drivers/net/veth.c

   1 /*
   2  *  drivers/net/veth.c
   3  *
   4  *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
   5  *
   6  * Author: Pavel Emelianov <xemul@openvz.org>
   7  * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
   8  *
   9  */
  10
  11 #include <linux/netdevice.h>
  12 #include <linux/ethtool.h>
  13 #include <linux/etherdevice.h>
  14
  15 #include <net/dst.h>
  16 #include <net/xfrm.h>
  17 #include <linux/veth.h>
  18
  19 #define DRV_NAME        "veth"
  20 #define DRV_VERSION     "1.0"
  21
  22 #define MIN_MTU 68              /* Min L3 MTU */
  23 #define MAX_MTU 65535           /* Max L3 MTU (arbitrary) */
  24 #define MTU_PAD (ETH_HLEN + 4)  /* Max difference between L2 and L3 size MTU */
  25
  26 struct veth_net_stats {
  27         unsigned long   rx_packets;
  28         unsigned long   tx_packets;
  29         unsigned long   rx_bytes;
  30         unsigned long   tx_bytes;
  31         unsigned long   tx_dropped;
  32         unsigned long   rx_dropped;
  33 };
  34
  35 struct veth_priv {
  36         struct net_device *peer;
  37         struct veth_net_stats *stats;
  38         unsigned ip_summed;
  39 };
  40
  41 /*
  42  * ethtool interface
  43  */
  44
  45 static struct {
  46         const char string[ETH_GSTRING_LEN];
  47 } ethtool_stats_keys[] = {
  48         { "peer_ifindex" },
  49 };
  50
  51 static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
  52 {
  53         cmd->supported          = 0;
  54         cmd->advertising        = 0;
  55         cmd->speed              = SPEED_10000;
  56         cmd->duplex             = DUPLEX_FULL;
  57         cmd->port               = PORT_TP;
  58         cmd->phy_address        = 0;
  59         cmd->transceiver        = XCVR_INTERNAL;
  60         cmd->autoneg            = AUTONEG_DISABLE;
  61         cmd->maxtxpkt           = 0;
  62         cmd->maxrxpkt           = 0;
  63         return 0;
  64 }
  65
  66 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
  67 {
  68         strcpy(info->driver, DRV_NAME);
  69         strcpy(info->version, DRV_VERSION);
  70         strcpy(info->fw_version, "N/A");
  71 }
  72
  73 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
  74 {
  75         switch(stringset) {
  76         case ETH_SS_STATS:
  77                 memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
  78                 break;
  79         }
  80 }
  81
  82 static int veth_get_sset_count(struct net_device *dev, int sset)
  83 {
  84         switch (sset) {
  85         case ETH_SS_STATS:
  86                 return ARRAY_SIZE(ethtool_stats_keys);
  87         default:
  88                 return -EOPNOTSUPP;
  89         }
  90 }
  91
  92 static void veth_get_ethtool_stats(struct net_device *dev,
  93                 struct ethtool_stats *stats, u64 *data)
  94 {
  95         struct veth_priv *priv;
  96
  97         priv = netdev_priv(dev);
  98         data[0] = priv->peer->ifindex;
  99 }
 100
 101 static u32 veth_get_rx_csum(struct net_device *dev)
 102 {
 103         struct veth_priv *priv;
 104
 105         priv = netdev_priv(dev);
 106         return priv->ip_summed == CHECKSUM_UNNECESSARY;
 107 }
 108
 109 static int veth_set_rx_csum(struct net_device *dev, u32 data)
 110 {
 111         struct veth_priv *priv;
 112
 113         priv = netdev_priv(dev);
 114         priv->ip_summed = data ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
 115         return 0;
 116 }
 117
 118 static u32 veth_get_tx_csum(struct net_device *dev)
 119 {
 120         return (dev->features & NETIF_F_NO_CSUM) != 0;
 121 }
 122
 123 static int veth_set_tx_csum(struct net_device *dev, u32 data)
 124 {
 125         if (data)
 126                 dev->features |= NETIF_F_NO_CSUM;
 127         else
 128                 dev->features &= ~NETIF_F_NO_CSUM;
 129         return 0;
 130 }
 131
 132 static struct ethtool_ops veth_ethtool_ops = {
 133         .get_settings           = veth_get_settings,
 134         .get_drvinfo            = veth_get_drvinfo,
 135         .get_link               = ethtool_op_get_link,
 136         .get_rx_csum            = veth_get_rx_csum,
 137         .set_rx_csum            = veth_set_rx_csum,
 138         .get_tx_csum            = veth_get_tx_csum,
 139         .set_tx_csum            = veth_set_tx_csum,
 140         .get_sg                 = ethtool_op_get_sg,
 141         .set_sg                 = ethtool_op_set_sg,
 142         .get_strings            = veth_get_strings,
 143         .get_sset_count         = veth_get_sset_count,
 144         .get_ethtool_stats      = veth_get_ethtool_stats,
 145 };
 146
 147 /*
 148  * xmit
 149  */
 150
 151 static int veth_xmit(struct sk_buff *skb, struct net_device *dev)
 152 {
 153         struct net_device *rcv = NULL;
 154         struct veth_priv *priv, *rcv_priv;
 155         struct veth_net_stats *stats, *rcv_stats;
 156         int length, cpu;
 157
 158         skb_orphan(skb);
 159
 160         priv = netdev_priv(dev);
 161         rcv = priv->peer;
 162         rcv_priv = netdev_priv(rcv);
 163
 164         cpu = smp_processor_id();
 165         stats = per_cpu_ptr(priv->stats, cpu);
 166         rcv_stats = per_cpu_ptr(rcv_priv->stats, cpu);
 167
 168         if (!(rcv->flags & IFF_UP))
 169                 goto tx_drop;
 170
 171         if (skb->len > (rcv->mtu + MTU_PAD))
 172                 goto rx_drop;
 173
 174         skb->pkt_type = PACKET_HOST;
 175         skb->protocol = eth_type_trans(skb, rcv);
 176         if (dev->features & NETIF_F_NO_CSUM)
 177                 skb->ip_summed = rcv_priv->ip_summed;
 178
 179         skb->mark = 0;
 180         secpath_reset(skb);
 181         nf_reset(skb);
 182
 183         length = skb->len;
 184
 185         stats->tx_bytes += length;
 186         stats->tx_packets++;
 187
 188         rcv_stats->rx_bytes += length;
 189         rcv_stats->rx_packets++;
 190
 191         netif_rx(skb);
 192         return 0;
 193
 194 tx_drop:
 195         kfree_skb(skb);
 196         stats->tx_dropped++;
 197         return 0;
 198
 199 rx_drop:
 200         kfree_skb(skb);
 201         rcv_stats->rx_dropped++;
 202         return 0;
 203 }
 204
 205 /*
 206  * general routines
 207  */
 208
 209 static struct net_device_stats *veth_get_stats(struct net_device *dev)
 210 {
 211         struct veth_priv *priv;
 212         struct net_device_stats *dev_stats;
 213         int cpu;
 214         struct veth_net_stats *stats;
 215
 216         priv = netdev_priv(dev);
 217         dev_stats = &dev->stats;
 218
 219         dev_stats->rx_packets = 0;
 220         dev_stats->tx_packets = 0;
 221         dev_stats->rx_bytes = 0;
 222         dev_stats->tx_bytes = 0;
 223         dev_stats->tx_dropped = 0;
 224         dev_stats->rx_dropped = 0;
 225
 226         for_each_online_cpu(cpu) {
 227                 stats = per_cpu_ptr(priv->stats, cpu);
 228
 229                 dev_stats->rx_packets += stats->rx_packets;
 230                 dev_stats->tx_packets += stats->tx_packets;
 231                 dev_stats->rx_bytes += stats->rx_bytes;
 232                 dev_stats->tx_bytes += stats->tx_bytes;
 233                 dev_stats->tx_dropped += stats->tx_dropped;
 234                 dev_stats->rx_dropped += stats->rx_dropped;
 235         }
 236
 237         return dev_stats;
 238 }
 239
 240 static int veth_open(struct net_device *dev)
 241 {
 242         struct veth_priv *priv;
 243
 244         priv = netdev_priv(dev);
 245         if (priv->peer == NULL)
 246                 return -ENOTCONN;
 247
 248         if (priv->peer->flags & IFF_UP) {
 249                 netif_carrier_on(dev);
 250                 netif_carrier_on(priv->peer);
 251         }
 252         return 0;
 253 }
 254
 255 static int veth_close(struct net_device *dev)
 256 {
 257         struct veth_priv *priv = netdev_priv(dev);
 258
 259         netif_carrier_off(dev);
 260         netif_carrier_off(priv->peer);
 261
 262         return 0;
 263 }
 264
 265 static int is_valid_veth_mtu(int new_mtu)
 266 {
 267         return (new_mtu >= MIN_MTU && new_mtu <= MAX_MTU);
 268 }
 269
 270 static int veth_change_mtu(struct net_device *dev, int new_mtu)
 271 {
 272         if (!is_valid_veth_mtu(new_mtu))
 273                 return -EINVAL;
 274         dev->mtu = new_mtu;
 275         return 0;
 276 }
 277
 278 static int veth_dev_init(struct net_device *dev)
 279 {
 280         struct veth_net_stats *stats;
 281         struct veth_priv *priv;
 282
 283         stats = alloc_percpu(struct veth_net_stats);
 284         if (stats == NULL)
 285                 return -ENOMEM;
 286
 287         priv = netdev_priv(dev);
 288         priv->stats = stats;
 289         return 0;
 290 }
 291
 292 static void veth_dev_free(struct net_device *dev)
 293 {
 294         struct veth_priv *priv;
 295
 296         priv = netdev_priv(dev);
 297         free_percpu(priv->stats);
 298         free_netdev(dev);
 299 }
 300
 301 static const struct net_device_ops veth_netdev_ops = {
 302         .ndo_init            = veth_dev_init,
 303         .ndo_open            = veth_open,
 304         .ndo_stop            = veth_close,
 305         .ndo_start_xmit      = veth_xmit,
 306         .ndo_change_mtu      = veth_change_mtu,
 307         .ndo_get_stats       = veth_get_stats,
 308         .ndo_set_mac_address = eth_mac_addr,
 309 };
 310
 311 static void veth_setup(struct net_device *dev)
 312 {
 313         ether_setup(dev);
 314
 315         dev->netdev_ops = &veth_netdev_ops;
 316         dev->ethtool_ops = &veth_ethtool_ops;
 317         dev->features |= NETIF_F_LLTX;
 318         dev->destructor = veth_dev_free;
 319 }
 320
 321 /*
 322  * netlink interface
 323  */
 324
 325 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
 326 {
 327         if (tb[IFLA_ADDRESS]) {
 328                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 329                         return -EINVAL;
 330                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 331                         return -EADDRNOTAVAIL;
 332         }
 333         if (tb[IFLA_MTU]) {
 334                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
 335                         return -EINVAL;
 336         }
 337         return 0;
 338 }
 339
 340 static struct rtnl_link_ops veth_link_ops;
 341
 342 static int veth_newlink(struct net_device *dev,
 343                          struct nlattr *tb[], struct nlattr *data[])
 344 {
 345         int err;
 346         struct net_device *peer;
 347         struct veth_priv *priv;
 348         char ifname[IFNAMSIZ];
 349         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
 350
 351         /*
 352          * create and register peer first
 353          *
 354          * struct ifinfomsg is at the head of VETH_INFO_PEER, but we
 355          * skip it since no info from it is useful yet
 356          */
 357
 358         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
 359                 struct nlattr *nla_peer;
 360
 361                 nla_peer = data[VETH_INFO_PEER];
 362                 err = nla_parse(peer_tb, IFLA_MAX,
 363                                 nla_data(nla_peer) + sizeof(struct ifinfomsg),
 364                                 nla_len(nla_peer) - sizeof(struct ifinfomsg),
 365                                 ifla_policy);
 366                 if (err < 0)
 367                         return err;
 368
 369                 err = veth_validate(peer_tb, NULL);
 370                 if (err < 0)
 371                         return err;
 372
 373                 tbp = peer_tb;
 374         } else
 375                 tbp = tb;
 376
 377         if (tbp[IFLA_IFNAME])
 378                 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
 379         else
 380                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
 381
 382         peer = rtnl_create_link(dev_net(dev), ifname, &veth_link_ops, tbp);
 383         if (IS_ERR(peer))
 384                 return PTR_ERR(peer);
 385
 386         if (tbp[IFLA_ADDRESS] == NULL)
 387                 random_ether_addr(peer->dev_addr);
 388
 389         err = register_netdevice(peer);
 390         if (err < 0)
 391                 goto err_register_peer;
 392
 393         netif_carrier_off(peer);
 394
 395         /*
 396          * register dev last
 397          *
 398          * note, that since we've registered new device the dev's name
 399          * should be re-allocated
 400          */
 401
 402         if (tb[IFLA_ADDRESS] == NULL)
 403                 random_ether_addr(dev->dev_addr);
 404
 405         if (tb[IFLA_IFNAME])
 406                 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
 407         else
 408                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
 409
 410         if (strchr(dev->name, '%')) {
 411                 err = dev_alloc_name(dev, dev->name);
 412                 if (err < 0)
 413                         goto err_alloc_name;
 414         }
 415
 416         err = register_netdevice(dev);
 417         if (err < 0)
 418                 goto err_register_dev;
 419
 420         netif_carrier_off(dev);
 421
 422         /*
 423          * tie the deviced together
 424          */
 425
 426         priv = netdev_priv(dev);
 427         priv->peer = peer;
 428
 429         priv = netdev_priv(peer);
 430         priv->peer = dev;
 431         return 0;
 432
 433 err_register_dev:
 434         /* nothing to do */
 435 err_alloc_name:
 436         unregister_netdevice(peer);
 437         return err;
 438
 439 err_register_peer:
 440         free_netdev(peer);
 441         return err;
 442 }
 443
 444 static void veth_dellink(struct net_device *dev)
 445 {
 446         struct veth_priv *priv;
 447         struct net_device *peer;
 448
 449         priv = netdev_priv(dev);
 450         peer = priv->peer;
 451
 452         unregister_netdevice(dev);
 453         unregister_netdevice(peer);
 454 }
 455
 456 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
 457
 458 static struct rtnl_link_ops veth_link_ops = {
 459         .kind           = DRV_NAME,
 460         .priv_size      = sizeof(struct veth_priv),
 461         .setup          = veth_setup,
 462         .validate       = veth_validate,
 463         .newlink        = veth_newlink,
 464         .dellink        = veth_dellink,
 465         .policy         = veth_policy,
 466         .maxtype        = VETH_INFO_MAX,
 467 };
 468
 469 /*
 470  * init/fini
 471  */
 472
 473 static __init int veth_init(void)
 474 {
 475         return rtnl_link_register(&veth_link_ops);
 476 }
 477
 478 static __exit void veth_exit(void)
 479 {
 480         rtnl_link_unregister(&veth_link_ops);
 481 }
 482
 483 module_init(veth_init);
 484 module_exit(veth_exit);
 485
 486 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
 487 MODULE_LICENSE("GPL v2");
 488 MODULE_ALIAS_RTNL_LINK(DRV_NAME);