net/batman-adv/hard-interface.c

   1 /*
   2  * Copyright (C) 2007-2011 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, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include "hard-interface.h"
  24 #include "soft-interface.h"
  25 #include "send.h"
  26 #include "translation-table.h"
  27 #include "routing.h"
  28 #include "bat_sysfs.h"
  29 #include "originator.h"
  30 #include "hash.h"
  31
  32 #include <linux/if_arp.h>
  33
  34 /* protect update critical side of hardif_list - but not the content */
  35 static DEFINE_SPINLOCK(hardif_list_lock);
  36
  37
  38 static int batman_skb_recv(struct sk_buff *skb,
  39                            struct net_device *dev,
  40                            struct packet_type *ptype,
  41                            struct net_device *orig_dev);
  42
  43 void hardif_free_rcu(struct rcu_head *rcu)
  44 {
  45         struct hard_iface *hard_iface;
  46
  47         hard_iface = container_of(rcu, struct hard_iface, rcu);
  48         dev_put(hard_iface->net_dev);
  49         kfree(hard_iface);
  50 }
  51
  52 struct hard_iface *hardif_get_by_netdev(struct net_device *net_dev)
  53 {
  54         struct hard_iface *hard_iface;
  55
  56         rcu_read_lock();
  57         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
  58                 if (hard_iface->net_dev == net_dev &&
  59                     atomic_inc_not_zero(&hard_iface->refcount))
  60                         goto out;
  61         }
  62
  63         hard_iface = NULL;
  64
  65 out:
  66         rcu_read_unlock();
  67         return hard_iface;
  68 }
  69
  70 static int is_valid_iface(struct net_device *net_dev)
  71 {
  72         if (net_dev->flags & IFF_LOOPBACK)
  73                 return 0;
  74
  75         if (net_dev->type != ARPHRD_ETHER)
  76                 return 0;
  77
  78         if (net_dev->addr_len != ETH_ALEN)
  79                 return 0;
  80
  81         /* no batman over batman */
  82         if (softif_is_valid(net_dev))
  83                 return 0;
  84
  85         /* Device is being bridged */
  86         /* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
  87                 return 0; */
  88
  89         return 1;
  90 }
  91
  92 static struct hard_iface *hardif_get_active(struct net_device *soft_iface)
  93 {
  94         struct hard_iface *hard_iface;
  95
  96         rcu_read_lock();
  97         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
  98                 if (hard_iface->soft_iface != soft_iface)
  99                         continue;
 100
 101                 if (hard_iface->if_status == IF_ACTIVE &&
 102                     atomic_inc_not_zero(&hard_iface->refcount))
 103                         goto out;
 104         }
 105
 106         hard_iface = NULL;
 107
 108 out:
 109         rcu_read_unlock();
 110         return hard_iface;
 111 }
 112
 113 static void update_primary_addr(struct bat_priv *bat_priv)
 114 {
 115         struct vis_packet *vis_packet;
 116
 117         vis_packet = (struct vis_packet *)
 118                                 bat_priv->my_vis_info->skb_packet->data;
 119         memcpy(vis_packet->vis_orig,
 120                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 121         memcpy(vis_packet->sender_orig,
 122                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 123 }
 124
 125 static void set_primary_if(struct bat_priv *bat_priv,
 126                            struct hard_iface *hard_iface)
 127 {
 128         struct batman_packet *batman_packet;
 129         struct hard_iface *old_if;
 130
 131         if (hard_iface && !atomic_inc_not_zero(&hard_iface->refcount))
 132                 hard_iface = NULL;
 133
 134         old_if = bat_priv->primary_if;
 135         bat_priv->primary_if = hard_iface;
 136
 137         if (old_if)
 138                 hardif_free_ref(old_if);
 139
 140         if (!bat_priv->primary_if)
 141                 return;
 142
 143         batman_packet = (struct batman_packet *)(hard_iface->packet_buff);
 144         batman_packet->flags = PRIMARIES_FIRST_HOP;
 145         batman_packet->ttl = TTL;
 146
 147         update_primary_addr(bat_priv);
 148
 149         /***
 150          * hacky trick to make sure that we send the HNA information via
 151          * our new primary interface
 152          */
 153         atomic_set(&bat_priv->hna_local_changed, 1);
 154 }
 155
 156 static bool hardif_is_iface_up(struct hard_iface *hard_iface)
 157 {
 158         if (hard_iface->net_dev->flags & IFF_UP)
 159                 return true;
 160
 161         return false;
 162 }
 163
 164 static void update_mac_addresses(struct hard_iface *hard_iface)
 165 {
 166         memcpy(((struct batman_packet *)(hard_iface->packet_buff))->orig,
 167                hard_iface->net_dev->dev_addr, ETH_ALEN);
 168         memcpy(((struct batman_packet *)(hard_iface->packet_buff))->prev_sender,
 169                hard_iface->net_dev->dev_addr, ETH_ALEN);
 170 }
 171
 172 static void check_known_mac_addr(struct net_device *net_dev)
 173 {
 174         struct hard_iface *hard_iface;
 175
 176         rcu_read_lock();
 177         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 178                 if ((hard_iface->if_status != IF_ACTIVE) &&
 179                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 180                         continue;
 181
 182                 if (hard_iface->net_dev == net_dev)
 183                         continue;
 184
 185                 if (!compare_eth(hard_iface->net_dev->dev_addr,
 186                                  net_dev->dev_addr))
 187                         continue;
 188
 189                 pr_warning("The newly added mac address (%pM) already exists "
 190                            "on: %s\n", net_dev->dev_addr,
 191                            hard_iface->net_dev->name);
 192                 pr_warning("It is strongly recommended to keep mac addresses "
 193                            "unique to avoid problems!\n");
 194         }
 195         rcu_read_unlock();
 196 }
 197
 198 int hardif_min_mtu(struct net_device *soft_iface)
 199 {
 200         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 201         struct hard_iface *hard_iface;
 202         /* allow big frames if all devices are capable to do so
 203          * (have MTU > 1500 + BAT_HEADER_LEN) */
 204         int min_mtu = ETH_DATA_LEN;
 205
 206         if (atomic_read(&bat_priv->fragmentation))
 207                 goto out;
 208
 209         rcu_read_lock();
 210         list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
 211                 if ((hard_iface->if_status != IF_ACTIVE) &&
 212                     (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 213                         continue;
 214
 215                 if (hard_iface->soft_iface != soft_iface)
 216                         continue;
 217
 218                 min_mtu = min_t(int, hard_iface->net_dev->mtu - BAT_HEADER_LEN,
 219                                 min_mtu);
 220         }
 221         rcu_read_unlock();
 222 out:
 223         return min_mtu;
 224 }
 225
 226 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 227 void update_min_mtu(struct net_device *soft_iface)
 228 {
 229         int min_mtu;
 230
 231         min_mtu = hardif_min_mtu(soft_iface);
 232         if (soft_iface->mtu != min_mtu)
 233                 soft_iface->mtu = min_mtu;
 234 }
 235
 236 static void hardif_activate_interface(struct hard_iface *hard_iface)
 237 {
 238         struct bat_priv *bat_priv;
 239
 240         if (hard_iface->if_status != IF_INACTIVE)
 241                 return;
 242
 243         bat_priv = netdev_priv(hard_iface->soft_iface);
 244
 245         update_mac_addresses(hard_iface);
 246         hard_iface->if_status = IF_TO_BE_ACTIVATED;
 247
 248         /**
 249          * the first active interface becomes our primary interface or
 250          * the next active interface after the old primay interface was removed
 251          */
 252         if (!bat_priv->primary_if)
 253                 set_primary_if(bat_priv, hard_iface);
 254
 255         bat_info(hard_iface->soft_iface, "Interface activated: %s\n",
 256                  hard_iface->net_dev->name);
 257
 258         update_min_mtu(hard_iface->soft_iface);
 259         return;
 260 }
 261
 262 static void hardif_deactivate_interface(struct hard_iface *hard_iface)
 263 {
 264         if ((hard_iface->if_status != IF_ACTIVE) &&
 265             (hard_iface->if_status != IF_TO_BE_ACTIVATED))
 266                 return;
 267
 268         hard_iface->if_status = IF_INACTIVE;
 269
 270         bat_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
 271                  hard_iface->net_dev->name);
 272
 273         update_min_mtu(hard_iface->soft_iface);
 274 }
 275
 276 int hardif_enable_interface(struct hard_iface *hard_iface, char *iface_name)
 277 {
 278         struct bat_priv *bat_priv;
 279         struct batman_packet *batman_packet;
 280         struct net_device *soft_iface;
 281         int ret;
 282
 283         if (hard_iface->if_status != IF_NOT_IN_USE)
 284                 goto out;
 285
 286         if (!atomic_inc_not_zero(&hard_iface->refcount))
 287                 goto out;
 288
 289         soft_iface = dev_get_by_name(&init_net, iface_name);
 290
 291         if (!soft_iface) {
 292                 soft_iface = softif_create(iface_name);
 293
 294                 if (!soft_iface) {
 295                         ret = -ENOMEM;
 296                         goto err;
 297                 }
 298
 299                 /* dev_get_by_name() increases the reference counter for us */
 300                 dev_hold(soft_iface);
 301         }
 302
 303         if (!softif_is_valid(soft_iface)) {
 304                 pr_err("Can't create batman mesh interface %s: "
 305                        "already exists as regular interface\n",
 306                        soft_iface->name);
 307                 dev_put(soft_iface);
 308                 ret = -EINVAL;
 309                 goto err;
 310         }
 311
 312         hard_iface->soft_iface = soft_iface;
 313         bat_priv = netdev_priv(hard_iface->soft_iface);
 314         hard_iface->packet_len = BAT_PACKET_LEN;
 315         hard_iface->packet_buff = kmalloc(hard_iface->packet_len, GFP_ATOMIC);
 316
 317         if (!hard_iface->packet_buff) {
 318                 bat_err(hard_iface->soft_iface, "Can't add interface packet "
 319                         "(%s): out of memory\n", hard_iface->net_dev->name);
 320                 ret = -ENOMEM;
 321                 goto err;
 322         }
 323
 324         batman_packet = (struct batman_packet *)(hard_iface->packet_buff);
 325         batman_packet->packet_type = BAT_PACKET;
 326         batman_packet->version = COMPAT_VERSION;
 327         batman_packet->flags = 0;
 328         batman_packet->ttl = 2;
 329         batman_packet->tq = TQ_MAX_VALUE;
 330         batman_packet->num_hna = 0;
 331
 332         hard_iface->if_num = bat_priv->num_ifaces;
 333         bat_priv->num_ifaces++;
 334         hard_iface->if_status = IF_INACTIVE;
 335         orig_hash_add_if(hard_iface, bat_priv->num_ifaces);
 336
 337         hard_iface->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
 338         hard_iface->batman_adv_ptype.func = batman_skb_recv;
 339         hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
 340         dev_add_pack(&hard_iface->batman_adv_ptype);
 341
 342         atomic_set(&hard_iface->seqno, 1);
 343         atomic_set(&hard_iface->frag_seqno, 1);
 344         bat_info(hard_iface->soft_iface, "Adding interface: %s\n",
 345                  hard_iface->net_dev->name);
 346
 347         if (atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 348                 ETH_DATA_LEN + BAT_HEADER_LEN)
 349                 bat_info(hard_iface->soft_iface,
 350                         "The MTU of interface %s is too small (%i) to handle "
 351                         "the transport of batman-adv packets. Packets going "
 352                         "over this interface will be fragmented on layer2 "
 353                         "which could impact the performance. Setting the MTU "
 354                         "to %zi would solve the problem.\n",
 355                         hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 356                         ETH_DATA_LEN + BAT_HEADER_LEN);
 357
 358         if (!atomic_read(&bat_priv->fragmentation) && hard_iface->net_dev->mtu <
 359                 ETH_DATA_LEN + BAT_HEADER_LEN)
 360                 bat_info(hard_iface->soft_iface,
 361                         "The MTU of interface %s is too small (%i) to handle "
 362                         "the transport of batman-adv packets. If you experience"
 363                         " problems getting traffic through try increasing the "
 364                         "MTU to %zi.\n",
 365                         hard_iface->net_dev->name, hard_iface->net_dev->mtu,
 366                         ETH_DATA_LEN + BAT_HEADER_LEN);
 367
 368         if (hardif_is_iface_up(hard_iface))
 369                 hardif_activate_interface(hard_iface);
 370         else
 371                 bat_err(hard_iface->soft_iface, "Not using interface %s "
 372                         "(retrying later): interface not active\n",
 373                         hard_iface->net_dev->name);
 374
 375         /* begin scheduling originator messages on that interface */
 376         schedule_own_packet(hard_iface);
 377
 378 out:
 379         return 0;
 380
 381 err:
 382         hardif_free_ref(hard_iface);
 383         return ret;
 384 }
 385
 386 void hardif_disable_interface(struct hard_iface *hard_iface)
 387 {
 388         struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
 389
 390         if (hard_iface->if_status == IF_ACTIVE)
 391                 hardif_deactivate_interface(hard_iface);
 392
 393         if (hard_iface->if_status != IF_INACTIVE)
 394                 return;
 395
 396         bat_info(hard_iface->soft_iface, "Removing interface: %s\n",
 397                  hard_iface->net_dev->name);
 398         dev_remove_pack(&hard_iface->batman_adv_ptype);
 399
 400         bat_priv->num_ifaces--;
 401         orig_hash_del_if(hard_iface, bat_priv->num_ifaces);
 402
 403         if (hard_iface == bat_priv->primary_if) {
 404                 struct hard_iface *new_if;
 405
 406                 new_if = hardif_get_active(hard_iface->soft_iface);
 407                 set_primary_if(bat_priv, new_if);
 408
 409                 if (new_if)
 410                         hardif_free_ref(new_if);
 411         }
 412
 413         kfree(hard_iface->packet_buff);
 414         hard_iface->packet_buff = NULL;
 415         hard_iface->if_status = IF_NOT_IN_USE;
 416
 417         /* delete all references to this hard_iface */
 418         purge_orig_ref(bat_priv);
 419         purge_outstanding_packets(bat_priv, hard_iface);
 420         dev_put(hard_iface->soft_iface);
 421
 422         /* nobody uses this interface anymore */
 423         if (!bat_priv->num_ifaces)
 424                 softif_destroy(hard_iface->soft_iface);
 425
 426         hard_iface->soft_iface = NULL;
 427         hardif_free_ref(hard_iface);
 428 }
 429
 430 static struct hard_iface *hardif_add_interface(struct net_device *net_dev)
 431 {
 432         struct hard_iface *hard_iface;
 433         int ret;
 434
 435         ret = is_valid_iface(net_dev);
 436         if (ret != 1)
 437                 goto out;
 438
 439         dev_hold(net_dev);
 440
 441         hard_iface = kmalloc(sizeof(struct hard_iface), GFP_ATOMIC);
 442         if (!hard_iface) {
 443                 pr_err("Can't add interface (%s): out of memory\n",
 444                        net_dev->name);
 445                 goto release_dev;
 446         }
 447
 448         ret = sysfs_add_hardif(&hard_iface->hardif_obj, net_dev);
 449         if (ret)
 450                 goto free_if;
 451
 452         hard_iface->if_num = -1;
 453         hard_iface->net_dev = net_dev;
 454         hard_iface->soft_iface = NULL;
 455         hard_iface->if_status = IF_NOT_IN_USE;
 456         INIT_LIST_HEAD(&hard_iface->list);
 457         /* extra reference for return */
 458         atomic_set(&hard_iface->refcount, 2);
 459
 460         check_known_mac_addr(hard_iface->net_dev);
 461
 462         spin_lock(&hardif_list_lock);
 463         list_add_tail_rcu(&hard_iface->list, &hardif_list);
 464         spin_unlock(&hardif_list_lock);
 465
 466         return hard_iface;
 467
 468 free_if:
 469         kfree(hard_iface);
 470 release_dev:
 471         dev_put(net_dev);
 472 out:
 473         return NULL;
 474 }
 475
 476 static void hardif_remove_interface(struct hard_iface *hard_iface)
 477 {
 478         /* first deactivate interface */
 479         if (hard_iface->if_status != IF_NOT_IN_USE)
 480                 hardif_disable_interface(hard_iface);
 481
 482         if (hard_iface->if_status != IF_NOT_IN_USE)
 483                 return;
 484
 485         hard_iface->if_status = IF_TO_BE_REMOVED;
 486         sysfs_del_hardif(&hard_iface->hardif_obj);
 487         hardif_free_ref(hard_iface);
 488 }
 489
 490 void hardif_remove_interfaces(void)
 491 {
 492         struct hard_iface *hard_iface, *hard_iface_tmp;
 493         struct list_head if_queue;
 494
 495         INIT_LIST_HEAD(&if_queue);
 496
 497         spin_lock(&hardif_list_lock);
 498         list_for_each_entry_safe(hard_iface, hard_iface_tmp,
 499                                  &hardif_list, list) {
 500                 list_del_rcu(&hard_iface->list);
 501                 list_add_tail(&hard_iface->list, &if_queue);
 502         }
 503         spin_unlock(&hardif_list_lock);
 504
 505         rtnl_lock();
 506         list_for_each_entry_safe(hard_iface, hard_iface_tmp, &if_queue, list) {
 507                 hardif_remove_interface(hard_iface);
 508         }
 509         rtnl_unlock();
 510 }
 511
 512 static int hard_if_event(struct notifier_block *this,
 513                          unsigned long event, void *ptr)
 514 {
 515         struct net_device *net_dev = (struct net_device *)ptr;
 516         struct hard_iface *hard_iface = hardif_get_by_netdev(net_dev);
 517         struct bat_priv *bat_priv;
 518
 519         if (!hard_iface && event == NETDEV_REGISTER)
 520                 hard_iface = hardif_add_interface(net_dev);
 521
 522         if (!hard_iface)
 523                 goto out;
 524
 525         switch (event) {
 526         case NETDEV_UP:
 527                 hardif_activate_interface(hard_iface);
 528                 break;
 529         case NETDEV_GOING_DOWN:
 530         case NETDEV_DOWN:
 531                 hardif_deactivate_interface(hard_iface);
 532                 break;
 533         case NETDEV_UNREGISTER:
 534                 spin_lock(&hardif_list_lock);
 535                 list_del_rcu(&hard_iface->list);
 536                 spin_unlock(&hardif_list_lock);
 537
 538                 hardif_remove_interface(hard_iface);
 539                 break;
 540         case NETDEV_CHANGEMTU:
 541                 if (hard_iface->soft_iface)
 542                         update_min_mtu(hard_iface->soft_iface);
 543                 break;
 544         case NETDEV_CHANGEADDR:
 545                 if (hard_iface->if_status == IF_NOT_IN_USE)
 546                         goto hardif_put;
 547
 548                 check_known_mac_addr(hard_iface->net_dev);
 549                 update_mac_addresses(hard_iface);
 550
 551                 bat_priv = netdev_priv(hard_iface->soft_iface);
 552                 if (hard_iface == bat_priv->primary_if)
 553                         update_primary_addr(bat_priv);
 554                 break;
 555         default:
 556                 break;
 557         };
 558
 559 hardif_put:
 560         hardif_free_ref(hard_iface);
 561 out:
 562         return NOTIFY_DONE;
 563 }
 564
 565 /* receive a packet with the batman ethertype coming on a hard
 566  * interface */
 567 static int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 568                            struct packet_type *ptype,
 569                            struct net_device *orig_dev)
 570 {
 571         struct bat_priv *bat_priv;
 572         struct batman_packet *batman_packet;
 573         struct hard_iface *hard_iface;
 574         int ret;
 575
 576         hard_iface = container_of(ptype, struct hard_iface, batman_adv_ptype);
 577         skb = skb_share_check(skb, GFP_ATOMIC);
 578
 579         /* skb was released by skb_share_check() */
 580         if (!skb)
 581                 goto err_out;
 582
 583         /* packet should hold at least type and version */
 584         if (unlikely(!pskb_may_pull(skb, 2)))
 585                 goto err_free;
 586
 587         /* expect a valid ethernet header here. */
 588         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 589                                 || !skb_mac_header(skb)))
 590                 goto err_free;
 591
 592         if (!hard_iface->soft_iface)
 593                 goto err_free;
 594
 595         bat_priv = netdev_priv(hard_iface->soft_iface);
 596
 597         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 598                 goto err_free;
 599
 600         /* discard frames on not active interfaces */
 601         if (hard_iface->if_status != IF_ACTIVE)
 602                 goto err_free;
 603
 604         batman_packet = (struct batman_packet *)skb->data;
 605
 606         if (batman_packet->version != COMPAT_VERSION) {
 607                 bat_dbg(DBG_BATMAN, bat_priv,
 608                         "Drop packet: incompatible batman version (%i)\n",
 609                         batman_packet->version);
 610                 goto err_free;
 611         }
 612
 613         /* all receive handlers return whether they received or reused
 614          * the supplied skb. if not, we have to free the skb. */
 615
 616         switch (batman_packet->packet_type) {
 617                 /* batman originator packet */
 618         case BAT_PACKET:
 619                 ret = recv_bat_packet(skb, hard_iface);
 620                 break;
 621
 622                 /* batman icmp packet */
 623         case BAT_ICMP:
 624                 ret = recv_icmp_packet(skb, hard_iface);
 625                 break;
 626
 627                 /* unicast packet */
 628         case BAT_UNICAST:
 629                 ret = recv_unicast_packet(skb, hard_iface);
 630                 break;
 631
 632                 /* fragmented unicast packet */
 633         case BAT_UNICAST_FRAG:
 634                 ret = recv_ucast_frag_packet(skb, hard_iface);
 635                 break;
 636
 637                 /* broadcast packet */
 638         case BAT_BCAST:
 639                 ret = recv_bcast_packet(skb, hard_iface);
 640                 break;
 641
 642                 /* vis packet */
 643         case BAT_VIS:
 644                 ret = recv_vis_packet(skb, hard_iface);
 645                 break;
 646         default:
 647                 ret = NET_RX_DROP;
 648         }
 649
 650         if (ret == NET_RX_DROP)
 651                 kfree_skb(skb);
 652
 653         /* return NET_RX_SUCCESS in any case as we
 654          * most probably dropped the packet for
 655          * routing-logical reasons. */
 656
 657         return NET_RX_SUCCESS;
 658
 659 err_free:
 660         kfree_skb(skb);
 661 err_out:
 662         return NET_RX_DROP;
 663 }
 664
 665 struct notifier_block hard_if_notifier = {
 666         .notifier_call = hard_if_event,
 667 };