xref: /openbmc/linux/net/mac80211/ocb.c (revision 9aa2cba7)
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 	enum nl80211_bss_scan_width scan_width;
48 	struct sta_info *sta;
49 	int band;
50 
51 	/* XXX: Consider removing the least recently used entry and
52 	 *      allow new one to be added.
53 	 */
54 	if (local->num_sta >= IEEE80211_OCB_MAX_STA_ENTRIES) {
55 		net_info_ratelimited("%s: No room for a new OCB STA entry %pM\n",
56 				     sdata->name, addr);
57 		return;
58 	}
59 
60 	ocb_dbg(sdata, "Adding new OCB station %pM\n", addr);
61 
62 	rcu_read_lock();
63 	chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
64 	if (WARN_ON_ONCE(!chanctx_conf)) {
65 		rcu_read_unlock();
66 		return;
67 	}
68 	band = chanctx_conf->def.chan->band;
69 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
70 	rcu_read_unlock();
71 
72 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
73 	if (!sta)
74 		return;
75 
76 	/* Add only mandatory rates for now */
77 	sband = local->hw.wiphy->bands[band];
78 	sta->sta.deflink.supp_rates[band] =
79 		ieee80211_mandatory_rates(sband, scan_width);
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 	ocb_dbg(sdata, "Adding new IBSS station %pM (dev=%s)\n",
96 		addr, sdata->name);
97 
98 	sta_info_move_state(sta, IEEE80211_STA_AUTH);
99 	sta_info_move_state(sta, IEEE80211_STA_ASSOC);
100 	sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
101 
102 	rate_control_rate_init(sta);
103 
104 	/* If it fails, maybe we raced another insertion? */
105 	if (sta_info_insert_rcu(sta))
106 		return sta_info_get(sdata, addr);
107 	return sta;
108 }
109 
110 static void ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data *sdata)
111 {
112 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
113 
114 	ocb_dbg(sdata, "Running ocb housekeeping\n");
115 
116 	ieee80211_sta_expire(sdata, IEEE80211_OCB_PEER_INACTIVITY_LIMIT);
117 
118 	mod_timer(&ifocb->housekeeping_timer,
119 		  round_jiffies(jiffies + IEEE80211_OCB_HOUSEKEEPING_INTERVAL));
120 }
121 
122 void ieee80211_ocb_work(struct ieee80211_sub_if_data *sdata)
123 {
124 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
125 	struct sta_info *sta;
126 
127 	if (ifocb->joined != true)
128 		return;
129 
130 	sdata_lock(sdata);
131 
132 	spin_lock_bh(&ifocb->incomplete_lock);
133 	while (!list_empty(&ifocb->incomplete_stations)) {
134 		sta = list_first_entry(&ifocb->incomplete_stations,
135 				       struct sta_info, list);
136 		list_del(&sta->list);
137 		spin_unlock_bh(&ifocb->incomplete_lock);
138 
139 		ieee80211_ocb_finish_sta(sta);
140 		rcu_read_unlock();
141 		spin_lock_bh(&ifocb->incomplete_lock);
142 	}
143 	spin_unlock_bh(&ifocb->incomplete_lock);
144 
145 	if (test_and_clear_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags))
146 		ieee80211_ocb_housekeeping(sdata);
147 
148 	sdata_unlock(sdata);
149 }
150 
151 static void ieee80211_ocb_housekeeping_timer(struct timer_list *t)
152 {
153 	struct ieee80211_sub_if_data *sdata =
154 		from_timer(sdata, t, u.ocb.housekeeping_timer);
155 	struct ieee80211_local *local = sdata->local;
156 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
157 
158 	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
159 
160 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
161 }
162 
163 void ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data *sdata)
164 {
165 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
166 
167 	timer_setup(&ifocb->housekeeping_timer,
168 		    ieee80211_ocb_housekeeping_timer, 0);
169 	INIT_LIST_HEAD(&ifocb->incomplete_stations);
170 	spin_lock_init(&ifocb->incomplete_lock);
171 }
172 
173 int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
174 		       struct ocb_setup *setup)
175 {
176 	struct ieee80211_local *local = sdata->local;
177 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
178 	u64 changed = BSS_CHANGED_OCB | BSS_CHANGED_BSSID;
179 	int err;
180 
181 	if (ifocb->joined == true)
182 		return -EINVAL;
183 
184 	sdata->deflink.operating_11g_mode = true;
185 	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
186 	sdata->deflink.needed_rx_chains = sdata->local->rx_chains;
187 
188 	mutex_lock(&sdata->local->mtx);
189 	err = ieee80211_link_use_channel(&sdata->deflink, &setup->chandef,
190 					 IEEE80211_CHANCTX_SHARED);
191 	mutex_unlock(&sdata->local->mtx);
192 	if (err)
193 		return err;
194 
195 	ieee80211_bss_info_change_notify(sdata, changed);
196 
197 	ifocb->joined = true;
198 
199 	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
200 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
201 
202 	netif_carrier_on(sdata->dev);
203 	return 0;
204 }
205 
206 int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
207 {
208 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
209 	struct ieee80211_local *local = sdata->local;
210 	struct sta_info *sta;
211 
212 	ifocb->joined = false;
213 	sta_info_flush(sdata);
214 
215 	spin_lock_bh(&ifocb->incomplete_lock);
216 	while (!list_empty(&ifocb->incomplete_stations)) {
217 		sta = list_first_entry(&ifocb->incomplete_stations,
218 				       struct sta_info, list);
219 		list_del(&sta->list);
220 		spin_unlock_bh(&ifocb->incomplete_lock);
221 
222 		sta_info_free(local, sta);
223 		spin_lock_bh(&ifocb->incomplete_lock);
224 	}
225 	spin_unlock_bh(&ifocb->incomplete_lock);
226 
227 	netif_carrier_off(sdata->dev);
228 	clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
229 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_OCB);
230 
231 	mutex_lock(&sdata->local->mtx);
232 	ieee80211_link_release_channel(&sdata->deflink);
233 	mutex_unlock(&sdata->local->mtx);
234 
235 	skb_queue_purge(&sdata->skb_queue);
236 
237 	del_timer_sync(&sdata->u.ocb.housekeeping_timer);
238 	/* If the timer fired while we waited for it, it will have
239 	 * requeued the work. Now the work will be running again
240 	 * but will not rearm the timer again because it checks
241 	 * whether we are connected to the network or not -- at this
242 	 * point we shouldn't be anymore.
243 	 */
244 
245 	return 0;
246 }
247