drivers/net/macvlan.c

   1 /*
   2  * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * The code this is based on carried the following copyright notice:
  10  * ---
  11  * (C) Copyright 2001-2006
  12  * Alex Zeffertt, Cambridge Broadband Ltd, ajz@cambridgebroadband.com
  13  * Re-worked by Ben Greear <greearb@candelatech.com>
  14  * ---
  15  */
  16 #include <linux/kernel.h>
  17 #include <linux/types.h>
  18 #include <linux/module.h>
  19 #include <linux/init.h>
  20 #include <linux/errno.h>
  21 #include <linux/slab.h>
  22 #include <linux/string.h>
  23 #include <linux/rculist.h>
  24 #include <linux/notifier.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/ethtool.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/if_link.h>
  30 #include <linux/if_macvlan.h>
  31 #include <net/rtnetlink.h>
  32
  33 #define MACVLAN_HASH_SIZE       (1 << BITS_PER_BYTE)
  34
  35 struct macvlan_port {
  36         struct net_device       *dev;
  37         struct hlist_head       vlan_hash[MACVLAN_HASH_SIZE];
  38         struct list_head        vlans;
  39 };
  40
  41 struct macvlan_dev {
  42         struct net_device       *dev;
  43         struct list_head        list;
  44         struct hlist_node       hlist;
  45         struct macvlan_port     *port;
  46         struct net_device       *lowerdev;
  47 };
  48
  49
  50 static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
  51                                                const unsigned char *addr)
  52 {
  53         struct macvlan_dev *vlan;
  54         struct hlist_node *n;
  55
  56         hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[addr[5]], hlist) {
  57                 if (!compare_ether_addr_64bits(vlan->dev->dev_addr, addr))
  58                         return vlan;
  59         }
  60         return NULL;
  61 }
  62
  63 static void macvlan_hash_add(struct macvlan_dev *vlan)
  64 {
  65         struct macvlan_port *port = vlan->port;
  66         const unsigned char *addr = vlan->dev->dev_addr;
  67
  68         hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[addr[5]]);
  69 }
  70
  71 static void macvlan_hash_del(struct macvlan_dev *vlan)
  72 {
  73         hlist_del_rcu(&vlan->hlist);
  74         synchronize_rcu();
  75 }
  76
  77 static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
  78                                         const unsigned char *addr)
  79 {
  80         macvlan_hash_del(vlan);
  81         /* Now that we are unhashed it is safe to change the device
  82          * address without confusing packet delivery.
  83          */
  84         memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
  85         macvlan_hash_add(vlan);
  86 }
  87
  88 static int macvlan_addr_busy(const struct macvlan_port *port,
  89                                 const unsigned char *addr)
  90 {
  91         /* Test to see if the specified multicast address is
  92          * currently in use by the underlying device or
  93          * another macvlan.
  94          */
  95         if (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
  96                 return 1;
  97
  98         if (macvlan_hash_lookup(port, addr))
  99                 return 1;
 100
 101         return 0;
 102 }
 103
 104 static void macvlan_broadcast(struct sk_buff *skb,
 105                               const struct macvlan_port *port)
 106 {
 107         const struct ethhdr *eth = eth_hdr(skb);
 108         const struct macvlan_dev *vlan;
 109         struct hlist_node *n;
 110         struct net_device *dev;
 111         struct sk_buff *nskb;
 112         unsigned int i;
 113
 114         if (skb->protocol == htons(ETH_P_PAUSE))
 115                 return;
 116
 117         for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
 118                 hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
 119                         dev = vlan->dev;
 120
 121                         nskb = skb_clone(skb, GFP_ATOMIC);
 122                         if (nskb == NULL) {
 123                                 dev->stats.rx_errors++;
 124                                 dev->stats.rx_dropped++;
 125                                 continue;
 126                         }
 127
 128                         dev->stats.rx_bytes += skb->len + ETH_HLEN;
 129                         dev->stats.rx_packets++;
 130                         dev->stats.multicast++;
 131
 132                         nskb->dev = dev;
 133                         if (!compare_ether_addr_64bits(eth->h_dest, dev->broadcast))
 134                                 nskb->pkt_type = PACKET_BROADCAST;
 135                         else
 136                                 nskb->pkt_type = PACKET_MULTICAST;
 137
 138                         netif_rx(nskb);
 139                 }
 140         }
 141 }
 142
 143 /* called under rcu_read_lock() from netif_receive_skb */
 144 static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
 145 {
 146         const struct ethhdr *eth = eth_hdr(skb);
 147         const struct macvlan_port *port;
 148         const struct macvlan_dev *vlan;
 149         struct net_device *dev;
 150
 151         port = rcu_dereference(skb->dev->macvlan_port);
 152         if (port == NULL)
 153                 return skb;
 154
 155         if (is_multicast_ether_addr(eth->h_dest)) {
 156                 macvlan_broadcast(skb, port);
 157                 return skb;
 158         }
 159
 160         vlan = macvlan_hash_lookup(port, eth->h_dest);
 161         if (vlan == NULL)
 162                 return skb;
 163
 164         dev = vlan->dev;
 165         if (unlikely(!(dev->flags & IFF_UP))) {
 166                 kfree_skb(skb);
 167                 return NULL;
 168         }
 169
 170         skb = skb_share_check(skb, GFP_ATOMIC);
 171         if (skb == NULL) {
 172                 dev->stats.rx_errors++;
 173                 dev->stats.rx_dropped++;
 174                 return NULL;
 175         }
 176
 177         dev->stats.rx_bytes += skb->len + ETH_HLEN;
 178         dev->stats.rx_packets++;
 179
 180         skb->dev = dev;
 181         skb->pkt_type = PACKET_HOST;
 182
 183         netif_rx(skb);
 184         return NULL;
 185 }
 186
 187 static netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
 188                                       struct net_device *dev)
 189 {
 190         int i = skb_get_queue_mapping(skb);
 191         struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 192         const struct macvlan_dev *vlan = netdev_priv(dev);
 193         unsigned int len = skb->len;
 194         int ret;
 195
 196         skb->dev = vlan->lowerdev;
 197         ret = dev_queue_xmit(skb);
 198
 199         if (likely(ret == NET_XMIT_SUCCESS)) {
 200                 txq->tx_packets++;
 201                 txq->tx_bytes += len;
 202         } else
 203                 txq->tx_dropped++;
 204
 205         return NETDEV_TX_OK;
 206 }
 207
 208 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
 209                                unsigned short type, const void *daddr,
 210                                const void *saddr, unsigned len)
 211 {
 212         const struct macvlan_dev *vlan = netdev_priv(dev);
 213         struct net_device *lowerdev = vlan->lowerdev;
 214
 215         return dev_hard_header(skb, lowerdev, type, daddr,
 216                                saddr ? : dev->dev_addr, len);
 217 }
 218
 219 static const struct header_ops macvlan_hard_header_ops = {
 220         .create         = macvlan_hard_header,
 221         .rebuild        = eth_rebuild_header,
 222         .parse          = eth_header_parse,
 223         .cache          = eth_header_cache,
 224         .cache_update   = eth_header_cache_update,
 225 };
 226
 227 static int macvlan_open(struct net_device *dev)
 228 {
 229         struct macvlan_dev *vlan = netdev_priv(dev);
 230         struct net_device *lowerdev = vlan->lowerdev;
 231         int err;
 232
 233         err = -EBUSY;
 234         if (macvlan_addr_busy(vlan->port, dev->dev_addr))
 235                 goto out;
 236
 237         err = dev_unicast_add(lowerdev, dev->dev_addr);
 238         if (err < 0)
 239                 goto out;
 240         if (dev->flags & IFF_ALLMULTI) {
 241                 err = dev_set_allmulti(lowerdev, 1);
 242                 if (err < 0)
 243                         goto del_unicast;
 244         }
 245         macvlan_hash_add(vlan);
 246         return 0;
 247
 248 del_unicast:
 249         dev_unicast_delete(lowerdev, dev->dev_addr);
 250 out:
 251         return err;
 252 }
 253
 254 static int macvlan_stop(struct net_device *dev)
 255 {
 256         struct macvlan_dev *vlan = netdev_priv(dev);
 257         struct net_device *lowerdev = vlan->lowerdev;
 258
 259         dev_mc_unsync(lowerdev, dev);
 260         if (dev->flags & IFF_ALLMULTI)
 261                 dev_set_allmulti(lowerdev, -1);
 262
 263         dev_unicast_delete(lowerdev, dev->dev_addr);
 264
 265         macvlan_hash_del(vlan);
 266         return 0;
 267 }
 268
 269 static int macvlan_set_mac_address(struct net_device *dev, void *p)
 270 {
 271         struct macvlan_dev *vlan = netdev_priv(dev);
 272         struct net_device *lowerdev = vlan->lowerdev;
 273         struct sockaddr *addr = p;
 274         int err;
 275
 276         if (!is_valid_ether_addr(addr->sa_data))
 277                 return -EADDRNOTAVAIL;
 278
 279         if (!(dev->flags & IFF_UP)) {
 280                 /* Just copy in the new address */
 281                 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 282         } else {
 283                 /* Rehash and update the device filters */
 284                 if (macvlan_addr_busy(vlan->port, addr->sa_data))
 285                         return -EBUSY;
 286
 287                 err = dev_unicast_add(lowerdev, addr->sa_data);
 288                 if (err)
 289                         return err;
 290
 291                 dev_unicast_delete(lowerdev, dev->dev_addr);
 292
 293                 macvlan_hash_change_addr(vlan, addr->sa_data);
 294         }
 295         return 0;
 296 }
 297
 298 static void macvlan_change_rx_flags(struct net_device *dev, int change)
 299 {
 300         struct macvlan_dev *vlan = netdev_priv(dev);
 301         struct net_device *lowerdev = vlan->lowerdev;
 302
 303         if (change & IFF_ALLMULTI)
 304                 dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
 305 }
 306
 307 static void macvlan_set_multicast_list(struct net_device *dev)
 308 {
 309         struct macvlan_dev *vlan = netdev_priv(dev);
 310
 311         dev_mc_sync(vlan->lowerdev, dev);
 312 }
 313
 314 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
 315 {
 316         struct macvlan_dev *vlan = netdev_priv(dev);
 317
 318         if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
 319                 return -EINVAL;
 320         dev->mtu = new_mtu;
 321         return 0;
 322 }
 323
 324 /*
 325  * macvlan network devices have devices nesting below it and are a special
 326  * "super class" of normal network devices; split their locks off into a
 327  * separate class since they always nest.
 328  */
 329 static struct lock_class_key macvlan_netdev_xmit_lock_key;
 330 static struct lock_class_key macvlan_netdev_addr_lock_key;
 331
 332 #define MACVLAN_FEATURES \
 333         (NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
 334          NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
 335          NETIF_F_TSO_ECN | NETIF_F_TSO6)
 336
 337 #define MACVLAN_STATE_MASK \
 338         ((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
 339
 340 static void macvlan_set_lockdep_class_one(struct net_device *dev,
 341                                           struct netdev_queue *txq,
 342                                           void *_unused)
 343 {
 344         lockdep_set_class(&txq->_xmit_lock,
 345                           &macvlan_netdev_xmit_lock_key);
 346 }
 347
 348 static void macvlan_set_lockdep_class(struct net_device *dev)
 349 {
 350         lockdep_set_class(&dev->addr_list_lock,
 351                           &macvlan_netdev_addr_lock_key);
 352         netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
 353 }
 354
 355 static int macvlan_init(struct net_device *dev)
 356 {
 357         struct macvlan_dev *vlan = netdev_priv(dev);
 358         const struct net_device *lowerdev = vlan->lowerdev;
 359
 360         dev->state              = (dev->state & ~MACVLAN_STATE_MASK) |
 361                                   (lowerdev->state & MACVLAN_STATE_MASK);
 362         dev->features           = lowerdev->features & MACVLAN_FEATURES;
 363         dev->iflink             = lowerdev->ifindex;
 364         dev->hard_header_len    = lowerdev->hard_header_len;
 365
 366         macvlan_set_lockdep_class(dev);
 367
 368         return 0;
 369 }
 370
 371 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
 372                                         struct ethtool_drvinfo *drvinfo)
 373 {
 374         snprintf(drvinfo->driver, 32, "macvlan");
 375         snprintf(drvinfo->version, 32, "0.1");
 376 }
 377
 378 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
 379 {
 380         const struct macvlan_dev *vlan = netdev_priv(dev);
 381         return dev_ethtool_get_rx_csum(vlan->lowerdev);
 382 }
 383
 384 static int macvlan_ethtool_get_settings(struct net_device *dev,
 385                                         struct ethtool_cmd *cmd)
 386 {
 387         const struct macvlan_dev *vlan = netdev_priv(dev);
 388         return dev_ethtool_get_settings(vlan->lowerdev, cmd);
 389 }
 390
 391 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
 392 {
 393         const struct macvlan_dev *vlan = netdev_priv(dev);
 394         return dev_ethtool_get_flags(vlan->lowerdev);
 395 }
 396
 397 static const struct ethtool_ops macvlan_ethtool_ops = {
 398         .get_link               = ethtool_op_get_link,
 399         .get_settings           = macvlan_ethtool_get_settings,
 400         .get_rx_csum            = macvlan_ethtool_get_rx_csum,
 401         .get_drvinfo            = macvlan_ethtool_get_drvinfo,
 402         .get_flags              = macvlan_ethtool_get_flags,
 403 };
 404
 405 static const struct net_device_ops macvlan_netdev_ops = {
 406         .ndo_init               = macvlan_init,
 407         .ndo_open               = macvlan_open,
 408         .ndo_stop               = macvlan_stop,
 409         .ndo_start_xmit         = macvlan_start_xmit,
 410         .ndo_change_mtu         = macvlan_change_mtu,
 411         .ndo_change_rx_flags    = macvlan_change_rx_flags,
 412         .ndo_set_mac_address    = macvlan_set_mac_address,
 413         .ndo_set_multicast_list = macvlan_set_multicast_list,
 414         .ndo_validate_addr      = eth_validate_addr,
 415 };
 416
 417 static void macvlan_setup(struct net_device *dev)
 418 {
 419         ether_setup(dev);
 420
 421         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
 422         dev->netdev_ops         = &macvlan_netdev_ops;
 423         dev->destructor         = free_netdev;
 424         dev->header_ops         = &macvlan_hard_header_ops,
 425         dev->ethtool_ops        = &macvlan_ethtool_ops;
 426         dev->tx_queue_len       = 0;
 427 }
 428
 429 static int macvlan_port_create(struct net_device *dev)
 430 {
 431         struct macvlan_port *port;
 432         unsigned int i;
 433
 434         if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
 435                 return -EINVAL;
 436
 437         port = kzalloc(sizeof(*port), GFP_KERNEL);
 438         if (port == NULL)
 439                 return -ENOMEM;
 440
 441         port->dev = dev;
 442         INIT_LIST_HEAD(&port->vlans);
 443         for (i = 0; i < MACVLAN_HASH_SIZE; i++)
 444                 INIT_HLIST_HEAD(&port->vlan_hash[i]);
 445         rcu_assign_pointer(dev->macvlan_port, port);
 446         return 0;
 447 }
 448
 449 static void macvlan_port_destroy(struct net_device *dev)
 450 {
 451         struct macvlan_port *port = dev->macvlan_port;
 452
 453         rcu_assign_pointer(dev->macvlan_port, NULL);
 454         synchronize_rcu();
 455         kfree(port);
 456 }
 457
 458 static void macvlan_transfer_operstate(struct net_device *dev)
 459 {
 460         struct macvlan_dev *vlan = netdev_priv(dev);
 461         const struct net_device *lowerdev = vlan->lowerdev;
 462
 463         if (lowerdev->operstate == IF_OPER_DORMANT)
 464                 netif_dormant_on(dev);
 465         else
 466                 netif_dormant_off(dev);
 467
 468         if (netif_carrier_ok(lowerdev)) {
 469                 if (!netif_carrier_ok(dev))
 470                         netif_carrier_on(dev);
 471         } else {
 472                 if (netif_carrier_ok(dev))
 473                         netif_carrier_off(dev);
 474         }
 475 }
 476
 477 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
 478 {
 479         if (tb[IFLA_ADDRESS]) {
 480                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 481                         return -EINVAL;
 482                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 483                         return -EADDRNOTAVAIL;
 484         }
 485         return 0;
 486 }
 487
 488 static int macvlan_get_tx_queues(struct net *net,
 489                                  struct nlattr *tb[],
 490                                  unsigned int *num_tx_queues,
 491                                  unsigned int *real_num_tx_queues)
 492 {
 493         struct net_device *real_dev;
 494
 495         if (!tb[IFLA_LINK])
 496                 return -EINVAL;
 497
 498         real_dev = __dev_get_by_index(net, nla_get_u32(tb[IFLA_LINK]));
 499         if (!real_dev)
 500                 return -ENODEV;
 501
 502         *num_tx_queues      = real_dev->num_tx_queues;
 503         *real_num_tx_queues = real_dev->real_num_tx_queues;
 504         return 0;
 505 }
 506
 507 static int macvlan_newlink(struct net_device *dev,
 508                            struct nlattr *tb[], struct nlattr *data[])
 509 {
 510         struct macvlan_dev *vlan = netdev_priv(dev);
 511         struct macvlan_port *port;
 512         struct net_device *lowerdev;
 513         int err;
 514
 515         if (!tb[IFLA_LINK])
 516                 return -EINVAL;
 517
 518         lowerdev = __dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
 519         if (lowerdev == NULL)
 520                 return -ENODEV;
 521
 522         /* When creating macvlans on top of other macvlans - use
 523          * the real device as the lowerdev.
 524          */
 525         if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
 526                 struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
 527                 lowerdev = lowervlan->lowerdev;
 528         }
 529
 530         if (!tb[IFLA_MTU])
 531                 dev->mtu = lowerdev->mtu;
 532         else if (dev->mtu > lowerdev->mtu)
 533                 return -EINVAL;
 534
 535         if (!tb[IFLA_ADDRESS])
 536                 random_ether_addr(dev->dev_addr);
 537
 538         if (lowerdev->macvlan_port == NULL) {
 539                 err = macvlan_port_create(lowerdev);
 540                 if (err < 0)
 541                         return err;
 542         }
 543         port = lowerdev->macvlan_port;
 544
 545         vlan->lowerdev = lowerdev;
 546         vlan->dev      = dev;
 547         vlan->port     = port;
 548
 549         err = register_netdevice(dev);
 550         if (err < 0)
 551                 return err;
 552
 553         list_add_tail(&vlan->list, &port->vlans);
 554         macvlan_transfer_operstate(dev);
 555         return 0;
 556 }
 557
 558 static void macvlan_dellink(struct net_device *dev)
 559 {
 560         struct macvlan_dev *vlan = netdev_priv(dev);
 561         struct macvlan_port *port = vlan->port;
 562
 563         list_del(&vlan->list);
 564         unregister_netdevice(dev);
 565
 566         if (list_empty(&port->vlans))
 567                 macvlan_port_destroy(port->dev);
 568 }
 569
 570 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
 571         .kind           = "macvlan",
 572         .priv_size      = sizeof(struct macvlan_dev),
 573         .get_tx_queues  = macvlan_get_tx_queues,
 574         .setup          = macvlan_setup,
 575         .validate       = macvlan_validate,
 576         .newlink        = macvlan_newlink,
 577         .dellink        = macvlan_dellink,
 578 };
 579
 580 static int macvlan_device_event(struct notifier_block *unused,
 581                                 unsigned long event, void *ptr)
 582 {
 583         struct net_device *dev = ptr;
 584         struct macvlan_dev *vlan, *next;
 585         struct macvlan_port *port;
 586
 587         port = dev->macvlan_port;
 588         if (port == NULL)
 589                 return NOTIFY_DONE;
 590
 591         switch (event) {
 592         case NETDEV_CHANGE:
 593                 list_for_each_entry(vlan, &port->vlans, list)
 594                         macvlan_transfer_operstate(vlan->dev);
 595                 break;
 596         case NETDEV_FEAT_CHANGE:
 597                 list_for_each_entry(vlan, &port->vlans, list) {
 598                         vlan->dev->features = dev->features & MACVLAN_FEATURES;
 599                         netdev_features_change(vlan->dev);
 600                 }
 601                 break;
 602         case NETDEV_UNREGISTER:
 603                 list_for_each_entry_safe(vlan, next, &port->vlans, list)
 604                         macvlan_dellink(vlan->dev);
 605                 break;
 606         }
 607         return NOTIFY_DONE;
 608 }
 609
 610 static struct notifier_block macvlan_notifier_block __read_mostly = {
 611         .notifier_call  = macvlan_device_event,
 612 };
 613
 614 static int __init macvlan_init_module(void)
 615 {
 616         int err;
 617
 618         register_netdevice_notifier(&macvlan_notifier_block);
 619         macvlan_handle_frame_hook = macvlan_handle_frame;
 620
 621         err = rtnl_link_register(&macvlan_link_ops);
 622         if (err < 0)
 623                 goto err1;
 624         return 0;
 625 err1:
 626         macvlan_handle_frame_hook = NULL;
 627         unregister_netdevice_notifier(&macvlan_notifier_block);
 628         return err;
 629 }
 630
 631 static void __exit macvlan_cleanup_module(void)
 632 {
 633         rtnl_link_unregister(&macvlan_link_ops);
 634         macvlan_handle_frame_hook = NULL;
 635         unregister_netdevice_notifier(&macvlan_notifier_block);
 636 }
 637
 638 module_init(macvlan_init_module);
 639 module_exit(macvlan_cleanup_module);
 640
 641 MODULE_LICENSE("GPL");
 642 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 643 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
 644 MODULE_ALIAS_RTNL_LINK("macvlan");