1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (C) 2007-2020 B.A.T.M.A.N. contributors: 3 * 4 * Marek Lindner, Simon Wunderlich 5 */ 6 7 #include "hard-interface.h" 8 #include "main.h" 9 10 #include <linux/atomic.h> 11 #include <linux/byteorder/generic.h> 12 #include <linux/errno.h> 13 #include <linux/gfp.h> 14 #include <linux/if.h> 15 #include <linux/if_arp.h> 16 #include <linux/if_ether.h> 17 #include <linux/kernel.h> 18 #include <linux/kref.h> 19 #include <linux/limits.h> 20 #include <linux/list.h> 21 #include <linux/minmax.h> 22 #include <linux/mutex.h> 23 #include <linux/netdevice.h> 24 #include <linux/printk.h> 25 #include <linux/rculist.h> 26 #include <linux/rtnetlink.h> 27 #include <linux/slab.h> 28 #include <linux/spinlock.h> 29 #include <net/net_namespace.h> 30 #include <net/rtnetlink.h> 31 #include <uapi/linux/batadv_packet.h> 32 33 #include "bat_v.h" 34 #include "bridge_loop_avoidance.h" 35 #include "distributed-arp-table.h" 36 #include "gateway_client.h" 37 #include "log.h" 38 #include "originator.h" 39 #include "send.h" 40 #include "soft-interface.h" 41 #include "translation-table.h" 42 43 /** 44 * batadv_hardif_release() - release hard interface from lists and queue for 45 * free after rcu grace period 46 * @ref: kref pointer of the hard interface 47 */ 48 void batadv_hardif_release(struct kref *ref) 49 { 50 struct batadv_hard_iface *hard_iface; 51 52 hard_iface = container_of(ref, struct batadv_hard_iface, refcount); 53 dev_put(hard_iface->net_dev); 54 55 kfree_rcu(hard_iface, rcu); 56 } 57 58 /** 59 * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device 60 * @net_dev: net_device to search for 61 * 62 * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors 63 */ 64 struct batadv_hard_iface * 65 batadv_hardif_get_by_netdev(const struct net_device *net_dev) 66 { 67 struct batadv_hard_iface *hard_iface; 68 69 rcu_read_lock(); 70 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 71 if (hard_iface->net_dev == net_dev && 72 kref_get_unless_zero(&hard_iface->refcount)) 73 goto out; 74 } 75 76 hard_iface = NULL; 77 78 out: 79 rcu_read_unlock(); 80 return hard_iface; 81 } 82 83 /** 84 * batadv_getlink_net() - return link net namespace (of use fallback) 85 * @netdev: net_device to check 86 * @fallback_net: return in case get_link_net is not available for @netdev 87 * 88 * Return: result of rtnl_link_ops->get_link_net or @fallback_net 89 */ 90 static struct net *batadv_getlink_net(const struct net_device *netdev, 91 struct net *fallback_net) 92 { 93 if (!netdev->rtnl_link_ops) 94 return fallback_net; 95 96 if (!netdev->rtnl_link_ops->get_link_net) 97 return fallback_net; 98 99 return netdev->rtnl_link_ops->get_link_net(netdev); 100 } 101 102 /** 103 * batadv_mutual_parents() - check if two devices are each others parent 104 * @dev1: 1st net dev 105 * @net1: 1st devices netns 106 * @dev2: 2nd net dev 107 * @net2: 2nd devices netns 108 * 109 * veth devices come in pairs and each is the parent of the other! 110 * 111 * Return: true if the devices are each others parent, otherwise false 112 */ 113 static bool batadv_mutual_parents(const struct net_device *dev1, 114 struct net *net1, 115 const struct net_device *dev2, 116 struct net *net2) 117 { 118 int dev1_parent_iflink = dev_get_iflink(dev1); 119 int dev2_parent_iflink = dev_get_iflink(dev2); 120 const struct net *dev1_parent_net; 121 const struct net *dev2_parent_net; 122 123 dev1_parent_net = batadv_getlink_net(dev1, net1); 124 dev2_parent_net = batadv_getlink_net(dev2, net2); 125 126 if (!dev1_parent_iflink || !dev2_parent_iflink) 127 return false; 128 129 return (dev1_parent_iflink == dev2->ifindex) && 130 (dev2_parent_iflink == dev1->ifindex) && 131 net_eq(dev1_parent_net, net2) && 132 net_eq(dev2_parent_net, net1); 133 } 134 135 /** 136 * batadv_is_on_batman_iface() - check if a device is a batman iface descendant 137 * @net_dev: the device to check 138 * 139 * If the user creates any virtual device on top of a batman-adv interface, it 140 * is important to prevent this new interface from being used to create a new 141 * mesh network (this behaviour would lead to a batman-over-batman 142 * configuration). This function recursively checks all the fathers of the 143 * device passed as argument looking for a batman-adv soft interface. 144 * 145 * Return: true if the device is descendant of a batman-adv mesh interface (or 146 * if it is a batman-adv interface itself), false otherwise 147 */ 148 static bool batadv_is_on_batman_iface(const struct net_device *net_dev) 149 { 150 struct net *net = dev_net(net_dev); 151 struct net_device *parent_dev; 152 struct net *parent_net; 153 bool ret; 154 155 /* check if this is a batman-adv mesh interface */ 156 if (batadv_softif_is_valid(net_dev)) 157 return true; 158 159 /* no more parents..stop recursion */ 160 if (dev_get_iflink(net_dev) == 0 || 161 dev_get_iflink(net_dev) == net_dev->ifindex) 162 return false; 163 164 parent_net = batadv_getlink_net(net_dev, net); 165 166 /* recurse over the parent device */ 167 parent_dev = __dev_get_by_index((struct net *)parent_net, 168 dev_get_iflink(net_dev)); 169 /* if we got a NULL parent_dev there is something broken.. */ 170 if (!parent_dev) { 171 pr_err("Cannot find parent device\n"); 172 return false; 173 } 174 175 if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net)) 176 return false; 177 178 ret = batadv_is_on_batman_iface(parent_dev); 179 180 return ret; 181 } 182 183 static bool batadv_is_valid_iface(const struct net_device *net_dev) 184 { 185 if (net_dev->flags & IFF_LOOPBACK) 186 return false; 187 188 if (net_dev->type != ARPHRD_ETHER) 189 return false; 190 191 if (net_dev->addr_len != ETH_ALEN) 192 return false; 193 194 /* no batman over batman */ 195 if (batadv_is_on_batman_iface(net_dev)) 196 return false; 197 198 return true; 199 } 200 201 /** 202 * batadv_get_real_netdevice() - check if the given netdev struct is a virtual 203 * interface on top of another 'real' interface 204 * @netdev: the device to check 205 * 206 * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev() 207 * instead of this. 208 * 209 * Return: the 'real' net device or the original net device and NULL in case 210 * of an error. 211 */ 212 static struct net_device *batadv_get_real_netdevice(struct net_device *netdev) 213 { 214 struct batadv_hard_iface *hard_iface = NULL; 215 struct net_device *real_netdev = NULL; 216 struct net *real_net; 217 struct net *net; 218 int ifindex; 219 220 ASSERT_RTNL(); 221 222 if (!netdev) 223 return NULL; 224 225 if (netdev->ifindex == dev_get_iflink(netdev)) { 226 dev_hold(netdev); 227 return netdev; 228 } 229 230 hard_iface = batadv_hardif_get_by_netdev(netdev); 231 if (!hard_iface || !hard_iface->soft_iface) 232 goto out; 233 234 net = dev_net(hard_iface->soft_iface); 235 ifindex = dev_get_iflink(netdev); 236 real_net = batadv_getlink_net(netdev, net); 237 real_netdev = dev_get_by_index(real_net, ifindex); 238 239 out: 240 if (hard_iface) 241 batadv_hardif_put(hard_iface); 242 return real_netdev; 243 } 244 245 /** 246 * batadv_get_real_netdev() - check if the given net_device struct is a virtual 247 * interface on top of another 'real' interface 248 * @net_device: the device to check 249 * 250 * Return: the 'real' net device or the original net device and NULL in case 251 * of an error. 252 */ 253 struct net_device *batadv_get_real_netdev(struct net_device *net_device) 254 { 255 struct net_device *real_netdev; 256 257 rtnl_lock(); 258 real_netdev = batadv_get_real_netdevice(net_device); 259 rtnl_unlock(); 260 261 return real_netdev; 262 } 263 264 /** 265 * batadv_is_wext_netdev() - check if the given net_device struct is a 266 * wext wifi interface 267 * @net_device: the device to check 268 * 269 * Return: true if the net device is a wext wireless device, false 270 * otherwise. 271 */ 272 static bool batadv_is_wext_netdev(struct net_device *net_device) 273 { 274 if (!net_device) 275 return false; 276 277 #ifdef CONFIG_WIRELESS_EXT 278 /* pre-cfg80211 drivers have to implement WEXT, so it is possible to 279 * check for wireless_handlers != NULL 280 */ 281 if (net_device->wireless_handlers) 282 return true; 283 #endif 284 285 return false; 286 } 287 288 /** 289 * batadv_is_cfg80211_netdev() - check if the given net_device struct is a 290 * cfg80211 wifi interface 291 * @net_device: the device to check 292 * 293 * Return: true if the net device is a cfg80211 wireless device, false 294 * otherwise. 295 */ 296 static bool batadv_is_cfg80211_netdev(struct net_device *net_device) 297 { 298 if (!net_device) 299 return false; 300 301 /* cfg80211 drivers have to set ieee80211_ptr */ 302 if (net_device->ieee80211_ptr) 303 return true; 304 305 return false; 306 } 307 308 /** 309 * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device 310 * @net_device: the device to check 311 * 312 * Return: batadv_hard_iface_wifi_flags flags of the device 313 */ 314 static u32 batadv_wifi_flags_evaluate(struct net_device *net_device) 315 { 316 u32 wifi_flags = 0; 317 struct net_device *real_netdev; 318 319 if (batadv_is_wext_netdev(net_device)) 320 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT; 321 322 if (batadv_is_cfg80211_netdev(net_device)) 323 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT; 324 325 real_netdev = batadv_get_real_netdevice(net_device); 326 if (!real_netdev) 327 return wifi_flags; 328 329 if (real_netdev == net_device) 330 goto out; 331 332 if (batadv_is_wext_netdev(real_netdev)) 333 wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT; 334 335 if (batadv_is_cfg80211_netdev(real_netdev)) 336 wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT; 337 338 out: 339 dev_put(real_netdev); 340 return wifi_flags; 341 } 342 343 /** 344 * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi 345 * interface 346 * @hard_iface: the device to check 347 * 348 * Return: true if the net device is a cfg80211 wireless device, false 349 * otherwise. 350 */ 351 bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface) 352 { 353 u32 allowed_flags = 0; 354 355 allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT; 356 allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT; 357 358 return !!(hard_iface->wifi_flags & allowed_flags); 359 } 360 361 /** 362 * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface 363 * @hard_iface: the device to check 364 * 365 * Return: true if the net device is a 802.11 wireless device, false otherwise. 366 */ 367 bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface) 368 { 369 if (!hard_iface) 370 return false; 371 372 return hard_iface->wifi_flags != 0; 373 } 374 375 /** 376 * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary 377 * @if_outgoing: the outgoing interface checked and considered for (re)broadcast 378 * @orig_addr: the originator of this packet 379 * @orig_neigh: originator address of the forwarder we just got the packet from 380 * (NULL if we originated) 381 * 382 * Checks whether a packet needs to be (re)broadcasted on the given interface. 383 * 384 * Return: 385 * BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface 386 * BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder 387 * BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator 388 * BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast 389 */ 390 int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing, 391 u8 *orig_addr, u8 *orig_neigh) 392 { 393 struct batadv_hardif_neigh_node *hardif_neigh; 394 struct hlist_node *first; 395 int ret = BATADV_HARDIF_BCAST_OK; 396 397 rcu_read_lock(); 398 399 /* 0 neighbors -> no (re)broadcast */ 400 first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list)); 401 if (!first) { 402 ret = BATADV_HARDIF_BCAST_NORECIPIENT; 403 goto out; 404 } 405 406 /* >1 neighbors -> (re)brodcast */ 407 if (rcu_dereference(hlist_next_rcu(first))) 408 goto out; 409 410 hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node, 411 list); 412 413 /* 1 neighbor, is the originator -> no rebroadcast */ 414 if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) { 415 ret = BATADV_HARDIF_BCAST_DUPORIG; 416 /* 1 neighbor, is the one we received from -> no rebroadcast */ 417 } else if (orig_neigh && 418 batadv_compare_eth(hardif_neigh->orig, orig_neigh)) { 419 ret = BATADV_HARDIF_BCAST_DUPFWD; 420 } 421 422 out: 423 rcu_read_unlock(); 424 return ret; 425 } 426 427 static struct batadv_hard_iface * 428 batadv_hardif_get_active(const struct net_device *soft_iface) 429 { 430 struct batadv_hard_iface *hard_iface; 431 432 rcu_read_lock(); 433 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 434 if (hard_iface->soft_iface != soft_iface) 435 continue; 436 437 if (hard_iface->if_status == BATADV_IF_ACTIVE && 438 kref_get_unless_zero(&hard_iface->refcount)) 439 goto out; 440 } 441 442 hard_iface = NULL; 443 444 out: 445 rcu_read_unlock(); 446 return hard_iface; 447 } 448 449 static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv, 450 struct batadv_hard_iface *oldif) 451 { 452 struct batadv_hard_iface *primary_if; 453 454 primary_if = batadv_primary_if_get_selected(bat_priv); 455 if (!primary_if) 456 goto out; 457 458 batadv_dat_init_own_addr(bat_priv, primary_if); 459 batadv_bla_update_orig_address(bat_priv, primary_if, oldif); 460 out: 461 if (primary_if) 462 batadv_hardif_put(primary_if); 463 } 464 465 static void batadv_primary_if_select(struct batadv_priv *bat_priv, 466 struct batadv_hard_iface *new_hard_iface) 467 { 468 struct batadv_hard_iface *curr_hard_iface; 469 470 ASSERT_RTNL(); 471 472 if (new_hard_iface) 473 kref_get(&new_hard_iface->refcount); 474 475 curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if, 476 new_hard_iface, 1); 477 478 if (!new_hard_iface) 479 goto out; 480 481 bat_priv->algo_ops->iface.primary_set(new_hard_iface); 482 batadv_primary_if_update_addr(bat_priv, curr_hard_iface); 483 484 out: 485 if (curr_hard_iface) 486 batadv_hardif_put(curr_hard_iface); 487 } 488 489 static bool 490 batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface) 491 { 492 if (hard_iface->net_dev->flags & IFF_UP) 493 return true; 494 495 return false; 496 } 497 498 static void batadv_check_known_mac_addr(const struct net_device *net_dev) 499 { 500 const struct batadv_hard_iface *hard_iface; 501 502 rcu_read_lock(); 503 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 504 if (hard_iface->if_status != BATADV_IF_ACTIVE && 505 hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED) 506 continue; 507 508 if (hard_iface->net_dev == net_dev) 509 continue; 510 511 if (!batadv_compare_eth(hard_iface->net_dev->dev_addr, 512 net_dev->dev_addr)) 513 continue; 514 515 pr_warn("The newly added mac address (%pM) already exists on: %s\n", 516 net_dev->dev_addr, hard_iface->net_dev->name); 517 pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n"); 518 } 519 rcu_read_unlock(); 520 } 521 522 /** 523 * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom 524 * @soft_iface: netdev struct of the mesh interface 525 */ 526 static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface) 527 { 528 const struct batadv_hard_iface *hard_iface; 529 unsigned short lower_header_len = ETH_HLEN; 530 unsigned short lower_headroom = 0; 531 unsigned short lower_tailroom = 0; 532 unsigned short needed_headroom; 533 534 rcu_read_lock(); 535 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 536 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE) 537 continue; 538 539 if (hard_iface->soft_iface != soft_iface) 540 continue; 541 542 lower_header_len = max_t(unsigned short, lower_header_len, 543 hard_iface->net_dev->hard_header_len); 544 545 lower_headroom = max_t(unsigned short, lower_headroom, 546 hard_iface->net_dev->needed_headroom); 547 548 lower_tailroom = max_t(unsigned short, lower_tailroom, 549 hard_iface->net_dev->needed_tailroom); 550 } 551 rcu_read_unlock(); 552 553 needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN); 554 needed_headroom += batadv_max_header_len(); 555 556 /* fragmentation headers don't strip the unicast/... header */ 557 needed_headroom += sizeof(struct batadv_frag_packet); 558 559 soft_iface->needed_headroom = needed_headroom; 560 soft_iface->needed_tailroom = lower_tailroom; 561 } 562 563 /** 564 * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface 565 * @soft_iface: netdev struct of the soft interface 566 * 567 * Return: MTU for the soft-interface (limited by the minimal MTU of all active 568 * slave interfaces) 569 */ 570 int batadv_hardif_min_mtu(struct net_device *soft_iface) 571 { 572 struct batadv_priv *bat_priv = netdev_priv(soft_iface); 573 const struct batadv_hard_iface *hard_iface; 574 int min_mtu = INT_MAX; 575 576 rcu_read_lock(); 577 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 578 if (hard_iface->if_status != BATADV_IF_ACTIVE && 579 hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED) 580 continue; 581 582 if (hard_iface->soft_iface != soft_iface) 583 continue; 584 585 min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu); 586 } 587 rcu_read_unlock(); 588 589 if (atomic_read(&bat_priv->fragmentation) == 0) 590 goto out; 591 592 /* with fragmentation enabled the maximum size of internally generated 593 * packets such as translation table exchanges or tvlv containers, etc 594 * has to be calculated 595 */ 596 min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE); 597 min_mtu -= sizeof(struct batadv_frag_packet); 598 min_mtu *= BATADV_FRAG_MAX_FRAGMENTS; 599 600 out: 601 /* report to the other components the maximum amount of bytes that 602 * batman-adv can send over the wire (without considering the payload 603 * overhead). For example, this value is used by TT to compute the 604 * maximum local table size 605 */ 606 atomic_set(&bat_priv->packet_size_max, min_mtu); 607 608 /* the real soft-interface MTU is computed by removing the payload 609 * overhead from the maximum amount of bytes that was just computed. 610 * 611 * However batman-adv does not support MTUs bigger than ETH_DATA_LEN 612 */ 613 return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN); 614 } 615 616 /** 617 * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller 618 * MTU appeared 619 * @soft_iface: netdev struct of the soft interface 620 */ 621 void batadv_update_min_mtu(struct net_device *soft_iface) 622 { 623 soft_iface->mtu = batadv_hardif_min_mtu(soft_iface); 624 625 /* Check if the local translate table should be cleaned up to match a 626 * new (and smaller) MTU. 627 */ 628 batadv_tt_local_resize_to_mtu(soft_iface); 629 } 630 631 static void 632 batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface) 633 { 634 struct batadv_priv *bat_priv; 635 struct batadv_hard_iface *primary_if = NULL; 636 637 if (hard_iface->if_status != BATADV_IF_INACTIVE) 638 goto out; 639 640 bat_priv = netdev_priv(hard_iface->soft_iface); 641 642 bat_priv->algo_ops->iface.update_mac(hard_iface); 643 hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED; 644 645 /* the first active interface becomes our primary interface or 646 * the next active interface after the old primary interface was removed 647 */ 648 primary_if = batadv_primary_if_get_selected(bat_priv); 649 if (!primary_if) 650 batadv_primary_if_select(bat_priv, hard_iface); 651 652 batadv_info(hard_iface->soft_iface, "Interface activated: %s\n", 653 hard_iface->net_dev->name); 654 655 batadv_update_min_mtu(hard_iface->soft_iface); 656 657 if (bat_priv->algo_ops->iface.activate) 658 bat_priv->algo_ops->iface.activate(hard_iface); 659 660 out: 661 if (primary_if) 662 batadv_hardif_put(primary_if); 663 } 664 665 static void 666 batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface) 667 { 668 if (hard_iface->if_status != BATADV_IF_ACTIVE && 669 hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED) 670 return; 671 672 hard_iface->if_status = BATADV_IF_INACTIVE; 673 674 batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n", 675 hard_iface->net_dev->name); 676 677 batadv_update_min_mtu(hard_iface->soft_iface); 678 } 679 680 /** 681 * batadv_master_del_slave() - remove hard_iface from the current master iface 682 * @slave: the interface enslaved in another master 683 * @master: the master from which slave has to be removed 684 * 685 * Invoke ndo_del_slave on master passing slave as argument. In this way the 686 * slave is free'd and the master can correctly change its internal state. 687 * 688 * Return: 0 on success, a negative value representing the error otherwise 689 */ 690 static int batadv_master_del_slave(struct batadv_hard_iface *slave, 691 struct net_device *master) 692 { 693 int ret; 694 695 if (!master) 696 return 0; 697 698 ret = -EBUSY; 699 if (master->netdev_ops->ndo_del_slave) 700 ret = master->netdev_ops->ndo_del_slave(master, slave->net_dev); 701 702 return ret; 703 } 704 705 /** 706 * batadv_hardif_enable_interface() - Enslave hard interface to soft interface 707 * @hard_iface: hard interface to add to soft interface 708 * @net: the applicable net namespace 709 * @iface_name: name of the soft interface 710 * 711 * Return: 0 on success or negative error number in case of failure 712 */ 713 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, 714 struct net *net, const char *iface_name) 715 { 716 struct batadv_priv *bat_priv; 717 struct net_device *soft_iface, *master; 718 __be16 ethertype = htons(ETH_P_BATMAN); 719 int max_header_len = batadv_max_header_len(); 720 int ret; 721 722 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) 723 goto out; 724 725 kref_get(&hard_iface->refcount); 726 727 soft_iface = dev_get_by_name(net, iface_name); 728 729 if (!soft_iface) { 730 soft_iface = batadv_softif_create(net, iface_name); 731 732 if (!soft_iface) { 733 ret = -ENOMEM; 734 goto err; 735 } 736 737 /* dev_get_by_name() increases the reference counter for us */ 738 dev_hold(soft_iface); 739 } 740 741 if (!batadv_softif_is_valid(soft_iface)) { 742 pr_err("Can't create batman mesh interface %s: already exists as regular interface\n", 743 soft_iface->name); 744 ret = -EINVAL; 745 goto err_dev; 746 } 747 748 /* check if the interface is enslaved in another virtual one and 749 * in that case unlink it first 750 */ 751 master = netdev_master_upper_dev_get(hard_iface->net_dev); 752 ret = batadv_master_del_slave(hard_iface, master); 753 if (ret) 754 goto err_dev; 755 756 hard_iface->soft_iface = soft_iface; 757 bat_priv = netdev_priv(hard_iface->soft_iface); 758 759 ret = netdev_master_upper_dev_link(hard_iface->net_dev, 760 soft_iface, NULL, NULL, NULL); 761 if (ret) 762 goto err_dev; 763 764 ret = bat_priv->algo_ops->iface.enable(hard_iface); 765 if (ret < 0) 766 goto err_upper; 767 768 hard_iface->if_status = BATADV_IF_INACTIVE; 769 770 kref_get(&hard_iface->refcount); 771 hard_iface->batman_adv_ptype.type = ethertype; 772 hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv; 773 hard_iface->batman_adv_ptype.dev = hard_iface->net_dev; 774 dev_add_pack(&hard_iface->batman_adv_ptype); 775 776 batadv_info(hard_iface->soft_iface, "Adding interface: %s\n", 777 hard_iface->net_dev->name); 778 779 if (atomic_read(&bat_priv->fragmentation) && 780 hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len) 781 batadv_info(hard_iface->soft_iface, 782 "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", 783 hard_iface->net_dev->name, hard_iface->net_dev->mtu, 784 ETH_DATA_LEN + max_header_len); 785 786 if (!atomic_read(&bat_priv->fragmentation) && 787 hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len) 788 batadv_info(hard_iface->soft_iface, 789 "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", 790 hard_iface->net_dev->name, hard_iface->net_dev->mtu, 791 ETH_DATA_LEN + max_header_len); 792 793 if (batadv_hardif_is_iface_up(hard_iface)) 794 batadv_hardif_activate_interface(hard_iface); 795 else 796 batadv_err(hard_iface->soft_iface, 797 "Not using interface %s (retrying later): interface not active\n", 798 hard_iface->net_dev->name); 799 800 batadv_hardif_recalc_extra_skbroom(soft_iface); 801 802 if (bat_priv->algo_ops->iface.enabled) 803 bat_priv->algo_ops->iface.enabled(hard_iface); 804 805 out: 806 return 0; 807 808 err_upper: 809 netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface); 810 err_dev: 811 hard_iface->soft_iface = NULL; 812 dev_put(soft_iface); 813 err: 814 batadv_hardif_put(hard_iface); 815 return ret; 816 } 817 818 /** 819 * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface 820 * @soft_iface: soft interface to check 821 * 822 * This function is only using RCU for locking - the result can therefore be 823 * off when another function is modifying the list at the same time. The 824 * caller can use the rtnl_lock to make sure that the count is accurate. 825 * 826 * Return: number of connected/enslaved hard interfaces 827 */ 828 static size_t batadv_hardif_cnt(const struct net_device *soft_iface) 829 { 830 struct batadv_hard_iface *hard_iface; 831 size_t count = 0; 832 833 rcu_read_lock(); 834 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { 835 if (hard_iface->soft_iface != soft_iface) 836 continue; 837 838 count++; 839 } 840 rcu_read_unlock(); 841 842 return count; 843 } 844 845 /** 846 * batadv_hardif_disable_interface() - Remove hard interface from soft interface 847 * @hard_iface: hard interface to be removed 848 */ 849 void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface) 850 { 851 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); 852 struct batadv_hard_iface *primary_if = NULL; 853 854 batadv_hardif_deactivate_interface(hard_iface); 855 856 if (hard_iface->if_status != BATADV_IF_INACTIVE) 857 goto out; 858 859 batadv_info(hard_iface->soft_iface, "Removing interface: %s\n", 860 hard_iface->net_dev->name); 861 dev_remove_pack(&hard_iface->batman_adv_ptype); 862 batadv_hardif_put(hard_iface); 863 864 primary_if = batadv_primary_if_get_selected(bat_priv); 865 if (hard_iface == primary_if) { 866 struct batadv_hard_iface *new_if; 867 868 new_if = batadv_hardif_get_active(hard_iface->soft_iface); 869 batadv_primary_if_select(bat_priv, new_if); 870 871 if (new_if) 872 batadv_hardif_put(new_if); 873 } 874 875 bat_priv->algo_ops->iface.disable(hard_iface); 876 hard_iface->if_status = BATADV_IF_NOT_IN_USE; 877 878 /* delete all references to this hard_iface */ 879 batadv_purge_orig_ref(bat_priv); 880 batadv_purge_outstanding_packets(bat_priv, hard_iface); 881 dev_put(hard_iface->soft_iface); 882 883 netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface); 884 batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface); 885 886 /* nobody uses this interface anymore */ 887 if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1) 888 batadv_gw_check_client_stop(bat_priv); 889 890 hard_iface->soft_iface = NULL; 891 batadv_hardif_put(hard_iface); 892 893 out: 894 if (primary_if) 895 batadv_hardif_put(primary_if); 896 } 897 898 static struct batadv_hard_iface * 899 batadv_hardif_add_interface(struct net_device *net_dev) 900 { 901 struct batadv_hard_iface *hard_iface; 902 903 ASSERT_RTNL(); 904 905 if (!batadv_is_valid_iface(net_dev)) 906 goto out; 907 908 dev_hold(net_dev); 909 910 hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC); 911 if (!hard_iface) 912 goto release_dev; 913 914 hard_iface->net_dev = net_dev; 915 hard_iface->soft_iface = NULL; 916 hard_iface->if_status = BATADV_IF_NOT_IN_USE; 917 918 INIT_LIST_HEAD(&hard_iface->list); 919 INIT_HLIST_HEAD(&hard_iface->neigh_list); 920 921 mutex_init(&hard_iface->bat_iv.ogm_buff_mutex); 922 spin_lock_init(&hard_iface->neigh_list_lock); 923 kref_init(&hard_iface->refcount); 924 925 hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT; 926 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev); 927 if (batadv_is_wifi_hardif(hard_iface)) 928 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS; 929 930 atomic_set(&hard_iface->hop_penalty, 0); 931 932 batadv_v_hardif_init(hard_iface); 933 934 batadv_check_known_mac_addr(hard_iface->net_dev); 935 kref_get(&hard_iface->refcount); 936 list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list); 937 batadv_hardif_generation++; 938 939 return hard_iface; 940 941 release_dev: 942 dev_put(net_dev); 943 out: 944 return NULL; 945 } 946 947 static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface) 948 { 949 ASSERT_RTNL(); 950 951 /* first deactivate interface */ 952 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) 953 batadv_hardif_disable_interface(hard_iface); 954 955 if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) 956 return; 957 958 hard_iface->if_status = BATADV_IF_TO_BE_REMOVED; 959 batadv_hardif_put(hard_iface); 960 } 961 962 /** 963 * batadv_hard_if_event_softif() - Handle events for soft interfaces 964 * @event: NETDEV_* event to handle 965 * @net_dev: net_device which generated an event 966 * 967 * Return: NOTIFY_* result 968 */ 969 static int batadv_hard_if_event_softif(unsigned long event, 970 struct net_device *net_dev) 971 { 972 struct batadv_priv *bat_priv; 973 974 switch (event) { 975 case NETDEV_REGISTER: 976 bat_priv = netdev_priv(net_dev); 977 batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS); 978 break; 979 } 980 981 return NOTIFY_DONE; 982 } 983 984 static int batadv_hard_if_event(struct notifier_block *this, 985 unsigned long event, void *ptr) 986 { 987 struct net_device *net_dev = netdev_notifier_info_to_dev(ptr); 988 struct batadv_hard_iface *hard_iface; 989 struct batadv_hard_iface *primary_if = NULL; 990 struct batadv_priv *bat_priv; 991 992 if (batadv_softif_is_valid(net_dev)) 993 return batadv_hard_if_event_softif(event, net_dev); 994 995 hard_iface = batadv_hardif_get_by_netdev(net_dev); 996 if (!hard_iface && (event == NETDEV_REGISTER || 997 event == NETDEV_POST_TYPE_CHANGE)) 998 hard_iface = batadv_hardif_add_interface(net_dev); 999 1000 if (!hard_iface) 1001 goto out; 1002 1003 switch (event) { 1004 case NETDEV_UP: 1005 batadv_hardif_activate_interface(hard_iface); 1006 break; 1007 case NETDEV_GOING_DOWN: 1008 case NETDEV_DOWN: 1009 batadv_hardif_deactivate_interface(hard_iface); 1010 break; 1011 case NETDEV_UNREGISTER: 1012 case NETDEV_PRE_TYPE_CHANGE: 1013 list_del_rcu(&hard_iface->list); 1014 batadv_hardif_generation++; 1015 1016 batadv_hardif_remove_interface(hard_iface); 1017 break; 1018 case NETDEV_CHANGEMTU: 1019 if (hard_iface->soft_iface) 1020 batadv_update_min_mtu(hard_iface->soft_iface); 1021 break; 1022 case NETDEV_CHANGEADDR: 1023 if (hard_iface->if_status == BATADV_IF_NOT_IN_USE) 1024 goto hardif_put; 1025 1026 batadv_check_known_mac_addr(hard_iface->net_dev); 1027 1028 bat_priv = netdev_priv(hard_iface->soft_iface); 1029 bat_priv->algo_ops->iface.update_mac(hard_iface); 1030 1031 primary_if = batadv_primary_if_get_selected(bat_priv); 1032 if (!primary_if) 1033 goto hardif_put; 1034 1035 if (hard_iface == primary_if) 1036 batadv_primary_if_update_addr(bat_priv, NULL); 1037 break; 1038 case NETDEV_CHANGEUPPER: 1039 hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev); 1040 if (batadv_is_wifi_hardif(hard_iface)) 1041 hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS; 1042 break; 1043 default: 1044 break; 1045 } 1046 1047 hardif_put: 1048 batadv_hardif_put(hard_iface); 1049 out: 1050 if (primary_if) 1051 batadv_hardif_put(primary_if); 1052 return NOTIFY_DONE; 1053 } 1054 1055 struct notifier_block batadv_hard_if_notifier = { 1056 .notifier_call = batadv_hard_if_event, 1057 }; 1058