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/slab.h>
  13 #include <linux/ethtool.h>
  14 #include <linux/etherdevice.h>
  15
  16 #include <net/dst.h>
  17 #include <net/xfrm.h>
  18 #include <linux/veth.h>
  19
  20 #define DRV_NAME        "veth"
  21 #define DRV_VERSION     "1.0"
  22
  23 #define MIN_MTU 68              /* Min L3 MTU */
  24 #define MAX_MTU 65535           /* Max L3 MTU (arbitrary) */
  25 #define MTU_PAD (ETH_HLEN + 4)  /* Max difference between L2 and L3 size MTU */
  26
  27 struct veth_net_stats {
  28         unsigned long   rx_packets;
  29         unsigned long   tx_packets;
  30         unsigned long   rx_bytes;
  31         unsigned long   tx_bytes;
  32         unsigned long   tx_dropped;
  33         unsigned long   rx_dropped;
  34 };
  35
  36 struct veth_priv {
  37         struct net_device *peer;
  38         struct veth_net_stats __percpu *stats;
  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 const struct ethtool_ops veth_ethtool_ops = {
 102         .get_settings           = veth_get_settings,
 103         .get_drvinfo            = veth_get_drvinfo,
 104         .get_link               = ethtool_op_get_link,
 105         .get_strings            = veth_get_strings,
 106         .get_sset_count         = veth_get_sset_count,
 107         .get_ethtool_stats      = veth_get_ethtool_stats,
 108 };
 109
 110 /*
 111  * xmit
 112  */
 113
 114 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 115 {
 116         struct net_device *rcv = NULL;
 117         struct veth_priv *priv, *rcv_priv;
 118         struct veth_net_stats *stats, *rcv_stats;
 119         int length;
 120
 121         priv = netdev_priv(dev);
 122         rcv = priv->peer;
 123         rcv_priv = netdev_priv(rcv);
 124
 125         stats = this_cpu_ptr(priv->stats);
 126         rcv_stats = this_cpu_ptr(rcv_priv->stats);
 127
 128         if (!(rcv->flags & IFF_UP))
 129                 goto tx_drop;
 130
 131         /* don't change ip_summed == CHECKSUM_PARTIAL, as that
 132            will cause bad checksum on forwarded packets */
 133         if (skb->ip_summed == CHECKSUM_NONE &&
 134             rcv->features & NETIF_F_RXCSUM)
 135                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 136
 137         length = skb->len;
 138         if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
 139                 goto rx_drop;
 140
 141         stats->tx_bytes += length;
 142         stats->tx_packets++;
 143
 144         rcv_stats->rx_bytes += length;
 145         rcv_stats->rx_packets++;
 146
 147         return NETDEV_TX_OK;
 148
 149 tx_drop:
 150         kfree_skb(skb);
 151         stats->tx_dropped++;
 152         return NETDEV_TX_OK;
 153
 154 rx_drop:
 155         rcv_stats->rx_dropped++;
 156         return NETDEV_TX_OK;
 157 }
 158
 159 /*
 160  * general routines
 161  */
 162
 163 static struct net_device_stats *veth_get_stats(struct net_device *dev)
 164 {
 165         struct veth_priv *priv;
 166         int cpu;
 167         struct veth_net_stats *stats, total = {0};
 168
 169         priv = netdev_priv(dev);
 170
 171         for_each_possible_cpu(cpu) {
 172                 stats = per_cpu_ptr(priv->stats, cpu);
 173
 174                 total.rx_packets += stats->rx_packets;
 175                 total.tx_packets += stats->tx_packets;
 176                 total.rx_bytes   += stats->rx_bytes;
 177                 total.tx_bytes   += stats->tx_bytes;
 178                 total.tx_dropped += stats->tx_dropped;
 179                 total.rx_dropped += stats->rx_dropped;
 180         }
 181         dev->stats.rx_packets = total.rx_packets;
 182         dev->stats.tx_packets = total.tx_packets;
 183         dev->stats.rx_bytes   = total.rx_bytes;
 184         dev->stats.tx_bytes   = total.tx_bytes;
 185         dev->stats.tx_dropped = total.tx_dropped;
 186         dev->stats.rx_dropped = total.rx_dropped;
 187
 188         return &dev->stats;
 189 }
 190
 191 static int veth_open(struct net_device *dev)
 192 {
 193         struct veth_priv *priv;
 194
 195         priv = netdev_priv(dev);
 196         if (priv->peer == NULL)
 197                 return -ENOTCONN;
 198
 199         if (priv->peer->flags & IFF_UP) {
 200                 netif_carrier_on(dev);
 201                 netif_carrier_on(priv->peer);
 202         }
 203         return 0;
 204 }
 205
 206 static int veth_close(struct net_device *dev)
 207 {
 208         struct veth_priv *priv = netdev_priv(dev);
 209
 210         netif_carrier_off(dev);
 211         netif_carrier_off(priv->peer);
 212
 213         return 0;
 214 }
 215
 216 static int is_valid_veth_mtu(int new_mtu)
 217 {
 218         return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
 219 }
 220
 221 static int veth_change_mtu(struct net_device *dev, int new_mtu)
 222 {
 223         if (!is_valid_veth_mtu(new_mtu))
 224                 return -EINVAL;
 225         dev->mtu = new_mtu;
 226         return 0;
 227 }
 228
 229 static int veth_dev_init(struct net_device *dev)
 230 {
 231         struct veth_net_stats __percpu *stats;
 232         struct veth_priv *priv;
 233
 234         stats = alloc_percpu(struct veth_net_stats);
 235         if (stats == NULL)
 236                 return -ENOMEM;
 237
 238         priv = netdev_priv(dev);
 239         priv->stats = stats;
 240         return 0;
 241 }
 242
 243 static void veth_dev_free(struct net_device *dev)
 244 {
 245         struct veth_priv *priv;
 246
 247         priv = netdev_priv(dev);
 248         free_percpu(priv->stats);
 249         free_netdev(dev);
 250 }
 251
 252 static const struct net_device_ops veth_netdev_ops = {
 253         .ndo_init            = veth_dev_init,
 254         .ndo_open            = veth_open,
 255         .ndo_stop            = veth_close,
 256         .ndo_start_xmit      = veth_xmit,
 257         .ndo_change_mtu      = veth_change_mtu,
 258         .ndo_get_stats       = veth_get_stats,
 259         .ndo_set_mac_address = eth_mac_addr,
 260 };
 261
 262 static void veth_setup(struct net_device *dev)
 263 {
 264         ether_setup(dev);
 265
 266         dev->netdev_ops = &veth_netdev_ops;
 267         dev->ethtool_ops = &veth_ethtool_ops;
 268         dev->features |= NETIF_F_LLTX;
 269         dev->destructor = veth_dev_free;
 270
 271         dev->hw_features = NETIF_F_NO_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
 272 }
 273
 274 /*
 275  * netlink interface
 276  */
 277
 278 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
 279 {
 280         if (tb[IFLA_ADDRESS]) {
 281                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 282                         return -EINVAL;
 283                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 284                         return -EADDRNOTAVAIL;
 285         }
 286         if (tb[IFLA_MTU]) {
 287                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
 288                         return -EINVAL;
 289         }
 290         return 0;
 291 }
 292
 293 static struct rtnl_link_ops veth_link_ops;
 294
 295 static int veth_newlink(struct net *src_net, struct net_device *dev,
 296                          struct nlattr *tb[], struct nlattr *data[])
 297 {
 298         int err;
 299         struct net_device *peer;
 300         struct veth_priv *priv;
 301         char ifname[IFNAMSIZ];
 302         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
 303         struct ifinfomsg *ifmp;
 304         struct net *net;
 305
 306         /*
 307          * create and register peer first
 308          */
 309         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
 310                 struct nlattr *nla_peer;
 311
 312                 nla_peer = data[VETH_INFO_PEER];
 313                 ifmp = nla_data(nla_peer);
 314                 err = nla_parse(peer_tb, IFLA_MAX,
 315                                 nla_data(nla_peer) + sizeof(struct ifinfomsg),
 316                                 nla_len(nla_peer) - sizeof(struct ifinfomsg),
 317                                 ifla_policy);
 318                 if (err < 0)
 319                         return err;
 320
 321                 err = veth_validate(peer_tb, NULL);
 322                 if (err < 0)
 323                         return err;
 324
 325                 tbp = peer_tb;
 326         } else {
 327                 ifmp = NULL;
 328                 tbp = tb;
 329         }
 330
 331         if (tbp[IFLA_IFNAME])
 332                 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
 333         else
 334                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
 335
 336         net = rtnl_link_get_net(src_net, tbp);
 337         if (IS_ERR(net))
 338                 return PTR_ERR(net);
 339
 340         peer = rtnl_create_link(src_net, net, ifname, &veth_link_ops, tbp);
 341         if (IS_ERR(peer)) {
 342                 put_net(net);
 343                 return PTR_ERR(peer);
 344         }
 345
 346         if (tbp[IFLA_ADDRESS] == NULL)
 347                 random_ether_addr(peer->dev_addr);
 348
 349         err = register_netdevice(peer);
 350         put_net(net);
 351         net = NULL;
 352         if (err < 0)
 353                 goto err_register_peer;
 354
 355         netif_carrier_off(peer);
 356
 357         err = rtnl_configure_link(peer, ifmp);
 358         if (err < 0)
 359                 goto err_configure_peer;
 360
 361         /*
 362          * register dev last
 363          *
 364          * note, that since we've registered new device the dev's name
 365          * should be re-allocated
 366          */
 367
 368         if (tb[IFLA_ADDRESS] == NULL)
 369                 random_ether_addr(dev->dev_addr);
 370
 371         err = register_netdevice(dev);
 372         if (err < 0)
 373                 goto err_register_dev;
 374
 375         netif_carrier_off(dev);
 376
 377         /*
 378          * tie the deviced together
 379          */
 380
 381         priv = netdev_priv(dev);
 382         priv->peer = peer;
 383
 384         priv = netdev_priv(peer);
 385         priv->peer = dev;
 386         return 0;
 387
 388 err_register_dev:
 389         /* nothing to do */
 390 err_configure_peer:
 391         unregister_netdevice(peer);
 392         return err;
 393
 394 err_register_peer:
 395         free_netdev(peer);
 396         return err;
 397 }
 398
 399 static void veth_dellink(struct net_device *dev, struct list_head *head)
 400 {
 401         struct veth_priv *priv;
 402         struct net_device *peer;
 403
 404         priv = netdev_priv(dev);
 405         peer = priv->peer;
 406
 407         unregister_netdevice_queue(dev, head);
 408         unregister_netdevice_queue(peer, head);
 409 }
 410
 411 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
 412
 413 static struct rtnl_link_ops veth_link_ops = {
 414         .kind           = DRV_NAME,
 415         .priv_size      = sizeof(struct veth_priv),
 416         .setup          = veth_setup,
 417         .validate       = veth_validate,
 418         .newlink        = veth_newlink,
 419         .dellink        = veth_dellink,
 420         .policy         = veth_policy,
 421         .maxtype        = VETH_INFO_MAX,
 422 };
 423
 424 /*
 425  * init/fini
 426  */
 427
 428 static __init int veth_init(void)
 429 {
 430         return rtnl_link_register(&veth_link_ops);
 431 }
 432
 433 static __exit void veth_exit(void)
 434 {
 435         rtnl_link_unregister(&veth_link_ops);
 436 }
 437
 438 module_init(veth_init);
 439 module_exit(veth_exit);
 440
 441 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
 442 MODULE_LICENSE("GPL v2");
 443 MODULE_ALIAS_RTNL_LINK(DRV_NAME);