net/mac80211/iface.c

   1 /*
   2  * Interface handling (except master interface)
   3  *
   4  * Copyright 2002-2005, Instant802 Networks, Inc.
   5  * Copyright 2005-2006, Devicescape Software, Inc.
   6  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
   7  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
   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 #include <linux/kernel.h>
  14 #include <linux/if_arp.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/rtnetlink.h>
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "sta_info.h"
  20 #include "debugfs_netdev.h"
  21 #include "mesh.h"
  22 #include "led.h"
  23
  24 /**
  25  * DOC: Interface list locking
  26  *
  27  * The interface list in each struct ieee80211_local is protected
  28  * three-fold:
  29  *
  30  * (1) modifications may only be done under the RTNL
  31  * (2) modifications and readers are protected against each other by
  32  *     the iflist_mtx.
  33  * (3) modifications are done in an RCU manner so atomic readers
  34  *     can traverse the list in RCU-safe blocks.
  35  *
  36  * As a consequence, reads (traversals) of the list can be protected
  37  * by either the RTNL, the iflist_mtx or RCU.
  38  */
  39
  40
  41 static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
  42 {
  43         int meshhdrlen;
  44         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  45
  46         meshhdrlen = (sdata->vif.type == NL80211_IFTYPE_MESH_POINT) ? 5 : 0;
  47
  48         /* FIX: what would be proper limits for MTU?
  49          * This interface uses 802.3 frames. */
  50         if (new_mtu < 256 ||
  51             new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
  52                 return -EINVAL;
  53         }
  54
  55 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
  56         printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
  57 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
  58         dev->mtu = new_mtu;
  59         return 0;
  60 }
  61
  62 static inline int identical_mac_addr_allowed(int type1, int type2)
  63 {
  64         return type1 == NL80211_IFTYPE_MONITOR ||
  65                 type2 == NL80211_IFTYPE_MONITOR ||
  66                 (type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_WDS) ||
  67                 (type1 == NL80211_IFTYPE_WDS &&
  68                         (type2 == NL80211_IFTYPE_WDS ||
  69                          type2 == NL80211_IFTYPE_AP)) ||
  70                 (type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_AP_VLAN) ||
  71                 (type1 == NL80211_IFTYPE_AP_VLAN &&
  72                         (type2 == NL80211_IFTYPE_AP ||
  73                          type2 == NL80211_IFTYPE_AP_VLAN));
  74 }
  75
  76 static int ieee80211_open(struct net_device *dev)
  77 {
  78         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  79         struct ieee80211_sub_if_data *nsdata;
  80         struct ieee80211_local *local = sdata->local;
  81         struct sta_info *sta;
  82         struct ieee80211_if_init_conf conf;
  83         u32 changed = 0;
  84         int res;
  85         u32 hw_reconf_flags = 0;
  86         u8 null_addr[ETH_ALEN] = {0};
  87
  88         /* fail early if user set an invalid address */
  89         if (compare_ether_addr(dev->dev_addr, null_addr) &&
  90             !is_valid_ether_addr(dev->dev_addr))
  91                 return -EADDRNOTAVAIL;
  92
  93         /* we hold the RTNL here so can safely walk the list */
  94         list_for_each_entry(nsdata, &local->interfaces, list) {
  95                 struct net_device *ndev = nsdata->dev;
  96
  97                 if (ndev != dev && netif_running(ndev)) {
  98                         /*
  99                          * Allow only a single IBSS interface to be up at any
 100                          * time. This is restricted because beacon distribution
 101                          * cannot work properly if both are in the same IBSS.
 102                          *
 103                          * To remove this restriction we'd have to disallow them
 104                          * from setting the same SSID on different IBSS interfaces
 105                          * belonging to the same hardware. Then, however, we're
 106                          * faced with having to adopt two different TSF timers...
 107                          */
 108                         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 109                             nsdata->vif.type == NL80211_IFTYPE_ADHOC)
 110                                 return -EBUSY;
 111
 112                         /*
 113                          * The remaining checks are only performed for interfaces
 114                          * with the same MAC address.
 115                          */
 116                         if (compare_ether_addr(dev->dev_addr, ndev->dev_addr))
 117                                 continue;
 118
 119                         /*
 120                          * check whether it may have the same address
 121                          */
 122                         if (!identical_mac_addr_allowed(sdata->vif.type,
 123                                                         nsdata->vif.type))
 124                                 return -ENOTUNIQ;
 125
 126                         /*
 127                          * can only add VLANs to enabled APs
 128                          */
 129                         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
 130                             nsdata->vif.type == NL80211_IFTYPE_AP)
 131                                 sdata->bss = &nsdata->u.ap;
 132                 }
 133         }
 134
 135         switch (sdata->vif.type) {
 136         case NL80211_IFTYPE_WDS:
 137                 if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
 138                         return -ENOLINK;
 139                 break;
 140         case NL80211_IFTYPE_AP_VLAN:
 141                 if (!sdata->bss)
 142                         return -ENOLINK;
 143                 list_add(&sdata->u.vlan.list, &sdata->bss->vlans);
 144                 break;
 145         case NL80211_IFTYPE_AP:
 146                 sdata->bss = &sdata->u.ap;
 147                 break;
 148         case NL80211_IFTYPE_MESH_POINT:
 149                 if (!ieee80211_vif_is_mesh(&sdata->vif))
 150                         break;
 151                 /* mesh ifaces must set allmulti to forward mcast traffic */
 152                 atomic_inc(&local->iff_allmultis);
 153                 break;
 154         case NL80211_IFTYPE_STATION:
 155         case NL80211_IFTYPE_MONITOR:
 156         case NL80211_IFTYPE_ADHOC:
 157                 /* no special treatment */
 158                 break;
 159         case NL80211_IFTYPE_UNSPECIFIED:
 160         case __NL80211_IFTYPE_AFTER_LAST:
 161                 /* cannot happen */
 162                 WARN_ON(1);
 163                 break;
 164         }
 165
 166         if (local->open_count == 0) {
 167                 res = 0;
 168                 if (local->ops->start)
 169                         res = local->ops->start(local_to_hw(local));
 170                 if (res)
 171                         goto err_del_bss;
 172                 /* we're brought up, everything changes */
 173                 hw_reconf_flags = ~0;
 174                 ieee80211_led_radio(local, local->hw.conf.radio_enabled);
 175         }
 176
 177         /*
 178          * Check all interfaces and copy the hopefully now-present
 179          * MAC address to those that have the special null one.
 180          */
 181         list_for_each_entry(nsdata, &local->interfaces, list) {
 182                 struct net_device *ndev = nsdata->dev;
 183
 184                 /*
 185                  * No need to check netif_running since we do not allow
 186                  * it to start up with this invalid address.
 187                  */
 188                 if (compare_ether_addr(null_addr, ndev->dev_addr) == 0)
 189                         memcpy(ndev->dev_addr,
 190                                local->hw.wiphy->perm_addr,
 191                                ETH_ALEN);
 192         }
 193
 194         if (compare_ether_addr(null_addr, local->mdev->dev_addr) == 0)
 195                 memcpy(local->mdev->dev_addr, local->hw.wiphy->perm_addr,
 196                        ETH_ALEN);
 197
 198         /*
 199          * Validate the MAC address for this device.
 200          */
 201         if (!is_valid_ether_addr(dev->dev_addr)) {
 202                 if (!local->open_count && local->ops->stop)
 203                         local->ops->stop(local_to_hw(local));
 204                 return -EADDRNOTAVAIL;
 205         }
 206
 207         switch (sdata->vif.type) {
 208         case NL80211_IFTYPE_AP_VLAN:
 209                 /* no need to tell driver */
 210                 break;
 211         case NL80211_IFTYPE_MONITOR:
 212                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
 213                         local->cooked_mntrs++;
 214                         break;
 215                 }
 216
 217                 /* must be before the call to ieee80211_configure_filter */
 218                 local->monitors++;
 219                 if (local->monitors == 1) {
 220                         local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
 221                         hw_reconf_flags |= IEEE80211_CONF_CHANGE_RADIOTAP;
 222                 }
 223
 224                 if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
 225                         local->fif_fcsfail++;
 226                 if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
 227                         local->fif_plcpfail++;
 228                 if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
 229                         local->fif_control++;
 230                 if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
 231                         local->fif_other_bss++;
 232
 233                 netif_addr_lock_bh(local->mdev);
 234                 ieee80211_configure_filter(local);
 235                 netif_addr_unlock_bh(local->mdev);
 236                 break;
 237         case NL80211_IFTYPE_STATION:
 238         case NL80211_IFTYPE_ADHOC:
 239                 if (sdata->vif.type == NL80211_IFTYPE_STATION)
 240                         sdata->u.mgd.flags &= ~IEEE80211_STA_PREV_BSSID_SET;
 241                 else
 242                         sdata->u.ibss.flags &= ~IEEE80211_IBSS_PREV_BSSID_SET;
 243                 /* fall through */
 244         default:
 245                 conf.vif = &sdata->vif;
 246                 conf.type = sdata->vif.type;
 247                 conf.mac_addr = dev->dev_addr;
 248                 res = local->ops->add_interface(local_to_hw(local), &conf);
 249                 if (res)
 250                         goto err_stop;
 251
 252                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
 253                         local->fif_other_bss++;
 254                         netif_addr_lock_bh(local->mdev);
 255                         ieee80211_configure_filter(local);
 256                         netif_addr_unlock_bh(local->mdev);
 257
 258                         ieee80211_start_mesh(sdata);
 259                 }
 260                 changed |= ieee80211_reset_erp_info(sdata);
 261                 ieee80211_bss_info_change_notify(sdata, changed);
 262                 ieee80211_enable_keys(sdata);
 263
 264                 if (sdata->vif.type == NL80211_IFTYPE_STATION)
 265                         netif_carrier_off(dev);
 266                 else
 267                         netif_carrier_on(dev);
 268         }
 269
 270         if (sdata->vif.type == NL80211_IFTYPE_WDS) {
 271                 /* Create STA entry for the WDS peer */
 272                 sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
 273                                      GFP_KERNEL);
 274                 if (!sta) {
 275                         res = -ENOMEM;
 276                         goto err_del_interface;
 277                 }
 278
 279                 /* no locking required since STA is not live yet */
 280                 sta->flags |= WLAN_STA_AUTHORIZED;
 281
 282                 res = sta_info_insert(sta);
 283                 if (res) {
 284                         /* STA has been freed */
 285                         goto err_del_interface;
 286                 }
 287         }
 288
 289         if (local->open_count == 0) {
 290                 res = dev_open(local->mdev);
 291                 WARN_ON(res);
 292                 if (res)
 293                         goto err_del_interface;
 294                 tasklet_enable(&local->tx_pending_tasklet);
 295                 tasklet_enable(&local->tasklet);
 296         }
 297
 298         /*
 299          * set_multicast_list will be invoked by the networking core
 300          * which will check whether any increments here were done in
 301          * error and sync them down to the hardware as filter flags.
 302          */
 303         if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
 304                 atomic_inc(&local->iff_allmultis);
 305
 306         if (sdata->flags & IEEE80211_SDATA_PROMISC)
 307                 atomic_inc(&local->iff_promiscs);
 308
 309         local->open_count++;
 310         if (hw_reconf_flags) {
 311                 ieee80211_hw_config(local, hw_reconf_flags);
 312                 /*
 313                  * set default queue parameters so drivers don't
 314                  * need to initialise the hardware if the hardware
 315                  * doesn't start up with sane defaults
 316                  */
 317                 ieee80211_set_wmm_default(sdata);
 318         }
 319
 320         /*
 321          * ieee80211_sta_work is disabled while network interface
 322          * is down. Therefore, some configuration changes may not
 323          * yet be effective. Trigger execution of ieee80211_sta_work
 324          * to fix this.
 325          */
 326         if (sdata->vif.type == NL80211_IFTYPE_STATION)
 327                 queue_work(local->hw.workqueue, &sdata->u.mgd.work);
 328         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 329                 queue_work(local->hw.workqueue, &sdata->u.ibss.work);
 330
 331         netif_tx_start_all_queues(dev);
 332
 333         return 0;
 334  err_del_interface:
 335         local->ops->remove_interface(local_to_hw(local), &conf);
 336  err_stop:
 337         if (!local->open_count && local->ops->stop)
 338                 local->ops->stop(local_to_hw(local));
 339  err_del_bss:
 340         sdata->bss = NULL;
 341         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 342                 list_del(&sdata->u.vlan.list);
 343         return res;
 344 }
 345
 346 static int ieee80211_stop(struct net_device *dev)
 347 {
 348         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 349         struct ieee80211_local *local = sdata->local;
 350         struct ieee80211_if_init_conf conf;
 351         struct sta_info *sta;
 352         u32 hw_reconf_flags = 0;
 353
 354         /*
 355          * Stop TX on this interface first.
 356          */
 357         netif_tx_stop_all_queues(dev);
 358
 359         /*
 360          * Now delete all active aggregation sessions.
 361          */
 362         rcu_read_lock();
 363
 364         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 365                 if (sta->sdata == sdata)
 366                         ieee80211_sta_tear_down_BA_sessions(sta);
 367         }
 368
 369         rcu_read_unlock();
 370
 371         /*
 372          * Announce that we are leaving the network, in case we are a
 373          * station interface type. This must be done before removing
 374          * all stations associated with sta_info_flush, otherwise STA
 375          * information will be gone and no announce being done.
 376          */
 377         if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 378                 if (sdata->u.mgd.state != IEEE80211_STA_MLME_DISABLED)
 379                         ieee80211_sta_deauthenticate(sdata,
 380                                 WLAN_REASON_DEAUTH_LEAVING);
 381         }
 382
 383         /*
 384          * Remove all stations associated with this interface.
 385          *
 386          * This must be done before calling ops->remove_interface()
 387          * because otherwise we can later invoke ops->sta_notify()
 388          * whenever the STAs are removed, and that invalidates driver
 389          * assumptions about always getting a vif pointer that is valid
 390          * (because if we remove a STA after ops->remove_interface()
 391          * the driver will have removed the vif info already!)
 392          *
 393          * We could relax this and only unlink the stations from the
 394          * hash table and list but keep them on a per-sdata list that
 395          * will be inserted back again when the interface is brought
 396          * up again, but I don't currently see a use case for that,
 397          * except with WDS which gets a STA entry created when it is
 398          * brought up.
 399          */
 400         sta_info_flush(local, sdata);
 401
 402         /*
 403          * Don't count this interface for promisc/allmulti while it
 404          * is down. dev_mc_unsync() will invoke set_multicast_list
 405          * on the master interface which will sync these down to the
 406          * hardware as filter flags.
 407          */
 408         if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
 409                 atomic_dec(&local->iff_allmultis);
 410
 411         if (sdata->flags & IEEE80211_SDATA_PROMISC)
 412                 atomic_dec(&local->iff_promiscs);
 413
 414         dev_mc_unsync(local->mdev, dev);
 415         del_timer_sync(&local->dynamic_ps_timer);
 416         cancel_work_sync(&local->dynamic_ps_enable_work);
 417
 418         /* APs need special treatment */
 419         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 420                 struct ieee80211_sub_if_data *vlan, *tmp;
 421                 struct beacon_data *old_beacon = sdata->u.ap.beacon;
 422
 423                 /* remove beacon */
 424                 rcu_assign_pointer(sdata->u.ap.beacon, NULL);
 425                 synchronize_rcu();
 426                 kfree(old_beacon);
 427
 428                 /* down all dependent devices, that is VLANs */
 429                 list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
 430                                          u.vlan.list)
 431                         dev_close(vlan->dev);
 432                 WARN_ON(!list_empty(&sdata->u.ap.vlans));
 433         }
 434
 435         local->open_count--;
 436
 437         switch (sdata->vif.type) {
 438         case NL80211_IFTYPE_AP_VLAN:
 439                 list_del(&sdata->u.vlan.list);
 440                 /* no need to tell driver */
 441                 break;
 442         case NL80211_IFTYPE_MONITOR:
 443                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
 444                         local->cooked_mntrs--;
 445                         break;
 446                 }
 447
 448                 local->monitors--;
 449                 if (local->monitors == 0) {
 450                         local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
 451                         hw_reconf_flags |= IEEE80211_CONF_CHANGE_RADIOTAP;
 452                 }
 453
 454                 if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
 455                         local->fif_fcsfail--;
 456                 if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
 457                         local->fif_plcpfail--;
 458                 if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL)
 459                         local->fif_control--;
 460                 if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
 461                         local->fif_other_bss--;
 462
 463                 netif_addr_lock_bh(local->mdev);
 464                 ieee80211_configure_filter(local);
 465                 netif_addr_unlock_bh(local->mdev);
 466                 break;
 467         case NL80211_IFTYPE_STATION:
 468                 memset(sdata->u.mgd.bssid, 0, ETH_ALEN);
 469                 del_timer_sync(&sdata->u.mgd.chswitch_timer);
 470                 del_timer_sync(&sdata->u.mgd.timer);
 471                 /*
 472                  * If the timer fired while we waited for it, it will have
 473                  * requeued the work. Now the work will be running again
 474                  * but will not rearm the timer again because it checks
 475                  * whether the interface is running, which, at this point,
 476                  * it no longer is.
 477                  */
 478                 cancel_work_sync(&sdata->u.mgd.work);
 479                 cancel_work_sync(&sdata->u.mgd.chswitch_work);
 480                 /*
 481                  * When we get here, the interface is marked down.
 482                  * Call synchronize_rcu() to wait for the RX path
 483                  * should it be using the interface and enqueuing
 484                  * frames at this very time on another CPU.
 485                  */
 486                 synchronize_rcu();
 487                 skb_queue_purge(&sdata->u.mgd.skb_queue);
 488
 489                 sdata->u.mgd.flags &= ~(IEEE80211_STA_PRIVACY_INVOKED |
 490                                         IEEE80211_STA_TKIP_WEP_USED);
 491                 kfree(sdata->u.mgd.extra_ie);
 492                 sdata->u.mgd.extra_ie = NULL;
 493                 sdata->u.mgd.extra_ie_len = 0;
 494                 /* fall through */
 495         case NL80211_IFTYPE_ADHOC:
 496                 if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 497                         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
 498                         del_timer_sync(&sdata->u.ibss.timer);
 499                         cancel_work_sync(&sdata->u.ibss.work);
 500                         synchronize_rcu();
 501                         skb_queue_purge(&sdata->u.ibss.skb_queue);
 502                 }
 503                 /* fall through */
 504         case NL80211_IFTYPE_MESH_POINT:
 505                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
 506                         /* other_bss and allmulti are always set on mesh
 507                          * ifaces */
 508                         local->fif_other_bss--;
 509                         atomic_dec(&local->iff_allmultis);
 510
 511                         netif_addr_lock_bh(local->mdev);
 512                         ieee80211_configure_filter(local);
 513                         netif_addr_unlock_bh(local->mdev);
 514
 515                         ieee80211_stop_mesh(sdata);
 516                 }
 517                 /* fall through */
 518         default:
 519                 if (local->scan_sdata == sdata) {
 520                         if (!local->ops->hw_scan)
 521                                 cancel_delayed_work_sync(&local->scan_work);
 522                         /*
 523                          * The software scan can no longer run now, so we can
 524                          * clear out the scan_sdata reference. However, the
 525                          * hardware scan may still be running. The complete
 526                          * function must be prepared to handle a NULL value.
 527                          */
 528                         local->scan_sdata = NULL;
 529                         /*
 530                          * The memory barrier guarantees that another CPU
 531                          * that is hardware-scanning will now see the fact
 532                          * that this interface is gone.
 533                          */
 534                         smp_mb();
 535                         /*
 536                          * If software scanning, complete the scan but since
 537                          * the scan_sdata is NULL already don't send out a
 538                          * scan event to userspace -- the scan is incomplete.
 539                          */
 540                         if (local->sw_scanning)
 541                                 ieee80211_scan_completed(&local->hw, true);
 542                 }
 543
 544                 conf.vif = &sdata->vif;
 545                 conf.type = sdata->vif.type;
 546                 conf.mac_addr = dev->dev_addr;
 547                 /* disable all keys for as long as this netdev is down */
 548                 ieee80211_disable_keys(sdata);
 549                 local->ops->remove_interface(local_to_hw(local), &conf);
 550         }
 551
 552         sdata->bss = NULL;
 553
 554         if (local->open_count == 0) {
 555                 if (netif_running(local->mdev))
 556                         dev_close(local->mdev);
 557
 558                 if (local->ops->stop)
 559                         local->ops->stop(local_to_hw(local));
 560
 561                 ieee80211_led_radio(local, 0);
 562
 563                 flush_workqueue(local->hw.workqueue);
 564
 565                 tasklet_disable(&local->tx_pending_tasklet);
 566                 tasklet_disable(&local->tasklet);
 567
 568                 /* no reconfiguring after stop! */
 569                 hw_reconf_flags = 0;
 570         }
 571
 572         /* do after stop to avoid reconfiguring when we stop anyway */
 573         if (hw_reconf_flags)
 574                 ieee80211_hw_config(local, hw_reconf_flags);
 575
 576         return 0;
 577 }
 578
 579 static void ieee80211_set_multicast_list(struct net_device *dev)
 580 {
 581         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 582         struct ieee80211_local *local = sdata->local;
 583         int allmulti, promisc, sdata_allmulti, sdata_promisc;
 584
 585         allmulti = !!(dev->flags & IFF_ALLMULTI);
 586         promisc = !!(dev->flags & IFF_PROMISC);
 587         sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
 588         sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);
 589
 590         if (allmulti != sdata_allmulti) {
 591                 if (dev->flags & IFF_ALLMULTI)
 592                         atomic_inc(&local->iff_allmultis);
 593                 else
 594                         atomic_dec(&local->iff_allmultis);
 595                 sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
 596         }
 597
 598         if (promisc != sdata_promisc) {
 599                 if (dev->flags & IFF_PROMISC)
 600                         atomic_inc(&local->iff_promiscs);
 601                 else
 602                         atomic_dec(&local->iff_promiscs);
 603                 sdata->flags ^= IEEE80211_SDATA_PROMISC;
 604         }
 605
 606         dev_mc_sync(local->mdev, dev);
 607 }
 608
 609 /*
 610  * Called when the netdev is removed or, by the code below, before
 611  * the interface type changes.
 612  */
 613 static void ieee80211_teardown_sdata(struct net_device *dev)
 614 {
 615         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 616         struct ieee80211_local *local = sdata->local;
 617         struct beacon_data *beacon;
 618         struct sk_buff *skb;
 619         int flushed;
 620         int i;
 621
 622         /* free extra data */
 623         ieee80211_free_keys(sdata);
 624
 625         ieee80211_debugfs_remove_netdev(sdata);
 626
 627         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
 628                 __skb_queue_purge(&sdata->fragments[i].skb_list);
 629         sdata->fragment_next = 0;
 630
 631         switch (sdata->vif.type) {
 632         case NL80211_IFTYPE_AP:
 633                 beacon = sdata->u.ap.beacon;
 634                 rcu_assign_pointer(sdata->u.ap.beacon, NULL);
 635                 synchronize_rcu();
 636                 kfree(beacon);
 637
 638                 while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
 639                         local->total_ps_buffered--;
 640                         dev_kfree_skb(skb);
 641                 }
 642
 643                 break;
 644         case NL80211_IFTYPE_MESH_POINT:
 645                 if (ieee80211_vif_is_mesh(&sdata->vif))
 646                         mesh_rmc_free(sdata);
 647                 break;
 648         case NL80211_IFTYPE_ADHOC:
 649                 kfree_skb(sdata->u.ibss.probe_resp);
 650                 break;
 651         case NL80211_IFTYPE_STATION:
 652                 kfree(sdata->u.mgd.extra_ie);
 653                 kfree(sdata->u.mgd.assocreq_ies);
 654                 kfree(sdata->u.mgd.assocresp_ies);
 655                 kfree(sdata->u.mgd.sme_auth_ie);
 656                 break;
 657         case NL80211_IFTYPE_WDS:
 658         case NL80211_IFTYPE_AP_VLAN:
 659         case NL80211_IFTYPE_MONITOR:
 660                 break;
 661         case NL80211_IFTYPE_UNSPECIFIED:
 662         case __NL80211_IFTYPE_AFTER_LAST:
 663                 BUG();
 664                 break;
 665         }
 666
 667         flushed = sta_info_flush(local, sdata);
 668         WARN_ON(flushed);
 669 }
 670
 671 static const struct net_device_ops ieee80211_dataif_ops = {
 672         .ndo_open               = ieee80211_open,
 673         .ndo_stop               = ieee80211_stop,
 674         .ndo_uninit             = ieee80211_teardown_sdata,
 675         .ndo_start_xmit         = ieee80211_subif_start_xmit,
 676         .ndo_set_multicast_list = ieee80211_set_multicast_list,
 677         .ndo_change_mtu         = ieee80211_change_mtu,
 678         .ndo_set_mac_address    = eth_mac_addr,
 679 };
 680
 681 static const struct net_device_ops ieee80211_monitorif_ops = {
 682         .ndo_open               = ieee80211_open,
 683         .ndo_stop               = ieee80211_stop,
 684         .ndo_uninit             = ieee80211_teardown_sdata,
 685         .ndo_start_xmit         = ieee80211_monitor_start_xmit,
 686         .ndo_set_multicast_list = ieee80211_set_multicast_list,
 687         .ndo_change_mtu         = ieee80211_change_mtu,
 688         .ndo_set_mac_address    = eth_mac_addr,
 689 };
 690
 691 static void ieee80211_if_setup(struct net_device *dev)
 692 {
 693         ether_setup(dev);
 694         dev->netdev_ops = &ieee80211_dataif_ops;
 695         dev->wireless_handlers = &ieee80211_iw_handler_def;
 696         dev->destructor = free_netdev;
 697 }
 698
 699 /*
 700  * Helper function to initialise an interface to a specific type.
 701  */
 702 static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 703                                   enum nl80211_iftype type)
 704 {
 705         /* clear type-dependent union */
 706         memset(&sdata->u, 0, sizeof(sdata->u));
 707
 708         /* and set some type-dependent values */
 709         sdata->vif.type = type;
 710         sdata->dev->netdev_ops = &ieee80211_dataif_ops;
 711         sdata->wdev.iftype = type;
 712
 713         /* only monitor differs */
 714         sdata->dev->type = ARPHRD_ETHER;
 715
 716         switch (type) {
 717         case NL80211_IFTYPE_AP:
 718                 skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
 719                 INIT_LIST_HEAD(&sdata->u.ap.vlans);
 720                 break;
 721         case NL80211_IFTYPE_STATION:
 722                 ieee80211_sta_setup_sdata(sdata);
 723                 break;
 724         case NL80211_IFTYPE_ADHOC:
 725                 ieee80211_ibss_setup_sdata(sdata);
 726                 break;
 727         case NL80211_IFTYPE_MESH_POINT:
 728                 if (ieee80211_vif_is_mesh(&sdata->vif))
 729                         ieee80211_mesh_init_sdata(sdata);
 730                 break;
 731         case NL80211_IFTYPE_MONITOR:
 732                 sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
 733                 sdata->dev->netdev_ops = &ieee80211_monitorif_ops;
 734                 sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
 735                                       MONITOR_FLAG_OTHER_BSS;
 736                 break;
 737         case NL80211_IFTYPE_WDS:
 738         case NL80211_IFTYPE_AP_VLAN:
 739                 break;
 740         case NL80211_IFTYPE_UNSPECIFIED:
 741         case __NL80211_IFTYPE_AFTER_LAST:
 742                 BUG();
 743                 break;
 744         }
 745
 746         ieee80211_debugfs_add_netdev(sdata);
 747 }
 748
 749 int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
 750                              enum nl80211_iftype type)
 751 {
 752         ASSERT_RTNL();
 753
 754         if (type == sdata->vif.type)
 755                 return 0;
 756
 757         /* Setting ad-hoc mode on non-IBSS channel is not supported. */
 758         if (sdata->local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS &&
 759             type == NL80211_IFTYPE_ADHOC)
 760                 return -EOPNOTSUPP;
 761
 762         /*
 763          * We could, here, on changes between IBSS/STA/MESH modes,
 764          * invoke an MLME function instead that disassociates etc.
 765          * and goes into the requested mode.
 766          */
 767
 768         if (netif_running(sdata->dev))
 769                 return -EBUSY;
 770
 771         /* Purge and reset type-dependent state. */
 772         ieee80211_teardown_sdata(sdata->dev);
 773         ieee80211_setup_sdata(sdata, type);
 774
 775         /* reset some values that shouldn't be kept across type changes */
 776         sdata->vif.bss_conf.basic_rates =
 777                 ieee80211_mandatory_rates(sdata->local,
 778                         sdata->local->hw.conf.channel->band);
 779         sdata->drop_unencrypted = 0;
 780
 781         return 0;
 782 }
 783
 784 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 785                      struct net_device **new_dev, enum nl80211_iftype type,
 786                      struct vif_params *params)
 787 {
 788         struct net_device *ndev;
 789         struct ieee80211_sub_if_data *sdata = NULL;
 790         int ret, i;
 791
 792         ASSERT_RTNL();
 793
 794         ndev = alloc_netdev(sizeof(*sdata) + local->hw.vif_data_size,
 795                             name, ieee80211_if_setup);
 796         if (!ndev)
 797                 return -ENOMEM;
 798
 799         ndev->needed_headroom = local->tx_headroom +
 800                                 4*6 /* four MAC addresses */
 801                                 + 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
 802                                 + 6 /* mesh */
 803                                 + 8 /* rfc1042/bridge tunnel */
 804                                 - ETH_HLEN /* ethernet hard_header_len */
 805                                 + IEEE80211_ENCRYPT_HEADROOM;
 806         ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
 807
 808         ret = dev_alloc_name(ndev, ndev->name);
 809         if (ret < 0)
 810                 goto fail;
 811
 812         memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
 813         SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
 814         ndev->features |= NETIF_F_NETNS_LOCAL;
 815
 816         /* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
 817         sdata = netdev_priv(ndev);
 818         ndev->ieee80211_ptr = &sdata->wdev;
 819
 820         /* initialise type-independent data */
 821         sdata->wdev.wiphy = local->hw.wiphy;
 822         sdata->local = local;
 823         sdata->dev = ndev;
 824
 825         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
 826                 skb_queue_head_init(&sdata->fragments[i].skb_list);
 827
 828         INIT_LIST_HEAD(&sdata->key_list);
 829
 830         sdata->force_unicast_rateidx = -1;
 831         sdata->max_ratectrl_rateidx = -1;
 832
 833         /* setup type-dependent data */
 834         ieee80211_setup_sdata(sdata, type);
 835
 836         ret = register_netdevice(ndev);
 837         if (ret)
 838                 goto fail;
 839
 840         if (ieee80211_vif_is_mesh(&sdata->vif) &&
 841             params && params->mesh_id_len)
 842                 ieee80211_sdata_set_mesh_id(sdata,
 843                                             params->mesh_id_len,
 844                                             params->mesh_id);
 845
 846         mutex_lock(&local->iflist_mtx);
 847         list_add_tail_rcu(&sdata->list, &local->interfaces);
 848         mutex_unlock(&local->iflist_mtx);
 849
 850         if (new_dev)
 851                 *new_dev = ndev;
 852
 853         return 0;
 854
 855  fail:
 856         free_netdev(ndev);
 857         return ret;
 858 }
 859
 860 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
 861 {
 862         ASSERT_RTNL();
 863
 864         mutex_lock(&sdata->local->iflist_mtx);
 865         list_del_rcu(&sdata->list);
 866         mutex_unlock(&sdata->local->iflist_mtx);
 867
 868         synchronize_rcu();
 869         unregister_netdevice(sdata->dev);
 870 }
 871
 872 /*
 873  * Remove all interfaces, may only be called at hardware unregistration
 874  * time because it doesn't do RCU-safe list removals.
 875  */
 876 void ieee80211_remove_interfaces(struct ieee80211_local *local)
 877 {
 878         struct ieee80211_sub_if_data *sdata, *tmp;
 879
 880         ASSERT_RTNL();
 881
 882         list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
 883                 /*
 884                  * we cannot hold the iflist_mtx across unregister_netdevice,
 885                  * but we only need to hold it for list modifications to lock
 886                  * out readers since we're under the RTNL here as all other
 887                  * writers.
 888                  */
 889                 mutex_lock(&local->iflist_mtx);
 890                 list_del(&sdata->list);
 891                 mutex_unlock(&local->iflist_mtx);
 892
 893                 unregister_netdevice(sdata->dev);
 894         }
 895 }