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 <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  
ieee80211_ocb_rx_no_sta(struct ieee80211_sub_if_data * sdata,const u8 * bssid,const u8 * addr,u32 supp_rates)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  
ieee80211_ocb_finish_sta(struct sta_info * sta)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  
ieee80211_ocb_housekeeping(struct ieee80211_sub_if_data * sdata)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  
ieee80211_ocb_work(struct ieee80211_sub_if_data * sdata)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  
ieee80211_ocb_housekeeping_timer(struct timer_list * t)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  
ieee80211_ocb_setup_sdata(struct ieee80211_sub_if_data * sdata)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  
ieee80211_ocb_join(struct ieee80211_sub_if_data * sdata,struct ocb_setup * setup)168  int ieee80211_ocb_join(struct ieee80211_sub_if_data *sdata,
169  		       struct ocb_setup *setup)
170  {
171  	struct ieee80211_chan_req chanreq = { .oper = setup->chandef };
172  	struct ieee80211_local *local = sdata->local;
173  	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
174  	u64 changed = BSS_CHANGED_OCB | BSS_CHANGED_BSSID;
175  	int err;
176  
177  	lockdep_assert_wiphy(sdata->local->hw.wiphy);
178  
179  	if (ifocb->joined == true)
180  		return -EINVAL;
181  
182  	sdata->deflink.operating_11g_mode = true;
183  	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
184  	sdata->deflink.needed_rx_chains = sdata->local->rx_chains;
185  
186  	err = ieee80211_link_use_channel(&sdata->deflink, &chanreq,
187  					 IEEE80211_CHANCTX_SHARED);
188  	if (err)
189  		return err;
190  
191  	ieee80211_bss_info_change_notify(sdata, changed);
192  
193  	ifocb->joined = true;
194  
195  	set_bit(OCB_WORK_HOUSEKEEPING, &ifocb->wrkq_flags);
196  	wiphy_work_queue(local->hw.wiphy, &sdata->work);
197  
198  	netif_carrier_on(sdata->dev);
199  	return 0;
200  }
201  
ieee80211_ocb_leave(struct ieee80211_sub_if_data * sdata)202  int ieee80211_ocb_leave(struct ieee80211_sub_if_data *sdata)
203  {
204  	struct ieee80211_if_ocb *ifocb = &sdata->u.ocb;
205  	struct ieee80211_local *local = sdata->local;
206  	struct sta_info *sta;
207  
208  	lockdep_assert_wiphy(sdata->local->hw.wiphy);
209  
210  	ifocb->joined = false;
211  	sta_info_flush(sdata, -1);
212  
213  	spin_lock_bh(&ifocb->incomplete_lock);
214  	while (!list_empty(&ifocb->incomplete_stations)) {
215  		sta = list_first_entry(&ifocb->incomplete_stations,
216  				       struct sta_info, list);
217  		list_del(&sta->list);
218  		spin_unlock_bh(&ifocb->incomplete_lock);
219  
220  		sta_info_free(local, sta);
221  		spin_lock_bh(&ifocb->incomplete_lock);
222  	}
223  	spin_unlock_bh(&ifocb->incomplete_lock);
224  
225  	netif_carrier_off(sdata->dev);
226  	clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
227  	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_OCB);
228  
229  	ieee80211_link_release_channel(&sdata->deflink);
230  
231  	skb_queue_purge(&sdata->skb_queue);
232  
233  	del_timer_sync(&sdata->u.ocb.housekeeping_timer);
234  	/* If the timer fired while we waited for it, it will have
235  	 * requeued the work. Now the work will be running again
236  	 * but will not rearm the timer again because it checks
237  	 * whether we are connected to the network or not -- at this
238  	 * point we shouldn't be anymore.
239  	 */
240  
241  	return 0;
242  }
243