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