drivers/staging/batman-adv/hard-interface.c

   1 /*
   2  * Copyright (C) 2007-2010 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 #define MIN(x, y) ((x) < (y) ? (x) : (y))
  35
  36 /* protect update critical side of if_list - but not the content */
  37 static DEFINE_SPINLOCK(if_list_lock);
  38
  39 struct batman_if *get_batman_if_by_netdev(struct net_device *net_dev)
  40 {
  41         struct batman_if *batman_if;
  42
  43         rcu_read_lock();
  44         list_for_each_entry_rcu(batman_if, &if_list, list) {
  45                 if (batman_if->net_dev == net_dev)
  46                         goto out;
  47         }
  48
  49         batman_if = NULL;
  50
  51 out:
  52         if (batman_if)
  53                 hardif_hold(batman_if);
  54
  55         rcu_read_unlock();
  56         return batman_if;
  57 }
  58
  59 static int is_valid_iface(struct net_device *net_dev)
  60 {
  61         if (net_dev->flags & IFF_LOOPBACK)
  62                 return 0;
  63
  64         if (net_dev->type != ARPHRD_ETHER)
  65                 return 0;
  66
  67         if (net_dev->addr_len != ETH_ALEN)
  68                 return 0;
  69
  70         /* no batman over batman */
  71 #ifdef HAVE_NET_DEVICE_OPS
  72         if (net_dev->netdev_ops->ndo_start_xmit == interface_tx)
  73                 return 0;
  74 #else
  75         if (net_dev->hard_start_xmit == interface_tx)
  76                 return 0;
  77 #endif
  78
  79         /* Device is being bridged */
  80         /* if (net_dev->priv_flags & IFF_BRIDGE_PORT)
  81                 return 0; */
  82
  83         return 1;
  84 }
  85
  86 static struct batman_if *get_active_batman_if(struct net_device *soft_iface)
  87 {
  88         struct batman_if *batman_if;
  89
  90         rcu_read_lock();
  91         list_for_each_entry_rcu(batman_if, &if_list, list) {
  92                 if (batman_if->soft_iface != soft_iface)
  93                         continue;
  94
  95                 if (batman_if->if_status == IF_ACTIVE)
  96                         goto out;
  97         }
  98
  99         batman_if = NULL;
 100
 101 out:
 102         if (batman_if)
 103                 hardif_hold(batman_if);
 104
 105         rcu_read_unlock();
 106         return batman_if;
 107 }
 108
 109 static void set_primary_if(struct bat_priv *bat_priv,
 110                            struct batman_if *batman_if)
 111 {
 112         struct batman_packet *batman_packet;
 113         struct vis_packet *vis_packet;
 114
 115         bat_priv->primary_if = batman_if;
 116
 117         if (!bat_priv->primary_if)
 118                 return;
 119
 120         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 121         batman_packet->flags = PRIMARIES_FIRST_HOP;
 122         batman_packet->ttl = TTL;
 123
 124         vis_packet = (struct vis_packet *)
 125                                 bat_priv->my_vis_info->skb_packet->data;
 126         memcpy(vis_packet->vis_orig,
 127                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 128         memcpy(vis_packet->sender_orig,
 129                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 130
 131         /***
 132          * hacky trick to make sure that we send the HNA information via
 133          * our new primary interface
 134          */
 135         atomic_set(&bat_priv->hna_local_changed, 1);
 136 }
 137
 138 static bool hardif_is_iface_up(struct batman_if *batman_if)
 139 {
 140         if (batman_if->net_dev->flags & IFF_UP)
 141                 return true;
 142
 143         return false;
 144 }
 145
 146 static void update_mac_addresses(struct batman_if *batman_if)
 147 {
 148         addr_to_string(batman_if->addr_str, batman_if->net_dev->dev_addr);
 149
 150         memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
 151                batman_if->net_dev->dev_addr, ETH_ALEN);
 152         memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
 153                batman_if->net_dev->dev_addr, ETH_ALEN);
 154 }
 155
 156 static void check_known_mac_addr(uint8_t *addr)
 157 {
 158         struct batman_if *batman_if;
 159
 160         rcu_read_lock();
 161         list_for_each_entry_rcu(batman_if, &if_list, list) {
 162                 if ((batman_if->if_status != IF_ACTIVE) &&
 163                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 164                         continue;
 165
 166                 if (!compare_orig(batman_if->net_dev->dev_addr, addr))
 167                         continue;
 168
 169                 pr_warning("The newly added mac address (%pM) already exists "
 170                            "on: %s\n", addr, batman_if->net_dev->name);
 171                 pr_warning("It is strongly recommended to keep mac addresses "
 172                            "unique to avoid problems!\n");
 173         }
 174         rcu_read_unlock();
 175 }
 176
 177 int hardif_min_mtu(struct net_device *soft_iface)
 178 {
 179         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 180         struct batman_if *batman_if;
 181         /* allow big frames if all devices are capable to do so
 182          * (have MTU > 1500 + BAT_HEADER_LEN) */
 183         int min_mtu = ETH_DATA_LEN;
 184
 185         if (atomic_read(&bat_priv->frag_enabled))
 186                 goto out;
 187
 188         rcu_read_lock();
 189         list_for_each_entry_rcu(batman_if, &if_list, list) {
 190                 if ((batman_if->if_status != IF_ACTIVE) &&
 191                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 192                         continue;
 193
 194                 if (batman_if->soft_iface != soft_iface)
 195                         continue;
 196
 197                 min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 198                               min_mtu);
 199         }
 200         rcu_read_unlock();
 201 out:
 202         return min_mtu;
 203 }
 204
 205 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 206 void update_min_mtu(struct net_device *soft_iface)
 207 {
 208         int min_mtu;
 209
 210         min_mtu = hardif_min_mtu(soft_iface);
 211         if (soft_iface->mtu != min_mtu)
 212                 soft_iface->mtu = min_mtu;
 213 }
 214
 215 static void hardif_activate_interface(struct batman_if *batman_if)
 216 {
 217         struct bat_priv *bat_priv;
 218
 219         if (batman_if->if_status != IF_INACTIVE)
 220                 return;
 221
 222         bat_priv = netdev_priv(batman_if->soft_iface);
 223
 224         update_mac_addresses(batman_if);
 225         batman_if->if_status = IF_TO_BE_ACTIVATED;
 226
 227         /**
 228          * the first active interface becomes our primary interface or
 229          * the next active interface after the old primay interface was removed
 230          */
 231         if (!bat_priv->primary_if)
 232                 set_primary_if(bat_priv, batman_if);
 233
 234         bat_info(batman_if->soft_iface, "Interface activated: %s\n",
 235                  batman_if->net_dev->name);
 236
 237         update_min_mtu(batman_if->soft_iface);
 238         return;
 239 }
 240
 241 static void hardif_deactivate_interface(struct batman_if *batman_if)
 242 {
 243         if ((batman_if->if_status != IF_ACTIVE) &&
 244            (batman_if->if_status != IF_TO_BE_ACTIVATED))
 245                 return;
 246
 247         batman_if->if_status = IF_INACTIVE;
 248
 249         bat_info(batman_if->soft_iface, "Interface deactivated: %s\n",
 250                  batman_if->net_dev->name);
 251
 252         update_min_mtu(batman_if->soft_iface);
 253 }
 254
 255 int hardif_enable_interface(struct batman_if *batman_if, char *iface_name)
 256 {
 257         struct bat_priv *bat_priv;
 258         struct batman_packet *batman_packet;
 259
 260         if (batman_if->if_status != IF_NOT_IN_USE)
 261                 goto out;
 262
 263         batman_if->soft_iface = dev_get_by_name(&init_net, iface_name);
 264
 265         if (!batman_if->soft_iface) {
 266                 batman_if->soft_iface = softif_create(iface_name);
 267
 268                 if (!batman_if->soft_iface)
 269                         goto err;
 270
 271                 /* dev_get_by_name() increases the reference counter for us */
 272                 dev_hold(batman_if->soft_iface);
 273         }
 274
 275         bat_priv = netdev_priv(batman_if->soft_iface);
 276         batman_if->packet_len = BAT_PACKET_LEN;
 277         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
 278
 279         if (!batman_if->packet_buff) {
 280                 bat_err(batman_if->soft_iface, "Can't add interface packet "
 281                         "(%s): out of memory\n", batman_if->net_dev->name);
 282                 goto err;
 283         }
 284
 285         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 286         batman_packet->packet_type = BAT_PACKET;
 287         batman_packet->version = COMPAT_VERSION;
 288         batman_packet->flags = 0;
 289         batman_packet->ttl = 2;
 290         batman_packet->tq = TQ_MAX_VALUE;
 291         batman_packet->num_hna = 0;
 292
 293         batman_if->if_num = bat_priv->num_ifaces;
 294         bat_priv->num_ifaces++;
 295         batman_if->if_status = IF_INACTIVE;
 296         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
 297
 298         batman_if->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
 299         batman_if->batman_adv_ptype.func = batman_skb_recv;
 300         batman_if->batman_adv_ptype.dev = batman_if->net_dev;
 301         hardif_hold(batman_if);
 302         dev_add_pack(&batman_if->batman_adv_ptype);
 303
 304         atomic_set(&batman_if->seqno, 1);
 305         atomic_set(&batman_if->frag_seqno, 1);
 306         bat_info(batman_if->soft_iface, "Adding interface: %s\n",
 307                  batman_if->net_dev->name);
 308
 309         if (atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 310                 ETH_DATA_LEN + BAT_HEADER_LEN)
 311                 bat_info(batman_if->soft_iface,
 312                         "The MTU of interface %s is too small (%i) to handle "
 313                         "the transport of batman-adv packets. Packets going "
 314                         "over this interface will be fragmented on layer2 "
 315                         "which could impact the performance. Setting the MTU "
 316                         "to %zi would solve the problem.\n",
 317                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 318                         ETH_DATA_LEN + BAT_HEADER_LEN);
 319
 320         if (!atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 321                 ETH_DATA_LEN + BAT_HEADER_LEN)
 322                 bat_info(batman_if->soft_iface,
 323                         "The MTU of interface %s is too small (%i) to handle "
 324                         "the transport of batman-adv packets. If you experience"
 325                         " problems getting traffic through try increasing the "
 326                         "MTU to %zi.\n",
 327                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 328                         ETH_DATA_LEN + BAT_HEADER_LEN);
 329
 330         if (hardif_is_iface_up(batman_if))
 331                 hardif_activate_interface(batman_if);
 332         else
 333                 bat_err(batman_if->soft_iface, "Not using interface %s "
 334                         "(retrying later): interface not active\n",
 335                         batman_if->net_dev->name);
 336
 337         /* begin scheduling originator messages on that interface */
 338         schedule_own_packet(batman_if);
 339
 340 out:
 341         return 0;
 342
 343 err:
 344         return -ENOMEM;
 345 }
 346
 347 void hardif_disable_interface(struct batman_if *batman_if)
 348 {
 349         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 350
 351         if (batman_if->if_status == IF_ACTIVE)
 352                 hardif_deactivate_interface(batman_if);
 353
 354         if (batman_if->if_status != IF_INACTIVE)
 355                 return;
 356
 357         bat_info(batman_if->soft_iface, "Removing interface: %s\n",
 358                  batman_if->net_dev->name);
 359         dev_remove_pack(&batman_if->batman_adv_ptype);
 360         hardif_put(batman_if);
 361
 362         bat_priv->num_ifaces--;
 363         orig_hash_del_if(batman_if, bat_priv->num_ifaces);
 364
 365         if (batman_if == bat_priv->primary_if) {
 366                 struct batman_if *new_if;
 367
 368                 new_if = get_active_batman_if(batman_if->soft_iface);
 369                 set_primary_if(bat_priv, new_if);
 370
 371                 if (new_if)
 372                         hardif_put(new_if);
 373         }
 374
 375         kfree(batman_if->packet_buff);
 376         batman_if->packet_buff = NULL;
 377         batman_if->if_status = IF_NOT_IN_USE;
 378
 379         /* delete all references to this batman_if */
 380         purge_orig_ref(bat_priv);
 381         purge_outstanding_packets(bat_priv, batman_if);
 382         dev_put(batman_if->soft_iface);
 383
 384         /* nobody uses this interface anymore */
 385         if (!bat_priv->num_ifaces)
 386                 softif_destroy(batman_if->soft_iface);
 387
 388         batman_if->soft_iface = NULL;
 389 }
 390
 391 static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 392 {
 393         struct batman_if *batman_if;
 394         int ret;
 395
 396         ret = is_valid_iface(net_dev);
 397         if (ret != 1)
 398                 goto out;
 399
 400         dev_hold(net_dev);
 401
 402         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 403         if (!batman_if) {
 404                 pr_err("Can't add interface (%s): out of memory\n",
 405                        net_dev->name);
 406                 goto release_dev;
 407         }
 408
 409         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
 410         if (ret)
 411                 goto free_if;
 412
 413         batman_if->if_num = -1;
 414         batman_if->net_dev = net_dev;
 415         batman_if->soft_iface = NULL;
 416         batman_if->if_status = IF_NOT_IN_USE;
 417         INIT_LIST_HEAD(&batman_if->list);
 418         atomic_set(&batman_if->refcnt, 0);
 419         hardif_hold(batman_if);
 420
 421         check_known_mac_addr(batman_if->net_dev->dev_addr);
 422
 423         spin_lock(&if_list_lock);
 424         list_add_tail_rcu(&batman_if->list, &if_list);
 425         spin_unlock(&if_list_lock);
 426
 427         /* extra reference for return */
 428         hardif_hold(batman_if);
 429         return batman_if;
 430
 431 free_if:
 432         kfree(batman_if);
 433 release_dev:
 434         dev_put(net_dev);
 435 out:
 436         return NULL;
 437 }
 438
 439 static void hardif_remove_interface(struct batman_if *batman_if)
 440 {
 441         /* first deactivate interface */
 442         if (batman_if->if_status != IF_NOT_IN_USE)
 443                 hardif_disable_interface(batman_if);
 444
 445         if (batman_if->if_status != IF_NOT_IN_USE)
 446                 return;
 447
 448         batman_if->if_status = IF_TO_BE_REMOVED;
 449
 450         /* caller must take if_list_lock */
 451         list_del_rcu(&batman_if->list);
 452         synchronize_rcu();
 453         sysfs_del_hardif(&batman_if->hardif_obj);
 454         hardif_put(batman_if);
 455 }
 456
 457 void hardif_remove_interfaces(void)
 458 {
 459         struct batman_if *batman_if, *batman_if_tmp;
 460
 461         rtnl_lock();
 462         spin_lock(&if_list_lock);
 463         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {
 464                 hardif_remove_interface(batman_if);
 465         }
 466         spin_unlock(&if_list_lock);
 467         rtnl_unlock();
 468 }
 469
 470 static int hard_if_event(struct notifier_block *this,
 471                          unsigned long event, void *ptr)
 472 {
 473         struct net_device *net_dev = (struct net_device *)ptr;
 474         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
 475         struct bat_priv *bat_priv;
 476
 477         if (!batman_if && event == NETDEV_REGISTER)
 478                 batman_if = hardif_add_interface(net_dev);
 479
 480         if (!batman_if)
 481                 goto out;
 482
 483         switch (event) {
 484         case NETDEV_UP:
 485                 hardif_activate_interface(batman_if);
 486                 break;
 487         case NETDEV_GOING_DOWN:
 488         case NETDEV_DOWN:
 489                 hardif_deactivate_interface(batman_if);
 490                 break;
 491         case NETDEV_UNREGISTER:
 492                 spin_lock(&if_list_lock);
 493                 hardif_remove_interface(batman_if);
 494                 spin_unlock(&if_list_lock);
 495                 break;
 496         case NETDEV_CHANGEMTU:
 497                 if (batman_if->soft_iface)
 498                         update_min_mtu(batman_if->soft_iface);
 499                 break;
 500         case NETDEV_CHANGEADDR:
 501                 if (batman_if->if_status == IF_NOT_IN_USE) {
 502                         hardif_put(batman_if);
 503                         goto out;
 504                 }
 505
 506                 check_known_mac_addr(batman_if->net_dev->dev_addr);
 507                 update_mac_addresses(batman_if);
 508
 509                 bat_priv = netdev_priv(batman_if->soft_iface);
 510                 if (batman_if == bat_priv->primary_if)
 511                         set_primary_if(bat_priv, batman_if);
 512                 break;
 513         default:
 514                 break;
 515         };
 516         hardif_put(batman_if);
 517
 518 out:
 519         return NOTIFY_DONE;
 520 }
 521
 522 /* receive a packet with the batman ethertype coming on a hard
 523  * interface */
 524 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 525         struct packet_type *ptype, struct net_device *orig_dev)
 526 {
 527         struct bat_priv *bat_priv;
 528         struct batman_packet *batman_packet;
 529         struct batman_if *batman_if;
 530         int ret;
 531
 532         batman_if = container_of(ptype, struct batman_if, batman_adv_ptype);
 533         skb = skb_share_check(skb, GFP_ATOMIC);
 534
 535         /* skb was released by skb_share_check() */
 536         if (!skb)
 537                 goto err_out;
 538
 539         /* packet should hold at least type and version */
 540         if (unlikely(!pskb_may_pull(skb, 2)))
 541                 goto err_free;
 542
 543         /* expect a valid ethernet header here. */
 544         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 545                                 || !skb_mac_header(skb)))
 546                 goto err_free;
 547
 548         if (!batman_if->soft_iface)
 549                 goto err_free;
 550
 551         bat_priv = netdev_priv(batman_if->soft_iface);
 552
 553         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 554                 goto err_free;
 555
 556         /* discard frames on not active interfaces */
 557         if (batman_if->if_status != IF_ACTIVE)
 558                 goto err_free;
 559
 560         batman_packet = (struct batman_packet *)skb->data;
 561
 562         if (batman_packet->version != COMPAT_VERSION) {
 563                 bat_dbg(DBG_BATMAN, bat_priv,
 564                         "Drop packet: incompatible batman version (%i)\n",
 565                         batman_packet->version);
 566                 goto err_free;
 567         }
 568
 569         /* all receive handlers return whether they received or reused
 570          * the supplied skb. if not, we have to free the skb. */
 571
 572         switch (batman_packet->packet_type) {
 573                 /* batman originator packet */
 574         case BAT_PACKET:
 575                 ret = recv_bat_packet(skb, batman_if);
 576                 break;
 577
 578                 /* batman icmp packet */
 579         case BAT_ICMP:
 580                 ret = recv_icmp_packet(skb, batman_if);
 581                 break;
 582
 583                 /* unicast packet */
 584         case BAT_UNICAST:
 585                 ret = recv_unicast_packet(skb, batman_if);
 586                 break;
 587
 588                 /* fragmented unicast packet */
 589         case BAT_UNICAST_FRAG:
 590                 ret = recv_ucast_frag_packet(skb, batman_if);
 591                 break;
 592
 593                 /* broadcast packet */
 594         case BAT_BCAST:
 595                 ret = recv_bcast_packet(skb, batman_if);
 596                 break;
 597
 598                 /* vis packet */
 599         case BAT_VIS:
 600                 ret = recv_vis_packet(skb, batman_if);
 601                 break;
 602         default:
 603                 ret = NET_RX_DROP;
 604         }
 605
 606         if (ret == NET_RX_DROP)
 607                 kfree_skb(skb);
 608
 609         /* return NET_RX_SUCCESS in any case as we
 610          * most probably dropped the packet for
 611          * routing-logical reasons. */
 612
 613         return NET_RX_SUCCESS;
 614
 615 err_free:
 616         kfree_skb(skb);
 617 err_out:
 618         return NET_RX_DROP;
 619 }
 620
 621 struct notifier_block hard_if_notifier = {
 622         .notifier_call = hard_if_event,
 623 };