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(vlan->dev->dev_addr, addr))
  58                         return vlan;
  59         }
  60         return NULL;
  61 }
  62
  63 static void macvlan_broadcast(struct sk_buff *skb,
  64                               const struct macvlan_port *port)
  65 {
  66         const struct ethhdr *eth = eth_hdr(skb);
  67         const struct macvlan_dev *vlan;
  68         struct hlist_node *n;
  69         struct net_device *dev;
  70         struct sk_buff *nskb;
  71         unsigned int i;
  72
  73         for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
  74                 hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
  75                         dev = vlan->dev;
  76
  77                         nskb = skb_clone(skb, GFP_ATOMIC);
  78                         if (nskb == NULL) {
  79                                 dev->stats.rx_errors++;
  80                                 dev->stats.rx_dropped++;
  81                                 continue;
  82                         }
  83
  84                         dev->stats.rx_bytes += skb->len + ETH_HLEN;
  85                         dev->stats.rx_packets++;
  86                         dev->stats.multicast++;
  87
  88                         nskb->dev = dev;
  89                         if (!compare_ether_addr(eth->h_dest, dev->broadcast))
  90                                 nskb->pkt_type = PACKET_BROADCAST;
  91                         else
  92                                 nskb->pkt_type = PACKET_MULTICAST;
  93
  94                         netif_rx(nskb);
  95                 }
  96         }
  97 }
  98
  99 /* called under rcu_read_lock() from netif_receive_skb */
 100 static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
 101 {
 102         const struct ethhdr *eth = eth_hdr(skb);
 103         const struct macvlan_port *port;
 104         const struct macvlan_dev *vlan;
 105         struct net_device *dev;
 106
 107         port = rcu_dereference(skb->dev->macvlan_port);
 108         if (port == NULL)
 109                 return skb;
 110
 111         if (is_multicast_ether_addr(eth->h_dest)) {
 112                 macvlan_broadcast(skb, port);
 113                 return skb;
 114         }
 115
 116         vlan = macvlan_hash_lookup(port, eth->h_dest);
 117         if (vlan == NULL)
 118                 return skb;
 119
 120         dev = vlan->dev;
 121         if (unlikely(!(dev->flags & IFF_UP))) {
 122                 kfree_skb(skb);
 123                 return NULL;
 124         }
 125
 126         skb = skb_share_check(skb, GFP_ATOMIC);
 127         if (skb == NULL) {
 128                 dev->stats.rx_errors++;
 129                 dev->stats.rx_dropped++;
 130                 return NULL;
 131         }
 132
 133         dev->stats.rx_bytes += skb->len + ETH_HLEN;
 134         dev->stats.rx_packets++;
 135
 136         skb->dev = dev;
 137         skb->pkt_type = PACKET_HOST;
 138
 139         netif_rx(skb);
 140         return NULL;
 141 }
 142
 143 static int macvlan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 144 {
 145         const struct macvlan_dev *vlan = netdev_priv(dev);
 146         unsigned int len = skb->len;
 147         int ret;
 148
 149         skb->dev = vlan->lowerdev;
 150         ret = dev_queue_xmit(skb);
 151
 152         if (likely(ret == NET_XMIT_SUCCESS)) {
 153                 dev->stats.tx_packets++;
 154                 dev->stats.tx_bytes += len;
 155         } else {
 156                 dev->stats.tx_errors++;
 157                 dev->stats.tx_aborted_errors++;
 158         }
 159         return NETDEV_TX_OK;
 160 }
 161
 162 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
 163                                unsigned short type, const void *daddr,
 164                                const void *saddr, unsigned len)
 165 {
 166         const struct macvlan_dev *vlan = netdev_priv(dev);
 167         struct net_device *lowerdev = vlan->lowerdev;
 168
 169         return dev_hard_header(skb, lowerdev, type, daddr,
 170                                saddr ? : dev->dev_addr, len);
 171 }
 172
 173 static const struct header_ops macvlan_hard_header_ops = {
 174         .create         = macvlan_hard_header,
 175         .rebuild        = eth_rebuild_header,
 176         .parse          = eth_header_parse,
 177         .cache          = eth_header_cache,
 178         .cache_update   = eth_header_cache_update,
 179 };
 180
 181 static int macvlan_open(struct net_device *dev)
 182 {
 183         struct macvlan_dev *vlan = netdev_priv(dev);
 184         struct macvlan_port *port = vlan->port;
 185         struct net_device *lowerdev = vlan->lowerdev;
 186         int err;
 187
 188         err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
 189         if (err < 0)
 190                 goto out;
 191         if (dev->flags & IFF_ALLMULTI) {
 192                 err = dev_set_allmulti(lowerdev, 1);
 193                 if (err < 0)
 194                         goto del_unicast;
 195         }
 196
 197         hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
 198         return 0;
 199
 200 del_unicast:
 201         dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
 202 out:
 203         return err;
 204 }
 205
 206 static int macvlan_stop(struct net_device *dev)
 207 {
 208         struct macvlan_dev *vlan = netdev_priv(dev);
 209         struct net_device *lowerdev = vlan->lowerdev;
 210
 211         dev_mc_unsync(lowerdev, dev);
 212         if (dev->flags & IFF_ALLMULTI)
 213                 dev_set_allmulti(lowerdev, -1);
 214
 215         dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
 216
 217         hlist_del_rcu(&vlan->hlist);
 218         synchronize_rcu();
 219         return 0;
 220 }
 221
 222 static int macvlan_set_mac_address(struct net_device *dev, void *p)
 223 {
 224         struct macvlan_dev *vlan = netdev_priv(dev);
 225         struct net_device *lowerdev = vlan->lowerdev;
 226         struct sockaddr *addr = p;
 227         int err;
 228
 229         if (!is_valid_ether_addr(addr->sa_data))
 230                 return -EADDRNOTAVAIL;
 231
 232         if (!(dev->flags & IFF_UP))
 233                 goto out;
 234
 235         err = dev_unicast_add(lowerdev, addr->sa_data, ETH_ALEN);
 236         if (err < 0)
 237                 return err;
 238         dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
 239
 240 out:
 241         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 242         return 0;
 243 }
 244
 245 static void macvlan_change_rx_flags(struct net_device *dev, int change)
 246 {
 247         struct macvlan_dev *vlan = netdev_priv(dev);
 248         struct net_device *lowerdev = vlan->lowerdev;
 249
 250         if (change & IFF_ALLMULTI)
 251                 dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
 252 }
 253
 254 static void macvlan_set_multicast_list(struct net_device *dev)
 255 {
 256         struct macvlan_dev *vlan = netdev_priv(dev);
 257
 258         dev_mc_sync(vlan->lowerdev, dev);
 259 }
 260
 261 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
 262 {
 263         struct macvlan_dev *vlan = netdev_priv(dev);
 264
 265         if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
 266                 return -EINVAL;
 267         dev->mtu = new_mtu;
 268         return 0;
 269 }
 270
 271 /*
 272  * macvlan network devices have devices nesting below it and are a special
 273  * "super class" of normal network devices; split their locks off into a
 274  * separate class since they always nest.
 275  */
 276 static struct lock_class_key macvlan_netdev_xmit_lock_key;
 277 static struct lock_class_key macvlan_netdev_addr_lock_key;
 278
 279 #define MACVLAN_FEATURES \
 280         (NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
 281          NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
 282          NETIF_F_TSO_ECN | NETIF_F_TSO6)
 283
 284 #define MACVLAN_STATE_MASK \
 285         ((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
 286
 287 static void macvlan_set_lockdep_class_one(struct net_device *dev,
 288                                           struct netdev_queue *txq,
 289                                           void *_unused)
 290 {
 291         lockdep_set_class(&txq->_xmit_lock,
 292                           &macvlan_netdev_xmit_lock_key);
 293 }
 294
 295 static void macvlan_set_lockdep_class(struct net_device *dev)
 296 {
 297         lockdep_set_class(&dev->addr_list_lock,
 298                           &macvlan_netdev_addr_lock_key);
 299         netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
 300 }
 301
 302 static int macvlan_init(struct net_device *dev)
 303 {
 304         struct macvlan_dev *vlan = netdev_priv(dev);
 305         const struct net_device *lowerdev = vlan->lowerdev;
 306
 307         dev->state              = (dev->state & ~MACVLAN_STATE_MASK) |
 308                                   (lowerdev->state & MACVLAN_STATE_MASK);
 309         dev->features           = lowerdev->features & MACVLAN_FEATURES;
 310         dev->iflink             = lowerdev->ifindex;
 311
 312         macvlan_set_lockdep_class(dev);
 313
 314         return 0;
 315 }
 316
 317 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
 318                                         struct ethtool_drvinfo *drvinfo)
 319 {
 320         snprintf(drvinfo->driver, 32, "macvlan");
 321         snprintf(drvinfo->version, 32, "0.1");
 322 }
 323
 324 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
 325 {
 326         const struct macvlan_dev *vlan = netdev_priv(dev);
 327         struct net_device *lowerdev = vlan->lowerdev;
 328
 329         if (lowerdev->ethtool_ops->get_rx_csum == NULL)
 330                 return 0;
 331         return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
 332 }
 333
 334 static int macvlan_ethtool_get_settings(struct net_device *dev,
 335                                         struct ethtool_cmd *cmd)
 336 {
 337         const struct macvlan_dev *vlan = netdev_priv(dev);
 338         struct net_device *lowerdev = vlan->lowerdev;
 339
 340         if (!lowerdev->ethtool_ops->get_settings)
 341                 return -EOPNOTSUPP;
 342
 343         return lowerdev->ethtool_ops->get_settings(lowerdev, cmd);
 344 }
 345
 346 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
 347 {
 348         const struct macvlan_dev *vlan = netdev_priv(dev);
 349         struct net_device *lowerdev = vlan->lowerdev;
 350
 351         if (!lowerdev->ethtool_ops->get_flags)
 352                 return 0;
 353         return lowerdev->ethtool_ops->get_flags(lowerdev);
 354 }
 355
 356 static const struct ethtool_ops macvlan_ethtool_ops = {
 357         .get_link               = ethtool_op_get_link,
 358         .get_settings           = macvlan_ethtool_get_settings,
 359         .get_rx_csum            = macvlan_ethtool_get_rx_csum,
 360         .get_drvinfo            = macvlan_ethtool_get_drvinfo,
 361         .get_flags              = macvlan_ethtool_get_flags,
 362 };
 363
 364 static const struct net_device_ops macvlan_netdev_ops = {
 365         .ndo_init               = macvlan_init,
 366         .ndo_open               = macvlan_open,
 367         .ndo_stop               = macvlan_stop,
 368         .ndo_start_xmit         = macvlan_start_xmit,
 369         .ndo_change_mtu         = macvlan_change_mtu,
 370         .ndo_change_rx_flags    = macvlan_change_rx_flags,
 371         .ndo_set_mac_address    = macvlan_set_mac_address,
 372         .ndo_set_multicast_list = macvlan_set_multicast_list,
 373         .ndo_validate_addr      = eth_validate_addr,
 374 };
 375
 376 static void macvlan_setup(struct net_device *dev)
 377 {
 378         ether_setup(dev);
 379
 380         dev->netdev_ops         = &macvlan_netdev_ops;
 381         dev->destructor         = free_netdev;
 382         dev->header_ops         = &macvlan_hard_header_ops,
 383         dev->ethtool_ops        = &macvlan_ethtool_ops;
 384         dev->tx_queue_len       = 0;
 385 }
 386
 387 static int macvlan_port_create(struct net_device *dev)
 388 {
 389         struct macvlan_port *port;
 390         unsigned int i;
 391
 392         if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
 393                 return -EINVAL;
 394
 395         port = kzalloc(sizeof(*port), GFP_KERNEL);
 396         if (port == NULL)
 397                 return -ENOMEM;
 398
 399         port->dev = dev;
 400         INIT_LIST_HEAD(&port->vlans);
 401         for (i = 0; i < MACVLAN_HASH_SIZE; i++)
 402                 INIT_HLIST_HEAD(&port->vlan_hash[i]);
 403         rcu_assign_pointer(dev->macvlan_port, port);
 404         return 0;
 405 }
 406
 407 static void macvlan_port_destroy(struct net_device *dev)
 408 {
 409         struct macvlan_port *port = dev->macvlan_port;
 410
 411         rcu_assign_pointer(dev->macvlan_port, NULL);
 412         synchronize_rcu();
 413         kfree(port);
 414 }
 415
 416 static void macvlan_transfer_operstate(struct net_device *dev)
 417 {
 418         struct macvlan_dev *vlan = netdev_priv(dev);
 419         const struct net_device *lowerdev = vlan->lowerdev;
 420
 421         if (lowerdev->operstate == IF_OPER_DORMANT)
 422                 netif_dormant_on(dev);
 423         else
 424                 netif_dormant_off(dev);
 425
 426         if (netif_carrier_ok(lowerdev)) {
 427                 if (!netif_carrier_ok(dev))
 428                         netif_carrier_on(dev);
 429         } else {
 430                 if (netif_carrier_ok(dev))
 431                         netif_carrier_off(dev);
 432         }
 433 }
 434
 435 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
 436 {
 437         if (tb[IFLA_ADDRESS]) {
 438                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 439                         return -EINVAL;
 440                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 441                         return -EADDRNOTAVAIL;
 442         }
 443         return 0;
 444 }
 445
 446 static int macvlan_newlink(struct net_device *dev,
 447                            struct nlattr *tb[], struct nlattr *data[])
 448 {
 449         struct macvlan_dev *vlan = netdev_priv(dev);
 450         struct macvlan_port *port;
 451         struct net_device *lowerdev;
 452         int err;
 453
 454         if (!tb[IFLA_LINK])
 455                 return -EINVAL;
 456
 457         lowerdev = __dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
 458         if (lowerdev == NULL)
 459                 return -ENODEV;
 460
 461         /* Don't allow macvlans on top of other macvlans - its not really
 462          * wrong, but lockdep can't handle it and its not useful for anything
 463          * you couldn't do directly on top of the real device.
 464          */
 465         if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops)
 466                 return -ENODEV;
 467
 468         if (!tb[IFLA_MTU])
 469                 dev->mtu = lowerdev->mtu;
 470         else if (dev->mtu > lowerdev->mtu)
 471                 return -EINVAL;
 472
 473         if (!tb[IFLA_ADDRESS])
 474                 random_ether_addr(dev->dev_addr);
 475
 476         if (lowerdev->macvlan_port == NULL) {
 477                 err = macvlan_port_create(lowerdev);
 478                 if (err < 0)
 479                         return err;
 480         }
 481         port = lowerdev->macvlan_port;
 482
 483         vlan->lowerdev = lowerdev;
 484         vlan->dev      = dev;
 485         vlan->port     = port;
 486
 487         err = register_netdevice(dev);
 488         if (err < 0)
 489                 return err;
 490
 491         list_add_tail(&vlan->list, &port->vlans);
 492         macvlan_transfer_operstate(dev);
 493         return 0;
 494 }
 495
 496 static void macvlan_dellink(struct net_device *dev)
 497 {
 498         struct macvlan_dev *vlan = netdev_priv(dev);
 499         struct macvlan_port *port = vlan->port;
 500
 501         list_del(&vlan->list);
 502         unregister_netdevice(dev);
 503
 504         if (list_empty(&port->vlans))
 505                 macvlan_port_destroy(port->dev);
 506 }
 507
 508 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
 509         .kind           = "macvlan",
 510         .priv_size      = sizeof(struct macvlan_dev),
 511         .setup          = macvlan_setup,
 512         .validate       = macvlan_validate,
 513         .newlink        = macvlan_newlink,
 514         .dellink        = macvlan_dellink,
 515 };
 516
 517 static int macvlan_device_event(struct notifier_block *unused,
 518                                 unsigned long event, void *ptr)
 519 {
 520         struct net_device *dev = ptr;
 521         struct macvlan_dev *vlan, *next;
 522         struct macvlan_port *port;
 523
 524         port = dev->macvlan_port;
 525         if (port == NULL)
 526                 return NOTIFY_DONE;
 527
 528         switch (event) {
 529         case NETDEV_CHANGE:
 530                 list_for_each_entry(vlan, &port->vlans, list)
 531                         macvlan_transfer_operstate(vlan->dev);
 532                 break;
 533         case NETDEV_FEAT_CHANGE:
 534                 list_for_each_entry(vlan, &port->vlans, list) {
 535                         vlan->dev->features = dev->features & MACVLAN_FEATURES;
 536                         netdev_features_change(vlan->dev);
 537                 }
 538                 break;
 539         case NETDEV_UNREGISTER:
 540                 list_for_each_entry_safe(vlan, next, &port->vlans, list)
 541                         macvlan_dellink(vlan->dev);
 542                 break;
 543         }
 544         return NOTIFY_DONE;
 545 }
 546
 547 static struct notifier_block macvlan_notifier_block __read_mostly = {
 548         .notifier_call  = macvlan_device_event,
 549 };
 550
 551 static int __init macvlan_init_module(void)
 552 {
 553         int err;
 554
 555         register_netdevice_notifier(&macvlan_notifier_block);
 556         macvlan_handle_frame_hook = macvlan_handle_frame;
 557
 558         err = rtnl_link_register(&macvlan_link_ops);
 559         if (err < 0)
 560                 goto err1;
 561         return 0;
 562 err1:
 563         macvlan_handle_frame_hook = NULL;
 564         unregister_netdevice_notifier(&macvlan_notifier_block);
 565         return err;
 566 }
 567
 568 static void __exit macvlan_cleanup_module(void)
 569 {
 570         rtnl_link_unregister(&macvlan_link_ops);
 571         macvlan_handle_frame_hook = NULL;
 572         unregister_netdevice_notifier(&macvlan_notifier_block);
 573 }
 574
 575 module_init(macvlan_init_module);
 576 module_exit(macvlan_cleanup_module);
 577
 578 MODULE_LICENSE("GPL");
 579 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 580 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
 581 MODULE_ALIAS_RTNL_LINK("macvlan");