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         int iflink;
 166         bool ret;
 167
 168         /* check if this is a batman-adv mesh interface */
 169         if (batadv_softif_is_valid(net_dev))
 170                 return true;
 171
 172         iflink = dev_get_iflink(net_dev);
 173         if (iflink == 0)
 174                 return false;
 175
 176         parent_net = batadv_getlink_net(net_dev, net);
 177
 178         /* iflink to itself, most likely physical device */
 179         if (net == parent_net && iflink == net_dev->ifindex)
 180                 return false;
 181
 182         /* recurse over the parent device */
 183         parent_dev = __dev_get_by_index((struct net *)parent_net, iflink);
 184         /* if we got a NULL parent_dev there is something broken.. */
 185         if (!parent_dev) {
 186                 pr_err("Cannot find parent device\n");
 187                 return false;
 188         }
 189
 190         if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
 191                 return false;
 192
 193         ret = batadv_is_on_batman_iface(parent_dev);
 194
 195         return ret;
 196 }
 197
 198 static bool batadv_is_valid_iface(const struct net_device *net_dev)
 199 {
 200         if (net_dev->flags & IFF_LOOPBACK)
 201                 return false;
 202
 203         if (net_dev->type != ARPHRD_ETHER)
 204                 return false;
 205
 206         if (net_dev->addr_len != ETH_ALEN)
 207                 return false;
 208
 209         /* no batman over batman */
 210         if (batadv_is_on_batman_iface(net_dev))
 211                 return false;
 212
 213         return true;
 214 }
 215
 216 /**
 217  * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
 218  *  interface on top of another 'real' interface
 219  * @netdev: the device to check
 220  *
 221  * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
 222  * instead of this.
 223  *
 224  * Return: the 'real' net device or the original net device and NULL in case
 225  *  of an error.
 226  */
 227 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
 228 {
 229         struct batadv_hard_iface *hard_iface = NULL;
 230         struct net_device *real_netdev = NULL;
 231         struct net *real_net;
 232         struct net *net;
 233         int iflink;
 234
 235         ASSERT_RTNL();
 236
 237         if (!netdev)
 238                 return NULL;
 239
 240         iflink = dev_get_iflink(netdev);
 241         if (iflink == 0) {
 242                 dev_hold(netdev);
 243                 return netdev;
 244         }
 245
 246         hard_iface = batadv_hardif_get_by_netdev(netdev);
 247         if (!hard_iface || !hard_iface->soft_iface)
 248                 goto out;
 249
 250         net = dev_net(hard_iface->soft_iface);
 251         real_net = batadv_getlink_net(netdev, net);
 252
 253         /* iflink to itself, most likely physical device */
 254         if (net == real_net && netdev->ifindex == iflink) {
 255                 real_netdev = netdev;
 256                 dev_hold(real_netdev);
 257                 goto out;
 258         }
 259
 260         real_netdev = dev_get_by_index(real_net, iflink);
 261
 262 out:
 263         if (hard_iface)
 264                 batadv_hardif_put(hard_iface);
 265         return real_netdev;
 266 }
 267
 268 /**
 269  * batadv_get_real_netdev() - check if the given net_device struct is a virtual
 270  *  interface on top of another 'real' interface
 271  * @net_device: the device to check
 272  *
 273  * Return: the 'real' net device or the original net device and NULL in case
 274  *  of an error.
 275  */
 276 struct net_device *batadv_get_real_netdev(struct net_device *net_device)
 277 {
 278         struct net_device *real_netdev;
 279
 280         rtnl_lock();
 281         real_netdev = batadv_get_real_netdevice(net_device);
 282         rtnl_unlock();
 283
 284         return real_netdev;
 285 }
 286
 287 /**
 288  * batadv_is_wext_netdev() - check if the given net_device struct is a
 289  *  wext wifi interface
 290  * @net_device: the device to check
 291  *
 292  * Return: true if the net device is a wext wireless device, false
 293  *  otherwise.
 294  */
 295 static bool batadv_is_wext_netdev(struct net_device *net_device)
 296 {
 297         if (!net_device)
 298                 return false;
 299
 300 #ifdef CONFIG_WIRELESS_EXT
 301         /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
 302          * check for wireless_handlers != NULL
 303          */
 304         if (net_device->wireless_handlers)
 305                 return true;
 306 #endif
 307
 308         return false;
 309 }
 310
 311 /**
 312  * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
 313  *  cfg80211 wifi interface
 314  * @net_device: the device to check
 315  *
 316  * Return: true if the net device is a cfg80211 wireless device, false
 317  *  otherwise.
 318  */
 319 static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
 320 {
 321         if (!net_device)
 322                 return false;
 323
 324         /* cfg80211 drivers have to set ieee80211_ptr */
 325         if (net_device->ieee80211_ptr)
 326                 return true;
 327
 328         return false;
 329 }
 330
 331 /**
 332  * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
 333  * @net_device: the device to check
 334  *
 335  * Return: batadv_hard_iface_wifi_flags flags of the device
 336  */
 337 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
 338 {
 339         u32 wifi_flags = 0;
 340         struct net_device *real_netdev;
 341
 342         if (batadv_is_wext_netdev(net_device))
 343                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
 344
 345         if (batadv_is_cfg80211_netdev(net_device))
 346                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 347
 348         real_netdev = batadv_get_real_netdevice(net_device);
 349         if (!real_netdev)
 350                 return wifi_flags;
 351
 352         if (real_netdev == net_device)
 353                 goto out;
 354
 355         if (batadv_is_wext_netdev(real_netdev))
 356                 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
 357
 358         if (batadv_is_cfg80211_netdev(real_netdev))
 359                 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 360
 361 out:
 362         dev_put(real_netdev);
 363         return wifi_flags;
 364 }
 365
 366 /**
 367  * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
 368  *  interface
 369  * @hard_iface: the device to check
 370  *
 371  * Return: true if the net device is a cfg80211 wireless device, false
 372  *  otherwise.
 373  */
 374 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
 375 {
 376         u32 allowed_flags = 0;
 377
 378         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
 379         allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
 380
 381         return !!(hard_iface->wifi_flags & allowed_flags);
 382 }
 383
 384 /**
 385  * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
 386  * @hard_iface: the device to check
 387  *
 388  * Return: true if the net device is a 802.11 wireless device, false otherwise.
 389  */
 390 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
 391 {
 392         if (!hard_iface)
 393                 return false;
 394
 395         return hard_iface->wifi_flags != 0;
 396 }
 397
 398 /**
 399  * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
 400  * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
 401  * @orig_addr: the originator of this packet
 402  * @orig_neigh: originator address of the forwarder we just got the packet from
 403  *  (NULL if we originated)
 404  *
 405  * Checks whether a packet needs to be (re)broadcasted on the given interface.
 406  *
 407  * Return:
 408  *      BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
 409  *      BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
 410  *      BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
 411  *      BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
 412  */
 413 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
 414                                u8 *orig_addr, u8 *orig_neigh)
 415 {
 416         struct batadv_hardif_neigh_node *hardif_neigh;
 417         struct hlist_node *first;
 418         int ret = BATADV_HARDIF_BCAST_OK;
 419
 420         rcu_read_lock();
 421
 422         /* 0 neighbors -> no (re)broadcast */
 423         first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
 424         if (!first) {
 425                 ret = BATADV_HARDIF_BCAST_NORECIPIENT;
 426                 goto out;
 427         }
 428
 429         /* >1 neighbors -> (re)brodcast */
 430         if (rcu_dereference(hlist_next_rcu(first)))
 431                 goto out;
 432
 433         hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
 434                                    list);
 435
 436         /* 1 neighbor, is the originator -> no rebroadcast */
 437         if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
 438                 ret = BATADV_HARDIF_BCAST_DUPORIG;
 439         /* 1 neighbor, is the one we received from -> no rebroadcast */
 440         } else if (orig_neigh &&
 441                    batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
 442                 ret = BATADV_HARDIF_BCAST_DUPFWD;
 443         }
 444
 445 out:
 446         rcu_read_unlock();
 447         return ret;
 448 }
 449
 450 static struct batadv_hard_iface *
 451 batadv_hardif_get_active(const struct net_device *soft_iface)
 452 {
 453         struct batadv_hard_iface *hard_iface;
 454
 455         rcu_read_lock();
 456         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 457                 if (hard_iface->soft_iface != soft_iface)
 458                         continue;
 459
 460                 if (hard_iface->if_status == BATADV_IF_ACTIVE &&
 461                     kref_get_unless_zero(&hard_iface->refcount))
 462                         goto out;
 463         }
 464
 465         hard_iface = NULL;
 466
 467 out:
 468         rcu_read_unlock();
 469         return hard_iface;
 470 }
 471
 472 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
 473                                           struct batadv_hard_iface *oldif)
 474 {
 475         struct batadv_hard_iface *primary_if;
 476
 477         primary_if = batadv_primary_if_get_selected(bat_priv);
 478         if (!primary_if)
 479                 goto out;
 480
 481         batadv_dat_init_own_addr(bat_priv, primary_if);
 482         batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
 483 out:
 484         if (primary_if)
 485                 batadv_hardif_put(primary_if);
 486 }
 487
 488 static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 489                                      struct batadv_hard_iface *new_hard_iface)
 490 {
 491         struct batadv_hard_iface *curr_hard_iface;
 492
 493         ASSERT_RTNL();
 494
 495         if (new_hard_iface)
 496                 kref_get(&new_hard_iface->refcount);
 497
 498         curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
 499         rcu_assign_pointer(bat_priv->primary_if, new_hard_iface);
 500
 501         if (!new_hard_iface)
 502                 goto out;
 503
 504         bat_priv->algo_ops->iface.primary_set(new_hard_iface);
 505         batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
 506
 507 out:
 508         if (curr_hard_iface)
 509                 batadv_hardif_put(curr_hard_iface);
 510 }
 511
 512 static bool
 513 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
 514 {
 515         if (hard_iface->net_dev->flags & IFF_UP)
 516                 return true;
 517
 518         return false;
 519 }
 520
 521 static void batadv_check_known_mac_addr(const struct net_device *net_dev)
 522 {
 523         const struct batadv_hard_iface *hard_iface;
 524
 525         rcu_read_lock();
 526         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 527                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 528                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 529                         continue;
 530
 531                 if (hard_iface->net_dev == net_dev)
 532                         continue;
 533
 534                 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
 535                                         net_dev->dev_addr))
 536                         continue;
 537
 538                 pr_warn("The newly added mac address (%pM) already exists on: %s\n",
 539                         net_dev->dev_addr, hard_iface->net_dev->name);
 540                 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 541         }
 542         rcu_read_unlock();
 543 }
 544
 545 /**
 546  * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
 547  * @soft_iface: netdev struct of the mesh interface
 548  */
 549 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
 550 {
 551         const struct batadv_hard_iface *hard_iface;
 552         unsigned short lower_header_len = ETH_HLEN;
 553         unsigned short lower_headroom = 0;
 554         unsigned short lower_tailroom = 0;
 555         unsigned short needed_headroom;
 556
 557         rcu_read_lock();
 558         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 559                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
 560                         continue;
 561
 562                 if (hard_iface->soft_iface != soft_iface)
 563                         continue;
 564
 565                 lower_header_len = max_t(unsigned short, lower_header_len,
 566                                          hard_iface->net_dev->hard_header_len);
 567
 568                 lower_headroom = max_t(unsigned short, lower_headroom,
 569                                        hard_iface->net_dev->needed_headroom);
 570
 571                 lower_tailroom = max_t(unsigned short, lower_tailroom,
 572                                        hard_iface->net_dev->needed_tailroom);
 573         }
 574         rcu_read_unlock();
 575
 576         needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
 577         needed_headroom += batadv_max_header_len();
 578
 579         /* fragmentation headers don't strip the unicast/... header */
 580         needed_headroom += sizeof(struct batadv_frag_packet);
 581
 582         soft_iface->needed_headroom = needed_headroom;
 583         soft_iface->needed_tailroom = lower_tailroom;
 584 }
 585
 586 /**
 587  * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
 588  * @soft_iface: netdev struct of the soft interface
 589  *
 590  * Return: MTU for the soft-interface (limited by the minimal MTU of all active
 591  *  slave interfaces)
 592  */
 593 int batadv_hardif_min_mtu(struct net_device *soft_iface)
 594 {
 595         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 596         const struct batadv_hard_iface *hard_iface;
 597         int min_mtu = INT_MAX;
 598
 599         rcu_read_lock();
 600         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
 601                 if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 602                     hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 603                         continue;
 604
 605                 if (hard_iface->soft_iface != soft_iface)
 606                         continue;
 607
 608                 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
 609         }
 610         rcu_read_unlock();
 611
 612         if (atomic_read(&bat_priv->fragmentation) == 0)
 613                 goto out;
 614
 615         /* with fragmentation enabled the maximum size of internally generated
 616          * packets such as translation table exchanges or tvlv containers, etc
 617          * has to be calculated
 618          */
 619         min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 620         min_mtu -= sizeof(struct batadv_frag_packet);
 621         min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
 622
 623 out:
 624         /* report to the other components the maximum amount of bytes that
 625          * batman-adv can send over the wire (without considering the payload
 626          * overhead). For example, this value is used by TT to compute the
 627          * maximum local table table size
 628          */
 629         atomic_set(&bat_priv->packet_size_max, min_mtu);
 630
 631         /* the real soft-interface MTU is computed by removing the payload
 632          * overhead from the maximum amount of bytes that was just computed.
 633          *
 634          * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
 635          */
 636         return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
 637 }
 638
 639 /**
 640  * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
 641  *  MTU appeared
 642  * @soft_iface: netdev struct of the soft interface
 643  */
 644 void batadv_update_min_mtu(struct net_device *soft_iface)
 645 {
 646         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 647         int limit_mtu;
 648         int mtu;
 649
 650         mtu = batadv_hardif_min_mtu(soft_iface);
 651
 652         if (bat_priv->mtu_set_by_user)
 653                 limit_mtu = bat_priv->mtu_set_by_user;
 654         else
 655                 limit_mtu = ETH_DATA_LEN;
 656
 657         mtu = min(mtu, limit_mtu);
 658         dev_set_mtu(soft_iface, mtu);
 659
 660         /* Check if the local translate table should be cleaned up to match a
 661          * new (and smaller) MTU.
 662          */
 663         batadv_tt_local_resize_to_mtu(soft_iface);
 664 }
 665
 666 static void
 667 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
 668 {
 669         struct batadv_priv *bat_priv;
 670         struct batadv_hard_iface *primary_if = NULL;
 671
 672         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 673                 goto out;
 674
 675         bat_priv = netdev_priv(hard_iface->soft_iface);
 676
 677         bat_priv->algo_ops->iface.update_mac(hard_iface);
 678         hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
 679
 680         /* the first active interface becomes our primary interface or
 681          * the next active interface after the old primary interface was removed
 682          */
 683         primary_if = batadv_primary_if_get_selected(bat_priv);
 684         if (!primary_if)
 685                 batadv_primary_if_select(bat_priv, hard_iface);
 686
 687         batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
 688                     hard_iface->net_dev->name);
 689
 690         batadv_update_min_mtu(hard_iface->soft_iface);
 691
 692         if (bat_priv->algo_ops->iface.activate)
 693                 bat_priv->algo_ops->iface.activate(hard_iface);
 694
 695 out:
 696         if (primary_if)
 697                 batadv_hardif_put(primary_if);
 698 }
 699
 700 static void
 701 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
 702 {
 703         if (hard_iface->if_status != BATADV_IF_ACTIVE &&
 704             hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
 705                 return;
 706
 707         hard_iface->if_status = BATADV_IF_INACTIVE;
 708
 709         batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 710                     hard_iface->net_dev->name);
 711
 712         batadv_update_min_mtu(hard_iface->soft_iface);
 713 }
 714
 715 /**
 716  * batadv_master_del_slave() - remove hard_iface from the current master iface
 717  * @slave: the interface enslaved in another master
 718  * @master: the master from which slave has to be removed
 719  *
 720  * Invoke ndo_del_slave on master passing slave as argument. In this way slave
 721  * is free'd and master can correctly change its internal state.
 722  *
 723  * Return: 0 on success, a negative value representing the error otherwise
 724  */
 725 static int batadv_master_del_slave(struct batadv_hard_iface *slave,
 726                                    struct net_device *master)
 727 {
 728         int ret;
 729
 730         if (!master)
 731                 return 0;
 732
 733         ret = -EBUSY;
 734         if (master->netdev_ops->ndo_del_slave)
 735                 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev);
 736
 737         return ret;
 738 }
 739
 740 /**
 741  * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
 742  * @hard_iface: hard interface to add to soft interface
 743  * @net: the applicable net namespace
 744  * @iface_name: name of the soft interface
 745  *
 746  * Return: 0 on success or negative error number in case of failure
 747  */
 748 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 749                                    struct net *net, const char *iface_name)
 750 {
 751         struct batadv_priv *bat_priv;
 752         struct net_device *soft_iface, *master;
 753         __be16 ethertype = htons(ETH_P_BATMAN);
 754         int max_header_len = batadv_max_header_len();
 755         int ret;
 756
 757         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 758                 goto out;
 759
 760         kref_get(&hard_iface->refcount);
 761
 762         soft_iface = dev_get_by_name(net, iface_name);
 763
 764         if (!soft_iface) {
 765                 soft_iface = batadv_softif_create(net, iface_name);
 766
 767                 if (!soft_iface) {
 768                         ret = -ENOMEM;
 769                         goto err;
 770                 }
 771
 772                 /* dev_get_by_name() increases the reference counter for us */
 773                 dev_hold(soft_iface);
 774         }
 775
 776         if (!batadv_softif_is_valid(soft_iface)) {
 777                 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n",
 778                        soft_iface->name);
 779                 ret = -EINVAL;
 780                 goto err_dev;
 781         }
 782
 783         /* check if the interface is enslaved in another virtual one and
 784          * in that case unlink it first
 785          */
 786         master = netdev_master_upper_dev_get(hard_iface->net_dev);
 787         ret = batadv_master_del_slave(hard_iface, master);
 788         if (ret)
 789                 goto err_dev;
 790
 791         hard_iface->soft_iface = soft_iface;
 792         bat_priv = netdev_priv(hard_iface->soft_iface);
 793
 794         if (bat_priv->num_ifaces >= UINT_MAX) {
 795                 ret = -ENOSPC;
 796                 goto err_dev;
 797         }
 798
 799         ret = netdev_master_upper_dev_link(hard_iface->net_dev,
 800                                            soft_iface, NULL, NULL, NULL);
 801         if (ret)
 802                 goto err_dev;
 803
 804         ret = bat_priv->algo_ops->iface.enable(hard_iface);
 805         if (ret < 0)
 806                 goto err_upper;
 807
 808         hard_iface->if_num = bat_priv->num_ifaces;
 809         bat_priv->num_ifaces++;
 810         hard_iface->if_status = BATADV_IF_INACTIVE;
 811         ret = batadv_orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 812         if (ret < 0) {
 813                 bat_priv->algo_ops->iface.disable(hard_iface);
 814                 bat_priv->num_ifaces--;
 815                 hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 816                 goto err_upper;
 817         }
 818
 819         kref_get(&hard_iface->refcount);
 820         hard_iface->batman_adv_ptype.type = ethertype;
 821         hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
 822         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 823         dev_add_pack(&hard_iface->batman_adv_ptype);
 824
 825         batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
 826                     hard_iface->net_dev->name);
 827
 828         if (atomic_read(&bat_priv->fragmentation) &&
 829             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 830                 batadv_info(hard_iface->soft_iface,
 831                             "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",
 832                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 833                             ETH_DATA_LEN + max_header_len);
 834
 835         if (!atomic_read(&bat_priv->fragmentation) &&
 836             hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
 837                 batadv_info(hard_iface->soft_iface,
 838                             "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",
 839                             hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 840                             ETH_DATA_LEN + max_header_len);
 841
 842         if (batadv_hardif_is_iface_up(hard_iface))
 843                 batadv_hardif_activate_interface(hard_iface);
 844         else
 845                 batadv_err(hard_iface->soft_iface,
 846                            "Not using interface %s (retrying later): interface not active\n",
 847                            hard_iface->net_dev->name);
 848
 849         batadv_hardif_recalc_extra_skbroom(soft_iface);
 850
 851         if (bat_priv->algo_ops->iface.enabled)
 852                 bat_priv->algo_ops->iface.enabled(hard_iface);
 853
 854 out:
 855         return 0;
 856
 857 err_upper:
 858         netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
 859 err_dev:
 860         hard_iface->soft_iface = NULL;
 861         dev_put(soft_iface);
 862 err:
 863         batadv_hardif_put(hard_iface);
 864         return ret;
 865 }
 866
 867 /**
 868  * batadv_hardif_disable_interface() - Remove hard interface from soft interface
 869  * @hard_iface: hard interface to be removed
 870  * @autodel: whether to delete soft interface when it doesn't contain any other
 871  *  slave interfaces
 872  */
 873 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 874                                      enum batadv_hard_if_cleanup autodel)
 875 {
 876         struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 877         struct batadv_hard_iface *primary_if = NULL;
 878
 879         batadv_hardif_deactivate_interface(hard_iface);
 880
 881         if (hard_iface->if_status != BATADV_IF_INACTIVE)
 882                 goto out;
 883
 884         batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
 885                     hard_iface->net_dev->name);
 886         dev_remove_pack(&hard_iface->batman_adv_ptype);
 887         batadv_hardif_put(hard_iface);
 888
 889         bat_priv->num_ifaces--;
 890         batadv_orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 891
 892         primary_if = batadv_primary_if_get_selected(bat_priv);
 893         if (hard_iface == primary_if) {
 894                 struct batadv_hard_iface *new_if;
 895
 896                 new_if = batadv_hardif_get_active(hard_iface->soft_iface);
 897                 batadv_primary_if_select(bat_priv, new_if);
 898
 899                 if (new_if)
 900                         batadv_hardif_put(new_if);
 901         }
 902
 903         bat_priv->algo_ops->iface.disable(hard_iface);
 904         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 905
 906         /* delete all references to this hard_iface */
 907         batadv_purge_orig_ref(bat_priv);
 908         batadv_purge_outstanding_packets(bat_priv, hard_iface);
 909         dev_put(hard_iface->soft_iface);
 910
 911         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 912         batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
 913
 914         /* nobody uses this interface anymore */
 915         if (bat_priv->num_ifaces == 0) {
 916                 batadv_gw_check_client_stop(bat_priv);
 917
 918                 if (autodel == BATADV_IF_CLEANUP_AUTO)
 919                         batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 920         }
 921
 922         hard_iface->soft_iface = NULL;
 923         batadv_hardif_put(hard_iface);
 924
 925 out:
 926         if (primary_if)
 927                 batadv_hardif_put(primary_if);
 928 }
 929
 930 static struct batadv_hard_iface *
 931 batadv_hardif_add_interface(struct net_device *net_dev)
 932 {
 933         struct batadv_hard_iface *hard_iface;
 934         int ret;
 935
 936         ASSERT_RTNL();
 937
 938         if (!batadv_is_valid_iface(net_dev))
 939                 goto out;
 940
 941         dev_hold(net_dev);
 942
 943         hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
 944         if (!hard_iface)
 945                 goto release_dev;
 946
 947         ret = batadv_sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 948         if (ret)
 949                 goto free_if;
 950
 951         hard_iface->if_num = 0;
 952         hard_iface->net_dev = net_dev;
 953         hard_iface->soft_iface = NULL;
 954         hard_iface->if_status = BATADV_IF_NOT_IN_USE;
 955
 956         ret = batadv_debugfs_add_hardif(hard_iface);
 957         if (ret)
 958                 goto free_sysfs;
 959
 960         INIT_LIST_HEAD(&hard_iface->list);
 961         INIT_HLIST_HEAD(&hard_iface->neigh_list);
 962
 963         mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
 964         spin_lock_init(&hard_iface->neigh_list_lock);
 965         kref_init(&hard_iface->refcount);
 966
 967         hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 968         hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
 969         if (batadv_is_wifi_hardif(hard_iface))
 970                 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 971
 972         batadv_v_hardif_init(hard_iface);
 973
 974         batadv_check_known_mac_addr(hard_iface->net_dev);
 975         kref_get(&hard_iface->refcount);
 976         list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
 977
 978         return hard_iface;
 979
 980 free_sysfs:
 981         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
 982 free_if:
 983         kfree(hard_iface);
 984 release_dev:
 985         dev_put(net_dev);
 986 out:
 987         return NULL;
 988 }
 989
 990 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
 991 {
 992         ASSERT_RTNL();
 993
 994         /* first deactivate interface */
 995         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
 996                 batadv_hardif_disable_interface(hard_iface,
 997                                                 BATADV_IF_CLEANUP_KEEP);
 998
 999         if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
1000                 return;
1001
1002         hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
1003         batadv_debugfs_del_hardif(hard_iface);
1004         batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
1005         batadv_hardif_put(hard_iface);
1006 }
1007
1008 /**
1009  * batadv_hardif_remove_interfaces() - Remove all hard interfaces
1010  */
1011 void batadv_hardif_remove_interfaces(void)
1012 {
1013         struct batadv_hard_iface *hard_iface, *hard_iface_tmp;
1014
1015         rtnl_lock();
1016         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
1017                                  &batadv_hardif_list, list) {
1018                 list_del_rcu(&hard_iface->list);
1019                 batadv_hardif_remove_interface(hard_iface);
1020         }
1021         rtnl_unlock();
1022 }
1023
1024 /**
1025  * batadv_hard_if_event_softif() - Handle events for soft interfaces
1026  * @event: NETDEV_* event to handle
1027  * @net_dev: net_device which generated an event
1028  *
1029  * Return: NOTIFY_* result
1030  */
1031 static int batadv_hard_if_event_softif(unsigned long event,
1032                                        struct net_device *net_dev)
1033 {
1034         struct batadv_priv *bat_priv;
1035
1036         switch (event) {
1037         case NETDEV_REGISTER:
1038                 batadv_sysfs_add_meshif(net_dev);
1039                 bat_priv = netdev_priv(net_dev);
1040                 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
1041                 break;
1042         case NETDEV_CHANGENAME:
1043                 batadv_debugfs_rename_meshif(net_dev);
1044                 break;
1045         }
1046
1047         return NOTIFY_DONE;
1048 }
1049
1050 static int batadv_hard_if_event(struct notifier_block *this,
1051                                 unsigned long event, void *ptr)
1052 {
1053         struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
1054         struct batadv_hard_iface *hard_iface;
1055         struct batadv_hard_iface *primary_if = NULL;
1056         struct batadv_priv *bat_priv;
1057
1058         if (batadv_softif_is_valid(net_dev))
1059                 return batadv_hard_if_event_softif(event, net_dev);
1060
1061         hard_iface = batadv_hardif_get_by_netdev(net_dev);
1062         if (!hard_iface && (event == NETDEV_REGISTER ||
1063                             event == NETDEV_POST_TYPE_CHANGE))
1064                 hard_iface = batadv_hardif_add_interface(net_dev);
1065
1066         if (!hard_iface)
1067                 goto out;
1068
1069         switch (event) {
1070         case NETDEV_UP:
1071                 batadv_hardif_activate_interface(hard_iface);
1072                 break;
1073         case NETDEV_GOING_DOWN:
1074         case NETDEV_DOWN:
1075                 batadv_hardif_deactivate_interface(hard_iface);
1076                 break;
1077         case NETDEV_UNREGISTER:
1078         case NETDEV_PRE_TYPE_CHANGE:
1079                 list_del_rcu(&hard_iface->list);
1080
1081                 batadv_hardif_remove_interface(hard_iface);
1082                 break;
1083         case NETDEV_CHANGEMTU:
1084                 if (hard_iface->soft_iface)
1085                         batadv_update_min_mtu(hard_iface->soft_iface);
1086                 break;
1087         case NETDEV_CHANGEADDR:
1088                 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
1089                         goto hardif_put;
1090
1091                 batadv_check_known_mac_addr(hard_iface->net_dev);
1092
1093                 bat_priv = netdev_priv(hard_iface->soft_iface);
1094                 bat_priv->algo_ops->iface.update_mac(hard_iface);
1095
1096                 primary_if = batadv_primary_if_get_selected(bat_priv);
1097                 if (!primary_if)
1098                         goto hardif_put;
1099
1100                 if (hard_iface == primary_if)
1101                         batadv_primary_if_update_addr(bat_priv, NULL);
1102                 break;
1103         case NETDEV_CHANGEUPPER:
1104                 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
1105                 if (batadv_is_wifi_hardif(hard_iface))
1106                         hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
1107                 break;
1108         case NETDEV_CHANGENAME:
1109                 batadv_debugfs_rename_hardif(hard_iface);
1110                 break;
1111         default:
1112                 break;
1113         }
1114
1115 hardif_put:
1116         batadv_hardif_put(hard_iface);
1117 out:
1118         if (primary_if)
1119                 batadv_hardif_put(primary_if);
1120         return NOTIFY_DONE;
1121 }
1122
1123 struct notifier_block batadv_hard_if_notifier = {
1124         .notifier_call = batadv_hard_if_event,
1125 };