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 update_primary_addr(struct bat_priv *bat_priv)
 110 {
 111         struct vis_packet *vis_packet;
 112
 113         vis_packet = (struct vis_packet *)
 114                                 bat_priv->my_vis_info->skb_packet->data;
 115         memcpy(vis_packet->vis_orig,
 116                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 117         memcpy(vis_packet->sender_orig,
 118                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 119 }
 120
 121 static void set_primary_if(struct bat_priv *bat_priv,
 122                            struct batman_if *batman_if)
 123 {
 124         struct batman_packet *batman_packet;
 125         struct batman_if *old_if;
 126
 127         if (batman_if)
 128                 hardif_hold(batman_if);
 129
 130         old_if = bat_priv->primary_if;
 131         bat_priv->primary_if = batman_if;
 132
 133         if (old_if)
 134                 hardif_put(old_if);
 135
 136         if (!bat_priv->primary_if)
 137                 return;
 138
 139         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 140         batman_packet->flags = PRIMARIES_FIRST_HOP;
 141         batman_packet->ttl = TTL;
 142
 143         update_primary_addr(bat_priv);
 144
 145         /***
 146          * hacky trick to make sure that we send the HNA information via
 147          * our new primary interface
 148          */
 149         atomic_set(&bat_priv->hna_local_changed, 1);
 150 }
 151
 152 static bool hardif_is_iface_up(struct batman_if *batman_if)
 153 {
 154         if (batman_if->net_dev->flags & IFF_UP)
 155                 return true;
 156
 157         return false;
 158 }
 159
 160 static void update_mac_addresses(struct batman_if *batman_if)
 161 {
 162         memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
 163                batman_if->net_dev->dev_addr, ETH_ALEN);
 164         memcpy(((struct batman_packet *)(batman_if->packet_buff))->prev_sender,
 165                batman_if->net_dev->dev_addr, ETH_ALEN);
 166 }
 167
 168 static void check_known_mac_addr(struct net_device *net_dev)
 169 {
 170         struct batman_if *batman_if;
 171
 172         rcu_read_lock();
 173         list_for_each_entry_rcu(batman_if, &if_list, list) {
 174                 if ((batman_if->if_status != IF_ACTIVE) &&
 175                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 176                         continue;
 177
 178                 if (batman_if->net_dev == net_dev)
 179                         continue;
 180
 181                 if (!compare_orig(batman_if->net_dev->dev_addr,
 182                                   net_dev->dev_addr))
 183                         continue;
 184
 185                 pr_warning("The newly added mac address (%pM) already exists "
 186                            "on: %s\n", net_dev->dev_addr,
 187                            batman_if->net_dev->name);
 188                 pr_warning("It is strongly recommended to keep mac addresses "
 189                            "unique to avoid problems!\n");
 190         }
 191         rcu_read_unlock();
 192 }
 193
 194 int hardif_min_mtu(struct net_device *soft_iface)
 195 {
 196         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 197         struct batman_if *batman_if;
 198         /* allow big frames if all devices are capable to do so
 199          * (have MTU > 1500 + BAT_HEADER_LEN) */
 200         int min_mtu = ETH_DATA_LEN;
 201
 202         if (atomic_read(&bat_priv->frag_enabled))
 203                 goto out;
 204
 205         rcu_read_lock();
 206         list_for_each_entry_rcu(batman_if, &if_list, list) {
 207                 if ((batman_if->if_status != IF_ACTIVE) &&
 208                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 209                         continue;
 210
 211                 if (batman_if->soft_iface != soft_iface)
 212                         continue;
 213
 214                 min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 215                               min_mtu);
 216         }
 217         rcu_read_unlock();
 218 out:
 219         return min_mtu;
 220 }
 221
 222 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 223 void update_min_mtu(struct net_device *soft_iface)
 224 {
 225         int min_mtu;
 226
 227         min_mtu = hardif_min_mtu(soft_iface);
 228         if (soft_iface->mtu != min_mtu)
 229                 soft_iface->mtu = min_mtu;
 230 }
 231
 232 static void hardif_activate_interface(struct batman_if *batman_if)
 233 {
 234         struct bat_priv *bat_priv;
 235
 236         if (batman_if->if_status != IF_INACTIVE)
 237                 return;
 238
 239         bat_priv = netdev_priv(batman_if->soft_iface);
 240
 241         update_mac_addresses(batman_if);
 242         batman_if->if_status = IF_TO_BE_ACTIVATED;
 243
 244         /**
 245          * the first active interface becomes our primary interface or
 246          * the next active interface after the old primay interface was removed
 247          */
 248         if (!bat_priv->primary_if)
 249                 set_primary_if(bat_priv, batman_if);
 250
 251         bat_info(batman_if->soft_iface, "Interface activated: %s\n",
 252                  batman_if->net_dev->name);
 253
 254         update_min_mtu(batman_if->soft_iface);
 255         return;
 256 }
 257
 258 static void hardif_deactivate_interface(struct batman_if *batman_if)
 259 {
 260         if ((batman_if->if_status != IF_ACTIVE) &&
 261            (batman_if->if_status != IF_TO_BE_ACTIVATED))
 262                 return;
 263
 264         batman_if->if_status = IF_INACTIVE;
 265
 266         bat_info(batman_if->soft_iface, "Interface deactivated: %s\n",
 267                  batman_if->net_dev->name);
 268
 269         update_min_mtu(batman_if->soft_iface);
 270 }
 271
 272 int hardif_enable_interface(struct batman_if *batman_if, char *iface_name)
 273 {
 274         struct bat_priv *bat_priv;
 275         struct batman_packet *batman_packet;
 276
 277         if (batman_if->if_status != IF_NOT_IN_USE)
 278                 goto out;
 279
 280         batman_if->soft_iface = dev_get_by_name(&init_net, iface_name);
 281
 282         if (!batman_if->soft_iface) {
 283                 batman_if->soft_iface = softif_create(iface_name);
 284
 285                 if (!batman_if->soft_iface)
 286                         goto err;
 287
 288                 /* dev_get_by_name() increases the reference counter for us */
 289                 dev_hold(batman_if->soft_iface);
 290         }
 291
 292         bat_priv = netdev_priv(batman_if->soft_iface);
 293         batman_if->packet_len = BAT_PACKET_LEN;
 294         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
 295
 296         if (!batman_if->packet_buff) {
 297                 bat_err(batman_if->soft_iface, "Can't add interface packet "
 298                         "(%s): out of memory\n", batman_if->net_dev->name);
 299                 goto err;
 300         }
 301
 302         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 303         batman_packet->packet_type = BAT_PACKET;
 304         batman_packet->version = COMPAT_VERSION;
 305         batman_packet->flags = 0;
 306         batman_packet->ttl = 2;
 307         batman_packet->tq = TQ_MAX_VALUE;
 308         batman_packet->num_hna = 0;
 309
 310         batman_if->if_num = bat_priv->num_ifaces;
 311         bat_priv->num_ifaces++;
 312         batman_if->if_status = IF_INACTIVE;
 313         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
 314
 315         batman_if->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
 316         batman_if->batman_adv_ptype.func = batman_skb_recv;
 317         batman_if->batman_adv_ptype.dev = batman_if->net_dev;
 318         hardif_hold(batman_if);
 319         dev_add_pack(&batman_if->batman_adv_ptype);
 320
 321         atomic_set(&batman_if->seqno, 1);
 322         atomic_set(&batman_if->frag_seqno, 1);
 323         bat_info(batman_if->soft_iface, "Adding interface: %s\n",
 324                  batman_if->net_dev->name);
 325
 326         if (atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 327                 ETH_DATA_LEN + BAT_HEADER_LEN)
 328                 bat_info(batman_if->soft_iface,
 329                         "The MTU of interface %s is too small (%i) to handle "
 330                         "the transport of batman-adv packets. Packets going "
 331                         "over this interface will be fragmented on layer2 "
 332                         "which could impact the performance. Setting the MTU "
 333                         "to %zi would solve the problem.\n",
 334                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 335                         ETH_DATA_LEN + BAT_HEADER_LEN);
 336
 337         if (!atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 338                 ETH_DATA_LEN + BAT_HEADER_LEN)
 339                 bat_info(batman_if->soft_iface,
 340                         "The MTU of interface %s is too small (%i) to handle "
 341                         "the transport of batman-adv packets. If you experience"
 342                         " problems getting traffic through try increasing the "
 343                         "MTU to %zi.\n",
 344                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 345                         ETH_DATA_LEN + BAT_HEADER_LEN);
 346
 347         if (hardif_is_iface_up(batman_if))
 348                 hardif_activate_interface(batman_if);
 349         else
 350                 bat_err(batman_if->soft_iface, "Not using interface %s "
 351                         "(retrying later): interface not active\n",
 352                         batman_if->net_dev->name);
 353
 354         /* begin scheduling originator messages on that interface */
 355         schedule_own_packet(batman_if);
 356
 357 out:
 358         return 0;
 359
 360 err:
 361         return -ENOMEM;
 362 }
 363
 364 void hardif_disable_interface(struct batman_if *batman_if)
 365 {
 366         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 367
 368         if (batman_if->if_status == IF_ACTIVE)
 369                 hardif_deactivate_interface(batman_if);
 370
 371         if (batman_if->if_status != IF_INACTIVE)
 372                 return;
 373
 374         bat_info(batman_if->soft_iface, "Removing interface: %s\n",
 375                  batman_if->net_dev->name);
 376         dev_remove_pack(&batman_if->batman_adv_ptype);
 377         hardif_put(batman_if);
 378
 379         bat_priv->num_ifaces--;
 380         orig_hash_del_if(batman_if, bat_priv->num_ifaces);
 381
 382         if (batman_if == bat_priv->primary_if) {
 383                 struct batman_if *new_if;
 384
 385                 new_if = get_active_batman_if(batman_if->soft_iface);
 386                 set_primary_if(bat_priv, new_if);
 387
 388                 if (new_if)
 389                         hardif_put(new_if);
 390         }
 391
 392         kfree(batman_if->packet_buff);
 393         batman_if->packet_buff = NULL;
 394         batman_if->if_status = IF_NOT_IN_USE;
 395
 396         /* delete all references to this batman_if */
 397         purge_orig_ref(bat_priv);
 398         purge_outstanding_packets(bat_priv, batman_if);
 399         dev_put(batman_if->soft_iface);
 400
 401         /* nobody uses this interface anymore */
 402         if (!bat_priv->num_ifaces)
 403                 softif_destroy(batman_if->soft_iface);
 404
 405         batman_if->soft_iface = NULL;
 406 }
 407
 408 static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 409 {
 410         struct batman_if *batman_if;
 411         int ret;
 412
 413         ret = is_valid_iface(net_dev);
 414         if (ret != 1)
 415                 goto out;
 416
 417         dev_hold(net_dev);
 418
 419         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 420         if (!batman_if) {
 421                 pr_err("Can't add interface (%s): out of memory\n",
 422                        net_dev->name);
 423                 goto release_dev;
 424         }
 425
 426         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
 427         if (ret)
 428                 goto free_if;
 429
 430         batman_if->if_num = -1;
 431         batman_if->net_dev = net_dev;
 432         batman_if->soft_iface = NULL;
 433         batman_if->if_status = IF_NOT_IN_USE;
 434         INIT_LIST_HEAD(&batman_if->list);
 435         atomic_set(&batman_if->refcnt, 0);
 436         hardif_hold(batman_if);
 437
 438         check_known_mac_addr(batman_if->net_dev);
 439
 440         spin_lock(&if_list_lock);
 441         list_add_tail_rcu(&batman_if->list, &if_list);
 442         spin_unlock(&if_list_lock);
 443
 444         /* extra reference for return */
 445         hardif_hold(batman_if);
 446         return batman_if;
 447
 448 free_if:
 449         kfree(batman_if);
 450 release_dev:
 451         dev_put(net_dev);
 452 out:
 453         return NULL;
 454 }
 455
 456 static void hardif_remove_interface(struct batman_if *batman_if)
 457 {
 458         /* first deactivate interface */
 459         if (batman_if->if_status != IF_NOT_IN_USE)
 460                 hardif_disable_interface(batman_if);
 461
 462         if (batman_if->if_status != IF_NOT_IN_USE)
 463                 return;
 464
 465         batman_if->if_status = IF_TO_BE_REMOVED;
 466         synchronize_rcu();
 467         sysfs_del_hardif(&batman_if->hardif_obj);
 468         hardif_put(batman_if);
 469 }
 470
 471 void hardif_remove_interfaces(void)
 472 {
 473         struct batman_if *batman_if, *batman_if_tmp;
 474         struct list_head if_queue;
 475
 476         INIT_LIST_HEAD(&if_queue);
 477
 478         spin_lock(&if_list_lock);
 479         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {
 480                 list_del_rcu(&batman_if->list);
 481                 list_add_tail(&batman_if->list, &if_queue);
 482         }
 483         spin_unlock(&if_list_lock);
 484
 485         rtnl_lock();
 486         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_queue, list) {
 487                 hardif_remove_interface(batman_if);
 488         }
 489         rtnl_unlock();
 490 }
 491
 492 static int hard_if_event(struct notifier_block *this,
 493                          unsigned long event, void *ptr)
 494 {
 495         struct net_device *net_dev = (struct net_device *)ptr;
 496         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
 497         struct bat_priv *bat_priv;
 498
 499         if (!batman_if && event == NETDEV_REGISTER)
 500                 batman_if = hardif_add_interface(net_dev);
 501
 502         if (!batman_if)
 503                 goto out;
 504
 505         switch (event) {
 506         case NETDEV_UP:
 507                 hardif_activate_interface(batman_if);
 508                 break;
 509         case NETDEV_GOING_DOWN:
 510         case NETDEV_DOWN:
 511                 hardif_deactivate_interface(batman_if);
 512                 break;
 513         case NETDEV_UNREGISTER:
 514                 spin_lock(&if_list_lock);
 515                 list_del_rcu(&batman_if->list);
 516                 spin_unlock(&if_list_lock);
 517
 518                 hardif_remove_interface(batman_if);
 519                 break;
 520         case NETDEV_CHANGEMTU:
 521                 if (batman_if->soft_iface)
 522                         update_min_mtu(batman_if->soft_iface);
 523                 break;
 524         case NETDEV_CHANGEADDR:
 525                 if (batman_if->if_status == IF_NOT_IN_USE) {
 526                         hardif_put(batman_if);
 527                         goto out;
 528                 }
 529
 530                 check_known_mac_addr(batman_if->net_dev);
 531                 update_mac_addresses(batman_if);
 532
 533                 bat_priv = netdev_priv(batman_if->soft_iface);
 534                 if (batman_if == bat_priv->primary_if)
 535                         update_primary_addr(bat_priv);
 536                 break;
 537         default:
 538                 break;
 539         };
 540         hardif_put(batman_if);
 541
 542 out:
 543         return NOTIFY_DONE;
 544 }
 545
 546 /* receive a packet with the batman ethertype coming on a hard
 547  * interface */
 548 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 549         struct packet_type *ptype, struct net_device *orig_dev)
 550 {
 551         struct bat_priv *bat_priv;
 552         struct batman_packet *batman_packet;
 553         struct batman_if *batman_if;
 554         int ret;
 555
 556         batman_if = container_of(ptype, struct batman_if, batman_adv_ptype);
 557         skb = skb_share_check(skb, GFP_ATOMIC);
 558
 559         /* skb was released by skb_share_check() */
 560         if (!skb)
 561                 goto err_out;
 562
 563         /* packet should hold at least type and version */
 564         if (unlikely(!pskb_may_pull(skb, 2)))
 565                 goto err_free;
 566
 567         /* expect a valid ethernet header here. */
 568         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 569                                 || !skb_mac_header(skb)))
 570                 goto err_free;
 571
 572         if (!batman_if->soft_iface)
 573                 goto err_free;
 574
 575         bat_priv = netdev_priv(batman_if->soft_iface);
 576
 577         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 578                 goto err_free;
 579
 580         /* discard frames on not active interfaces */
 581         if (batman_if->if_status != IF_ACTIVE)
 582                 goto err_free;
 583
 584         batman_packet = (struct batman_packet *)skb->data;
 585
 586         if (batman_packet->version != COMPAT_VERSION) {
 587                 bat_dbg(DBG_BATMAN, bat_priv,
 588                         "Drop packet: incompatible batman version (%i)\n",
 589                         batman_packet->version);
 590                 goto err_free;
 591         }
 592
 593         /* all receive handlers return whether they received or reused
 594          * the supplied skb. if not, we have to free the skb. */
 595
 596         switch (batman_packet->packet_type) {
 597                 /* batman originator packet */
 598         case BAT_PACKET:
 599                 ret = recv_bat_packet(skb, batman_if);
 600                 break;
 601
 602                 /* batman icmp packet */
 603         case BAT_ICMP:
 604                 ret = recv_icmp_packet(skb, batman_if);
 605                 break;
 606
 607                 /* unicast packet */
 608         case BAT_UNICAST:
 609                 ret = recv_unicast_packet(skb, batman_if);
 610                 break;
 611
 612                 /* fragmented unicast packet */
 613         case BAT_UNICAST_FRAG:
 614                 ret = recv_ucast_frag_packet(skb, batman_if);
 615                 break;
 616
 617                 /* broadcast packet */
 618         case BAT_BCAST:
 619                 ret = recv_bcast_packet(skb, batman_if);
 620                 break;
 621
 622                 /* vis packet */
 623         case BAT_VIS:
 624                 ret = recv_vis_packet(skb, batman_if);
 625                 break;
 626         default:
 627                 ret = NET_RX_DROP;
 628         }
 629
 630         if (ret == NET_RX_DROP)
 631                 kfree_skb(skb);
 632
 633         /* return NET_RX_SUCCESS in any case as we
 634          * most probably dropped the packet for
 635          * routing-logical reasons. */
 636
 637         return NET_RX_SUCCESS;
 638
 639 err_free:
 640         kfree_skb(skb);
 641 err_out:
 642         return NET_RX_DROP;
 643 }
 644
 645 struct notifier_block hard_if_notifier = {
 646         .notifier_call = hard_if_event,
 647 };