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:The newly added mac address (%pM) already exists on: %s\n",
 153                        addr, batman_if->dev);
 154                 printk(KERN_WARNING "batman-adv:It is strongly recommended to keep mac addresses unique to avoid problems!\n");
 155         }
 156         rcu_read_unlock();
 157 }
 158
 159 int hardif_min_mtu(void)
 160 {
 161         struct batman_if *batman_if;
 162         /* allow big frames if all devices are capable to do so
 163          * (have MTU > 1500 + BAT_HEADER_LEN) */
 164         int min_mtu = ETH_DATA_LEN;
 165
 166         rcu_read_lock();
 167         list_for_each_entry_rcu(batman_if, &if_list, list) {
 168                 if ((batman_if->if_status == IF_ACTIVE) ||
 169                     (batman_if->if_status == IF_TO_BE_ACTIVATED))
 170                         min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 171                                       min_mtu);
 172         }
 173         rcu_read_unlock();
 174
 175         return min_mtu;
 176 }
 177
 178 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 179 void update_min_mtu(void)
 180 {
 181         int min_mtu;
 182
 183         min_mtu = hardif_min_mtu();
 184         if (soft_device->mtu != min_mtu)
 185                 soft_device->mtu = min_mtu;
 186 }
 187
 188 static void hardif_activate_interface(struct bat_priv *bat_priv,
 189                                       struct batman_if *batman_if)
 190 {
 191         if (batman_if->if_status != IF_INACTIVE)
 192                 return;
 193
 194         dev_hold(batman_if->net_dev);
 195
 196         update_mac_addresses(batman_if);
 197         batman_if->if_status = IF_TO_BE_ACTIVATED;
 198
 199         /**
 200          * the first active interface becomes our primary interface or
 201          * the next active interface after the old primay interface was removed
 202          */
 203         if (!bat_priv->primary_if)
 204                 set_primary_if(bat_priv, batman_if);
 205
 206         printk(KERN_INFO "batman-adv:Interface activated: %s\n",
 207                batman_if->dev);
 208
 209         if (atomic_read(&module_state) == MODULE_INACTIVE)
 210                 activate_module();
 211
 212         update_min_mtu();
 213         return;
 214 }
 215
 216 static void hardif_deactivate_interface(struct batman_if *batman_if)
 217 {
 218         if ((batman_if->if_status != IF_ACTIVE) &&
 219            (batman_if->if_status != IF_TO_BE_ACTIVATED))
 220                 return;
 221
 222         dev_put(batman_if->net_dev);
 223
 224         batman_if->if_status = IF_INACTIVE;
 225
 226         printk(KERN_INFO "batman-adv:Interface deactivated: %s\n",
 227                batman_if->dev);
 228
 229         update_min_mtu();
 230 }
 231
 232 int hardif_enable_interface(struct batman_if *batman_if)
 233 {
 234         /* FIXME: each batman_if will be attached to a softif */
 235         struct bat_priv *bat_priv = netdev_priv(soft_device);
 236         struct batman_packet *batman_packet;
 237
 238         if (batman_if->if_status != IF_NOT_IN_USE)
 239                 goto out;
 240
 241         batman_if->packet_len = BAT_PACKET_LEN;
 242         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
 243
 244         if (!batman_if->packet_buff) {
 245                 printk(KERN_ERR "batman-adv:Can't add interface packet (%s): out of memory\n",
 246                        batman_if->dev);
 247                 goto err;
 248         }
 249
 250         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 251         batman_packet->packet_type = BAT_PACKET;
 252         batman_packet->version = COMPAT_VERSION;
 253         batman_packet->flags = 0;
 254         batman_packet->ttl = 2;
 255         batman_packet->tq = TQ_MAX_VALUE;
 256         batman_packet->num_hna = 0;
 257
 258         batman_if->if_num = bat_priv->num_ifaces;
 259         bat_priv->num_ifaces++;
 260         batman_if->if_status = IF_INACTIVE;
 261         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
 262
 263         atomic_set(&batman_if->seqno, 1);
 264         printk(KERN_INFO "batman-adv:Adding interface: %s\n", batman_if->dev);
 265
 266         if (hardif_is_iface_up(batman_if))
 267                 hardif_activate_interface(bat_priv, batman_if);
 268         else
 269                 printk(KERN_ERR "batman-adv:Not using interface %s (retrying later): interface not active\n", batman_if->dev);
 270
 271         /* begin scheduling originator messages on that interface */
 272         schedule_own_packet(batman_if);
 273
 274 out:
 275         return 0;
 276
 277 err:
 278         return -ENOMEM;
 279 }
 280
 281 void hardif_disable_interface(struct batman_if *batman_if)
 282 {
 283         /* FIXME: each batman_if will be attached to a softif */
 284         struct bat_priv *bat_priv = netdev_priv(soft_device);
 285
 286         if (batman_if->if_status == IF_ACTIVE)
 287                 hardif_deactivate_interface(batman_if);
 288
 289         if (batman_if->if_status != IF_INACTIVE)
 290                 return;
 291
 292         printk(KERN_INFO "batman-adv: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         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 318         if (!batman_if) {
 319                 printk(KERN_ERR "batman-adv:Can't add interface (%s): out of memory\n",
 320                        net_dev->name);
 321                 goto out;
 322         }
 323
 324         batman_if->dev = kstrdup(net_dev->name, GFP_ATOMIC);
 325         if (!batman_if->dev)
 326                 goto free_if;
 327
 328         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
 329         if (ret)
 330                 goto free_dev;
 331
 332         batman_if->if_num = -1;
 333         batman_if->net_dev = net_dev;
 334         batman_if->if_status = IF_NOT_IN_USE;
 335         INIT_RCU_HEAD(&batman_if->rcu);
 336         INIT_LIST_HEAD(&batman_if->list);
 337
 338         check_known_mac_addr(batman_if->net_dev->dev_addr);
 339         list_add_tail_rcu(&batman_if->list, &if_list);
 340         return batman_if;
 341
 342 free_dev:
 343         kfree(batman_if->dev);
 344 free_if:
 345         kfree(batman_if);
 346 out:
 347         return NULL;
 348 }
 349
 350 static void hardif_free_interface(struct rcu_head *rcu)
 351 {
 352         struct batman_if *batman_if = container_of(rcu, struct batman_if, rcu);
 353
 354         /* delete all references to this batman_if */
 355         purge_orig(NULL);
 356         purge_outstanding_packets(batman_if);
 357
 358         kfree(batman_if->dev);
 359         kfree(batman_if);
 360 }
 361
 362 static void hardif_remove_interface(struct batman_if *batman_if)
 363 {
 364         /* first deactivate interface */
 365         if (batman_if->if_status != IF_NOT_IN_USE)
 366                 hardif_disable_interface(batman_if);
 367
 368         if (batman_if->if_status != IF_NOT_IN_USE)
 369                 return;
 370
 371         batman_if->if_status = IF_TO_BE_REMOVED;
 372         list_del_rcu(&batman_if->list);
 373         sysfs_del_hardif(&batman_if->hardif_obj);
 374         call_rcu(&batman_if->rcu, hardif_free_interface);
 375 }
 376
 377 void hardif_remove_interfaces(void)
 378 {
 379         struct batman_if *batman_if, *batman_if_tmp;
 380
 381         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list)
 382                 hardif_remove_interface(batman_if);
 383 }
 384
 385 static int hard_if_event(struct notifier_block *this,
 386                          unsigned long event, void *ptr)
 387 {
 388         struct net_device *net_dev = (struct net_device *)ptr;
 389         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
 390         /* FIXME: each batman_if will be attached to a softif */
 391         struct bat_priv *bat_priv = netdev_priv(soft_device);
 392
 393         if (!batman_if)
 394                 batman_if = hardif_add_interface(net_dev);
 395
 396         if (!batman_if)
 397                 goto out;
 398
 399         switch (event) {
 400         case NETDEV_REGISTER:
 401                 break;
 402         case NETDEV_UP:
 403                 hardif_activate_interface(bat_priv, batman_if);
 404                 break;
 405         case NETDEV_GOING_DOWN:
 406         case NETDEV_DOWN:
 407                 hardif_deactivate_interface(batman_if);
 408                 break;
 409         case NETDEV_UNREGISTER:
 410                 hardif_remove_interface(batman_if);
 411                 break;
 412         case NETDEV_CHANGENAME:
 413                 break;
 414         case NETDEV_CHANGEADDR:
 415                 check_known_mac_addr(batman_if->net_dev->dev_addr);
 416                 update_mac_addresses(batman_if);
 417                 if (batman_if == bat_priv->primary_if)
 418                         set_primary_if(bat_priv, batman_if);
 419                 break;
 420         default:
 421                 break;
 422         };
 423
 424 out:
 425         return NOTIFY_DONE;
 426 }
 427
 428 /* receive a packet with the batman ethertype coming on a hard
 429  * interface */
 430 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 431         struct packet_type *ptype, struct net_device *orig_dev)
 432 {
 433         struct batman_packet *batman_packet;
 434         struct batman_if *batman_if;
 435         struct net_device_stats *stats;
 436         int ret;
 437
 438         skb = skb_share_check(skb, GFP_ATOMIC);
 439
 440         /* skb was released by skb_share_check() */
 441         if (!skb)
 442                 goto err_out;
 443
 444         if (atomic_read(&module_state) != MODULE_ACTIVE)
 445                 goto err_free;
 446
 447         /* packet should hold at least type and version */
 448         if (unlikely(skb_headlen(skb) < 2))
 449                 goto err_free;
 450
 451         /* expect a valid ethernet header here. */
 452         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 453                                 || !skb_mac_header(skb)))
 454                 goto err_free;
 455
 456         batman_if = get_batman_if_by_netdev(skb->dev);
 457         if (!batman_if)
 458                 goto err_free;
 459
 460         /* discard frames on not active interfaces */
 461         if (batman_if->if_status != IF_ACTIVE)
 462                 goto err_free;
 463
 464         stats = (struct net_device_stats *)dev_get_stats(skb->dev);
 465         if (stats) {
 466                 stats->rx_packets++;
 467                 stats->rx_bytes += skb->len;
 468         }
 469
 470         batman_packet = (struct batman_packet *)skb->data;
 471
 472         if (batman_packet->version != COMPAT_VERSION) {
 473                 bat_dbg(DBG_BATMAN,
 474                         "Drop packet: incompatible batman version (%i)\n",
 475                         batman_packet->version);
 476                 goto err_free;
 477         }
 478
 479         /* all receive handlers return whether they received or reused
 480          * the supplied skb. if not, we have to free the skb. */
 481
 482         switch (batman_packet->packet_type) {
 483                 /* batman originator packet */
 484         case BAT_PACKET:
 485                 ret = recv_bat_packet(skb, batman_if);
 486                 break;
 487
 488                 /* batman icmp packet */
 489         case BAT_ICMP:
 490                 ret = recv_icmp_packet(skb);
 491                 break;
 492
 493                 /* unicast packet */
 494         case BAT_UNICAST:
 495                 ret = recv_unicast_packet(skb);
 496                 break;
 497
 498                 /* broadcast packet */
 499         case BAT_BCAST:
 500                 ret = recv_bcast_packet(skb);
 501                 break;
 502
 503                 /* vis packet */
 504         case BAT_VIS:
 505                 ret = recv_vis_packet(skb);
 506                 break;
 507         default:
 508                 ret = NET_RX_DROP;
 509         }
 510
 511         if (ret == NET_RX_DROP)
 512                 kfree_skb(skb);
 513
 514         /* return NET_RX_SUCCESS in any case as we
 515          * most probably dropped the packet for
 516          * routing-logical reasons. */
 517
 518         return NET_RX_SUCCESS;
 519
 520 err_free:
 521         kfree_skb(skb);
 522 err_out:
 523         return NET_RX_DROP;
 524 }
 525
 526
 527 struct notifier_block hard_if_notifier = {
 528         .notifier_call = hard_if_event,
 529 };