net/batman-adv/hard-interface.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (C) 2007-2018  B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner, Simon Wunderlich
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include "hard-interface.h"
  20 #include "main.h"
  21
  22 #include <linux/atomic.h>
  23 #include <linux/byteorder/generic.h>
  24 #include <linux/errno.h>
  25 #include <linux/gfp.h>
  26 #include <linux/if.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/kernel.h>
  30 #include <linux/kref.h>
  31 #include <linux/list.h>
  32 #include <linux/mutex.h>
  33 #include <linux/netdevice.h>
  34 #include <linux/printk.h>
  35 #include <linux/rculist.h>
  36 #include <linux/rtnetlink.h>
  37 #include <linux/slab.h>
  38 #include <linux/spinlock.h>
  39 #include <net/net_namespace.h>
  40 #include <net/rtnetlink.h>
  41 #include <uapi/linux/batadv_packet.h>
  42
  43 #include "bat_v.h"
  44 #include "bridge_loop_avoidance.h"
  45 #include "debugfs.h"
  46 #include "distributed-arp-table.h"
  47 #include "gateway_client.h"
  48 #include "log.h"
  49 #include "originator.h"
  50 #include "send.h"
  51 #include "soft-interface.h"
  52 #include "sysfs.h"
  53 #include "translation-table.h"
  54
  55 /**
  56  * batadv_hardif_release() - release hard interface from lists and queue for
  57  *  free after rcu grace period
  58  * @ref: kref pointer of the hard interface
  59  */
  60 void batadv_hardif_release(struct kref *ref)
  61 {
  62         struct batadv_hard_iface *hard_iface;
  63
  64         hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
  65         dev_put(hard_iface->net_dev);
  66
  67         kfree_rcu(hard_iface, rcu);
  68 }
  69
  70 /**
  71  * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
  72  * @net_dev: net_device to search for
  73  *
  74  * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
  75  */
  76 struct batadv_hard_iface *
  77 batadv_hardif_get_by_netdev(const struct net_device *net_dev)
  78 {
  79         struct batadv_hard_iface *hard_iface;
  80
  81         rcu_read_lock();
  82         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  83                 if (hard_iface->net_dev == net_dev &&
  84                     kref_get_unless_zero(&hard_iface->refcount))
  85                         goto out;
  86         }
  87
  88         hard_iface = NULL;
  89
  90 out:
  91         rcu_read_unlock();
  92         return hard_iface;
  93 }
  94
  95 /**
  96  * batadv_getlink_net() - return link net namespace (of use fallback)
  97  * @netdev: net_device to check
  98  * @fallback_net: return in case get_link_net is not available for @netdev
  99  *
 100  * Return: result of rtnl_link_ops->get_link_net or @fallback_net
 101  */
 102 static struct net *batadv_getlink_net(const struct net_device *netdev,
 103                                       struct net *fallback_net)
 104 {
 105         if (!netdev->rtnl_link_ops)
 106                 return fallback_net;
 107
 108         if (!netdev->rtnl_link_ops->get_link_net)
 109                 return fallback_net;
 110
 111         return netdev->rtnl_link_ops->get_link_net(netdev);
 112 }
 113
 114 /**
 115  * batadv_mutual_parents() - check if two devices are each others parent
 116  * @dev1: 1st net dev
 117  * @net1: 1st devices netns
 118  * @dev2: 2nd net dev
 119  * @net2: 2nd devices netns
 120  *
 121  * veth devices come in pairs and each is the parent of the other!
 122  *
 123  * Return: true if the devices are each others parent, otherwise false
 124  */
 125 static bool batadv_mutual_parents(const struct net_device *dev1,
 126                                   struct net *net1,
 127                                   const struct net_device *dev2,
 128                                   struct net *net2)
 129 {
 130         int dev1_parent_iflink = dev_get_iflink(dev1);
 131         int dev2_parent_iflink = dev_get_iflink(dev2);
 132         const struct net *dev1_parent_net;
 133         const struct net *dev2_parent_net;
 134
 135         dev1_parent_net = batadv_getlink_net(dev1, net1);
 136         dev2_parent_net = batadv_getlink_net(dev2, net2);
 137
 138         if (!dev1_parent_iflink || !dev2_parent_iflink)
 139                 return false;
 140
 141         return (dev1_parent_iflink == dev2->ifindex) &&
 142                (dev2_parent_iflink == dev1->ifindex) &&
 143                net_eq(dev1_parent_net, net2) &&
 144                net_eq(dev2_parent_net, net1);
 145 }
 146
 147 /**
 148  * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
 149  * @net_dev: the device to check
 150  *
 151  * If the user creates any virtual device on top of a batman-adv interface, it
 152  * is important to prevent this new interface to be used to create a new mesh
 153  * network (this behaviour would lead to a batman-over-batman configuration).
 154  * This function recursively checks all the fathers of the device passed as
 155  * argument looking for a batman-adv soft interface.
 156  *
 157  * Return: true if the device is descendant of a batman-adv mesh interface (or
 158  * if it is a batman-adv interface itself), false otherwise
 159  */
 160 static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
 161 {
 162         struct net *net = dev_net(net_dev);
 163         struct net_device *parent_dev;
 164         struct net *parent_net;
 165         bool ret;
 166
 167         /* check if this is a batman-adv mesh interface */
 168         if (batadv_softif_is_valid(net_dev))
 169                 return true;
 170
 171         /* no more parents..stop recursion */
 172         if (dev_get_iflink(net_dev) == 0 ||
 173             dev_get_iflink(net_dev) == net_dev->ifindex)
 174                 return false;
 175
 176         parent_net = batadv_getlink_net(net_dev, net);
 177
 178         /* recurse over the parent device */
 179         parent_dev = __dev_get_by_index((struct net *)parent_net,
 180                                         dev_get_iflink(net_dev));
 181         /* if we got a NULL parent_dev there is something broken.. */
 182         if (!parent_dev) {
 183                 pr_err("Cannot find parent device\n");
 184                 return false;
 185         }
 186
 187         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 188                 return false;
 189
 190         ret = batadv_is_on_batman_iface(parent_dev);
 191
 192         return ret;
 193 }
 194
 195 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 196 {
 197         if (net_dev->flags & IFF_LOOPBACK)
 198                 return false;
 199
 200         if (net_dev->type != ARPHRD_ETHER)
 201                 return false;
 202
 203         if (net_dev->addr_len != ETH_ALEN)
 204                 return false;
 205
 206         /* no batman over batman */
 207         if (batadv_is_on_batman_iface(net_dev))
 208                 return false;
 209
 210         return true;
 211 }
 212
 213 /**
 214  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 215  *  interface on top of another 'real' interface
 216  * @netdev: the device to check
 217  *
 218  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 219  * instead of this.
 220  *
 221  * Return: the 'real' net device or the original net device and NULL in case
 222  *  of an error.
 223  */
 224 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 225 {
 226         struct batadv_hard_iface *hard_iface = NULL;
 227         struct net_device *real_netdev = NULL;
 228         struct net *real_net;
 229         struct net *net;
 230         int ifindex;
 231
 232         ASSERT_RTNL();
 233
 234         if (!netdev)
 235                 return NULL;
 236
 237         if (netdev->ifindex == dev_get_iflink(netdev)) {
 238                 dev_hold(netdev);
 239                 return netdev;
 240         }
 241
 242         hard_iface = batadv_hardif_get_by_netdev(netdev);
 243         if (!hard_iface || !hard_iface->soft_iface)
 244                 goto out;
 245
 246         net = dev_net(hard_iface->soft_iface);
 247         ifindex = dev_get_iflink(netdev);
 248         real_net = batadv_getlink_net(netdev, net);
 249         real_netdev = dev_get_by_index(real_net, ifindex);
 250
 251 out:
 252         if (hard_iface)
 253                 batadv_hardif_put(hard_iface);
 254         return real_netdev;
 255 }
 256
 257 /**
 258  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 259  *  interface on top of another 'real' interface
 260  * @net_device: the device to check
 261  *
 262  * Return: the 'real' net device or the original net device and NULL in case
 263  *  of an error.
 264  */
 265 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 266 {
 267         struct net_device *real_netdev;
 268
 269         rtnl_lock();
 270         real_netdev = batadv_get_real_netdevice(net_device);
 271         rtnl_unlock();
 272
 273         return real_netdev;
 274 }
 275
 276 /**
 277  * batadv_is_wext_netdev() - check if the given net_device struct is a
 278  *  wext wifi interface
 279  * @net_device: the device to check
 280  *
 281  * Return: true if the net device is a wext wireless device, false
 282  *  otherwise.
 283  */
 284 static bool batadv_is_wext_netdev(struct net_device *net_device)
 285 {
 286         if (!net_device)
 287                 return false;
 288
 289 #ifdef CONFIG_WIRELESS_EXT
 290         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 291          * check for wireless_handlers != NULL
 292          */
 293         if (net_device->wireless_handlers)
 294                 return true;
 295 #endif
 296
 297         return false;
 298 }
 299
 300 /**
 301  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 302  *  cfg80211 wifi interface
 303  * @net_device: the device to check
 304  *
 305  * Return: true if the net device is a cfg80211 wireless device, false
 306  *  otherwise.
 307  */
 308 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 309 {
 310         if (!net_device)
 311                 return false;
 312
 313         /* cfg80211 drivers have to set ieee80211_ptr */
 314         if (net_device->ieee80211_ptr)
 315                 return true;
 316
 317         return false;
 318 }
 319
 320 /**
 321  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 322  * @net_device: the device to check
 323  *
 324  * Return: batadv_hard_iface_wifi_flags flags of the device
 325  */
 326 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 327 {
 328         u32 wifi_flags = 0;
 329         struct net_device *real_netdev;
 330
 331         if (batadv_is_wext_netdev(net_device))
 332                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 333
 334         if (batadv_is_cfg80211_netdev(net_device))
 335                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 336
 337         real_netdev = batadv_get_real_netdevice(net_device);
 338         if (!real_netdev)
 339                 return wifi_flags;
 340
 341         if (real_netdev == net_device)
 342                 goto out;
 343
 344         if (batadv_is_wext_netdev(real_netdev))
 345                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 346
 347         if (batadv_is_cfg80211_netdev(real_netdev))
 348                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 349
 350 out:
 351         dev_put(real_netdev);
 352         return wifi_flags;
 353 }
 354
 355 /**
 356  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 357  *  interface
 358  * @hard_iface: the device to check
 359  *
 360  * Return: true if the net device is a cfg80211 wireless device, false
 361  *  otherwise.
 362  */
 363 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 364 {
 365         u32 allowed_flags = 0;
 366
 367         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 368         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 369
 370         return !!(hard_iface->wifi_flags & allowed_flags);
 371 }
 372
 373 /**
 374  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 375  * @hard_iface: the device to check
 376  *
 377  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 378  */
 379 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 380 {
 381         if (!hard_iface)
 382                 return false;
 383
 384         return hard_iface->wifi_flags != 0;
 385 }
 386
 387 /**
 388  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 389  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 390  * @orig_addr: the originator of this packet
 391  * @orig_neigh: originator address of the forwarder we just got the packet from
 392  *  (NULL if we originated)
 393  *
 394  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 395  *
 396  * Return:
 397  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 398  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 399  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 400  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 401  */
 402 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 403                                u8 *orig_addr, u8 *orig_neigh)
 404 {
 405         struct batadv_hardif_neigh_node *hardif_neigh;
 406         struct hlist_node *first;
 407         int ret = BATADV_HARDIF_BCAST_OK;
 408
 409         rcu_read_lock();
 410
 411         /* 0 neighbors -> no (re)broadcast */
 412         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 413         if (!first) {
 414                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 415                 goto out;
 416         }
 417
 418         /* >1 neighbors -> (re)brodcast */
 419         if (rcu_dereference(hlist_next_rcu(first)))
 420                 goto out;
 421
 422         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 423                                    list);
 424
 425         /* 1 neighbor, is the originator -> no rebroadcast */
 426         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 427                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 428         /* 1 neighbor, is the one we received from -> no rebroadcast */
 429         } else if (orig_neigh &&
 430                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 431                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 432         }
 433
 434 out:
 435         rcu_read_unlock();
 436         return ret;
 437 }
 438
 439 static struct batadv_hard_iface *
 440 batadv_hardif_get_active(const struct net_device *soft_iface)
 441 {
 442         struct batadv_hard_iface *hard_iface;
 443
 444         rcu_read_lock();
 445         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 446                 if (hard_iface->soft_iface != soft_iface)
 447                         continue;
 448
 449                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 450                     kref_get_unless_zero(&hard_iface->refcount))
 451                         goto out;
 452         }
 453
 454         hard_iface = NULL;
 455
 456 out:
 457         rcu_read_unlock();
 458         return hard_iface;
 459 }
 460
 461 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 462                                           struct batadv_hard_iface *oldif)
 463 {
 464         struct batadv_hard_iface *primary_if;
 465
 466         primary_if = batadv_primary_if_get_selected(bat_priv);
 467         if (!primary_if)
 468                 goto out;
 469
 470         batadv_dat_init_own_addr(bat_priv, primary_if);
 471         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 472 out:
 473         if (primary_if)
 474                 batadv_hardif_put(primary_if);
 475 }
 476
 477 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 478                                      struct batadv_hard_iface *new_hard_iface)
 479 {
 480         struct batadv_hard_iface *curr_hard_iface;
 481
 482         ASSERT_RTNL();
 483
 484         if (new_hard_iface)
 485                 kref_get(&new_hard_iface->refcount);
 486
 487         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 488         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 489
 490         if (!new_hard_iface)
 491                 goto out;
 492
 493         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 494         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 495
 496 out:
 497         if (curr_hard_iface)
 498                 batadv_hardif_put(curr_hard_iface);
 499 }
 500
 501 static bool
 502 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 503 {
 504         if (hard_iface->net_dev->flags & IFF_UP)
 505                 return true;
 506
 507         return false;
 508 }
 509
 510 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 511 {
 512         const struct batadv_hard_iface *hard_iface;
 513
 514         rcu_read_lock();
 515         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 516                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 517                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 518                         continue;
 519
 520                 if (hard_iface->net_dev == net_dev)
 521                         continue;
 522
 523                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 524                                         net_dev->dev_addr))
 525                         continue;
 526
 527                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 528                         net_dev->dev_addr, hard_iface->net_dev->name);
 529                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 530         }
 531         rcu_read_unlock();
 532 }
 533
 534 /**
 535  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 536  * @soft_iface: netdev struct of the mesh interface
 537  */
 538 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 539 {
 540         const struct batadv_hard_iface *hard_iface;
 541         unsigned short lower_header_len = ETH_HLEN;
 542         unsigned short lower_headroom = 0;
 543         unsigned short lower_tailroom = 0;
 544         unsigned short needed_headroom;
 545
 546         rcu_read_lock();
 547         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 548                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 549                         continue;
 550
 551                 if (hard_iface->soft_iface != soft_iface)
 552                         continue;
 553
 554                 lower_header_len = max_t(unsigned short, lower_header_len,
 555                                          hard_iface->net_dev->hard_header_len);
 556
 557                 lower_headroom = max_t(unsigned short, lower_headroom,
 558                                        hard_iface->net_dev->needed_headroom);
 559
 560                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 561                                        hard_iface->net_dev->needed_tailroom);
 562         }
 563         rcu_read_unlock();
 564
 565         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 566         needed_headroom += batadv_max_header_len();
 567
 568         soft_iface->needed_headroom = needed_headroom;
 569         soft_iface->needed_tailroom = lower_tailroom;
 570 }
 571
 572 /**
 573  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 574  * @soft_iface: netdev struct of the soft interface
 575  *
 576  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 577  *  slave interfaces)
 578  */
 579 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 580 {
 581         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 582         const struct batadv_hard_iface *hard_iface;
 583         int min_mtu = INT_MAX;
 584
 585         rcu_read_lock();
 586         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 587                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 588                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 589                         continue;
 590
 591                 if (hard_iface->soft_iface != soft_iface)
 592                         continue;
 593
 594                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 595         }
 596         rcu_read_unlock();
 597
 598         if (atomic_read(&bat_priv->fragmentation) == 0)
 599                 goto out;
 600
 601         /* with fragmentation enabled the maximum size of internally generated
 602          * packets such as translation table exchanges or tvlv containers, etc
 603          * has to be calculated
 604          */
 605         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 606         min_mtu -= sizeof(struct batadv_frag_packet);
 607         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 608
 609 out:
 610         /* report to the other components the maximum amount of bytes that
 611          * batman-adv can send over the wire (without considering the payload
 612          * overhead). For example, this value is used by TT to compute the
 613          * maximum local table table size
 614          */
 615         atomic_set(&bat_priv->packet_size_max, min_mtu);
 616
 617         /* the real soft-interface MTU is computed by removing the payload
 618          * overhead from the maximum amount of bytes that was just computed.
 619          *
 620          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 621          */
 622         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 623 }
 624
 625 /**
 626  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 627  *  MTU appeared
 628  * @soft_iface: netdev struct of the soft interface
 629  */
 630 void batadv_update_min_mtu(struct net_device *soft_iface)
 631 {
 632         soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
 633
 634         /* Check if the local translate table should be cleaned up to match a
 635          * new (and smaller) MTU.
 636          */
 637         batadv_tt_local_resize_to_mtu(soft_iface);
 638 }
 639
 640 static void
 641 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 642 {
 643         struct batadv_priv *bat_priv;
 644         struct batadv_hard_iface *primary_if = NULL;
 645
 646         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 647                 goto out;
 648
 649         bat_priv = netdev_priv(hard_iface->soft_iface);
 650
 651         bat_priv->algo_ops->iface.update_mac(hard_iface);
 652         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 653
 654         /* the first active interface becomes our primary interface or
 655          * the next active interface after the old primary interface was removed
 656          */
 657         primary_if = batadv_primary_if_get_selected(bat_priv);
 658         if (!primary_if)
 659                 batadv_primary_if_select(bat_priv, hard_iface);
 660
 661         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 662                     hard_iface->net_dev->name);
 663
 664         batadv_update_min_mtu(hard_iface->soft_iface);
 665
 666         if (bat_priv->algo_ops->iface.activate)
 667                 bat_priv->algo_ops->iface.activate(hard_iface);
 668
 669 out:
 670         if (primary_if)
 671                 batadv_hardif_put(primary_if);
 672 }
 673
 674 static void
 675 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 676 {
 677         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 678             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 679                 return;
 680
 681         hard_iface->if_status = BATADV_IF_INACTIVE;
 682
 683         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 684                     hard_iface->net_dev->name);
 685
 686         batadv_update_min_mtu(hard_iface->soft_iface);
 687 }
 688
 689 /**
 690  * batadv_master_del_slave() - remove hard_iface from the current master iface
 691  * @slave: the interface enslaved in another master
 692  * @master: the master from which slave has to be removed
 693  *
 694  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 695  * is free'd and master can correctly change its internal state.
 696  *
 697  * Return: 0 on success, a negative value representing the error otherwise
 698  */
 699 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 700                                    struct net_device *master)
 701 {
 702         int ret;
 703
 704         if (!master)
 705                 return 0;
 706
 707         ret = -EBUSY;
 708         if (master->netdev_ops->ndo_del_slave)
 709                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 710
 711         return ret;
 712 }
 713
 714 /**
 715  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 716  * @hard_iface: hard interface to add to soft interface
 717  * @net: the applicable net namespace
 718  * @iface_name: name of the soft interface
 719  *
 720  * Return: 0 on success or negative error number in case of failure
 721  */
 722 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 723                                    struct net *net, const char *iface_name)
 724 {
 725         struct batadv_priv *bat_priv;
 726         struct net_device *soft_iface, *master;
 727         __be16 ethertype = htons(ETH_P_BATMAN);
 728         int max_header_len = batadv_max_header_len();
 729         int ret;
 730
 731         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 732                 goto out;
 733
 734         kref_get(&hard_iface->refcount);
 735
 736         soft_iface = dev_get_by_name(net, iface_name);
 737
 738         if (!soft_iface) {
 739                 soft_iface = batadv_softif_create(net, iface_name);
 740
 741                 if (!soft_iface) {
 742                         ret = -ENOMEM;
 743                         goto err;
 744                 }
 745
 746                 /* dev_get_by_name() increases the reference counter for us */
 747                 dev_hold(soft_iface);
 748         }
 749
 750         if (!batadv_softif_is_valid(soft_iface)) {
 751                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 752                        soft_iface->name);
 753                 ret = -EINVAL;
 754                 goto err_dev;
 755         }
 756
 757         /* check if the interface is enslaved in another virtual one and
 758          * in that case unlink it first
 759          */
 760         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 761         ret = batadv_master_del_slave(hard_iface, master);
 762         if (ret)
 763                 goto err_dev;
 764
 765         hard_iface->soft_iface = soft_iface;
 766         bat_priv = netdev_priv(hard_iface->soft_iface);
 767
 768         if (bat_priv->num_ifaces >= UINT_MAX) {
 769                 ret = -ENOSPC;
 770                 goto err_dev;
 771         }
 772
 773         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 774                                            soft_iface, NULL, NULL, NULL);
 775         if (ret)
 776                 goto err_dev;
 777
 778         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 779         if (ret < 0)
 780                 goto err_upper;
 781
 782         hard_iface->if_num = bat_priv->num_ifaces;
 783         bat_priv->num_ifaces++;
 784         hard_iface->if_status = BATADV_IF_INACTIVE;
 785         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 786         if (ret < 0) {
 787                 bat_priv->algo_ops->iface.disable(hard_iface);
 788                 bat_priv->num_ifaces--;
 789                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 790                 goto err_upper;
 791         }
 792
 793         kref_get(&hard_iface->refcount);
 794         hard_iface->batman_adv_ptype.type = ethertype;
 795         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 796         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 797         dev_add_pack(&hard_iface->batman_adv_ptype);
 798
 799         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 800                     hard_iface->net_dev->name);
 801
 802         if (atomic_read(&bat_priv->fragmentation) &&
 803             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 804                 batadv_info(hard_iface->soft_iface,
 805                             "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %i would solve the problem.\n",
 806                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 807                             ETH_DATA_LEN + max_header_len);
 808
 809         if (!atomic_read(&bat_priv->fragmentation) &&
 810             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 811                 batadv_info(hard_iface->soft_iface,
 812                             "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %i.\n",
 813                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 814                             ETH_DATA_LEN + max_header_len);
 815
 816         if (batadv_hardif_is_iface_up(hard_iface))
 817                 batadv_hardif_activate_interface(hard_iface);
 818         else
 819                 batadv_err(hard_iface->soft_iface,
 820                            "Not using interface %s (retrying later): interface not active\n",
 821                            hard_iface->net_dev->name);
 822
 823         batadv_hardif_recalc_extra_skbroom(soft_iface);
 824
 825         if (bat_priv->algo_ops->iface.enabled)
 826                 bat_priv->algo_ops->iface.enabled(hard_iface);
 827
 828 out:
 829         return 0;
 830
 831 err_upper:
 832         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 833 err_dev:
 834         hard_iface->soft_iface = NULL;
 835         dev_put(soft_iface);
 836 err:
 837         batadv_hardif_put(hard_iface);
 838         return ret;
 839 }
 840
 841 /**
 842  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 843  * @hard_iface: hard interface to be removed
 844  * @autodel: whether to delete soft interface when it doesn't contain any other
 845  *  slave interfaces
 846  */
 847 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 848                                      enum batadv_hard_if_cleanup autodel)
 849 {
 850         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 851         struct batadv_hard_iface *primary_if = NULL;
 852
 853         batadv_hardif_deactivate_interface(hard_iface);
 854
 855         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 856                 goto out;
 857
 858         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 859                     hard_iface->net_dev->name);
 860         dev_remove_pack(&hard_iface->batman_adv_ptype);
 861         batadv_hardif_put(hard_iface);
 862
 863         bat_priv->num_ifaces--;
 864         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 865
 866         primary_if = batadv_primary_if_get_selected(bat_priv);
 867         if (hard_iface == primary_if) {
 868                 struct batadv_hard_iface *new_if;
 869
 870                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 871                 batadv_primary_if_select(bat_priv, new_if);
 872
 873                 if (new_if)
 874                         batadv_hardif_put(new_if);
 875         }
 876
 877         bat_priv->algo_ops->iface.disable(hard_iface);
 878         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 879
 880         /* delete all references to this hard_iface */
 881         batadv_purge_orig_ref(bat_priv);
 882         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 883         dev_put(hard_iface->soft_iface);
 884
 885         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 886         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 887
 888         /* nobody uses this interface anymore */
 889         if (bat_priv->num_ifaces == 0) {
 890                 batadv_gw_check_client_stop(bat_priv);
 891
 892                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 893                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 894         }
 895
 896         hard_iface->soft_iface = NULL;
 897         batadv_hardif_put(hard_iface);
 898
 899 out:
 900         if (primary_if)
 901                 batadv_hardif_put(primary_if);
 902 }
 903
 904 static struct batadv_hard_iface *
 905 batadv_hardif_add_interface(struct net_device *net_dev)
 906 {
 907         struct batadv_hard_iface *hard_iface;
 908         int ret;
 909
 910         ASSERT_RTNL();
 911
 912         if (!batadv_is_valid_iface(net_dev))
 913                 goto out;
 914
 915         dev_hold(net_dev);
 916
 917         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 918         if (!hard_iface)
 919                 goto release_dev;
 920
 921         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 922         if (ret)
 923                 goto free_if;
 924
 925         hard_iface->if_num = 0;
 926         hard_iface->net_dev = net_dev;
 927         hard_iface->soft_iface = NULL;
 928         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 929
 930         ret = batadv_debugfs_add_hardif(hard_iface);
 931         if (ret)
 932                 goto free_sysfs;
 933
 934         INIT_LIST_HEAD(&hard_iface->list);
 935         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 936
 937         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 938         spin_lock_init(&hard_iface->neigh_list_lock);
 939         kref_init(&hard_iface->refcount);
 940
 941         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 942         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 943         if (batadv_is_wifi_hardif(hard_iface))
 944                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 945
 946         batadv_v_hardif_init(hard_iface);
 947
 948         batadv_check_known_mac_addr(hard_iface->net_dev);
 949         kref_get(&hard_iface->refcount);
 950         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 951
 952         return hard_iface;
 953
 954 free_sysfs:
 955         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 956 free_if:
 957         kfree(hard_iface);
 958 release_dev:
 959         dev_put(net_dev);
 960 out:
 961         return NULL;
 962 }
 963
 964 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 965 {
 966         ASSERT_RTNL();
 967
 968         /* first deactivate interface */
 969         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 970                 batadv_hardif_disable_interface(hard_iface,
 971                                                 BATADV_IF_CLEANUP_KEEP);
 972
 973         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 974                 return;
 975
 976         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
 977         batadv_debugfs_del_hardif(hard_iface);
 978         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 979         batadv_hardif_put(hard_iface);
 980 }
 981
 982 /**
 983  * batadv_hardif_remove_interfaces() - Remove all hard interfaces
 984  */
 985 void batadv_hardif_remove_interfaces(void)
 986 {
 987         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
 988
 989         rtnl_lock();
 990         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 991                                  &batadv_hardif_list, list) {
 992                 list_del_rcu(&hard_iface->list);
 993                 batadv_hardif_remove_interface(hard_iface);
 994         }
 995         rtnl_unlock();
 996 }
 997
 998 /**
 999  * batadv_hard_if_event_softif() - Handle events for soft interfaces
1000  * @event: NETDEV_* event to handle
1001  * @net_dev: net_device which generated an event
1002  *
1003  * Return: NOTIFY_* result
1004  */
1005 static int batadv_hard_if_event_softif(unsigned long event,
1006                                        struct net_device *net_dev)
1007 {
1008         struct batadv_priv *bat_priv;
1009
1010         switch (event) {
1011         case NETDEV_REGISTER:
1012                 batadv_sysfs_add_meshif(net_dev);
1013                 bat_priv = netdev_priv(net_dev);
1014                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
1015                 break;
1016         case NETDEV_CHANGENAME:
1017                 batadv_debugfs_rename_meshif(net_dev);
1018                 break;
1019         }
1020
1021         return NOTIFY_DONE;
1022 }
1023
1024 static int batadv_hard_if_event(struct notifier_block *this,
1025                                 unsigned long event, void *ptr)
1026 {
1027         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1028         struct batadv_hard_iface *hard_iface;
1029         struct batadv_hard_iface *primary_if = NULL;
1030         struct batadv_priv *bat_priv;
1031
1032         if (batadv_softif_is_valid(net_dev))
1033                 return batadv_hard_if_event_softif(event, net_dev);
1034
1035         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1036         if (!hard_iface && (event == NETDEV_REGISTER ||
1037                             event == NETDEV_POST_TYPE_CHANGE))
1038                 hard_iface = batadv_hardif_add_interface(net_dev);
1039
1040         if (!hard_iface)
1041                 goto out;
1042
1043         switch (event) {
1044         case NETDEV_UP:
1045                 batadv_hardif_activate_interface(hard_iface);
1046                 break;
1047         case NETDEV_GOING_DOWN:
1048         case NETDEV_DOWN:
1049                 batadv_hardif_deactivate_interface(hard_iface);
1050                 break;
1051         case NETDEV_UNREGISTER:
1052         case NETDEV_PRE_TYPE_CHANGE:
1053                 list_del_rcu(&hard_iface->list);
1054
1055                 batadv_hardif_remove_interface(hard_iface);
1056                 break;
1057         case NETDEV_CHANGEMTU:
1058                 if (hard_iface->soft_iface)
1059                         batadv_update_min_mtu(hard_iface->soft_iface);
1060                 break;
1061         case NETDEV_CHANGEADDR:
1062                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1063                         goto hardif_put;
1064
1065                 batadv_check_known_mac_addr(hard_iface->net_dev);
1066
1067                 bat_priv = netdev_priv(hard_iface->soft_iface);
1068                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1069
1070                 primary_if = batadv_primary_if_get_selected(bat_priv);
1071                 if (!primary_if)
1072                         goto hardif_put;
1073
1074                 if (hard_iface == primary_if)
1075                         batadv_primary_if_update_addr(bat_priv, NULL);
1076                 break;
1077         case NETDEV_CHANGEUPPER:
1078                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1079                 if (batadv_is_wifi_hardif(hard_iface))
1080                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1081                 break;
1082         case NETDEV_CHANGENAME:
1083                 batadv_debugfs_rename_hardif(hard_iface);
1084                 break;
1085         default:
1086                 break;
1087         }
1088
1089 hardif_put:
1090         batadv_hardif_put(hard_iface);
1091 out:
1092         if (primary_if)
1093                 batadv_hardif_put(primary_if);
1094         return NOTIFY_DONE;
1095 }
1096
1097 struct notifier_block batadv_hard_if_notifier = {
1098         .notifier_call = batadv_hard_if_event,
1099 };