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