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(uint8_t *addr)
 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 (!compare_orig(batman_if->net_dev->dev_addr, addr))
 179                         continue;
 180
 181                 pr_warning("The newly added mac address (%pM) already exists "
 182                            "on: %s\n", addr, batman_if->net_dev->name);
 183                 pr_warning("It is strongly recommended to keep mac addresses "
 184                            "unique to avoid problems!\n");
 185         }
 186         rcu_read_unlock();
 187 }
 188
 189 int hardif_min_mtu(struct net_device *soft_iface)
 190 {
 191         struct bat_priv *bat_priv = netdev_priv(soft_iface);
 192         struct batman_if *batman_if;
 193         /* allow big frames if all devices are capable to do so
 194          * (have MTU > 1500 + BAT_HEADER_LEN) */
 195         int min_mtu = ETH_DATA_LEN;
 196
 197         if (atomic_read(&bat_priv->frag_enabled))
 198                 goto out;
 199
 200         rcu_read_lock();
 201         list_for_each_entry_rcu(batman_if, &if_list, list) {
 202                 if ((batman_if->if_status != IF_ACTIVE) &&
 203                     (batman_if->if_status != IF_TO_BE_ACTIVATED))
 204                         continue;
 205
 206                 if (batman_if->soft_iface != soft_iface)
 207                         continue;
 208
 209                 min_mtu = MIN(batman_if->net_dev->mtu - BAT_HEADER_LEN,
 210                               min_mtu);
 211         }
 212         rcu_read_unlock();
 213 out:
 214         return min_mtu;
 215 }
 216
 217 /* adjusts the MTU if a new interface with a smaller MTU appeared. */
 218 void update_min_mtu(struct net_device *soft_iface)
 219 {
 220         int min_mtu;
 221
 222         min_mtu = hardif_min_mtu(soft_iface);
 223         if (soft_iface->mtu != min_mtu)
 224                 soft_iface->mtu = min_mtu;
 225 }
 226
 227 static void hardif_activate_interface(struct batman_if *batman_if)
 228 {
 229         struct bat_priv *bat_priv;
 230
 231         if (batman_if->if_status != IF_INACTIVE)
 232                 return;
 233
 234         bat_priv = netdev_priv(batman_if->soft_iface);
 235
 236         update_mac_addresses(batman_if);
 237         batman_if->if_status = IF_TO_BE_ACTIVATED;
 238
 239         /**
 240          * the first active interface becomes our primary interface or
 241          * the next active interface after the old primay interface was removed
 242          */
 243         if (!bat_priv->primary_if)
 244                 set_primary_if(bat_priv, batman_if);
 245
 246         bat_info(batman_if->soft_iface, "Interface activated: %s\n",
 247                  batman_if->net_dev->name);
 248
 249         update_min_mtu(batman_if->soft_iface);
 250         return;
 251 }
 252
 253 static void hardif_deactivate_interface(struct batman_if *batman_if)
 254 {
 255         if ((batman_if->if_status != IF_ACTIVE) &&
 256            (batman_if->if_status != IF_TO_BE_ACTIVATED))
 257                 return;
 258
 259         batman_if->if_status = IF_INACTIVE;
 260
 261         bat_info(batman_if->soft_iface, "Interface deactivated: %s\n",
 262                  batman_if->net_dev->name);
 263
 264         update_min_mtu(batman_if->soft_iface);
 265 }
 266
 267 int hardif_enable_interface(struct batman_if *batman_if, char *iface_name)
 268 {
 269         struct bat_priv *bat_priv;
 270         struct batman_packet *batman_packet;
 271
 272         if (batman_if->if_status != IF_NOT_IN_USE)
 273                 goto out;
 274
 275         batman_if->soft_iface = dev_get_by_name(&init_net, iface_name);
 276
 277         if (!batman_if->soft_iface) {
 278                 batman_if->soft_iface = softif_create(iface_name);
 279
 280                 if (!batman_if->soft_iface)
 281                         goto err;
 282
 283                 /* dev_get_by_name() increases the reference counter for us */
 284                 dev_hold(batman_if->soft_iface);
 285         }
 286
 287         bat_priv = netdev_priv(batman_if->soft_iface);
 288         batman_if->packet_len = BAT_PACKET_LEN;
 289         batman_if->packet_buff = kmalloc(batman_if->packet_len, GFP_ATOMIC);
 290
 291         if (!batman_if->packet_buff) {
 292                 bat_err(batman_if->soft_iface, "Can't add interface packet "
 293                         "(%s): out of memory\n", batman_if->net_dev->name);
 294                 goto err;
 295         }
 296
 297         batman_packet = (struct batman_packet *)(batman_if->packet_buff);
 298         batman_packet->packet_type = BAT_PACKET;
 299         batman_packet->version = COMPAT_VERSION;
 300         batman_packet->flags = 0;
 301         batman_packet->ttl = 2;
 302         batman_packet->tq = TQ_MAX_VALUE;
 303         batman_packet->num_hna = 0;
 304
 305         batman_if->if_num = bat_priv->num_ifaces;
 306         bat_priv->num_ifaces++;
 307         batman_if->if_status = IF_INACTIVE;
 308         orig_hash_add_if(batman_if, bat_priv->num_ifaces);
 309
 310         batman_if->batman_adv_ptype.type = __constant_htons(ETH_P_BATMAN);
 311         batman_if->batman_adv_ptype.func = batman_skb_recv;
 312         batman_if->batman_adv_ptype.dev = batman_if->net_dev;
 313         hardif_hold(batman_if);
 314         dev_add_pack(&batman_if->batman_adv_ptype);
 315
 316         atomic_set(&batman_if->seqno, 1);
 317         atomic_set(&batman_if->frag_seqno, 1);
 318         bat_info(batman_if->soft_iface, "Adding interface: %s\n",
 319                  batman_if->net_dev->name);
 320
 321         if (atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 322                 ETH_DATA_LEN + BAT_HEADER_LEN)
 323                 bat_info(batman_if->soft_iface,
 324                         "The MTU of interface %s is too small (%i) to handle "
 325                         "the transport of batman-adv packets. Packets going "
 326                         "over this interface will be fragmented on layer2 "
 327                         "which could impact the performance. Setting the MTU "
 328                         "to %zi would solve the problem.\n",
 329                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 330                         ETH_DATA_LEN + BAT_HEADER_LEN);
 331
 332         if (!atomic_read(&bat_priv->frag_enabled) && batman_if->net_dev->mtu <
 333                 ETH_DATA_LEN + BAT_HEADER_LEN)
 334                 bat_info(batman_if->soft_iface,
 335                         "The MTU of interface %s is too small (%i) to handle "
 336                         "the transport of batman-adv packets. If you experience"
 337                         " problems getting traffic through try increasing the "
 338                         "MTU to %zi.\n",
 339                         batman_if->net_dev->name, batman_if->net_dev->mtu,
 340                         ETH_DATA_LEN + BAT_HEADER_LEN);
 341
 342         if (hardif_is_iface_up(batman_if))
 343                 hardif_activate_interface(batman_if);
 344         else
 345                 bat_err(batman_if->soft_iface, "Not using interface %s "
 346                         "(retrying later): interface not active\n",
 347                         batman_if->net_dev->name);
 348
 349         /* begin scheduling originator messages on that interface */
 350         schedule_own_packet(batman_if);
 351
 352 out:
 353         return 0;
 354
 355 err:
 356         return -ENOMEM;
 357 }
 358
 359 void hardif_disable_interface(struct batman_if *batman_if)
 360 {
 361         struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
 362
 363         if (batman_if->if_status == IF_ACTIVE)
 364                 hardif_deactivate_interface(batman_if);
 365
 366         if (batman_if->if_status != IF_INACTIVE)
 367                 return;
 368
 369         bat_info(batman_if->soft_iface, "Removing interface: %s\n",
 370                  batman_if->net_dev->name);
 371         dev_remove_pack(&batman_if->batman_adv_ptype);
 372         hardif_put(batman_if);
 373
 374         bat_priv->num_ifaces--;
 375         orig_hash_del_if(batman_if, bat_priv->num_ifaces);
 376
 377         if (batman_if == bat_priv->primary_if) {
 378                 struct batman_if *new_if;
 379
 380                 new_if = get_active_batman_if(batman_if->soft_iface);
 381                 set_primary_if(bat_priv, new_if);
 382
 383                 if (new_if)
 384                         hardif_put(new_if);
 385         }
 386
 387         kfree(batman_if->packet_buff);
 388         batman_if->packet_buff = NULL;
 389         batman_if->if_status = IF_NOT_IN_USE;
 390
 391         /* delete all references to this batman_if */
 392         purge_orig_ref(bat_priv);
 393         purge_outstanding_packets(bat_priv, batman_if);
 394         dev_put(batman_if->soft_iface);
 395
 396         /* nobody uses this interface anymore */
 397         if (!bat_priv->num_ifaces)
 398                 softif_destroy(batman_if->soft_iface);
 399
 400         batman_if->soft_iface = NULL;
 401 }
 402
 403 static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 404 {
 405         struct batman_if *batman_if;
 406         int ret;
 407
 408         ret = is_valid_iface(net_dev);
 409         if (ret != 1)
 410                 goto out;
 411
 412         dev_hold(net_dev);
 413
 414         batman_if = kmalloc(sizeof(struct batman_if), GFP_ATOMIC);
 415         if (!batman_if) {
 416                 pr_err("Can't add interface (%s): out of memory\n",
 417                        net_dev->name);
 418                 goto release_dev;
 419         }
 420
 421         ret = sysfs_add_hardif(&batman_if->hardif_obj, net_dev);
 422         if (ret)
 423                 goto free_if;
 424
 425         batman_if->if_num = -1;
 426         batman_if->net_dev = net_dev;
 427         batman_if->soft_iface = NULL;
 428         batman_if->if_status = IF_NOT_IN_USE;
 429         INIT_LIST_HEAD(&batman_if->list);
 430         atomic_set(&batman_if->refcnt, 0);
 431         hardif_hold(batman_if);
 432
 433         check_known_mac_addr(batman_if->net_dev->dev_addr);
 434
 435         spin_lock(&if_list_lock);
 436         list_add_tail_rcu(&batman_if->list, &if_list);
 437         spin_unlock(&if_list_lock);
 438
 439         /* extra reference for return */
 440         hardif_hold(batman_if);
 441         return batman_if;
 442
 443 free_if:
 444         kfree(batman_if);
 445 release_dev:
 446         dev_put(net_dev);
 447 out:
 448         return NULL;
 449 }
 450
 451 static void hardif_remove_interface(struct batman_if *batman_if)
 452 {
 453         /* first deactivate interface */
 454         if (batman_if->if_status != IF_NOT_IN_USE)
 455                 hardif_disable_interface(batman_if);
 456
 457         if (batman_if->if_status != IF_NOT_IN_USE)
 458                 return;
 459
 460         batman_if->if_status = IF_TO_BE_REMOVED;
 461
 462         /* caller must take if_list_lock */
 463         list_del_rcu(&batman_if->list);
 464         synchronize_rcu();
 465         sysfs_del_hardif(&batman_if->hardif_obj);
 466         hardif_put(batman_if);
 467 }
 468
 469 void hardif_remove_interfaces(void)
 470 {
 471         struct batman_if *batman_if, *batman_if_tmp;
 472
 473         rtnl_lock();
 474         spin_lock(&if_list_lock);
 475         list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {
 476                 hardif_remove_interface(batman_if);
 477         }
 478         spin_unlock(&if_list_lock);
 479         rtnl_unlock();
 480 }
 481
 482 static int hard_if_event(struct notifier_block *this,
 483                          unsigned long event, void *ptr)
 484 {
 485         struct net_device *net_dev = (struct net_device *)ptr;
 486         struct batman_if *batman_if = get_batman_if_by_netdev(net_dev);
 487         struct bat_priv *bat_priv;
 488
 489         if (!batman_if && event == NETDEV_REGISTER)
 490                 batman_if = hardif_add_interface(net_dev);
 491
 492         if (!batman_if)
 493                 goto out;
 494
 495         switch (event) {
 496         case NETDEV_UP:
 497                 hardif_activate_interface(batman_if);
 498                 break;
 499         case NETDEV_GOING_DOWN:
 500         case NETDEV_DOWN:
 501                 hardif_deactivate_interface(batman_if);
 502                 break;
 503         case NETDEV_UNREGISTER:
 504                 spin_lock(&if_list_lock);
 505                 hardif_remove_interface(batman_if);
 506                 spin_unlock(&if_list_lock);
 507                 break;
 508         case NETDEV_CHANGEMTU:
 509                 if (batman_if->soft_iface)
 510                         update_min_mtu(batman_if->soft_iface);
 511                 break;
 512         case NETDEV_CHANGEADDR:
 513                 if (batman_if->if_status == IF_NOT_IN_USE) {
 514                         hardif_put(batman_if);
 515                         goto out;
 516                 }
 517
 518                 check_known_mac_addr(batman_if->net_dev->dev_addr);
 519                 update_mac_addresses(batman_if);
 520
 521                 bat_priv = netdev_priv(batman_if->soft_iface);
 522                 if (batman_if == bat_priv->primary_if)
 523                         update_primary_addr(bat_priv);
 524                 break;
 525         default:
 526                 break;
 527         };
 528         hardif_put(batman_if);
 529
 530 out:
 531         return NOTIFY_DONE;
 532 }
 533
 534 /* receive a packet with the batman ethertype coming on a hard
 535  * interface */
 536 int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
 537         struct packet_type *ptype, struct net_device *orig_dev)
 538 {
 539         struct bat_priv *bat_priv;
 540         struct batman_packet *batman_packet;
 541         struct batman_if *batman_if;
 542         int ret;
 543
 544         batman_if = container_of(ptype, struct batman_if, batman_adv_ptype);
 545         skb = skb_share_check(skb, GFP_ATOMIC);
 546
 547         /* skb was released by skb_share_check() */
 548         if (!skb)
 549                 goto err_out;
 550
 551         /* packet should hold at least type and version */
 552         if (unlikely(!pskb_may_pull(skb, 2)))
 553                 goto err_free;
 554
 555         /* expect a valid ethernet header here. */
 556         if (unlikely(skb->mac_len != sizeof(struct ethhdr)
 557                                 || !skb_mac_header(skb)))
 558                 goto err_free;
 559
 560         if (!batman_if->soft_iface)
 561                 goto err_free;
 562
 563         bat_priv = netdev_priv(batman_if->soft_iface);
 564
 565         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 566                 goto err_free;
 567
 568         /* discard frames on not active interfaces */
 569         if (batman_if->if_status != IF_ACTIVE)
 570                 goto err_free;
 571
 572         batman_packet = (struct batman_packet *)skb->data;
 573
 574         if (batman_packet->version != COMPAT_VERSION) {
 575                 bat_dbg(DBG_BATMAN, bat_priv,
 576                         "Drop packet: incompatible batman version (%i)\n",
 577                         batman_packet->version);
 578                 goto err_free;
 579         }
 580
 581         /* all receive handlers return whether they received or reused
 582          * the supplied skb. if not, we have to free the skb. */
 583
 584         switch (batman_packet->packet_type) {
 585                 /* batman originator packet */
 586         case BAT_PACKET:
 587                 ret = recv_bat_packet(skb, batman_if);
 588                 break;
 589
 590                 /* batman icmp packet */
 591         case BAT_ICMP:
 592                 ret = recv_icmp_packet(skb, batman_if);
 593                 break;
 594
 595                 /* unicast packet */
 596         case BAT_UNICAST:
 597                 ret = recv_unicast_packet(skb, batman_if);
 598                 break;
 599
 600                 /* fragmented unicast packet */
 601         case BAT_UNICAST_FRAG:
 602                 ret = recv_ucast_frag_packet(skb, batman_if);
 603                 break;
 604
 605                 /* broadcast packet */
 606         case BAT_BCAST:
 607                 ret = recv_bcast_packet(skb, batman_if);
 608                 break;
 609
 610                 /* vis packet */
 611         case BAT_VIS:
 612                 ret = recv_vis_packet(skb, batman_if);
 613                 break;
 614         default:
 615                 ret = NET_RX_DROP;
 616         }
 617
 618         if (ret == NET_RX_DROP)
 619                 kfree_skb(skb);
 620
 621         /* return NET_RX_SUCCESS in any case as we
 622          * most probably dropped the packet for
 623          * routing-logical reasons. */
 624
 625         return NET_RX_SUCCESS;
 626
 627 err_free:
 628         kfree_skb(skb);
 629 err_out:
 630         return NET_RX_DROP;
 631 }
 632
 633 struct notifier_block hard_if_notifier = {
 634         .notifier_call = hard_if_event,
 635 };