xref: /linux/net/mac80211/ocb.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * OCB mode implementation
3  *
4  * Copyright: (c) 2014 Czech Technical University in Prague
5  *            (c) 2014 Volkswagen Group Research
6  * Author:    Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
7  * Funded by: Volkswagen Group Research
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/delay.h>
15 #include <linux/if_ether.h>
16 #include <linux/skbuff.h>
17 #include <linux/if_arp.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
20 #include <net/mac80211.h>
21 #include <asm/unaligned.h>
22 
23 #include "ieee80211_i.h"
24 #include "driver-ops.h"
25 #include "rate.h"
26 
27 #define IEEE80211_OCB_HOUSEKEEPING_INTERVAL		(60 * HZ)
28 #define IEEE80211_OCB_PEER_INACTIVITY_LIMIT		(240 * HZ)
29 #define IEEE80211_OCB_MAX_STA_ENTRIES			128
30 
31 /**
32  * enum ocb_deferred_task_flags - mac80211 OCB deferred tasks
33  * @OCB_WORK_HOUSEKEEPING: run the periodic OCB housekeeping tasks
34  *
35  * These flags are used in @wrkq_flags field of &struct ieee80211_if_ocb
36  */
37 enum ocb_deferred_task_flags {
38 	OCB_WORK_HOUSEKEEPING,
39 };
40 
41 void ieee80211_ocb_rx_no_sta(struct ieee80211_sub_if_data *sdata,
42 			     const u8 *bssid, const u8 *addr,
43 			     u32 supp_rates)
44 {
45 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
46 	struct ieee80211_local *local = sdata->local;
47 	struct ieee80211_chanctx_conf *chanctx_conf;
48 	struct ieee80211_supported_band *sband;
49 	enum nl80211_bss_scan_width scan_width;
50 	struct sta_info *sta;
51 	int band;
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.chanctx_conf);
66 	if (WARN_ON_ONCE(!chanctx_conf)) {
67 		rcu_read_unlock();
68 		return;
69 	}
70 	band = chanctx_conf->def.chan->band;
71 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
72 	rcu_read_unlock();
73 
74 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
75 	if (!sta)
76 		return;
77 
78 	sta->last_rx = jiffies;
79 
80 	/* Add only mandatory rates for now */
81 	sband = local->hw.wiphy->bands[band];
82 	sta->sta.supp_rates[band] =
83 		ieee80211_mandatory_rates(sband, scan_width);
84 
85 	spin_lock(&ifocb->incomplete_lock);
86 	list_add(&sta->list, &ifocb->incomplete_stations);
87 	spin_unlock(&ifocb->incomplete_lock);
88 	ieee80211_queue_work(&local->hw, &sdata->work);
89 }
90 
91 static struct sta_info *ieee80211_ocb_finish_sta(struct sta_info *sta)
92 	__acquires(RCU)
93 {
94 	struct ieee80211_sub_if_data *sdata = sta->sdata;
95 	u8 addr[ETH_ALEN];
96 
97 	memcpy(addr, sta->sta.addr, ETH_ALEN);
98 
99 	ocb_dbg(sdata, "Adding new IBSS station %pM (dev=%s)\n",
100 		addr, sdata->name);
101 
102 	sta_info_move_state(sta, IEEE80211_STA_AUTH);
103 	sta_info_move_state(sta, IEEE80211_STA_ASSOC);
104 	sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
105 
106 	rate_control_rate_init(sta);
107 
108 	/* If it fails, maybe we raced another insertion? */
109 	if (sta_info_insert_rcu(sta))
110 		return sta_info_get(sdata, addr);
111 	return sta;
112 }
113 
114 static void ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data *sdata)
115 {
116 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
117 
118 	ocb_dbg(sdata, "Running ocb housekeeping\n");
119 
120 	ieee80211_sta_expire(sdata, IEEE80211_OCB_PEER_INACTIVITY_LIMIT);
121 
122 	mod_timer(&ifocb->housekeeping_timer,
123 		  round_jiffies(jiffies + IEEE80211_OCB_HOUSEKEEPING_INTERVAL));
124 }
125 
126 void ieee80211_ocb_work(struct ieee80211_sub_if_data *sdata)
127 {
128 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
129 	struct sta_info *sta;
130 
131 	if (ifocb->joined != true)
132 		return;
133 
134 	sdata_lock(sdata);
135 
136 	spin_lock_bh(&ifocb->incomplete_lock);
137 	while (!list_empty(&ifocb->incomplete_stations)) {
138 		sta = list_first_entry(&ifocb->incomplete_stations,
139 				       struct sta_info, list);
140 		list_del(&sta->list);
141 		spin_unlock_bh(&ifocb->incomplete_lock);
142 
143 		ieee80211_ocb_finish_sta(sta);
144 		rcu_read_unlock();
145 		spin_lock_bh(&ifocb->incomplete_lock);
146 	}
147 	spin_unlock_bh(&ifocb->incomplete_lock);
148 
149 	if (test_and_clear_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags))
150 		ieee80211_ocb_housekeeping(sdata);
151 
152 	sdata_unlock(sdata);
153 }
154 
155 static void ieee80211_ocb_housekeeping_timer(unsigned long data)
156 {
157 	struct ieee80211_sub_if_data *sdata = (void *)data;
158 	struct ieee80211_local *local = sdata->local;
159 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
160 
161 	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
162 
163 	ieee80211_queue_work(&local->hw, &sdata->work);
164 }
165 
166 void ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data *sdata)
167 {
168 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
169 
170 	setup_timer(&ifocb->housekeeping_timer,
171 		    ieee80211_ocb_housekeeping_timer,
172 		    (unsigned long)sdata);
173 	INIT_LIST_HEAD(&ifocb->incomplete_stations);
174 	spin_lock_init(&ifocb->incomplete_lock);
175 }
176 
177 int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
178 		       struct ocb_setup *setup)
179 {
180 	struct ieee80211_local *local = sdata->local;
181 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
182 	u32 changed = BSS_CHANGED_OCB | BSS_CHANGED_BSSID;
183 	int err;
184 
185 	if (ifocb->joined == true)
186 		return -EINVAL;
187 
188 	sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
189 	sdata->smps_mode = IEEE80211_SMPS_OFF;
190 	sdata->needed_rx_chains = sdata->local->rx_chains;
191 
192 	mutex_lock(&sdata->local->mtx);
193 	err = ieee80211_vif_use_channel(sdata, &setup->chandef,
194 					IEEE80211_CHANCTX_SHARED);
195 	mutex_unlock(&sdata->local->mtx);
196 	if (err)
197 		return err;
198 
199 	ieee80211_bss_info_change_notify(sdata, changed);
200 
201 	ifocb->joined = true;
202 
203 	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
204 	ieee80211_queue_work(&local->hw, &sdata->work);
205 
206 	netif_carrier_on(sdata->dev);
207 	return 0;
208 }
209 
210 int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
211 {
212 	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
213 	struct ieee80211_local *local = sdata->local;
214 	struct sta_info *sta;
215 
216 	ifocb->joined = false;
217 	sta_info_flush(sdata);
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 	mutex_lock(&sdata->local->mtx);
236 	ieee80211_vif_release_channel(sdata);
237 	mutex_unlock(&sdata->local->mtx);
238 
239 	skb_queue_purge(&sdata->skb_queue);
240 
241 	del_timer_sync(&sdata->u.ocb.housekeeping_timer);
242 	/* If the timer fired while we waited for it, it will have
243 	 * requeued the work. Now the work will be running again
244 	 * but will not rearm the timer again because it checks
245 	 * whether we are connected to the network or not -- at this
246 	 * point we shouldn't be anymore.
247 	 */
248 
249 	return 0;
250 }
251