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
  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 __percpu *stats;
  38 };
  39
  40 /*
  41  * ethtool interface
  42  */
  43
  44 static struct {
  45         const char string[ETH_GSTRING_LEN];
  46 } ethtool_stats_keys[] = {
  47         { "peer_ifindex" },
  48 };
  49
  50 static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
  51 {
  52         cmd->supported          = 0;
  53         cmd->advertising        = 0;
  54         ethtool_cmd_speed_set(cmd, SPEED_10000);
  55         cmd->duplex             = DUPLEX_FULL;
  56         cmd->port               = PORT_TP;
  57         cmd->phy_address        = 0;
  58         cmd->transceiver        = XCVR_INTERNAL;
  59         cmd->autoneg            = AUTONEG_DISABLE;
  60         cmd->maxtxpkt           = 0;
  61         cmd->maxrxpkt           = 0;
  62         return 0;
  63 }
  64
  65 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
  66 {
  67         strcpy(info->driver, DRV_NAME);
  68         strcpy(info->version, DRV_VERSION);
  69         strcpy(info->fw_version, "N/A");
  70 }
  71
  72 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
  73 {
  74         switch(stringset) {
  75         case ETH_SS_STATS:
  76                 memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
  77                 break;
  78         }
  79 }
  80
  81 static int veth_get_sset_count(struct net_device *dev, int sset)
  82 {
  83         switch (sset) {
  84         case ETH_SS_STATS:
  85                 return ARRAY_SIZE(ethtool_stats_keys);
  86         default:
  87                 return -EOPNOTSUPP;
  88         }
  89 }
  90
  91 static void veth_get_ethtool_stats(struct net_device *dev,
  92                 struct ethtool_stats *stats, u64 *data)
  93 {
  94         struct veth_priv *priv;
  95
  96         priv = netdev_priv(dev);
  97         data[0] = priv->peer->ifindex;
  98 }
  99
 100 static const struct ethtool_ops veth_ethtool_ops = {
 101         .get_settings           = veth_get_settings,
 102         .get_drvinfo            = veth_get_drvinfo,
 103         .get_link               = ethtool_op_get_link,
 104         .get_strings            = veth_get_strings,
 105         .get_sset_count         = veth_get_sset_count,
 106         .get_ethtool_stats      = veth_get_ethtool_stats,
 107 };
 108
 109 /*
 110  * xmit
 111  */
 112
 113 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 114 {
 115         struct net_device *rcv = NULL;
 116         struct veth_priv *priv, *rcv_priv;
 117         struct veth_net_stats *stats, *rcv_stats;
 118         int length;
 119
 120         priv = netdev_priv(dev);
 121         rcv = priv->peer;
 122         rcv_priv = netdev_priv(rcv);
 123
 124         stats = this_cpu_ptr(priv->stats);
 125         rcv_stats = this_cpu_ptr(rcv_priv->stats);
 126
 127         if (!(rcv->flags & IFF_UP))
 128                 goto tx_drop;
 129
 130         /* don't change ip_summed == CHECKSUM_PARTIAL, as that
 131            will cause bad checksum on forwarded packets */
 132         if (skb->ip_summed == CHECKSUM_NONE &&
 133             rcv->features & NETIF_F_RXCSUM)
 134                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 135
 136         length = skb->len;
 137         if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
 138                 goto rx_drop;
 139
 140         stats->tx_bytes += length;
 141         stats->tx_packets++;
 142
 143         rcv_stats->rx_bytes += length;
 144         rcv_stats->rx_packets++;
 145
 146         return NETDEV_TX_OK;
 147
 148 tx_drop:
 149         kfree_skb(skb);
 150         stats->tx_dropped++;
 151         return NETDEV_TX_OK;
 152
 153 rx_drop:
 154         rcv_stats->rx_dropped++;
 155         return NETDEV_TX_OK;
 156 }
 157
 158 /*
 159  * general routines
 160  */
 161
 162 static struct net_device_stats *veth_get_stats(struct net_device *dev)
 163 {
 164         struct veth_priv *priv;
 165         int cpu;
 166         struct veth_net_stats *stats, total = {0};
 167
 168         priv = netdev_priv(dev);
 169
 170         for_each_possible_cpu(cpu) {
 171                 stats = per_cpu_ptr(priv->stats, cpu);
 172
 173                 total.rx_packets += stats->rx_packets;
 174                 total.tx_packets += stats->tx_packets;
 175                 total.rx_bytes   += stats->rx_bytes;
 176                 total.tx_bytes   += stats->tx_bytes;
 177                 total.tx_dropped += stats->tx_dropped;
 178                 total.rx_dropped += stats->rx_dropped;
 179         }
 180         dev->stats.rx_packets = total.rx_packets;
 181         dev->stats.tx_packets = total.tx_packets;
 182         dev->stats.rx_bytes   = total.rx_bytes;
 183         dev->stats.tx_bytes   = total.tx_bytes;
 184         dev->stats.tx_dropped = total.tx_dropped;
 185         dev->stats.rx_dropped = total.rx_dropped;
 186
 187         return &dev->stats;
 188 }
 189
 190 static int veth_open(struct net_device *dev)
 191 {
 192         struct veth_priv *priv;
 193
 194         priv = netdev_priv(dev);
 195         if (priv->peer == NULL)
 196                 return -ENOTCONN;
 197
 198         if (priv->peer->flags & IFF_UP) {
 199                 netif_carrier_on(dev);
 200                 netif_carrier_on(priv->peer);
 201         }
 202         return 0;
 203 }
 204
 205 static int veth_close(struct net_device *dev)
 206 {
 207         struct veth_priv *priv = netdev_priv(dev);
 208
 209         netif_carrier_off(dev);
 210         netif_carrier_off(priv->peer);
 211
 212         return 0;
 213 }
 214
 215 static int is_valid_veth_mtu(int new_mtu)
 216 {
 217         return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
 218 }
 219
 220 static int veth_change_mtu(struct net_device *dev, int new_mtu)
 221 {
 222         if (!is_valid_veth_mtu(new_mtu))
 223                 return -EINVAL;
 224         dev->mtu = new_mtu;
 225         return 0;
 226 }
 227
 228 static int veth_dev_init(struct net_device *dev)
 229 {
 230         struct veth_net_stats __percpu *stats;
 231         struct veth_priv *priv;
 232
 233         stats = alloc_percpu(struct veth_net_stats);
 234         if (stats == NULL)
 235                 return -ENOMEM;
 236
 237         priv = netdev_priv(dev);
 238         priv->stats = stats;
 239         return 0;
 240 }
 241
 242 static void veth_dev_free(struct net_device *dev)
 243 {
 244         struct veth_priv *priv;
 245
 246         priv = netdev_priv(dev);
 247         free_percpu(priv->stats);
 248         free_netdev(dev);
 249 }
 250
 251 static const struct net_device_ops veth_netdev_ops = {
 252         .ndo_init            = veth_dev_init,
 253         .ndo_open            = veth_open,
 254         .ndo_stop            = veth_close,
 255         .ndo_start_xmit      = veth_xmit,
 256         .ndo_change_mtu      = veth_change_mtu,
 257         .ndo_get_stats       = veth_get_stats,
 258         .ndo_set_mac_address = eth_mac_addr,
 259 };
 260
 261 static void veth_setup(struct net_device *dev)
 262 {
 263         ether_setup(dev);
 264
 265         dev->netdev_ops = &veth_netdev_ops;
 266         dev->ethtool_ops = &veth_ethtool_ops;
 267         dev->features |= NETIF_F_LLTX;
 268         dev->destructor = veth_dev_free;
 269
 270         dev->hw_features = NETIF_F_NO_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
 271 }
 272
 273 /*
 274  * netlink interface
 275  */
 276
 277 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
 278 {
 279         if (tb[IFLA_ADDRESS]) {
 280                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 281                         return -EINVAL;
 282                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 283                         return -EADDRNOTAVAIL;
 284         }
 285         if (tb[IFLA_MTU]) {
 286                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
 287                         return -EINVAL;
 288         }
 289         return 0;
 290 }
 291
 292 static struct rtnl_link_ops veth_link_ops;
 293
 294 static int veth_newlink(struct net *src_net, struct net_device *dev,
 295                          struct nlattr *tb[], struct nlattr *data[])
 296 {
 297         int err;
 298         struct net_device *peer;
 299         struct veth_priv *priv;
 300         char ifname[IFNAMSIZ];
 301         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
 302         struct ifinfomsg *ifmp;
 303         struct net *net;
 304
 305         /*
 306          * create and register peer first
 307          */
 308         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
 309                 struct nlattr *nla_peer;
 310
 311                 nla_peer = data[VETH_INFO_PEER];
 312                 ifmp = nla_data(nla_peer);
 313                 err = nla_parse(peer_tb, IFLA_MAX,
 314                                 nla_data(nla_peer) + sizeof(struct ifinfomsg),
 315                                 nla_len(nla_peer) - sizeof(struct ifinfomsg),
 316                                 ifla_policy);
 317                 if (err < 0)
 318                         return err;
 319
 320                 err = veth_validate(peer_tb, NULL);
 321                 if (err < 0)
 322                         return err;
 323
 324                 tbp = peer_tb;
 325         } else {
 326                 ifmp = NULL;
 327                 tbp = tb;
 328         }
 329
 330         if (tbp[IFLA_IFNAME])
 331                 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
 332         else
 333                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
 334
 335         net = rtnl_link_get_net(src_net, tbp);
 336         if (IS_ERR(net))
 337                 return PTR_ERR(net);
 338
 339         peer = rtnl_create_link(src_net, net, ifname, &veth_link_ops, tbp);
 340         if (IS_ERR(peer)) {
 341                 put_net(net);
 342                 return PTR_ERR(peer);
 343         }
 344
 345         if (tbp[IFLA_ADDRESS] == NULL)
 346                 random_ether_addr(peer->dev_addr);
 347
 348         err = register_netdevice(peer);
 349         put_net(net);
 350         net = NULL;
 351         if (err < 0)
 352                 goto err_register_peer;
 353
 354         netif_carrier_off(peer);
 355
 356         err = rtnl_configure_link(peer, ifmp);
 357         if (err < 0)
 358                 goto err_configure_peer;
 359
 360         /*
 361          * register dev last
 362          *
 363          * note, that since we've registered new device the dev's name
 364          * should be re-allocated
 365          */
 366
 367         if (tb[IFLA_ADDRESS] == NULL)
 368                 random_ether_addr(dev->dev_addr);
 369
 370         if (tb[IFLA_IFNAME])
 371                 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
 372         else
 373                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
 374
 375         if (strchr(dev->name, '%')) {
 376                 err = dev_alloc_name(dev, dev->name);
 377                 if (err < 0)
 378                         goto err_alloc_name;
 379         }
 380
 381         err = register_netdevice(dev);
 382         if (err < 0)
 383                 goto err_register_dev;
 384
 385         netif_carrier_off(dev);
 386
 387         /*
 388          * tie the deviced together
 389          */
 390
 391         priv = netdev_priv(dev);
 392         priv->peer = peer;
 393
 394         priv = netdev_priv(peer);
 395         priv->peer = dev;
 396         return 0;
 397
 398 err_register_dev:
 399         /* nothing to do */
 400 err_alloc_name:
 401 err_configure_peer:
 402         unregister_netdevice(peer);
 403         return err;
 404
 405 err_register_peer:
 406         free_netdev(peer);
 407         return err;
 408 }
 409
 410 static void veth_dellink(struct net_device *dev, struct list_head *head)
 411 {
 412         struct veth_priv *priv;
 413         struct net_device *peer;
 414
 415         priv = netdev_priv(dev);
 416         peer = priv->peer;
 417
 418         unregister_netdevice_queue(dev, head);
 419         unregister_netdevice_queue(peer, head);
 420 }
 421
 422 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
 423
 424 static struct rtnl_link_ops veth_link_ops = {
 425         .kind           = DRV_NAME,
 426         .priv_size      = sizeof(struct veth_priv),
 427         .setup          = veth_setup,
 428         .validate       = veth_validate,
 429         .newlink        = veth_newlink,
 430         .dellink        = veth_dellink,
 431         .policy         = veth_policy,
 432         .maxtype        = VETH_INFO_MAX,
 433 };
 434
 435 /*
 436  * init/fini
 437  */
 438
 439 static __init int veth_init(void)
 440 {
 441         return rtnl_link_register(&veth_link_ops);
 442 }
 443
 444 static __exit void veth_exit(void)
 445 {
 446         rtnl_link_unregister(&veth_link_ops);
 447 }
 448
 449 module_init(veth_init);
 450 module_exit(veth_exit);
 451
 452 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
 453 MODULE_LICENSE("GPL v2");
 454 MODULE_ALIAS_RTNL_LINK(DRV_NAME);