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 * Author: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
8 * Funded by: Volkswagen Group Research
9 */
10
11 #include <linux/delay.h>
12 #include <linux/if_ether.h>
13 #include <linux/skbuff.h>
14 #include <linux/if_arp.h>
15 #include <linux/etherdevice.h>
16 #include <linux/rtnetlink.h>
17 #include <net/mac80211.h>
18 #include <asm/unaligned.h>
19
20 #include "ieee80211_i.h"
21 #include "driver-ops.h"
22 #include "rate.h"
23
24 #define IEEE80211_OCB_HOUSEKEEPING_INTERVAL (60 * HZ)
25 #define IEEE80211_OCB_PEER_INACTIVITY_LIMIT (240 * HZ)
26 #define IEEE80211_OCB_MAX_STA_ENTRIES 128
27
28 /**
29 * enum ocb_deferred_task_flags - mac80211 OCB deferred tasks
30 * @OCB_WORK_HOUSEKEEPING: run the periodic OCB housekeeping tasks
31 *
32 * These flags are used in @wrkq_flags field of &struct ieee80211_if_ocb
33 */
34 enum ocb_deferred_task_flags {
35 OCB_WORK_HOUSEKEEPING,
36 };
37
ieee80211_ocb_rx_no_sta(struct ieee80211_sub_if_data * sdata,const u8 * bssid,const u8 * addr,u32 supp_rates)38 void ieee80211_ocb_rx_no_sta(struct ieee80211_sub_if_data *sdata,
39 const u8 *bssid, const u8 *addr,
40 u32 supp_rates)
41 {
42 struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
43 struct ieee80211_local *local = sdata->local;
44 struct ieee80211_chanctx_conf *chanctx_conf;
45 struct ieee80211_supported_band *sband;
46 enum nl80211_bss_scan_width scan_width;
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.chanctx_conf);
63 if (WARN_ON_ONCE(!chanctx_conf)) {
64 rcu_read_unlock();
65 return;
66 }
67 band = chanctx_conf->def.chan->band;
68 scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
69 rcu_read_unlock();
70
71 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
72 if (!sta)
73 return;
74
75 /* Add only mandatory rates for now */
76 sband = local->hw.wiphy->bands[band];
77 sta->sta.supp_rates[band] =
78 ieee80211_mandatory_rates(sband, scan_width);
79
80 spin_lock(&ifocb->incomplete_lock);
81 list_add(&sta->list, &ifocb->incomplete_stations);
82 spin_unlock(&ifocb->incomplete_lock);
83 ieee80211_queue_work(&local->hw, &sdata->work);
84 }
85
ieee80211_ocb_finish_sta(struct sta_info * sta)86 static struct sta_info *ieee80211_ocb_finish_sta(struct sta_info *sta)
87 __acquires(RCU)
88 {
89 struct ieee80211_sub_if_data *sdata = sta->sdata;
90 u8 addr[ETH_ALEN];
91
92 memcpy(addr, sta->sta.addr, ETH_ALEN);
93
94 ocb_dbg(sdata, "Adding new IBSS station %pM (dev=%s)\n",
95 addr, sdata->name);
96
97 sta_info_move_state(sta, IEEE80211_STA_AUTH);
98 sta_info_move_state(sta, IEEE80211_STA_ASSOC);
99 sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
100
101 rate_control_rate_init(sta);
102
103 /* If it fails, maybe we raced another insertion? */
104 if (sta_info_insert_rcu(sta))
105 return sta_info_get(sdata, addr);
106 return sta;
107 }
108
ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data * sdata)109 static void ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data *sdata)
110 {
111 struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
112
113 ocb_dbg(sdata, "Running ocb housekeeping\n");
114
115 ieee80211_sta_expire(sdata, IEEE80211_OCB_PEER_INACTIVITY_LIMIT);
116
117 mod_timer(&ifocb->housekeeping_timer,
118 round_jiffies(jiffies + IEEE80211_OCB_HOUSEKEEPING_INTERVAL));
119 }
120
ieee80211_ocb_work(struct ieee80211_sub_if_data * sdata)121 void ieee80211_ocb_work(struct ieee80211_sub_if_data *sdata)
122 {
123 struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
124 struct sta_info *sta;
125
126 if (ifocb->joined != true)
127 return;
128
129 sdata_lock(sdata);
130
131 spin_lock_bh(&ifocb->incomplete_lock);
132 while (!list_empty(&ifocb->incomplete_stations)) {
133 sta = list_first_entry(&ifocb->incomplete_stations,
134 struct sta_info, list);
135 list_del(&sta->list);
136 spin_unlock_bh(&ifocb->incomplete_lock);
137
138 ieee80211_ocb_finish_sta(sta);
139 rcu_read_unlock();
140 spin_lock_bh(&ifocb->incomplete_lock);
141 }
142 spin_unlock_bh(&ifocb->incomplete_lock);
143
144 if (test_and_clear_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags))
145 ieee80211_ocb_housekeeping(sdata);
146
147 sdata_unlock(sdata);
148 }
149
ieee80211_ocb_housekeeping_timer(struct timer_list * t)150 static void ieee80211_ocb_housekeeping_timer(struct timer_list *t)
151 {
152 struct ieee80211_sub_if_data *sdata =
153 from_timer(sdata, t, u.ocb.housekeeping_timer);
154 struct ieee80211_local *local = sdata->local;
155 struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
156
157 set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
158
159 ieee80211_queue_work(&local->hw, &sdata->work);
160 }
161
ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data * sdata)162 void ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data *sdata)
163 {
164 struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
165
166 timer_setup(&ifocb->housekeeping_timer,
167 ieee80211_ocb_housekeeping_timer, 0);
168 INIT_LIST_HEAD(&ifocb->incomplete_stations);
169 spin_lock_init(&ifocb->incomplete_lock);
170 }
171
ieee80211_ocb_join(struct ieee80211_sub_if_data * sdata,struct ocb_setup * setup)172 int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
173 struct ocb_setup *setup)
174 {
175 struct ieee80211_local *local = sdata->local;
176 struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
177 u32 changed = BSS_CHANGED_OCB | BSS_CHANGED_BSSID;
178 int err;
179
180 if (ifocb->joined == true)
181 return -EINVAL;
182
183 sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
184 sdata->smps_mode = IEEE80211_SMPS_OFF;
185 sdata->needed_rx_chains = sdata->local->rx_chains;
186
187 mutex_lock(&sdata->local->mtx);
188 err = ieee80211_vif_use_channel(sdata, &setup->chandef,
189 IEEE80211_CHANCTX_SHARED);
190 mutex_unlock(&sdata->local->mtx);
191 if (err)
192 return err;
193
194 ieee80211_bss_info_change_notify(sdata, changed);
195
196 ifocb->joined = true;
197
198 set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
199 ieee80211_queue_work(&local->hw, &sdata->work);
200
201 netif_carrier_on(sdata->dev);
202 return 0;
203 }
204
ieee80211_ocb_leave(struct ieee80211_sub_if_data * sdata)205 int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
206 {
207 struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
208 struct ieee80211_local *local = sdata->local;
209 struct sta_info *sta;
210
211 ifocb->joined = false;
212 sta_info_flush(sdata);
213
214 spin_lock_bh(&ifocb->incomplete_lock);
215 while (!list_empty(&ifocb->incomplete_stations)) {
216 sta = list_first_entry(&ifocb->incomplete_stations,
217 struct sta_info, list);
218 list_del(&sta->list);
219 spin_unlock_bh(&ifocb->incomplete_lock);
220
221 sta_info_free(local, sta);
222 spin_lock_bh(&ifocb->incomplete_lock);
223 }
224 spin_unlock_bh(&ifocb->incomplete_lock);
225
226 netif_carrier_off(sdata->dev);
227 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
228 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_OCB);
229
230 mutex_lock(&sdata->local->mtx);
231 ieee80211_vif_release_channel(sdata);
232 mutex_unlock(&sdata->local->mtx);
233
234 skb_queue_purge(&sdata->skb_queue);
235
236 del_timer_sync(&sdata->u.ocb.housekeeping_timer);
237 /* If the timer fired while we waited for it, it will have
238 * requeued the work. Now the work will be running again
239 * but will not rearm the timer again because it checks
240 * whether we are connected to the network or not -- at this
241 * point we shouldn't be anymore.
242 */
243
244 return 0;
245 }
246