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         /* free extra data */
  35         ieee80211_free_keys(sdata);
  36
  37         ieee80211_debugfs_remove_netdev(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 NL80211_IFTYPE_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 NL80211_IFTYPE_MESH_POINT:
  57                 if (ieee80211_vif_is_mesh(&sdata->vif))
  58                         mesh_rmc_free(sdata);
  59                 break;
  60         case NL80211_IFTYPE_STATION:
  61         case NL80211_IFTYPE_ADHOC:
  62                 kfree(sdata->u.sta.extra_ie);
  63                 kfree(sdata->u.sta.assocreq_ies);
  64                 kfree(sdata->u.sta.assocresp_ies);
  65                 kfree_skb(sdata->u.sta.probe_resp);
  66                 break;
  67         case NL80211_IFTYPE_WDS:
  68         case NL80211_IFTYPE_AP_VLAN:
  69         case NL80211_IFTYPE_MONITOR:
  70                 break;
  71         case NL80211_IFTYPE_UNSPECIFIED:
  72         case __NL80211_IFTYPE_AFTER_LAST:
  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 nl80211_iftype type)
  86 {
  87         /* clear type-dependent union */
  88         memset(&sdata->u, 0, sizeof(sdata->u));
  89
  90         /* and set some type-dependent values */
  91         sdata->vif.type = type;
  92
  93         /* only monitor differs */
  94         sdata->dev->type = ARPHRD_ETHER;
  95
  96         switch (type) {
  97         case NL80211_IFTYPE_AP:
  98                 skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
  99                 INIT_LIST_HEAD(&sdata->u.ap.vlans);
 100                 break;
 101         case NL80211_IFTYPE_STATION:
 102         case NL80211_IFTYPE_ADHOC:
 103                 ieee80211_sta_setup_sdata(sdata);
 104                 break;
 105         case NL80211_IFTYPE_MESH_POINT:
 106                 if (ieee80211_vif_is_mesh(&sdata->vif))
 107                         ieee80211_mesh_init_sdata(sdata);
 108                 break;
 109         case NL80211_IFTYPE_MONITOR:
 110                 sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
 111                 sdata->dev->hard_start_xmit = ieee80211_monitor_start_xmit;
 112                 sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
 113                                       MONITOR_FLAG_OTHER_BSS;
 114                 break;
 115         case NL80211_IFTYPE_WDS:
 116         case NL80211_IFTYPE_AP_VLAN:
 117                 break;
 118         case NL80211_IFTYPE_UNSPECIFIED:
 119         case __NL80211_IFTYPE_AFTER_LAST:
 120                 BUG();
 121                 break;
 122         }
 123
 124         ieee80211_debugfs_add_netdev(sdata);
 125 }
 126
 127 int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
 128                              enum nl80211_iftype type)
 129 {
 130         ASSERT_RTNL();
 131
 132         if (type == sdata->vif.type)
 133                 return 0;
 134
 135         /*
 136          * We could, here, on changes between IBSS/STA/MESH modes,
 137          * invoke an MLME function instead that disassociates etc.
 138          * and goes into the requested mode.
 139          */
 140
 141         if (netif_running(sdata->dev))
 142                 return -EBUSY;
 143
 144         /* Purge and reset type-dependent state. */
 145         ieee80211_teardown_sdata(sdata->dev);
 146         ieee80211_setup_sdata(sdata, type);
 147
 148         /* reset some values that shouldn't be kept across type changes */
 149         sdata->bss_conf.basic_rates =
 150                 ieee80211_mandatory_rates(sdata->local,
 151                         sdata->local->hw.conf.channel->band);
 152         sdata->drop_unencrypted = 0;
 153
 154         return 0;
 155 }
 156
 157 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 158                      struct net_device **new_dev, enum nl80211_iftype type,
 159                      struct vif_params *params)
 160 {
 161         struct net_device *ndev;
 162         struct ieee80211_sub_if_data *sdata = NULL;
 163         int ret, i;
 164
 165         ASSERT_RTNL();
 166
 167         ndev = alloc_netdev(sizeof(*sdata) + local->hw.vif_data_size,
 168                             name, ieee80211_if_setup);
 169         if (!ndev)
 170                 return -ENOMEM;
 171
 172         ndev->needed_headroom = local->tx_headroom +
 173                                 4*6 /* four MAC addresses */
 174                                 + 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
 175                                 + 6 /* mesh */
 176                                 + 8 /* rfc1042/bridge tunnel */
 177                                 - ETH_HLEN /* ethernet hard_header_len */
 178                                 + IEEE80211_ENCRYPT_HEADROOM;
 179         ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
 180
 181         ret = dev_alloc_name(ndev, ndev->name);
 182         if (ret < 0)
 183                 goto fail;
 184
 185         memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
 186         SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
 187
 188         /* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
 189         sdata = netdev_priv(ndev);
 190         ndev->ieee80211_ptr = &sdata->wdev;
 191
 192         /* initialise type-independent data */
 193         sdata->wdev.wiphy = local->hw.wiphy;
 194         sdata->local = local;
 195         sdata->dev = ndev;
 196
 197         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
 198                 skb_queue_head_init(&sdata->fragments[i].skb_list);
 199
 200         INIT_LIST_HEAD(&sdata->key_list);
 201
 202         sdata->force_unicast_rateidx = -1;
 203         sdata->max_ratectrl_rateidx = -1;
 204
 205         /* setup type-dependent data */
 206         ieee80211_setup_sdata(sdata, type);
 207
 208         ret = register_netdevice(ndev);
 209         if (ret)
 210                 goto fail;
 211
 212         ndev->uninit = ieee80211_teardown_sdata;
 213
 214         if (ieee80211_vif_is_mesh(&sdata->vif) &&
 215             params && params->mesh_id_len)
 216                 ieee80211_sdata_set_mesh_id(sdata,
 217                                             params->mesh_id_len,
 218                                             params->mesh_id);
 219
 220         list_add_tail_rcu(&sdata->list, &local->interfaces);
 221
 222         if (new_dev)
 223                 *new_dev = ndev;
 224
 225         return 0;
 226
 227  fail:
 228         free_netdev(ndev);
 229         return ret;
 230 }
 231
 232 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
 233 {
 234         ASSERT_RTNL();
 235
 236         list_del_rcu(&sdata->list);
 237         synchronize_rcu();
 238         unregister_netdevice(sdata->dev);
 239 }
 240
 241 /*
 242  * Remove all interfaces, may only be called at hardware unregistration
 243  * time because it doesn't do RCU-safe list removals.
 244  */
 245 void ieee80211_remove_interfaces(struct ieee80211_local *local)
 246 {
 247         struct ieee80211_sub_if_data *sdata, *tmp;
 248
 249         ASSERT_RTNL();
 250
 251         list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
 252                 list_del(&sdata->list);
 253                 unregister_netdevice(sdata->dev);
 254         }
 255 }