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