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                         if (unlikely(!(dev->flags & IFF_UP)))
  77                                 continue;
  78
  79                         nskb = skb_clone(skb, GFP_ATOMIC);
  80                         if (nskb == NULL) {
  81                                 dev->stats.rx_errors++;
  82                                 dev->stats.rx_dropped++;
  83                                 continue;
  84                         }
  85
  86                         dev->stats.rx_bytes += skb->len + ETH_HLEN;
  87                         dev->stats.rx_packets++;
  88                         dev->stats.multicast++;
  89                         dev->last_rx = jiffies;
  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         dev->last_rx = jiffies;
 139
 140         skb->dev = dev;
 141         skb->pkt_type = PACKET_HOST;
 142
 143         netif_rx(skb);
 144         return NULL;
 145 }
 146
 147 static int macvlan_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 148 {
 149         const struct macvlan_dev *vlan = netdev_priv(dev);
 150         unsigned int len = skb->len;
 151         int ret;
 152
 153         skb->dev = vlan->lowerdev;
 154         ret = dev_queue_xmit(skb);
 155
 156         if (likely(ret == NET_XMIT_SUCCESS)) {
 157                 dev->stats.tx_packets++;
 158                 dev->stats.tx_bytes += len;
 159         } else {
 160                 dev->stats.tx_errors++;
 161                 dev->stats.tx_aborted_errors++;
 162         }
 163         return NETDEV_TX_OK;
 164 }
 165
 166 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
 167                                unsigned short type, const void *daddr,
 168                                const void *saddr, unsigned len)
 169 {
 170         const struct macvlan_dev *vlan = netdev_priv(dev);
 171         struct net_device *lowerdev = vlan->lowerdev;
 172
 173         return dev_hard_header(skb, lowerdev, type, daddr,
 174                                saddr ? : dev->dev_addr, len);
 175 }
 176
 177 static const struct header_ops macvlan_hard_header_ops = {
 178         .create         = macvlan_hard_header,
 179         .rebuild        = eth_rebuild_header,
 180         .parse          = eth_header_parse,
 181         .cache          = eth_header_cache,
 182         .cache_update   = eth_header_cache_update,
 183 };
 184
 185 static int macvlan_open(struct net_device *dev)
 186 {
 187         struct macvlan_dev *vlan = netdev_priv(dev);
 188         struct macvlan_port *port = vlan->port;
 189         struct net_device *lowerdev = vlan->lowerdev;
 190         int err;
 191
 192         err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
 193         if (err < 0)
 194                 return err;
 195         if (dev->flags & IFF_ALLMULTI)
 196                 dev_set_allmulti(lowerdev, 1);
 197
 198         hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
 199         return 0;
 200 }
 201
 202 static int macvlan_stop(struct net_device *dev)
 203 {
 204         struct macvlan_dev *vlan = netdev_priv(dev);
 205         struct net_device *lowerdev = vlan->lowerdev;
 206
 207         dev_mc_unsync(lowerdev, dev);
 208         if (dev->flags & IFF_ALLMULTI)
 209                 dev_set_allmulti(lowerdev, -1);
 210
 211         dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
 212
 213         hlist_del_rcu(&vlan->hlist);
 214         synchronize_rcu();
 215         return 0;
 216 }
 217
 218 static void macvlan_change_rx_flags(struct net_device *dev, int change)
 219 {
 220         struct macvlan_dev *vlan = netdev_priv(dev);
 221         struct net_device *lowerdev = vlan->lowerdev;
 222
 223         if (change & IFF_ALLMULTI)
 224                 dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
 225 }
 226
 227 static void macvlan_set_multicast_list(struct net_device *dev)
 228 {
 229         struct macvlan_dev *vlan = netdev_priv(dev);
 230
 231         dev_mc_sync(vlan->lowerdev, dev);
 232 }
 233
 234 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
 235 {
 236         struct macvlan_dev *vlan = netdev_priv(dev);
 237
 238         if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
 239                 return -EINVAL;
 240         dev->mtu = new_mtu;
 241         return 0;
 242 }
 243
 244 /*
 245  * macvlan network devices have devices nesting below it and are a special
 246  * "super class" of normal network devices; split their locks off into a
 247  * separate class since they always nest.
 248  */
 249 static struct lock_class_key macvlan_netdev_xmit_lock_key;
 250
 251 #define MACVLAN_FEATURES \
 252         (NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
 253          NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
 254          NETIF_F_TSO_ECN | NETIF_F_TSO6)
 255
 256 #define MACVLAN_STATE_MASK \
 257         ((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
 258
 259 static int macvlan_init(struct net_device *dev)
 260 {
 261         struct macvlan_dev *vlan = netdev_priv(dev);
 262         const struct net_device *lowerdev = vlan->lowerdev;
 263
 264         dev->state              = (dev->state & ~MACVLAN_STATE_MASK) |
 265                                   (lowerdev->state & MACVLAN_STATE_MASK);
 266         dev->features           = lowerdev->features & MACVLAN_FEATURES;
 267         dev->iflink             = lowerdev->ifindex;
 268
 269         lockdep_set_class(&dev->_xmit_lock, &macvlan_netdev_xmit_lock_key);
 270         return 0;
 271 }
 272
 273 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
 274                                         struct ethtool_drvinfo *drvinfo)
 275 {
 276         snprintf(drvinfo->driver, 32, "macvlan");
 277         snprintf(drvinfo->version, 32, "0.1");
 278 }
 279
 280 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
 281 {
 282         const struct macvlan_dev *vlan = netdev_priv(dev);
 283         struct net_device *lowerdev = vlan->lowerdev;
 284
 285         if (lowerdev->ethtool_ops->get_rx_csum == NULL)
 286                 return 0;
 287         return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
 288 }
 289
 290 static const struct ethtool_ops macvlan_ethtool_ops = {
 291         .get_link               = ethtool_op_get_link,
 292         .get_rx_csum            = macvlan_ethtool_get_rx_csum,
 293         .get_drvinfo            = macvlan_ethtool_get_drvinfo,
 294 };
 295
 296 static void macvlan_setup(struct net_device *dev)
 297 {
 298         ether_setup(dev);
 299
 300         dev->init               = macvlan_init;
 301         dev->open               = macvlan_open;
 302         dev->stop               = macvlan_stop;
 303         dev->change_mtu         = macvlan_change_mtu;
 304         dev->change_rx_flags    = macvlan_change_rx_flags;
 305         dev->set_multicast_list = macvlan_set_multicast_list;
 306         dev->hard_start_xmit    = macvlan_hard_start_xmit;
 307         dev->destructor         = free_netdev;
 308         dev->header_ops         = &macvlan_hard_header_ops,
 309         dev->ethtool_ops        = &macvlan_ethtool_ops;
 310         dev->tx_queue_len       = 0;
 311 }
 312
 313 static int macvlan_port_create(struct net_device *dev)
 314 {
 315         struct macvlan_port *port;
 316         unsigned int i;
 317
 318         if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
 319                 return -EINVAL;
 320
 321         port = kzalloc(sizeof(*port), GFP_KERNEL);
 322         if (port == NULL)
 323                 return -ENOMEM;
 324
 325         port->dev = dev;
 326         INIT_LIST_HEAD(&port->vlans);
 327         for (i = 0; i < MACVLAN_HASH_SIZE; i++)
 328                 INIT_HLIST_HEAD(&port->vlan_hash[i]);
 329         rcu_assign_pointer(dev->macvlan_port, port);
 330         return 0;
 331 }
 332
 333 static void macvlan_port_destroy(struct net_device *dev)
 334 {
 335         struct macvlan_port *port = dev->macvlan_port;
 336
 337         rcu_assign_pointer(dev->macvlan_port, NULL);
 338         synchronize_rcu();
 339         kfree(port);
 340 }
 341
 342 static void macvlan_transfer_operstate(struct net_device *dev)
 343 {
 344         struct macvlan_dev *vlan = netdev_priv(dev);
 345         const struct net_device *lowerdev = vlan->lowerdev;
 346
 347         if (lowerdev->operstate == IF_OPER_DORMANT)
 348                 netif_dormant_on(dev);
 349         else
 350                 netif_dormant_off(dev);
 351
 352         if (netif_carrier_ok(lowerdev)) {
 353                 if (!netif_carrier_ok(dev))
 354                         netif_carrier_on(dev);
 355         } else {
 356                 if (netif_carrier_ok(lowerdev))
 357                         netif_carrier_off(dev);
 358         }
 359 }
 360
 361 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
 362 {
 363         if (tb[IFLA_ADDRESS]) {
 364                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 365                         return -EINVAL;
 366                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 367                         return -EADDRNOTAVAIL;
 368         }
 369         return 0;
 370 }
 371
 372 static int macvlan_newlink(struct net_device *dev,
 373                            struct nlattr *tb[], struct nlattr *data[])
 374 {
 375         struct macvlan_dev *vlan = netdev_priv(dev);
 376         struct macvlan_port *port;
 377         struct net_device *lowerdev;
 378         int err;
 379
 380         if (!tb[IFLA_LINK])
 381                 return -EINVAL;
 382
 383         lowerdev = __dev_get_by_index(dev->nd_net, nla_get_u32(tb[IFLA_LINK]));
 384         if (lowerdev == NULL)
 385                 return -ENODEV;
 386
 387         /* Don't allow macvlans on top of other macvlans - its not really
 388          * wrong, but lockdep can't handle it and its not useful for anything
 389          * you couldn't do directly on top of the real device.
 390          */
 391         if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops)
 392                 return -ENODEV;
 393
 394         if (!tb[IFLA_MTU])
 395                 dev->mtu = lowerdev->mtu;
 396         else if (dev->mtu > lowerdev->mtu)
 397                 return -EINVAL;
 398
 399         if (!tb[IFLA_ADDRESS])
 400                 random_ether_addr(dev->dev_addr);
 401
 402         if (lowerdev->macvlan_port == NULL) {
 403                 err = macvlan_port_create(lowerdev);
 404                 if (err < 0)
 405                         return err;
 406         }
 407         port = lowerdev->macvlan_port;
 408
 409         vlan->lowerdev = lowerdev;
 410         vlan->dev      = dev;
 411         vlan->port     = port;
 412
 413         err = register_netdevice(dev);
 414         if (err < 0)
 415                 return err;
 416
 417         list_add_tail(&vlan->list, &port->vlans);
 418         macvlan_transfer_operstate(dev);
 419         return 0;
 420 }
 421
 422 static void macvlan_dellink(struct net_device *dev)
 423 {
 424         struct macvlan_dev *vlan = netdev_priv(dev);
 425         struct macvlan_port *port = vlan->port;
 426
 427         list_del(&vlan->list);
 428         unregister_netdevice(dev);
 429
 430         if (list_empty(&port->vlans))
 431                 macvlan_port_destroy(dev);
 432 }
 433
 434 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
 435         .kind           = "macvlan",
 436         .priv_size      = sizeof(struct macvlan_dev),
 437         .setup          = macvlan_setup,
 438         .validate       = macvlan_validate,
 439         .newlink        = macvlan_newlink,
 440         .dellink        = macvlan_dellink,
 441 };
 442
 443 static int macvlan_device_event(struct notifier_block *unused,
 444                                 unsigned long event, void *ptr)
 445 {
 446         struct net_device *dev = ptr;
 447         struct macvlan_dev *vlan, *next;
 448         struct macvlan_port *port;
 449
 450         port = dev->macvlan_port;
 451         if (port == NULL)
 452                 return NOTIFY_DONE;
 453
 454         switch (event) {
 455         case NETDEV_CHANGE:
 456                 list_for_each_entry(vlan, &port->vlans, list)
 457                         macvlan_transfer_operstate(vlan->dev);
 458                 break;
 459         case NETDEV_FEAT_CHANGE:
 460                 list_for_each_entry(vlan, &port->vlans, list) {
 461                         vlan->dev->features = dev->features & MACVLAN_FEATURES;
 462                         netdev_features_change(vlan->dev);
 463                 }
 464                 break;
 465         case NETDEV_UNREGISTER:
 466                 list_for_each_entry_safe(vlan, next, &port->vlans, list)
 467                         macvlan_dellink(vlan->dev);
 468                 break;
 469         }
 470         return NOTIFY_DONE;
 471 }
 472
 473 static struct notifier_block macvlan_notifier_block __read_mostly = {
 474         .notifier_call  = macvlan_device_event,
 475 };
 476
 477 static int __init macvlan_init_module(void)
 478 {
 479         int err;
 480
 481         register_netdevice_notifier(&macvlan_notifier_block);
 482         macvlan_handle_frame_hook = macvlan_handle_frame;
 483
 484         err = rtnl_link_register(&macvlan_link_ops);
 485         if (err < 0)
 486                 goto err1;
 487         return 0;
 488 err1:
 489         macvlan_handle_frame_hook = macvlan_handle_frame;
 490         unregister_netdevice_notifier(&macvlan_notifier_block);
 491         return err;
 492 }
 493
 494 static void __exit macvlan_cleanup_module(void)
 495 {
 496         rtnl_link_unregister(&macvlan_link_ops);
 497         macvlan_handle_frame_hook = NULL;
 498         unregister_netdevice_notifier(&macvlan_notifier_block);
 499 }
 500
 501 module_init(macvlan_init_module);
 502 module_exit(macvlan_cleanup_module);
 503
 504 MODULE_LICENSE("GPL");
 505 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 506 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
 507 MODULE_ALIAS_RTNL_LINK("macvlan");