	spin_unlock(&ifocb->incomplete_lock);
84 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
85 }
86 
87 static struct sta_info *ieee80211_ocb_finish_sta(struct sta_info *sta)
88 	__acquires(RCU)
89 {
90 	struct ieee80211_sub_if_data *sdata = sta->sdata;
91 	u8 addr[ETH_ALEN];
92 
93 	memcpy(addr, sta->sta.addr, ETH_ALEN);
94 
95 	ieee80211_sta_init_nss_bw_capa(&sta->deflink,
96 				       &sdata->deflink.conf->chanreq.oper);
97 
98 	ocb_dbg(sdata, "Adding new IBSS station %pM (dev=%s)\n",
99 		addr, sdata->name);
100 
101 	sta_info_move_state(sta, IEEE80211_STA_AUTH);
102 	sta_info_move_state(sta, IEEE80211_STA_ASSOC);
103 	sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
104 
105 	rate_control_rate_init(&sta->deflink);
106 
107 	/* If it fails, maybe we raced another insertion? */
108 	if (sta_info_insert_rcu(sta))
109 		return sta_info_get(sdata, addr);
110 	return sta;
111 }
112 
113 static void ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data *sdata)
114 {
115 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
116 
117 	ocb_dbg(sdata, "Running ocb housekeeping\n");
118 
119 	ieee80211_sta_expire(sdata, IEEE80211_OCB_PEER_INACTIVITY_LIMIT);
120 
121 	mod_timer(&ifocb->housekeeping_timer,
122 		  round_jiffies(jiffies + IEEE80211_OCB_HOUSEKEEPING_INTERVAL));
123 }
124 
125 void ieee80211_ocb_work(struct ieee80211_sub_if_data *sdata)
126 {
127 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
128 	struct sta_info *sta;
129 
130 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
131 
132 	if (ifocb->joined != true)
133 		return;
134 
135 	spin_lock_bh(&ifocb->incomplete_lock);
136 	while (!list_empty(&ifocb->incomplete_stations)) {
137 		sta = list_first_entry(&ifocb->incomplete_stations,
138 				       struct sta_info, list);
139 		list_del(&sta->list);
140 		spin_unlock_bh(&ifocb->incomplete_lock);
141 
142 		ieee80211_ocb_finish_sta(sta);
143 		rcu_read_unlock();
144 		spin_lock_bh(&ifocb->incomplete_lock);
145 	}
146 	spin_unlock_bh(&ifocb->incomplete_lock);
147 
148 	if (test_and_clear_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags))
149 		ieee80211_ocb_housekeeping(sdata);
150 }
151 
152 static void ieee80211_ocb_housekeeping_timer(struct timer_list *t)
153 {
154 	struct ieee80211_sub_if_data *sdata =
155 		timer_container_of(sdata, t, u.ocb.housekeeping_timer);
156 	struct ieee80211_local *local = sdata->local;
157 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
158 
159 	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
160 
161 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
162 }
163 
164 void ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data *sdata)
165 {
166 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
167 
168 	timer_setup(&ifocb->housekeeping_timer,
169 		    ieee80211_ocb_housekeeping_timer, 0);
170 	INIT_LIST_HEAD(&ifocb->incomplete_stations);
171 	spin_lock_init(&ifocb->incomplete_lock);
172 }
173 
174 int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
175 		       struct ocb_setup *setup)
176 {
177 	struct ieee80211_chan_req chanreq = { .oper = setup->chandef };
178 	struct ieee80211_local *local = sdata->local;
179 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
180 	u64 changed = BSS_CHANGED_OCB | BSS_CHANGED_BSSID;
181 	int err;
182 
183 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
184 
185 	if (ifocb->joined == true)
186 		return -EINVAL;
187 
188 	sdata->deflink.operating_11g_mode = true;
189 	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
190 	sdata->deflink.needed_rx_chains = sdata->local->rx_chains;
191 
192 	err = ieee80211_link_use_channel(&sdata->deflink, &chanreq,
193 					 IEEE80211_CHANCTX_SHARED);
194 	if (err)
195 		return err;
196 
197 	ieee80211_bss_info_change_notify(sdata, changed);
198 
199 	ifocb->joined = true;
200 
201 	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
202 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
203 
204 	netif_carrier_on(sdata->dev);
205 	return 0;
206 }
207 
208 int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
209 {
210 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
211 	struct ieee80211_local *local = sdata->local;
212 	struct sta_info *sta;
213 
214 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
215 
216 	ifocb->joined = false;
217 	sta_info_flush(sdata, -1);
218 
219 	spin_lock_bh(&ifocb->incomplete_lock);
220 	while (!list_empty(&ifocb->incomplete_stations)) {
221 		sta = list_first_entry(&ifocb->incomplete_stations,
222 				       struct sta_info, list);
223 		list_del(&sta->list);
224 		spin_unlock_bh(&ifocb->incomplete_lock);
225 
226 		sta_info_free(local, sta);
227 		spin_lock_bh(&ifocb->incomplete_lock);
228 	}
229 	spin_unlock_bh(&ifocb->incomplete_lock);
230 
231 	netif_carrier_off(sdata->dev);
232 	clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
233 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_OCB);
234 
235 	ieee80211_link_release_channel(&sdata->deflink);
236 
237 	skb_queue_purge(&sdata->skb_queue);
238 
239 	timer_delete_sync(&sdata->u.ocb.housekeeping_timer);
240 	/* If the timer fired while we waited for it, it will have
241 	 * requeued the work. Now the work will be running again
242 	 * but will not rearm the timer again because it checks
243 	 * whether we are connected to the network or not -- at this
244 	 * point we shouldn't be anymore.
245 	 */
246 
247 	return 0;
248 }
249