xref: /linux/net/mac80211/ocb.c (revision ab58a2f319de945f631150a190653a90e307df8e)
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  */
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 	/* 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 
84 static 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 
107 static 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 
119 void 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 
146 static 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 
158 void 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 
168 int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
169 		       struct ocb_setup *setup)
170 {
171 	struct ieee80211_local *local = sdata->local;
172 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
173 	u64 changed = BSS_CHANGED_OCB | BSS_CHANGED_BSSID;
174 	int err;
175 
176 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
177 
178 	if (ifocb->joined == true)
179 		return -EINVAL;
180 
181 	sdata->deflink.operating_11g_mode = true;
182 	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
183 	sdata->deflink.needed_rx_chains = sdata->local->rx_chains;
184 
185 	err = ieee80211_link_use_channel(&sdata->deflink, &setup->chandef,
186 					 IEEE80211_CHANCTX_SHARED);
187 	if (err)
188 		return err;
189 
190 	ieee80211_bss_info_change_notify(sdata, changed);
191 
192 	ifocb->joined = true;
193 
194 	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
195 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
196 
197 	netif_carrier_on(sdata->dev);
198 	return 0;
199 }
200 
201 int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
202 {
203 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
204 	struct ieee80211_local *local = sdata->local;
205 	struct sta_info *sta;
206 
207 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
208 
209 	ifocb->joined = false;
210 	sta_info_flush(sdata);
211 
212 	spin_lock_bh(&ifocb->incomplete_lock);
213 	while (!list_empty(&ifocb->incomplete_stations)) {
214 		sta = list_first_entry(&ifocb->incomplete_stations,
215 				       struct sta_info, list);
216 		list_del(&sta->list);
217 		spin_unlock_bh(&ifocb->incomplete_lock);
218 
219 		sta_info_free(local, sta);
220 		spin_lock_bh(&ifocb->incomplete_lock);
221 	}
222 	spin_unlock_bh(&ifocb->incomplete_lock);
223 
224 	netif_carrier_off(sdata->dev);
225 	clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
226 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_OCB);
227 
228 	ieee80211_link_release_channel(&sdata->deflink);
229 
230 	skb_queue_purge(&sdata->skb_queue);
231 
232 	del_timer_sync(&sdata->u.ocb.housekeeping_timer);
233 	/* If the timer fired while we waited for it, it will have
234 	 * requeued the work. Now the work will be running again
235 	 * but will not rearm the timer again because it checks
236 	 * whether we are connected to the network or not -- at this
237 	 * point we shouldn't be anymore.
238 	 */
239 
240 	return 0;
241 }
242