SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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 <net/ieee80211_radiotap.h>
  19 #include "ieee80211_i.h"
  20 #include "sta_info.h"
  21 #include "debugfs_netdev.h"
  22 #include "mesh.h"
  23 #include "led.h"
  24 #include "driver-ops.h"
  25 #include "wme.h"
  26
  27 /**
  28  * DOC: Interface list locking
  29  *
  30  * The interface list in each struct ieee80211_local is protected
  31  * three-fold:
  32  *
  33  * (1) modifications may only be done under the RTNL
  34  * (2) modifications and readers are protected against each other by
  35  *     the iflist_mtx.
  36  * (3) modifications are done in an RCU manner so atomic readers
  37  *     can traverse the list in RCU-safe blocks.
  38  *
  39  * As a consequence, reads (traversals) of the list can be protected
  40  * by either the RTNL, the iflist_mtx or RCU.
  41  */
  42
  43
  44 static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
  45 {
  46         int meshhdrlen;
  47         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  48
  49         meshhdrlen = (sdata->vif.type == NL80211_IFTYPE_MESH_POINT) ? 5 : 0;
  50
  51         /* FIX: what would be proper limits for MTU?
  52          * This interface uses 802.3 frames. */
  53         if (new_mtu < 256 ||
  54             new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
  55                 return -EINVAL;
  56         }
  57
  58 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
  59         printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
  60 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
  61         dev->mtu = new_mtu;
  62         return 0;
  63 }
  64
  65 static inline int identical_mac_addr_allowed(int type1, int type2)
  66 {
  67         return type1 == NL80211_IFTYPE_MONITOR ||
  68                 type2 == NL80211_IFTYPE_MONITOR ||
  69                 (type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_WDS) ||
  70                 (type1 == NL80211_IFTYPE_WDS &&
  71                         (type2 == NL80211_IFTYPE_WDS ||
  72                          type2 == NL80211_IFTYPE_AP)) ||
  73                 (type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_AP_VLAN) ||
  74                 (type1 == NL80211_IFTYPE_AP_VLAN &&
  75                         (type2 == NL80211_IFTYPE_AP ||
  76                          type2 == NL80211_IFTYPE_AP_VLAN));
  77 }
  78
  79 static int ieee80211_open(struct net_device *dev)
  80 {
  81         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  82         struct ieee80211_sub_if_data *nsdata;
  83         struct ieee80211_local *local = sdata->local;
  84         struct sta_info *sta;
  85         struct ieee80211_if_init_conf conf;
  86         u32 changed = 0;
  87         int res;
  88         u32 hw_reconf_flags = 0;
  89         u8 null_addr[ETH_ALEN] = {0};
  90
  91         /* fail early if user set an invalid address */
  92         if (compare_ether_addr(dev->dev_addr, null_addr) &&
  93             !is_valid_ether_addr(dev->dev_addr))
  94                 return -EADDRNOTAVAIL;
  95
  96         /* we hold the RTNL here so can safely walk the list */
  97         list_for_each_entry(nsdata, &local->interfaces, list) {
  98                 struct net_device *ndev = nsdata->dev;
  99
 100                 if (ndev != dev && netif_running(ndev)) {
 101                         /*
 102                          * Allow only a single IBSS interface to be up at any
 103                          * time. This is restricted because beacon distribution
 104                          * cannot work properly if both are in the same IBSS.
 105                          *
 106                          * To remove this restriction we'd have to disallow them
 107                          * from setting the same SSID on different IBSS interfaces
 108                          * belonging to the same hardware. Then, however, we're
 109                          * faced with having to adopt two different TSF timers...
 110                          */
 111                         if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 112                             nsdata->vif.type == NL80211_IFTYPE_ADHOC)
 113                                 return -EBUSY;
 114
 115                         /*
 116                          * The remaining checks are only performed for interfaces
 117                          * with the same MAC address.
 118                          */
 119                         if (compare_ether_addr(dev->dev_addr, ndev->dev_addr))
 120                                 continue;
 121
 122                         /*
 123                          * check whether it may have the same address
 124                          */
 125                         if (!identical_mac_addr_allowed(sdata->vif.type,
 126                                                         nsdata->vif.type))
 127                                 return -ENOTUNIQ;
 128
 129                         /*
 130                          * can only add VLANs to enabled APs
 131                          */
 132                         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
 133                             nsdata->vif.type == NL80211_IFTYPE_AP)
 134                                 sdata->bss = &nsdata->u.ap;
 135                 }
 136         }
 137
 138         switch (sdata->vif.type) {
 139         case NL80211_IFTYPE_WDS:
 140                 if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
 141                         return -ENOLINK;
 142                 break;
 143         case NL80211_IFTYPE_AP_VLAN:
 144                 if (!sdata->bss)
 145                         return -ENOLINK;
 146                 list_add(&sdata->u.vlan.list, &sdata->bss->vlans);
 147                 break;
 148         case NL80211_IFTYPE_AP:
 149                 sdata->bss = &sdata->u.ap;
 150                 break;
 151         case NL80211_IFTYPE_MESH_POINT:
 152                 if (!ieee80211_vif_is_mesh(&sdata->vif))
 153                         break;
 154                 /* mesh ifaces must set allmulti to forward mcast traffic */
 155                 atomic_inc(&local->iff_allmultis);
 156                 break;
 157         case NL80211_IFTYPE_STATION:
 158         case NL80211_IFTYPE_MONITOR:
 159         case NL80211_IFTYPE_ADHOC:
 160                 /* no special treatment */
 161                 break;
 162         case NL80211_IFTYPE_UNSPECIFIED:
 163         case __NL80211_IFTYPE_AFTER_LAST:
 164                 /* cannot happen */
 165                 WARN_ON(1);
 166                 break;
 167         }
 168
 169         if (local->open_count == 0) {
 170                 res = drv_start(local);
 171                 if (res)
 172                         goto err_del_bss;
 173                 /* we're brought up, everything changes */
 174                 hw_reconf_flags = ~0;
 175                 ieee80211_led_radio(local, true);
 176         }
 177
 178         /*
 179          * Check all interfaces and copy the hopefully now-present
 180          * MAC address to those that have the special null one.
 181          */
 182         list_for_each_entry(nsdata, &local->interfaces, list) {
 183                 struct net_device *ndev = nsdata->dev;
 184
 185                 /*
 186                  * No need to check netif_running since we do not allow
 187                  * it to start up with this invalid address.
 188                  */
 189                 if (compare_ether_addr(null_addr, ndev->dev_addr) == 0) {
 190                         memcpy(ndev->dev_addr,
 191                                local->hw.wiphy->perm_addr,
 192                                ETH_ALEN);
 193                         memcpy(ndev->perm_addr, ndev->dev_addr, ETH_ALEN);
 194                 }
 195         }
 196
 197         /*
 198          * Validate the MAC address for this device.
 199          */
 200         if (!is_valid_ether_addr(dev->dev_addr)) {
 201                 if (!local->open_count)
 202                         drv_stop(local);
 203                 return -EADDRNOTAVAIL;
 204         }
 205
 206         switch (sdata->vif.type) {
 207         case NL80211_IFTYPE_AP_VLAN:
 208                 /* no need to tell driver */
 209                 break;
 210         case NL80211_IFTYPE_MONITOR:
 211                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
 212                         local->cooked_mntrs++;
 213                         break;
 214                 }
 215
 216                 /* must be before the call to ieee80211_configure_filter */
 217                 local->monitors++;
 218                 if (local->monitors == 1) {
 219                         local->hw.conf.flags |= IEEE80211_CONF_MONITOR;
 220                         hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;
 221                 }
 222
 223                 if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
 224                         local->fif_fcsfail++;
 225                 if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
 226                         local->fif_plcpfail++;
 227                 if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL) {
 228                         local->fif_control++;
 229                         local->fif_pspoll++;
 230                 }
 231                 if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
 232                         local->fif_other_bss++;
 233
 234                 ieee80211_configure_filter(local);
 235                 break;
 236         default:
 237                 conf.vif = &sdata->vif;
 238                 conf.type = sdata->vif.type;
 239                 conf.mac_addr = dev->dev_addr;
 240                 res = drv_add_interface(local, &conf);
 241                 if (res)
 242                         goto err_stop;
 243
 244                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
 245                         local->fif_other_bss++;
 246                         ieee80211_configure_filter(local);
 247
 248                         ieee80211_start_mesh(sdata);
 249                 } else if (sdata->vif.type == NL80211_IFTYPE_AP) {
 250                         local->fif_pspoll++;
 251
 252                         ieee80211_configure_filter(local);
 253                 }
 254
 255                 changed |= ieee80211_reset_erp_info(sdata);
 256                 ieee80211_bss_info_change_notify(sdata, changed);
 257                 ieee80211_enable_keys(sdata);
 258
 259                 if (sdata->vif.type == NL80211_IFTYPE_STATION)
 260                         netif_carrier_off(dev);
 261                 else
 262                         netif_carrier_on(dev);
 263         }
 264
 265         if (sdata->vif.type == NL80211_IFTYPE_WDS) {
 266                 /* Create STA entry for the WDS peer */
 267                 sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
 268                                      GFP_KERNEL);
 269                 if (!sta) {
 270                         res = -ENOMEM;
 271                         goto err_del_interface;
 272                 }
 273
 274                 /* no locking required since STA is not live yet */
 275                 sta->flags |= WLAN_STA_AUTHORIZED;
 276
 277                 res = sta_info_insert(sta);
 278                 if (res) {
 279                         /* STA has been freed */
 280                         goto err_del_interface;
 281                 }
 282         }
 283
 284         /*
 285          * set_multicast_list will be invoked by the networking core
 286          * which will check whether any increments here were done in
 287          * error and sync them down to the hardware as filter flags.
 288          */
 289         if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
 290                 atomic_inc(&local->iff_allmultis);
 291
 292         if (sdata->flags & IEEE80211_SDATA_PROMISC)
 293                 atomic_inc(&local->iff_promiscs);
 294
 295         hw_reconf_flags |= __ieee80211_recalc_idle(local);
 296
 297         local->open_count++;
 298         if (hw_reconf_flags) {
 299                 ieee80211_hw_config(local, hw_reconf_flags);
 300                 /*
 301                  * set default queue parameters so drivers don't
 302                  * need to initialise the hardware if the hardware
 303                  * doesn't start up with sane defaults
 304                  */
 305                 ieee80211_set_wmm_default(sdata);
 306         }
 307
 308         ieee80211_recalc_ps(local, -1);
 309
 310         /*
 311          * ieee80211_sta_work is disabled while network interface
 312          * is down. Therefore, some configuration changes may not
 313          * yet be effective. Trigger execution of ieee80211_sta_work
 314          * to fix this.
 315          */
 316         if (sdata->vif.type == NL80211_IFTYPE_STATION)
 317                 ieee80211_queue_work(&local->hw, &sdata->u.mgd.work);
 318
 319         netif_tx_start_all_queues(dev);
 320
 321         return 0;
 322  err_del_interface:
 323         drv_remove_interface(local, &conf);
 324  err_stop:
 325         if (!local->open_count)
 326                 drv_stop(local);
 327  err_del_bss:
 328         sdata->bss = NULL;
 329         if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 330                 list_del(&sdata->u.vlan.list);
 331         return res;
 332 }
 333
 334 static int ieee80211_stop(struct net_device *dev)
 335 {
 336         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 337         struct ieee80211_local *local = sdata->local;
 338         struct ieee80211_if_init_conf conf;
 339         struct sta_info *sta;
 340         unsigned long flags;
 341         struct sk_buff *skb, *tmp;
 342         u32 hw_reconf_flags = 0;
 343         int i;
 344
 345         /*
 346          * Stop TX on this interface first.
 347          */
 348         netif_tx_stop_all_queues(dev);
 349
 350         /*
 351          * Now delete all active aggregation sessions.
 352          */
 353         rcu_read_lock();
 354
 355         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 356                 if (sta->sdata == sdata)
 357                         ieee80211_sta_tear_down_BA_sessions(sta);
 358         }
 359
 360         rcu_read_unlock();
 361
 362         /*
 363          * Remove all stations associated with this interface.
 364          *
 365          * This must be done before calling ops->remove_interface()
 366          * because otherwise we can later invoke ops->sta_notify()
 367          * whenever the STAs are removed, and that invalidates driver
 368          * assumptions about always getting a vif pointer that is valid
 369          * (because if we remove a STA after ops->remove_interface()
 370          * the driver will have removed the vif info already!)
 371          *
 372          * We could relax this and only unlink the stations from the
 373          * hash table and list but keep them on a per-sdata list that
 374          * will be inserted back again when the interface is brought
 375          * up again, but I don't currently see a use case for that,
 376          * except with WDS which gets a STA entry created when it is
 377          * brought up.
 378          */
 379         sta_info_flush(local, sdata);
 380
 381         /*
 382          * Don't count this interface for promisc/allmulti while it
 383          * is down. dev_mc_unsync() will invoke set_multicast_list
 384          * on the master interface which will sync these down to the
 385          * hardware as filter flags.
 386          */
 387         if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
 388                 atomic_dec(&local->iff_allmultis);
 389
 390         if (sdata->flags & IEEE80211_SDATA_PROMISC)
 391                 atomic_dec(&local->iff_promiscs);
 392
 393         if (sdata->vif.type == NL80211_IFTYPE_AP)
 394                 local->fif_pspoll--;
 395
 396         netif_addr_lock_bh(dev);
 397         spin_lock_bh(&local->filter_lock);
 398         __dev_addr_unsync(&local->mc_list, &local->mc_count,
 399                           &dev->mc_list, &dev->mc_count);
 400         spin_unlock_bh(&local->filter_lock);
 401         netif_addr_unlock_bh(dev);
 402
 403         ieee80211_configure_filter(local);
 404
 405         del_timer_sync(&local->dynamic_ps_timer);
 406         cancel_work_sync(&local->dynamic_ps_enable_work);
 407
 408         /* APs need special treatment */
 409         if (sdata->vif.type == NL80211_IFTYPE_AP) {
 410                 struct ieee80211_sub_if_data *vlan, *tmpsdata;
 411                 struct beacon_data *old_beacon = sdata->u.ap.beacon;
 412
 413                 /* remove beacon */
 414                 rcu_assign_pointer(sdata->u.ap.beacon, NULL);
 415                 synchronize_rcu();
 416                 kfree(old_beacon);
 417
 418                 /* down all dependent devices, that is VLANs */
 419                 list_for_each_entry_safe(vlan, tmpsdata, &sdata->u.ap.vlans,
 420                                          u.vlan.list)
 421                         dev_close(vlan->dev);
 422                 WARN_ON(!list_empty(&sdata->u.ap.vlans));
 423         }
 424
 425         local->open_count--;
 426
 427         switch (sdata->vif.type) {
 428         case NL80211_IFTYPE_AP_VLAN:
 429                 list_del(&sdata->u.vlan.list);
 430                 /* no need to tell driver */
 431                 break;
 432         case NL80211_IFTYPE_MONITOR:
 433                 if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
 434                         local->cooked_mntrs--;
 435                         break;
 436                 }
 437
 438                 local->monitors--;
 439                 if (local->monitors == 0) {
 440                         local->hw.conf.flags &= ~IEEE80211_CONF_MONITOR;
 441                         hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;
 442                 }
 443
 444                 if (sdata->u.mntr_flags & MONITOR_FLAG_FCSFAIL)
 445                         local->fif_fcsfail--;
 446                 if (sdata->u.mntr_flags & MONITOR_FLAG_PLCPFAIL)
 447                         local->fif_plcpfail--;
 448                 if (sdata->u.mntr_flags & MONITOR_FLAG_CONTROL) {
 449                         local->fif_pspoll--;
 450                         local->fif_control--;
 451                 }
 452                 if (sdata->u.mntr_flags & MONITOR_FLAG_OTHER_BSS)
 453                         local->fif_other_bss--;
 454
 455                 ieee80211_configure_filter(local);
 456                 break;
 457         case NL80211_IFTYPE_STATION:
 458                 del_timer_sync(&sdata->u.mgd.chswitch_timer);
 459                 del_timer_sync(&sdata->u.mgd.timer);
 460                 del_timer_sync(&sdata->u.mgd.conn_mon_timer);
 461                 del_timer_sync(&sdata->u.mgd.bcn_mon_timer);
 462                 /*
 463                  * If any of the timers fired while we waited for it, it will
 464                  * have queued its work. Now the work will be running again
 465                  * but will not rearm the timer again because it checks
 466                  * whether the interface is running, which, at this point,
 467                  * it no longer is.
 468                  */
 469                 cancel_work_sync(&sdata->u.mgd.work);
 470                 cancel_work_sync(&sdata->u.mgd.chswitch_work);
 471                 cancel_work_sync(&sdata->u.mgd.monitor_work);
 472                 cancel_work_sync(&sdata->u.mgd.beacon_loss_work);
 473
 474                 /*
 475                  * When we get here, the interface is marked down.
 476                  * Call synchronize_rcu() to wait for the RX path
 477                  * should it be using the interface and enqueuing
 478                  * frames at this very time on another CPU.
 479                  */
 480                 synchronize_rcu();
 481                 skb_queue_purge(&sdata->u.mgd.skb_queue);
 482                 /* fall through */
 483         case NL80211_IFTYPE_ADHOC:
 484                 if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
 485                         del_timer_sync(&sdata->u.ibss.timer);
 486                         cancel_work_sync(&sdata->u.ibss.work);
 487                         synchronize_rcu();
 488                         skb_queue_purge(&sdata->u.ibss.skb_queue);
 489                 }
 490                 /* fall through */
 491         case NL80211_IFTYPE_MESH_POINT:
 492                 if (ieee80211_vif_is_mesh(&sdata->vif)) {
 493                         /* other_bss and allmulti are always set on mesh
 494                          * ifaces */
 495                         local->fif_other_bss--;
 496                         atomic_dec(&local->iff_allmultis);
 497
 498                         ieee80211_configure_filter(local);
 499
 500                         ieee80211_stop_mesh(sdata);
 501                 }
 502                 /* fall through */
 503         default:
 504                 if (local->scan_sdata == sdata)
 505                         ieee80211_scan_cancel(local);
 506
 507                 /*
 508                  * Disable beaconing for AP and mesh, IBSS can't
 509                  * still be joined to a network at this point.
 510                  */
 511                 if (sdata->vif.type == NL80211_IFTYPE_AP ||
 512                     sdata->vif.type == NL80211_IFTYPE_MESH_POINT) {
 513                         ieee80211_bss_info_change_notify(sdata,
 514                                 BSS_CHANGED_BEACON_ENABLED);
 515                 }
 516
 517                 conf.vif = &sdata->vif;
 518                 conf.type = sdata->vif.type;
 519                 conf.mac_addr = dev->dev_addr;
 520                 /* disable all keys for as long as this netdev is down */
 521                 ieee80211_disable_keys(sdata);
 522                 drv_remove_interface(local, &conf);
 523         }
 524
 525         sdata->bss = NULL;
 526
 527         hw_reconf_flags |= __ieee80211_recalc_idle(local);
 528
 529         ieee80211_recalc_ps(local, -1);
 530
 531         if (local->open_count == 0) {
 532                 ieee80211_clear_tx_pending(local);
 533                 ieee80211_stop_device(local);
 534
 535                 /* no reconfiguring after stop! */
 536                 hw_reconf_flags = 0;
 537         }
 538
 539         /* do after stop to avoid reconfiguring when we stop anyway */
 540         if (hw_reconf_flags)
 541                 ieee80211_hw_config(local, hw_reconf_flags);
 542
 543         spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
 544         for (i = 0; i < IEEE80211_MAX_QUEUES; i++) {
 545                 skb_queue_walk_safe(&local->pending[i], skb, tmp) {
 546                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 547                         if (info->control.vif == &sdata->vif) {
 548                                 __skb_unlink(skb, &local->pending[i]);
 549                                 dev_kfree_skb_irq(skb);
 550                         }
 551                 }
 552         }
 553         spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
 554
 555         return 0;
 556 }
 557
 558 static void ieee80211_set_multicast_list(struct net_device *dev)
 559 {
 560         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 561         struct ieee80211_local *local = sdata->local;
 562         int allmulti, promisc, sdata_allmulti, sdata_promisc;
 563
 564         allmulti = !!(dev->flags & IFF_ALLMULTI);
 565         promisc = !!(dev->flags & IFF_PROMISC);
 566         sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
 567         sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);
 568
 569         if (allmulti != sdata_allmulti) {
 570                 if (dev->flags & IFF_ALLMULTI)
 571                         atomic_inc(&local->iff_allmultis);
 572                 else
 573                         atomic_dec(&local->iff_allmultis);
 574                 sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
 575         }
 576
 577         if (promisc != sdata_promisc) {
 578                 if (dev->flags & IFF_PROMISC)
 579                         atomic_inc(&local->iff_promiscs);
 580                 else
 581                         atomic_dec(&local->iff_promiscs);
 582                 sdata->flags ^= IEEE80211_SDATA_PROMISC;
 583         }
 584         spin_lock_bh(&local->filter_lock);
 585         __dev_addr_sync(&local->mc_list, &local->mc_count,
 586                         &dev->mc_list, &dev->mc_count);
 587         spin_unlock_bh(&local->filter_lock);
 588         ieee80211_queue_work(&local->hw, &local->reconfig_filter);
 589 }
 590
 591 /*
 592  * Called when the netdev is removed or, by the code below, before
 593  * the interface type changes.
 594  */
 595 static void ieee80211_teardown_sdata(struct net_device *dev)
 596 {
 597         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 598         struct ieee80211_local *local = sdata->local;
 599         struct beacon_data *beacon;
 600         struct sk_buff *skb;
 601         int flushed;
 602         int i;
 603
 604         /* free extra data */
 605         ieee80211_free_keys(sdata);
 606
 607         ieee80211_debugfs_remove_netdev(sdata);
 608
 609         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
 610                 __skb_queue_purge(&sdata->fragments[i].skb_list);
 611         sdata->fragment_next = 0;
 612
 613         switch (sdata->vif.type) {
 614         case NL80211_IFTYPE_AP:
 615                 beacon = sdata->u.ap.beacon;
 616                 rcu_assign_pointer(sdata->u.ap.beacon, NULL);
 617                 synchronize_rcu();
 618                 kfree(beacon);
 619
 620                 while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
 621                         local->total_ps_buffered--;
 622                         dev_kfree_skb(skb);
 623                 }
 624
 625                 break;
 626         case NL80211_IFTYPE_MESH_POINT:
 627                 if (ieee80211_vif_is_mesh(&sdata->vif))
 628                         mesh_rmc_free(sdata);
 629                 break;
 630         case NL80211_IFTYPE_ADHOC:
 631                 if (WARN_ON(sdata->u.ibss.presp))
 632                         kfree_skb(sdata->u.ibss.presp);
 633                 break;
 634         case NL80211_IFTYPE_STATION:
 635         case NL80211_IFTYPE_WDS:
 636         case NL80211_IFTYPE_AP_VLAN:
 637         case NL80211_IFTYPE_MONITOR:
 638                 break;
 639         case NL80211_IFTYPE_UNSPECIFIED:
 640         case __NL80211_IFTYPE_AFTER_LAST:
 641                 BUG();
 642                 break;
 643         }
 644
 645         flushed = sta_info_flush(local, sdata);
 646         WARN_ON(flushed);
 647 }
 648
 649 static u16 ieee80211_netdev_select_queue(struct net_device *dev,
 650                                          struct sk_buff *skb)
 651 {
 652         return ieee80211_select_queue(IEEE80211_DEV_TO_SUB_IF(dev), skb);
 653 }
 654
 655 static const struct net_device_ops ieee80211_dataif_ops = {
 656         .ndo_open               = ieee80211_open,
 657         .ndo_stop               = ieee80211_stop,
 658         .ndo_uninit             = ieee80211_teardown_sdata,
 659         .ndo_start_xmit         = ieee80211_subif_start_xmit,
 660         .ndo_set_multicast_list = ieee80211_set_multicast_list,
 661         .ndo_change_mtu         = ieee80211_change_mtu,
 662         .ndo_set_mac_address    = eth_mac_addr,
 663         .ndo_select_queue       = ieee80211_netdev_select_queue,
 664 };
 665
 666 static u16 ieee80211_monitor_select_queue(struct net_device *dev,
 667                                           struct sk_buff *skb)
 668 {
 669         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 670         struct ieee80211_local *local = sdata->local;
 671         struct ieee80211_hdr *hdr;
 672         struct ieee80211_radiotap_header *rtap = (void *)skb->data;
 673
 674         if (local->hw.queues < 4)
 675                 return 0;
 676
 677         if (skb->len < 4 ||
 678             skb->len < rtap->it_len + 2 /* frame control */)
 679                 return 0; /* doesn't matter, frame will be dropped */
 680
 681         hdr = (void *)((u8 *)skb->data + rtap->it_len);
 682
 683         if (!ieee80211_is_data(hdr->frame_control)) {
 684                 skb->priority = 7;
 685                 return ieee802_1d_to_ac[skb->priority];
 686         }
 687
 688         return ieee80211_downgrade_queue(local, skb);
 689 }
 690
 691 static const struct net_device_ops ieee80211_monitorif_ops = {
 692         .ndo_open               = ieee80211_open,
 693         .ndo_stop               = ieee80211_stop,
 694         .ndo_uninit             = ieee80211_teardown_sdata,
 695         .ndo_start_xmit         = ieee80211_monitor_start_xmit,
 696         .ndo_set_multicast_list = ieee80211_set_multicast_list,
 697         .ndo_change_mtu         = ieee80211_change_mtu,
 698         .ndo_set_mac_address    = eth_mac_addr,
 699         .ndo_select_queue       = ieee80211_monitor_select_queue,
 700 };
 701
 702 static void ieee80211_if_setup(struct net_device *dev)
 703 {
 704         ether_setup(dev);
 705         dev->netdev_ops = &ieee80211_dataif_ops;
 706         dev->destructor = free_netdev;
 707 }
 708
 709 /*
 710  * Helper function to initialise an interface to a specific type.
 711  */
 712 static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,
 713                                   enum nl80211_iftype type)
 714 {
 715         /* clear type-dependent union */
 716         memset(&sdata->u, 0, sizeof(sdata->u));
 717
 718         /* and set some type-dependent values */
 719         sdata->vif.type = type;
 720         sdata->dev->netdev_ops = &ieee80211_dataif_ops;
 721         sdata->wdev.iftype = type;
 722
 723         /* only monitor differs */
 724         sdata->dev->type = ARPHRD_ETHER;
 725
 726         switch (type) {
 727         case NL80211_IFTYPE_AP:
 728                 skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
 729                 INIT_LIST_HEAD(&sdata->u.ap.vlans);
 730                 break;
 731         case NL80211_IFTYPE_STATION:
 732                 ieee80211_sta_setup_sdata(sdata);
 733                 break;
 734         case NL80211_IFTYPE_ADHOC:
 735                 ieee80211_ibss_setup_sdata(sdata);
 736                 break;
 737         case NL80211_IFTYPE_MESH_POINT:
 738                 if (ieee80211_vif_is_mesh(&sdata->vif))
 739                         ieee80211_mesh_init_sdata(sdata);
 740                 break;
 741         case NL80211_IFTYPE_MONITOR:
 742                 sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;
 743                 sdata->dev->netdev_ops = &ieee80211_monitorif_ops;
 744                 sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
 745                                       MONITOR_FLAG_OTHER_BSS;
 746                 break;
 747         case NL80211_IFTYPE_WDS:
 748         case NL80211_IFTYPE_AP_VLAN:
 749                 break;
 750         case NL80211_IFTYPE_UNSPECIFIED:
 751         case __NL80211_IFTYPE_AFTER_LAST:
 752                 BUG();
 753                 break;
 754         }
 755
 756         ieee80211_debugfs_add_netdev(sdata);
 757 }
 758
 759 int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
 760                              enum nl80211_iftype type)
 761 {
 762         ASSERT_RTNL();
 763
 764         if (type == sdata->vif.type)
 765                 return 0;
 766
 767         /* Setting ad-hoc mode on non-IBSS channel is not supported. */
 768         if (sdata->local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS &&
 769             type == NL80211_IFTYPE_ADHOC)
 770                 return -EOPNOTSUPP;
 771
 772         /*
 773          * We could, here, on changes between IBSS/STA/MESH modes,
 774          * invoke an MLME function instead that disassociates etc.
 775          * and goes into the requested mode.
 776          */
 777
 778         if (netif_running(sdata->dev))
 779                 return -EBUSY;
 780
 781         /* Purge and reset type-dependent state. */
 782         ieee80211_teardown_sdata(sdata->dev);
 783         ieee80211_setup_sdata(sdata, type);
 784
 785         /* reset some values that shouldn't be kept across type changes */
 786         sdata->vif.bss_conf.basic_rates =
 787                 ieee80211_mandatory_rates(sdata->local,
 788                         sdata->local->hw.conf.channel->band);
 789         sdata->drop_unencrypted = 0;
 790         if (type == NL80211_IFTYPE_STATION)
 791                 sdata->u.mgd.use_4addr = false;
 792
 793         return 0;
 794 }
 795
 796 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 797                      struct net_device **new_dev, enum nl80211_iftype type,
 798                      struct vif_params *params)
 799 {
 800         struct net_device *ndev;
 801         struct ieee80211_sub_if_data *sdata = NULL;
 802         int ret, i;
 803
 804         ASSERT_RTNL();
 805
 806         ndev = alloc_netdev_mq(sizeof(*sdata) + local->hw.vif_data_size,
 807                                name, ieee80211_if_setup, local->hw.queues);
 808         if (!ndev)
 809                 return -ENOMEM;
 810         dev_net_set(ndev, wiphy_net(local->hw.wiphy));
 811
 812         ndev->needed_headroom = local->tx_headroom +
 813                                 4*6 /* four MAC addresses */
 814                                 + 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
 815                                 + 6 /* mesh */
 816                                 + 8 /* rfc1042/bridge tunnel */
 817                                 - ETH_HLEN /* ethernet hard_header_len */
 818                                 + IEEE80211_ENCRYPT_HEADROOM;
 819         ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;
 820
 821         ret = dev_alloc_name(ndev, ndev->name);
 822         if (ret < 0)
 823                 goto fail;
 824
 825         memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
 826         memcpy(ndev->perm_addr, ndev->dev_addr, ETH_ALEN);
 827         SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
 828
 829         /* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
 830         sdata = netdev_priv(ndev);
 831         ndev->ieee80211_ptr = &sdata->wdev;
 832
 833         /* initialise type-independent data */
 834         sdata->wdev.wiphy = local->hw.wiphy;
 835         sdata->local = local;
 836         sdata->dev = ndev;
 837
 838         for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
 839                 skb_queue_head_init(&sdata->fragments[i].skb_list);
 840
 841         INIT_LIST_HEAD(&sdata->key_list);
 842
 843         sdata->force_unicast_rateidx = -1;
 844         sdata->max_ratectrl_rateidx = -1;
 845
 846         /* setup type-dependent data */
 847         ieee80211_setup_sdata(sdata, type);
 848
 849         if (params) {
 850                 ndev->ieee80211_ptr->use_4addr = params->use_4addr;
 851                 if (type == NL80211_IFTYPE_STATION)
 852                         sdata->u.mgd.use_4addr = params->use_4addr;
 853         }
 854
 855         ret = register_netdevice(ndev);
 856         if (ret)
 857                 goto fail;
 858
 859         if (ieee80211_vif_is_mesh(&sdata->vif) &&
 860             params && params->mesh_id_len)
 861                 ieee80211_sdata_set_mesh_id(sdata,
 862                                             params->mesh_id_len,
 863                                             params->mesh_id);
 864
 865         mutex_lock(&local->iflist_mtx);
 866         list_add_tail_rcu(&sdata->list, &local->interfaces);
 867         mutex_unlock(&local->iflist_mtx);
 868
 869         if (new_dev)
 870                 *new_dev = ndev;
 871
 872         return 0;
 873
 874  fail:
 875         free_netdev(ndev);
 876         return ret;
 877 }
 878
 879 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
 880 {
 881         ASSERT_RTNL();
 882
 883         mutex_lock(&sdata->local->iflist_mtx);
 884         list_del_rcu(&sdata->list);
 885         mutex_unlock(&sdata->local->iflist_mtx);
 886
 887         synchronize_rcu();
 888         unregister_netdevice(sdata->dev);
 889 }
 890
 891 /*
 892  * Remove all interfaces, may only be called at hardware unregistration
 893  * time because it doesn't do RCU-safe list removals.
 894  */
 895 void ieee80211_remove_interfaces(struct ieee80211_local *local)
 896 {
 897         struct ieee80211_sub_if_data *sdata, *tmp;
 898         LIST_HEAD(unreg_list);
 899
 900         ASSERT_RTNL();
 901
 902         mutex_lock(&local->iflist_mtx);
 903         list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
 904                 list_del(&sdata->list);
 905
 906                 unregister_netdevice_queue(sdata->dev, &unreg_list);
 907         }
 908         mutex_unlock(&local->iflist_mtx);
 909         unregister_netdevice_many(&unreg_list);
 910 }
 911
 912 static u32 ieee80211_idle_off(struct ieee80211_local *local,
 913                               const char *reason)
 914 {
 915         if (!(local->hw.conf.flags & IEEE80211_CONF_IDLE))
 916                 return 0;
 917
 918 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 919         printk(KERN_DEBUG "%s: device no longer idle - %s\n",
 920                wiphy_name(local->hw.wiphy), reason);
 921 #endif
 922
 923         local->hw.conf.flags &= ~IEEE80211_CONF_IDLE;
 924         return IEEE80211_CONF_CHANGE_IDLE;
 925 }
 926
 927 static u32 ieee80211_idle_on(struct ieee80211_local *local)
 928 {
 929         if (local->hw.conf.flags & IEEE80211_CONF_IDLE)
 930                 return 0;
 931
 932 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 933         printk(KERN_DEBUG "%s: device now idle\n",
 934                wiphy_name(local->hw.wiphy));
 935 #endif
 936
 937         local->hw.conf.flags |= IEEE80211_CONF_IDLE;
 938         return IEEE80211_CONF_CHANGE_IDLE;
 939 }
 940
 941 u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
 942 {
 943         struct ieee80211_sub_if_data *sdata;
 944         int count = 0;
 945
 946         if (local->scanning)
 947                 return ieee80211_idle_off(local, "scanning");
 948
 949         list_for_each_entry(sdata, &local->interfaces, list) {
 950                 if (!netif_running(sdata->dev))
 951                         continue;
 952                 /* do not count disabled managed interfaces */
 953                 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 954                     !sdata->u.mgd.associated &&
 955                     list_empty(&sdata->u.mgd.work_list))
 956                         continue;
 957                 /* do not count unused IBSS interfaces */
 958                 if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
 959                     !sdata->u.ibss.ssid_len)
 960                         continue;
 961                 /* count everything else */
 962                 count++;
 963         }
 964
 965         if (!count)
 966                 return ieee80211_idle_on(local);
 967         else
 968                 return ieee80211_idle_off(local, "in use");
 969
 970         return 0;
 971 }
 972
 973 void ieee80211_recalc_idle(struct ieee80211_local *local)
 974 {
 975         u32 chg;
 976
 977         mutex_lock(&local->iflist_mtx);
 978         chg = __ieee80211_recalc_idle(local);
 979         mutex_unlock(&local->iflist_mtx);
 980         if (chg)
 981                 ieee80211_hw_config(local, chg);
 982 }