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->br_port != NULL)
  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 = 0;
 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         addr_to_string(batman_if->addr_str, batman_if->net_dev->dev_addr);
 132
 133         memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
 134                batman_if->net_dev->dev_addr, ETH_ALEN);
 135         memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
 136                batman_if->net_dev->dev_addr, ETH_ALEN);
 137 }
 138
 139 static void check_known_mac_addr(uint8_t *addr)
 140 {
 141         struct batman_if *batman_if;
 142
 143         rcu_read_lock();
 144         list_for_each_entry_rcu(batman_if, &if_list, list) {
 145                 if ((batman_if->if_status != IF_ACTIVE) &&
 146                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 147                         continue;
 148
 149                 if (!compare_orig(batman_if->net_dev->dev_addr, addr))
 150                         continue;
 151
 152                 printk(KERN_WARNING "batman-adv:"
 153                     "The newly added mac address (%pM) already exists on: %s\n",
 154                     addr, batman_if->dev);
 155                 printk(KERN_WARNING "batman-adv:"
 156                     "It is strongly recommended to keep mac addresses unique"
 157                     "to avoid problems!\n");
 158         }
 159         rcu_read_unlock();
 160 }
 161
 162 int hardif_min_mtu(void)
 163 {
 164         struct batman_if *batman_if;
 165         /* allow big frames if all devices are capable to do so
 166          * (have MTU > 1500 + BAT_HEADER_LEN) */
 167         int min_mtu = ETH_DATA_LEN;
 168
 169         rcu_read_lock();
 170         list_for_each_entry_rcu(batman_if, &if_list, list) {
 171                 if ((batman_if->if_status == IF_ACTIVE) ||
 172                     (batman_if->if_status == IF_TO_BE_ACTIVATED))
 173                         min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 174                                       min_mtu);
 175         }
 176         rcu_read_unlock();
 177
 178         return min_mtu;
 179 }
 180
 181 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 182 void update_min_mtu(void)
 183 {
 184         int min_mtu;
 185
 186         min_mtu = hardif_min_mtu();
 187         if (soft_device->mtu != min_mtu)
 188                 soft_device->mtu = min_mtu;
 189 }
 190
 191 static void hardif_activate_interface(struct bat_priv *bat_priv,
 192                                       struct batman_if *batman_if)
 193 {
 194         if (batman_if->if_status != IF_INACTIVE)
 195                 return;
 196
 197         dev_hold(batman_if->net_dev);
 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         printk(KERN_INFO "batman-adv:Interface activated: %s\n",
 210                batman_if->dev);
 211
 212         if (atomic_read(&module_state) == MODULE_INACTIVE)
 213                 activate_module();
 214
 215         update_min_mtu();
 216         return;
 217 }
 218
 219 static void hardif_deactivate_interface(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         dev_put(batman_if->net_dev);
 226
 227         batman_if->if_status = IF_INACTIVE;
 228
 229         printk(KERN_INFO "batman-adv:Interface deactivated: %s\n",
 230                batman_if->dev);
 231
 232         update_min_mtu();
 233 }
 234
 235 int hardif_enable_interface(struct batman_if *batman_if)
 236 {
 237         /* FIXME: each batman_if will be attached to a softif */
 238         struct bat_priv *bat_priv = netdev_priv(soft_device);
 239         struct batman_packet *batman_packet;
 240
 241         if (batman_if->if_status != IF_NOT_IN_USE)
 242                 goto out;
 243
 244         batman_if->packet_len = BAT_PACKET_LEN;
 245         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
 246
 247         if (!batman_if->packet_buff) {
 248                 printk(KERN_ERR "batman-adv:"
 249                        "Can't add interface packet (%s): out of memory\n",
 250                        batman_if->dev);
 251                 goto err;
 252         }
 253
 254         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 255         batman_packet->packet_type = BAT_PACKET;
 256         batman_packet->version = COMPAT_VERSION;
 257         batman_packet->flags = 0;
 258         batman_packet->ttl = 2;
 259         batman_packet->tq = TQ_MAX_VALUE;
 260         batman_packet->num_hna = 0;
 261
 262         batman_if->if_num = bat_priv->num_ifaces;
 263         bat_priv->num_ifaces++;
 264         batman_if->if_status = IF_INACTIVE;
 265         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
 266
 267         atomic_set(&batman_if->seqno, 1);
 268         printk(KERN_INFO "batman-adv:Adding interface: %s\n", batman_if->dev);
 269
 270         if (hardif_is_iface_up(batman_if))
 271                 hardif_activate_interface(bat_priv, batman_if);
 272         else
 273                 printk(KERN_ERR "batman-adv:"
 274                        "Not using interface %s "
 275                        "(retrying later): interface not active\n",
 276                        batman_if->dev);
 277
 278         /* begin scheduling originator messages on that interface */
 279         schedule_own_packet(batman_if);
 280
 281 out:
 282         return 0;
 283
 284 err:
 285         return -ENOMEM;
 286 }
 287
 288 void hardif_disable_interface(struct batman_if *batman_if)
 289 {
 290         /* FIXME: each batman_if will be attached to a softif */
 291         struct bat_priv *bat_priv = netdev_priv(soft_device);
 292
 293         if (batman_if->if_status == IF_ACTIVE)
 294                 hardif_deactivate_interface(batman_if);
 295
 296         if (batman_if->if_status != IF_INACTIVE)
 297                 return;
 298
 299         printk(KERN_INFO "batman-adv:Removing interface: %s\n", batman_if->dev);
 300         bat_priv->num_ifaces--;
 301         orig_hash_del_if(batman_if, bat_priv->num_ifaces);
 302
 303         if (batman_if == bat_priv->primary_if)
 304                 set_primary_if(bat_priv, get_active_batman_if());
 305
 306         kfree(batman_if->packet_buff);
 307         batman_if->packet_buff = NULL;
 308         batman_if->if_status = IF_NOT_IN_USE;
 309
 310         if ((atomic_read(&module_state) == MODULE_ACTIVE) &&
 311             (bat_priv->num_ifaces == 0))
 312                 deactivate_module();
 313 }
 314
 315 static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 316 {
 317         struct batman_if *batman_if;
 318         int ret;
 319
 320         ret = is_valid_iface(net_dev);
 321         if (ret != 1)
 322                 goto out;
 323
 324         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 325         if (!batman_if) {
 326                 printk(KERN_ERR "batman-adv:"
 327                        "Can't add interface (%s): out of memory\n",
 328                        net_dev->name);
 329                 goto out;
 330         }
 331
 332         batman_if->dev = kstrdup(net_dev->name, GFP_ATOMIC);
 333         if (!batman_if->dev)
 334                 goto free_if;
 335
 336         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
 337         if (ret)
 338                 goto free_dev;
 339
 340         batman_if->if_num = -1;
 341         batman_if->net_dev = net_dev;
 342         batman_if->if_status = IF_NOT_IN_USE;
 343         INIT_LIST_HEAD(&batman_if->list);
 344
 345         check_known_mac_addr(batman_if->net_dev->dev_addr);
 346         list_add_tail_rcu(&batman_if->list, &if_list);
 347         return batman_if;
 348
 349 free_dev:
 350         kfree(batman_if->dev);
 351 free_if:
 352         kfree(batman_if);
 353 out:
 354         return NULL;
 355 }
 356
 357 static void hardif_free_interface(struct rcu_head *rcu)
 358 {
 359         struct batman_if *batman_if = container_of(rcu, struct batman_if, rcu);
 360
 361         /* delete all references to this batman_if */
 362         purge_orig(NULL);
 363         purge_outstanding_packets(batman_if);
 364
 365         kfree(batman_if->dev);
 366         kfree(batman_if);
 367 }
 368
 369 static void hardif_remove_interface(struct batman_if *batman_if)
 370 {
 371         /* first deactivate interface */
 372         if (batman_if->if_status != IF_NOT_IN_USE)
 373                 hardif_disable_interface(batman_if);
 374
 375         if (batman_if->if_status != IF_NOT_IN_USE)
 376                 return;
 377
 378         batman_if->if_status = IF_TO_BE_REMOVED;
 379         list_del_rcu(&batman_if->list);
 380         sysfs_del_hardif(&batman_if->hardif_obj);
 381         call_rcu(&batman_if->rcu, hardif_free_interface);
 382 }
 383
 384 void hardif_remove_interfaces(void)
 385 {
 386         struct batman_if *batman_if, *batman_if_tmp;
 387
 388         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list)
 389                 hardif_remove_interface(batman_if);
 390 }
 391
 392 static int hard_if_event(struct notifier_block *this,
 393                          unsigned long event, void *ptr)
 394 {
 395         struct net_device *net_dev = (struct net_device *)ptr;
 396         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
 397         /* FIXME: each batman_if will be attached to a softif */
 398         struct bat_priv *bat_priv = netdev_priv(soft_device);
 399
 400         if (!batman_if)
 401                 batman_if = hardif_add_interface(net_dev);
 402
 403         if (!batman_if)
 404                 goto out;
 405
 406         switch (event) {
 407         case NETDEV_REGISTER:
 408                 break;
 409         case NETDEV_UP:
 410                 hardif_activate_interface(bat_priv, batman_if);
 411                 break;
 412         case NETDEV_GOING_DOWN:
 413         case NETDEV_DOWN:
 414                 hardif_deactivate_interface(batman_if);
 415                 break;
 416         case NETDEV_UNREGISTER:
 417                 hardif_remove_interface(batman_if);
 418                 break;
 419         case NETDEV_CHANGENAME:
 420                 break;
 421         case NETDEV_CHANGEADDR:
 422                 check_known_mac_addr(batman_if->net_dev->dev_addr);
 423                 update_mac_addresses(batman_if);
 424                 if (batman_if == bat_priv->primary_if)
 425                         set_primary_if(bat_priv, batman_if);
 426                 break;
 427         default:
 428                 break;
 429         };
 430
 431 out:
 432         return NOTIFY_DONE;
 433 }
 434
 435 /* receive a packet with the batman ethertype coming on a hard
 436  * interface */
 437 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 438         struct packet_type *ptype, struct net_device *orig_dev)
 439 {
 440         struct batman_packet *batman_packet;
 441         struct batman_if *batman_if;
 442         struct net_device_stats *stats;
 443         int ret;
 444
 445         skb = skb_share_check(skb, GFP_ATOMIC);
 446
 447         /* skb was released by skb_share_check() */
 448         if (!skb)
 449                 goto err_out;
 450
 451         if (atomic_read(&module_state) != MODULE_ACTIVE)
 452                 goto err_free;
 453
 454         /* packet should hold at least type and version */
 455         if (unlikely(skb_headlen(skb) < 2))
 456                 goto err_free;
 457
 458         /* expect a valid ethernet header here. */
 459         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 460                                 || !skb_mac_header(skb)))
 461                 goto err_free;
 462
 463         batman_if = get_batman_if_by_netdev(skb->dev);
 464         if (!batman_if)
 465                 goto err_free;
 466
 467         /* discard frames on not active interfaces */
 468         if (batman_if->if_status != IF_ACTIVE)
 469                 goto err_free;
 470
 471         stats = (struct net_device_stats *)dev_get_stats(skb->dev);
 472         if (stats) {
 473                 stats->rx_packets++;
 474                 stats->rx_bytes += skb->len;
 475         }
 476
 477         batman_packet = (struct batman_packet *)skb->data;
 478
 479         if (batman_packet->version != COMPAT_VERSION) {
 480                 bat_dbg(DBG_BATMAN,
 481                         "Drop packet: incompatible batman version (%i)\n",
 482                         batman_packet->version);
 483                 goto err_free;
 484         }
 485
 486         /* all receive handlers return whether they received or reused
 487          * the supplied skb. if not, we have to free the skb. */
 488
 489         switch (batman_packet->packet_type) {
 490                 /* batman originator packet */
 491         case BAT_PACKET:
 492                 ret = recv_bat_packet(skb, batman_if);
 493                 break;
 494
 495                 /* batman icmp packet */
 496         case BAT_ICMP:
 497                 ret = recv_icmp_packet(skb);
 498                 break;
 499
 500                 /* unicast packet */
 501         case BAT_UNICAST:
 502                 ret = recv_unicast_packet(skb);
 503                 break;
 504
 505                 /* broadcast packet */
 506         case BAT_BCAST:
 507                 ret = recv_bcast_packet(skb);
 508                 break;
 509
 510                 /* vis packet */
 511         case BAT_VIS:
 512                 ret = recv_vis_packet(skb);
 513                 break;
 514         default:
 515                 ret = NET_RX_DROP;
 516         }
 517
 518         if (ret == NET_RX_DROP)
 519                 kfree_skb(skb);
 520
 521         /* return NET_RX_SUCCESS in any case as we
 522          * most probably dropped the packet for
 523          * routing-logical reasons. */
 524
 525         return NET_RX_SUCCESS;
 526
 527 err_free:
 528         kfree_skb(skb);
 529 err_out:
 530         return NET_RX_DROP;
 531 }
 532
 533
 534 struct notifier_block hard_if_notifier = {
 535         .notifier_call = hard_if_event,
 536 };