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