release/src-rt-6.x.4708/linux/linux-2.6.36/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
 170         rcu_read_lock();
 171         list_for_each_entry_rcu(batman_if, &if_list, list) {
 172                 if ((batman_if->if_status == IF_ACTIVE) ||
 173                     (batman_if->if_status == IF_TO_BE_ACTIVATED))
 174                         min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 175                                       min_mtu);
 176         }
 177         rcu_read_unlock();
 178
 179         return min_mtu;
 180 }
 181
 182 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 183 void update_min_mtu(void)
 184 {
 185         int min_mtu;
 186
 187         min_mtu = hardif_min_mtu();
 188         if (soft_device->mtu != min_mtu)
 189                 soft_device->mtu = min_mtu;
 190 }
 191
 192 static void hardif_activate_interface(struct net_device *net_dev,
 193                                       struct bat_priv *bat_priv,
 194                                       struct batman_if *batman_if)
 195 {
 196         if (batman_if->if_status != IF_INACTIVE)
 197                 return;
 198
 199         update_mac_addresses(batman_if);
 200         batman_if->if_status = IF_TO_BE_ACTIVATED;
 201
 202         /**
 203          * the first active interface becomes our primary interface or
 204          * the next active interface after the old primay interface was removed
 205          */
 206         if (!bat_priv->primary_if)
 207                 set_primary_if(bat_priv, batman_if);
 208
 209         bat_info(net_dev, "Interface activated: %s\n", batman_if->dev);
 210
 211         if (atomic_read(&module_state) == MODULE_INACTIVE)
 212                 activate_module();
 213
 214         update_min_mtu();
 215         return;
 216 }
 217
 218 static void hardif_deactivate_interface(struct net_device *net_dev,
 219                                         struct batman_if *batman_if)
 220 {
 221         if ((batman_if->if_status != IF_ACTIVE) &&
 222            (batman_if->if_status != IF_TO_BE_ACTIVATED))
 223                 return;
 224
 225         batman_if->if_status = IF_INACTIVE;
 226
 227         bat_info(net_dev, "Interface deactivated: %s\n", batman_if->dev);
 228
 229         update_min_mtu();
 230 }
 231
 232 int hardif_enable_interface(struct batman_if *batman_if)
 233 {
 234         struct bat_priv *bat_priv = netdev_priv(soft_device);
 235         struct batman_packet *batman_packet;
 236
 237         if (batman_if->if_status != IF_NOT_IN_USE)
 238                 goto out;
 239
 240         batman_if->packet_len = BAT_PACKET_LEN;
 241         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
 242
 243         if (!batman_if->packet_buff) {
 244                 bat_err(soft_device, "Can't add interface packet (%s): "
 245                         "out of memory\n", batman_if->dev);
 246                 goto err;
 247         }
 248
 249         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 250         batman_packet->packet_type = BAT_PACKET;
 251         batman_packet->version = COMPAT_VERSION;
 252         batman_packet->flags = 0;
 253         batman_packet->ttl = 2;
 254         batman_packet->tq = TQ_MAX_VALUE;
 255         batman_packet->num_hna = 0;
 256
 257         batman_if->if_num = bat_priv->num_ifaces;
 258         bat_priv->num_ifaces++;
 259         batman_if->if_status = IF_INACTIVE;
 260         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
 261
 262         atomic_set(&batman_if->seqno, 1);
 263         bat_info(soft_device, "Adding interface: %s\n", batman_if->dev);
 264
 265         if (hardif_is_iface_up(batman_if))
 266                 hardif_activate_interface(soft_device, bat_priv, batman_if);
 267         else
 268                 bat_err(soft_device, "Not using interface %s "
 269                         "(retrying later): interface not active\n",
 270                         batman_if->dev);
 271
 272         /* begin scheduling originator messages on that interface */
 273         schedule_own_packet(batman_if);
 274
 275 out:
 276         return 0;
 277
 278 err:
 279         return -ENOMEM;
 280 }
 281
 282 void hardif_disable_interface(struct batman_if *batman_if)
 283 {
 284         struct bat_priv *bat_priv = netdev_priv(soft_device);
 285
 286         if (batman_if->if_status == IF_ACTIVE)
 287                 hardif_deactivate_interface(soft_device, batman_if);
 288
 289         if (batman_if->if_status != IF_INACTIVE)
 290                 return;
 291
 292         bat_info(soft_device, "Removing interface: %s\n", batman_if->dev);
 293         bat_priv->num_ifaces--;
 294         orig_hash_del_if(batman_if, bat_priv->num_ifaces);
 295
 296         if (batman_if == bat_priv->primary_if)
 297                 set_primary_if(bat_priv, get_active_batman_if());
 298
 299         kfree(batman_if->packet_buff);
 300         batman_if->packet_buff = NULL;
 301         batman_if->if_status = IF_NOT_IN_USE;
 302
 303         if ((atomic_read(&module_state) == MODULE_ACTIVE) &&
 304             (bat_priv->num_ifaces == 0))
 305                 deactivate_module();
 306 }
 307
 308 static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 309 {
 310         struct batman_if *batman_if;
 311         int ret;
 312
 313         ret = is_valid_iface(net_dev);
 314         if (ret != 1)
 315                 goto out;
 316
 317         dev_hold(net_dev);
 318
 319         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 320         if (!batman_if) {
 321                 pr_err("Can't add interface (%s): out of memory\n",
 322                        net_dev->name);
 323                 goto release_dev;
 324         }
 325
 326         batman_if->dev = kstrdup(net_dev->name, GFP_ATOMIC);
 327         if (!batman_if->dev)
 328                 goto free_if;
 329
 330         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
 331         if (ret)
 332                 goto free_dev;
 333
 334         batman_if->if_num = -1;
 335         batman_if->net_dev = net_dev;
 336         batman_if->if_status = IF_NOT_IN_USE;
 337         batman_if->packet_buff = NULL;
 338         INIT_LIST_HEAD(&batman_if->list);
 339
 340         check_known_mac_addr(batman_if->net_dev->dev_addr);
 341         list_add_tail_rcu(&batman_if->list, &if_list);
 342         return batman_if;
 343
 344 free_dev:
 345         kfree(batman_if->dev);
 346 free_if:
 347         kfree(batman_if);
 348 release_dev:
 349         dev_put(net_dev);
 350 out:
 351         return NULL;
 352 }
 353
 354 static void hardif_free_interface(struct rcu_head *rcu)
 355 {
 356         struct batman_if *batman_if = container_of(rcu, struct batman_if, rcu);
 357
 358         /* delete all references to this batman_if */
 359         purge_orig(NULL);
 360         purge_outstanding_packets(batman_if);
 361
 362         kfree(batman_if->dev);
 363         kfree(batman_if);
 364 }
 365
 366 static void hardif_remove_interface(struct batman_if *batman_if)
 367 {
 368         /* first deactivate interface */
 369         if (batman_if->if_status != IF_NOT_IN_USE)
 370                 hardif_disable_interface(batman_if);
 371
 372         if (batman_if->if_status != IF_NOT_IN_USE)
 373                 return;
 374
 375         batman_if->if_status = IF_TO_BE_REMOVED;
 376         list_del_rcu(&batman_if->list);
 377         sysfs_del_hardif(&batman_if->hardif_obj);
 378         dev_put(batman_if->net_dev);
 379         call_rcu(&batman_if->rcu, hardif_free_interface);
 380 }
 381
 382 void hardif_remove_interfaces(void)
 383 {
 384         struct batman_if *batman_if, *batman_if_tmp;
 385
 386         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list)
 387                 hardif_remove_interface(batman_if);
 388 }
 389
 390 static int hard_if_event(struct notifier_block *this,
 391                          unsigned long event, void *ptr)
 392 {
 393         struct net_device *net_dev = (struct net_device *)ptr;
 394         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
 395         struct bat_priv *bat_priv = netdev_priv(soft_device);
 396
 397         if (!batman_if && event == NETDEV_REGISTER)
 398                         batman_if = hardif_add_interface(net_dev);
 399
 400         if (!batman_if)
 401                 goto out;
 402
 403         switch (event) {
 404         case NETDEV_UP:
 405                 hardif_activate_interface(soft_device, bat_priv, batman_if);
 406                 break;
 407         case NETDEV_GOING_DOWN:
 408         case NETDEV_DOWN:
 409                 hardif_deactivate_interface(soft_device, batman_if);
 410                 break;
 411         case NETDEV_UNREGISTER:
 412                 hardif_remove_interface(batman_if);
 413                 break;
 414         case NETDEV_CHANGENAME:
 415                 break;
 416         case NETDEV_CHANGEADDR:
 417                 check_known_mac_addr(batman_if->net_dev->dev_addr);
 418                 update_mac_addresses(batman_if);
 419                 if (batman_if == bat_priv->primary_if)
 420                         set_primary_if(bat_priv, batman_if);
 421                 break;
 422         default:
 423                 break;
 424         };
 425
 426 out:
 427         return NOTIFY_DONE;
 428 }
 429
 430 /* receive a packet with the batman ethertype coming on a hard
 431  * interface */
 432 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 433         struct packet_type *ptype, struct net_device *orig_dev)
 434 {
 435         struct bat_priv *bat_priv = netdev_priv(soft_device);
 436         struct batman_packet *batman_packet;
 437         struct batman_if *batman_if;
 438         int ret;
 439
 440         skb = skb_share_check(skb, GFP_ATOMIC);
 441
 442         /* skb was released by skb_share_check() */
 443         if (!skb)
 444                 goto err_out;
 445
 446         if (atomic_read(&module_state) != MODULE_ACTIVE)
 447                 goto err_free;
 448
 449         /* packet should hold at least type and version */
 450         if (unlikely(skb_headlen(skb) < 2))
 451                 goto err_free;
 452
 453         /* expect a valid ethernet header here. */
 454         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 455                                 || !skb_mac_header(skb)))
 456                 goto err_free;
 457
 458         batman_if = get_batman_if_by_netdev(skb->dev);
 459         if (!batman_if)
 460                 goto err_free;
 461
 462         /* discard frames on not active interfaces */
 463         if (batman_if->if_status != IF_ACTIVE)
 464                 goto err_free;
 465
 466         batman_packet = (struct batman_packet *)skb->data;
 467
 468         if (batman_packet->version != COMPAT_VERSION) {
 469                 bat_dbg(DBG_BATMAN, bat_priv,
 470                         "Drop packet: incompatible batman version (%i)\n",
 471                         batman_packet->version);
 472                 goto err_free;
 473         }
 474
 475         /* all receive handlers return whether they received or reused
 476          * the supplied skb. if not, we have to free the skb. */
 477
 478         switch (batman_packet->packet_type) {
 479                 /* batman originator packet */
 480         case BAT_PACKET:
 481                 ret = recv_bat_packet(skb, batman_if);
 482                 break;
 483
 484                 /* batman icmp packet */
 485         case BAT_ICMP:
 486                 ret = recv_icmp_packet(skb);
 487                 break;
 488
 489                 /* unicast packet */
 490         case BAT_UNICAST:
 491                 ret = recv_unicast_packet(skb, batman_if);
 492                 break;
 493
 494                 /* broadcast packet */
 495         case BAT_BCAST:
 496                 ret = recv_bcast_packet(skb);
 497                 break;
 498
 499                 /* vis packet */
 500         case BAT_VIS:
 501                 ret = recv_vis_packet(skb);
 502                 break;
 503         default:
 504                 ret = NET_RX_DROP;
 505         }
 506
 507         if (ret == NET_RX_DROP)
 508                 kfree_skb(skb);
 509
 510         /* return NET_RX_SUCCESS in any case as we
 511          * most probably dropped the packet for
 512          * routing-logical reasons. */
 513
 514         return NET_RX_SUCCESS;
 515
 516 err_free:
 517         kfree_skb(skb);
 518 err_out:
 519         return NET_RX_DROP;
 520 }
 521
 522 struct notifier_block hard_if_notifier = {
 523         .notifier_call = hard_if_event,
 524 };