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