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