kprobes: remove redundant config check
[linux-2.6] / net / mac80211 / iface.c
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
5  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/kernel.h>
12 #include <linux/if_arp.h>
13 #include <linux/netdevice.h>
14 #include <linux/rtnetlink.h>
15 #include <net/mac80211.h>
16 #include "ieee80211_i.h"
17 #include "sta_info.h"
18 #include "debugfs_netdev.h"
19 #include "mesh.h"
20
21 /*
22  * Called when the netdev is removed or, by the code below, before
23  * the interface type changes.
24  */
25 static void ieee80211_teardown_sdata(struct net_device *dev)
26 {
27         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
28         struct ieee80211_local *local = sdata->local;
29         struct beacon_data *beacon;
30         struct sk_buff *skb;
31         int flushed;
32         int i;
33
34         ieee80211_debugfs_remove_netdev(sdata);
35
36         /* free extra data */
37         ieee80211_free_keys(sdata);
38
39         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
40                 __skb_queue_purge(&sdata->fragments[i].skb_list);
41         sdata->fragment_next = 0;
42
43         switch (sdata->vif.type) {
44         case IEEE80211_IF_TYPE_AP:
45                 beacon = sdata->u.ap.beacon;
46                 rcu_assign_pointer(sdata->u.ap.beacon, NULL);
47                 synchronize_rcu();
48                 kfree(beacon);
49
50                 while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
51                         local->total_ps_buffered--;
52                         dev_kfree_skb(skb);
53                 }
54
55                 break;
56         case IEEE80211_IF_TYPE_MESH_POINT:
57                 /* Allow compiler to elide mesh_rmc_free call. */
58                 if (ieee80211_vif_is_mesh(&sdata->vif))
59                         mesh_rmc_free(dev);
60                 /* fall through */
61         case IEEE80211_IF_TYPE_STA:
62         case IEEE80211_IF_TYPE_IBSS:
63                 kfree(sdata->u.sta.extra_ie);
64                 kfree(sdata->u.sta.assocreq_ies);
65                 kfree(sdata->u.sta.assocresp_ies);
66                 kfree_skb(sdata->u.sta.probe_resp);
67                 break;
68         case IEEE80211_IF_TYPE_WDS:
69         case IEEE80211_IF_TYPE_VLAN:
70         case IEEE80211_IF_TYPE_MNTR:
71                 break;
72         case IEEE80211_IF_TYPE_INVALID:
73                 BUG();
74                 break;
75         }
76
77         flushed = sta_info_flush(local, sdata);
78         WARN_ON(flushed);
79 }
80
81 /*
82  * Helper function to initialise an interface to a specific type.
83  */
84 static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
85                                   enum ieee80211_if_types type)
86 {
87         struct ieee80211_if_sta *ifsta;
88
89         /* clear type-dependent union */
90         memset(&sdata->u, 0, sizeof(sdata->u));
91
92         /* and set some type-dependent values */
93         sdata->vif.type = type;
94
95         /* only monitor differs */
96         sdata->dev->type = ARPHRD_ETHER;
97
98         switch (type) {
99         case IEEE80211_IF_TYPE_AP:
100                 skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
101                 INIT_LIST_HEAD(&sdata->u.ap.vlans);
102                 break;
103         case IEEE80211_IF_TYPE_MESH_POINT:
104         case IEEE80211_IF_TYPE_STA:
105         case IEEE80211_IF_TYPE_IBSS:
106                 ifsta = &sdata->u.sta;
107                 INIT_WORK(&ifsta->work, ieee80211_sta_work);
108                 setup_timer(&ifsta->timer, ieee80211_sta_timer,
109                             (unsigned long) sdata);
110                 skb_queue_head_init(&ifsta->skb_queue);
111
112                 ifsta->capab = WLAN_CAPABILITY_ESS;
113                 ifsta->auth_algs = IEEE80211_AUTH_ALG_OPEN |
114                         IEEE80211_AUTH_ALG_SHARED_KEY;
115                 ifsta->flags |= IEEE80211_STA_CREATE_IBSS |
116                         IEEE80211_STA_AUTO_BSSID_SEL |
117                         IEEE80211_STA_AUTO_CHANNEL_SEL;
118                 if (ieee80211_num_regular_queues(&sdata->local->hw) >= 4)
119                         ifsta->flags |= IEEE80211_STA_WMM_ENABLED;
120
121                 if (ieee80211_vif_is_mesh(&sdata->vif))
122                         ieee80211_mesh_init_sdata(sdata);
123                 break;
124         case IEEE80211_IF_TYPE_MNTR:
125                 sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
126                 sdata->dev->hard_start_xmit = ieee80211_monitor_start_xmit;
127                 sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
128                                       MONITOR_FLAG_OTHER_BSS;
129                 break;
130         case IEEE80211_IF_TYPE_WDS:
131         case IEEE80211_IF_TYPE_VLAN:
132                 break;
133         case IEEE80211_IF_TYPE_INVALID:
134                 BUG();
135                 break;
136         }
137
138         ieee80211_debugfs_add_netdev(sdata);
139 }
140
141 int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
142                              enum ieee80211_if_types type)
143 {
144         ASSERT_RTNL();
145
146         if (type == sdata->vif.type)
147                 return 0;
148
149         /*
150          * We could, here, on changes between IBSS/STA/MESH modes,
151          * invoke an MLME function instead that disassociates etc.
152          * and goes into the requested mode.
153          */
154
155         if (netif_running(sdata->dev))
156                 return -EBUSY;
157
158         /* Purge and reset type-dependent state. */
159         ieee80211_teardown_sdata(sdata->dev);
160         ieee80211_setup_sdata(sdata, type);
161
162         /* reset some values that shouldn't be kept across type changes */
163         sdata->basic_rates = 0;
164         sdata->drop_unencrypted = 0;
165
166         return 0;
167 }
168
169 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
170                      struct net_device **new_dev, enum ieee80211_if_types type,
171                      struct vif_params *params)
172 {
173         struct net_device *ndev;
174         struct ieee80211_sub_if_data *sdata = NULL;
175         int ret, i;
176
177         ASSERT_RTNL();
178
179         ndev = alloc_netdev(sizeof(*sdata) + local->hw.vif_data_size,
180                             name, ieee80211_if_setup);
181         if (!ndev)
182                 return -ENOMEM;
183
184         ndev->needed_headroom = local->tx_headroom +
185                                 4*6 /* four MAC addresses */
186                                 + 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
187                                 + 6 /* mesh */
188                                 + 8 /* rfc1042/bridge tunnel */
189                                 - ETH_HLEN /* ethernet hard_header_len */
190                                 + IEEE80211_ENCRYPT_HEADROOM;
191         ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
192
193         ret = dev_alloc_name(ndev, ndev->name);
194         if (ret < 0)
195                 goto fail;
196
197         memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
198         SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
199
200         /* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
201         sdata = netdev_priv(ndev);
202         ndev->ieee80211_ptr = &sdata->wdev;
203
204         /* initialise type-independent data */
205         sdata->wdev.wiphy = local->hw.wiphy;
206         sdata->local = local;
207         sdata->dev = ndev;
208
209         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
210                 skb_queue_head_init(&sdata->fragments[i].skb_list);
211
212         INIT_LIST_HEAD(&sdata->key_list);
213
214         sdata->force_unicast_rateidx = -1;
215         sdata->max_ratectrl_rateidx = -1;
216
217         /* setup type-dependent data */
218         ieee80211_setup_sdata(sdata, type);
219
220         ret = register_netdevice(ndev);
221         if (ret)
222                 goto fail;
223
224         ndev->uninit = ieee80211_teardown_sdata;
225
226         if (ieee80211_vif_is_mesh(&sdata->vif) &&
227             params && params->mesh_id_len)
228                 ieee80211_if_sta_set_mesh_id(&sdata->u.sta,
229                                              params->mesh_id_len,
230                                              params->mesh_id);
231
232         list_add_tail_rcu(&sdata->list, &local->interfaces);
233
234         if (new_dev)
235                 *new_dev = ndev;
236
237         return 0;
238
239  fail:
240         free_netdev(ndev);
241         return ret;
242 }
243
244 void ieee80211_if_remove(struct net_device *dev)
245 {
246         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
247
248         ASSERT_RTNL();
249
250         list_del_rcu(&sdata->list);
251         synchronize_rcu();
252         unregister_netdevice(dev);
253 }
254
255 /*
256  * Remove all interfaces, may only be called at hardware unregistration
257  * time because it doesn't do RCU-safe list removals.
258  */
259 void ieee80211_remove_interfaces(struct ieee80211_local *local)
260 {
261         struct ieee80211_sub_if_data *sdata, *tmp;
262
263         ASSERT_RTNL();
264
265         list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
266                 list_del(&sdata->list);
267                 unregister_netdevice(sdata->dev);
268         }
269 }