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         struct batman_if *old_if;
 115
 116         if (batman_if)
 117                 hardif_hold(batman_if);
 118
 119         old_if = bat_priv->primary_if;
 120         bat_priv->primary_if = batman_if;
 121
 122         if (old_if)
 123                 hardif_put(old_if);
 124
 125         if (!bat_priv->primary_if)
 126                 return;
 127
 128         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 129         batman_packet->flags = PRIMARIES_FIRST_HOP;
 130         batman_packet->ttl = TTL;
 131
 132         vis_packet = (struct vis_packet *)
 133                                 bat_priv->my_vis_info->skb_packet->data;
 134         memcpy(vis_packet->vis_orig,
 135                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 136         memcpy(vis_packet->sender_orig,
 137                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 138
 139         /***
 140          * hacky trick to make sure that we send the HNA information via
 141          * our new primary interface
 142          */
 143         atomic_set(&bat_priv->hna_local_changed, 1);
 144 }
 145
 146 static bool hardif_is_iface_up(struct batman_if *batman_if)
 147 {
 148         if (batman_if->net_dev->flags & IFF_UP)
 149                 return true;
 150
 151         return false;
 152 }
 153
 154 static void update_mac_addresses(struct batman_if *batman_if)
 155 {
 156         addr_to_string(batman_if->addr_str, batman_if->net_dev->dev_addr);
 157
 158         memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
 159                batman_if->net_dev->dev_addr, ETH_ALEN);
 160         memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
 161                batman_if->net_dev->dev_addr, ETH_ALEN);
 162 }
 163
 164 static void check_known_mac_addr(uint8_t *addr)
 165 {
 166         struct batman_if *batman_if;
 167
 168         rcu_read_lock();
 169         list_for_each_entry_rcu(batman_if, &if_list, list) {
 170                 if ((batman_if->if_status != IF_ACTIVE) &&
 171                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 172                         continue;
 173
 174                 if (!compare_orig(batman_if->net_dev->dev_addr, addr))
 175                         continue;
 176
 177                 pr_warning("The newly added mac address (%pM) already exists "
 178                            "on: %s\n", addr, batman_if->net_dev->name);
 179                 pr_warning("It is strongly recommended to keep mac addresses "
 180                            "unique to avoid problems!\n");
 181         }
 182         rcu_read_unlock();
 183 }
 184
 185 int hardif_min_mtu(struct net_device *soft_iface)
 186 {
 187         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 188         struct batman_if *batman_if;
 189         /* allow big frames if all devices are capable to do so
 190          * (have MTU > 1500 + BAT_HEADER_LEN) */
 191         int min_mtu = ETH_DATA_LEN;
 192
 193         if (atomic_read(&bat_priv->frag_enabled))
 194                 goto out;
 195
 196         rcu_read_lock();
 197         list_for_each_entry_rcu(batman_if, &if_list, list) {
 198                 if ((batman_if->if_status != IF_ACTIVE) &&
 199                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 200                         continue;
 201
 202                 if (batman_if->soft_iface != soft_iface)
 203                         continue;
 204
 205                 min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 206                               min_mtu);
 207         }
 208         rcu_read_unlock();
 209 out:
 210         return min_mtu;
 211 }
 212
 213 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 214 void update_min_mtu(struct net_device *soft_iface)
 215 {
 216         int min_mtu;
 217
 218         min_mtu = hardif_min_mtu(soft_iface);
 219         if (soft_iface->mtu != min_mtu)
 220                 soft_iface->mtu = min_mtu;
 221 }
 222
 223 static void hardif_activate_interface(struct batman_if *batman_if)
 224 {
 225         struct bat_priv *bat_priv;
 226
 227         if (batman_if->if_status != IF_INACTIVE)
 228                 return;
 229
 230         bat_priv = netdev_priv(batman_if->soft_iface);
 231
 232         update_mac_addresses(batman_if);
 233         batman_if->if_status = IF_TO_BE_ACTIVATED;
 234
 235         /**
 236          * the first active interface becomes our primary interface or
 237          * the next active interface after the old primay interface was removed
 238          */
 239         if (!bat_priv->primary_if)
 240                 set_primary_if(bat_priv, batman_if);
 241
 242         bat_info(batman_if->soft_iface, "Interface activated: %s\n",
 243                  batman_if->net_dev->name);
 244
 245         update_min_mtu(batman_if->soft_iface);
 246         return;
 247 }
 248
 249 static void hardif_deactivate_interface(struct batman_if *batman_if)
 250 {
 251         if ((batman_if->if_status != IF_ACTIVE) &&
 252            (batman_if->if_status != IF_TO_BE_ACTIVATED))
 253                 return;
 254
 255         batman_if->if_status = IF_INACTIVE;
 256
 257         bat_info(batman_if->soft_iface, "Interface deactivated: %s\n",
 258                  batman_if->net_dev->name);
 259
 260         update_min_mtu(batman_if->soft_iface);
 261 }
 262
 263 int hardif_enable_interface(struct batman_if *batman_if, char *iface_name)
 264 {
 265         struct bat_priv *bat_priv;
 266         struct batman_packet *batman_packet;
 267
 268         if (batman_if->if_status != IF_NOT_IN_USE)
 269                 goto out;
 270
 271         batman_if->soft_iface = dev_get_by_name(&init_net, iface_name);
 272
 273         if (!batman_if->soft_iface) {
 274                 batman_if->soft_iface = softif_create(iface_name);
 275
 276                 if (!batman_if->soft_iface)
 277                         goto err;
 278
 279                 /* dev_get_by_name() increases the reference counter for us */
 280                 dev_hold(batman_if->soft_iface);
 281         }
 282
 283         bat_priv = netdev_priv(batman_if->soft_iface);
 284         batman_if->packet_len = BAT_PACKET_LEN;
 285         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
 286
 287         if (!batman_if->packet_buff) {
 288                 bat_err(batman_if->soft_iface, "Can't add interface packet "
 289                         "(%s): out of memory\n", batman_if->net_dev->name);
 290                 goto err;
 291         }
 292
 293         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 294         batman_packet->packet_type = BAT_PACKET;
 295         batman_packet->version = COMPAT_VERSION;
 296         batman_packet->flags = 0;
 297         batman_packet->ttl = 2;
 298         batman_packet->tq = TQ_MAX_VALUE;
 299         batman_packet->num_hna = 0;
 300
 301         batman_if->if_num = bat_priv->num_ifaces;
 302         bat_priv->num_ifaces++;
 303         batman_if->if_status = IF_INACTIVE;
 304         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
 305
 306         batman_if->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
 307         batman_if->batman_adv_ptype.func = batman_skb_recv;
 308         batman_if->batman_adv_ptype.dev = batman_if->net_dev;
 309         hardif_hold(batman_if);
 310         dev_add_pack(&batman_if->batman_adv_ptype);
 311
 312         atomic_set(&batman_if->seqno, 1);
 313         atomic_set(&batman_if->frag_seqno, 1);
 314         bat_info(batman_if->soft_iface, "Adding interface: %s\n",
 315                  batman_if->net_dev->name);
 316
 317         if (atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 318                 ETH_DATA_LEN + BAT_HEADER_LEN)
 319                 bat_info(batman_if->soft_iface,
 320                         "The MTU of interface %s is too small (%i) to handle "
 321                         "the transport of batman-adv packets. Packets going "
 322                         "over this interface will be fragmented on layer2 "
 323                         "which could impact the performance. Setting the MTU "
 324                         "to %zi would solve the problem.\n",
 325                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 326                         ETH_DATA_LEN + BAT_HEADER_LEN);
 327
 328         if (!atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 329                 ETH_DATA_LEN + BAT_HEADER_LEN)
 330                 bat_info(batman_if->soft_iface,
 331                         "The MTU of interface %s is too small (%i) to handle "
 332                         "the transport of batman-adv packets. If you experience"
 333                         " problems getting traffic through try increasing the "
 334                         "MTU to %zi.\n",
 335                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 336                         ETH_DATA_LEN + BAT_HEADER_LEN);
 337
 338         if (hardif_is_iface_up(batman_if))
 339                 hardif_activate_interface(batman_if);
 340         else
 341                 bat_err(batman_if->soft_iface, "Not using interface %s "
 342                         "(retrying later): interface not active\n",
 343                         batman_if->net_dev->name);
 344
 345         /* begin scheduling originator messages on that interface */
 346         schedule_own_packet(batman_if);
 347
 348 out:
 349         return 0;
 350
 351 err:
 352         return -ENOMEM;
 353 }
 354
 355 void hardif_disable_interface(struct batman_if *batman_if)
 356 {
 357         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 358
 359         if (batman_if->if_status == IF_ACTIVE)
 360                 hardif_deactivate_interface(batman_if);
 361
 362         if (batman_if->if_status != IF_INACTIVE)
 363                 return;
 364
 365         bat_info(batman_if->soft_iface, "Removing interface: %s\n",
 366                  batman_if->net_dev->name);
 367         dev_remove_pack(&batman_if->batman_adv_ptype);
 368         hardif_put(batman_if);
 369
 370         bat_priv->num_ifaces--;
 371         orig_hash_del_if(batman_if, bat_priv->num_ifaces);
 372
 373         if (batman_if == bat_priv->primary_if) {
 374                 struct batman_if *new_if;
 375
 376                 new_if = get_active_batman_if(batman_if->soft_iface);
 377                 set_primary_if(bat_priv, new_if);
 378
 379                 if (new_if)
 380                         hardif_put(new_if);
 381         }
 382
 383         kfree(batman_if->packet_buff);
 384         batman_if->packet_buff = NULL;
 385         batman_if->if_status = IF_NOT_IN_USE;
 386
 387         /* delete all references to this batman_if */
 388         purge_orig_ref(bat_priv);
 389         purge_outstanding_packets(bat_priv, batman_if);
 390         dev_put(batman_if->soft_iface);
 391
 392         /* nobody uses this interface anymore */
 393         if (!bat_priv->num_ifaces)
 394                 softif_destroy(batman_if->soft_iface);
 395
 396         batman_if->soft_iface = NULL;
 397 }
 398
 399 static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 400 {
 401         struct batman_if *batman_if;
 402         int ret;
 403
 404         ret = is_valid_iface(net_dev);
 405         if (ret != 1)
 406                 goto out;
 407
 408         dev_hold(net_dev);
 409
 410         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 411         if (!batman_if) {
 412                 pr_err("Can't add interface (%s): out of memory\n",
 413                        net_dev->name);
 414                 goto release_dev;
 415         }
 416
 417         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
 418         if (ret)
 419                 goto free_if;
 420
 421         batman_if->if_num = -1;
 422         batman_if->net_dev = net_dev;
 423         batman_if->soft_iface = NULL;
 424         batman_if->if_status = IF_NOT_IN_USE;
 425         INIT_LIST_HEAD(&batman_if->list);
 426         atomic_set(&batman_if->refcnt, 0);
 427         hardif_hold(batman_if);
 428
 429         check_known_mac_addr(batman_if->net_dev->dev_addr);
 430
 431         spin_lock(&if_list_lock);
 432         list_add_tail_rcu(&batman_if->list, &if_list);
 433         spin_unlock(&if_list_lock);
 434
 435         /* extra reference for return */
 436         hardif_hold(batman_if);
 437         return batman_if;
 438
 439 free_if:
 440         kfree(batman_if);
 441 release_dev:
 442         dev_put(net_dev);
 443 out:
 444         return NULL;
 445 }
 446
 447 static void hardif_remove_interface(struct batman_if *batman_if)
 448 {
 449         /* first deactivate interface */
 450         if (batman_if->if_status != IF_NOT_IN_USE)
 451                 hardif_disable_interface(batman_if);
 452
 453         if (batman_if->if_status != IF_NOT_IN_USE)
 454                 return;
 455
 456         batman_if->if_status = IF_TO_BE_REMOVED;
 457
 458         /* caller must take if_list_lock */
 459         list_del_rcu(&batman_if->list);
 460         synchronize_rcu();
 461         sysfs_del_hardif(&batman_if->hardif_obj);
 462         hardif_put(batman_if);
 463 }
 464
 465 void hardif_remove_interfaces(void)
 466 {
 467         struct batman_if *batman_if, *batman_if_tmp;
 468
 469         rtnl_lock();
 470         spin_lock(&if_list_lock);
 471         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {
 472                 hardif_remove_interface(batman_if);
 473         }
 474         spin_unlock(&if_list_lock);
 475         rtnl_unlock();
 476 }
 477
 478 static int hard_if_event(struct notifier_block *this,
 479                          unsigned long event, void *ptr)
 480 {
 481         struct net_device *net_dev = (struct net_device *)ptr;
 482         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
 483         struct bat_priv *bat_priv;
 484
 485         if (!batman_if && event == NETDEV_REGISTER)
 486                 batman_if = hardif_add_interface(net_dev);
 487
 488         if (!batman_if)
 489                 goto out;
 490
 491         switch (event) {
 492         case NETDEV_UP:
 493                 hardif_activate_interface(batman_if);
 494                 break;
 495         case NETDEV_GOING_DOWN:
 496         case NETDEV_DOWN:
 497                 hardif_deactivate_interface(batman_if);
 498                 break;
 499         case NETDEV_UNREGISTER:
 500                 spin_lock(&if_list_lock);
 501                 hardif_remove_interface(batman_if);
 502                 spin_unlock(&if_list_lock);
 503                 break;
 504         case NETDEV_CHANGEMTU:
 505                 if (batman_if->soft_iface)
 506                         update_min_mtu(batman_if->soft_iface);
 507                 break;
 508         case NETDEV_CHANGEADDR:
 509                 if (batman_if->if_status == IF_NOT_IN_USE) {
 510                         hardif_put(batman_if);
 511                         goto out;
 512                 }
 513
 514                 check_known_mac_addr(batman_if->net_dev->dev_addr);
 515                 update_mac_addresses(batman_if);
 516
 517                 bat_priv = netdev_priv(batman_if->soft_iface);
 518                 if (batman_if == bat_priv->primary_if)
 519                         set_primary_if(bat_priv, batman_if);
 520                 break;
 521         default:
 522                 break;
 523         };
 524         hardif_put(batman_if);
 525
 526 out:
 527         return NOTIFY_DONE;
 528 }
 529
 530 /* receive a packet with the batman ethertype coming on a hard
 531  * interface */
 532 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 533         struct packet_type *ptype, struct net_device *orig_dev)
 534 {
 535         struct bat_priv *bat_priv;
 536         struct batman_packet *batman_packet;
 537         struct batman_if *batman_if;
 538         int ret;
 539
 540         batman_if = container_of(ptype, struct batman_if, batman_adv_ptype);
 541         skb = skb_share_check(skb, GFP_ATOMIC);
 542
 543         /* skb was released by skb_share_check() */
 544         if (!skb)
 545                 goto err_out;
 546
 547         /* packet should hold at least type and version */
 548         if (unlikely(!pskb_may_pull(skb, 2)))
 549                 goto err_free;
 550
 551         /* expect a valid ethernet header here. */
 552         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 553                                 || !skb_mac_header(skb)))
 554                 goto err_free;
 555
 556         if (!batman_if->soft_iface)
 557                 goto err_free;
 558
 559         bat_priv = netdev_priv(batman_if->soft_iface);
 560
 561         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 562                 goto err_free;
 563
 564         /* discard frames on not active interfaces */
 565         if (batman_if->if_status != IF_ACTIVE)
 566                 goto err_free;
 567
 568         batman_packet = (struct batman_packet *)skb->data;
 569
 570         if (batman_packet->version != COMPAT_VERSION) {
 571                 bat_dbg(DBG_BATMAN, bat_priv,
 572                         "Drop packet: incompatible batman version (%i)\n",
 573                         batman_packet->version);
 574                 goto err_free;
 575         }
 576
 577         /* all receive handlers return whether they received or reused
 578          * the supplied skb. if not, we have to free the skb. */
 579
 580         switch (batman_packet->packet_type) {
 581                 /* batman originator packet */
 582         case BAT_PACKET:
 583                 ret = recv_bat_packet(skb, batman_if);
 584                 break;
 585
 586                 /* batman icmp packet */
 587         case BAT_ICMP:
 588                 ret = recv_icmp_packet(skb, batman_if);
 589                 break;
 590
 591                 /* unicast packet */
 592         case BAT_UNICAST:
 593                 ret = recv_unicast_packet(skb, batman_if);
 594                 break;
 595
 596                 /* fragmented unicast packet */
 597         case BAT_UNICAST_FRAG:
 598                 ret = recv_ucast_frag_packet(skb, batman_if);
 599                 break;
 600
 601                 /* broadcast packet */
 602         case BAT_BCAST:
 603                 ret = recv_bcast_packet(skb, batman_if);
 604                 break;
 605
 606                 /* vis packet */
 607         case BAT_VIS:
 608                 ret = recv_vis_packet(skb, batman_if);
 609                 break;
 610         default:
 611                 ret = NET_RX_DROP;
 612         }
 613
 614         if (ret == NET_RX_DROP)
 615                 kfree_skb(skb);
 616
 617         /* return NET_RX_SUCCESS in any case as we
 618          * most probably dropped the packet for
 619          * routing-logical reasons. */
 620
 621         return NET_RX_SUCCESS;
 622
 623 err_free:
 624         kfree_skb(skb);
 625 err_out:
 626         return NET_RX_DROP;
 627 }
 628
 629 struct notifier_block hard_if_notifier = {
 630         .notifier_call = hard_if_event,
 631 };