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 #include <linux/u64_stats_sync.h>
  16
  17 #include <net/dst.h>
  18 #include <net/xfrm.h>
  19 #include <linux/veth.h>
  20
  21 #define DRV_NAME        "veth"
  22 #define DRV_VERSION     "1.0"
  23
  24 #define MIN_MTU 68              /* Min L3 MTU */
  25 #define MAX_MTU 65535           /* Max L3 MTU (arbitrary) */
  26
  27 struct veth_net_stats {
  28         u64                     rx_packets;
  29         u64                     tx_packets;
  30         u64                     rx_bytes;
  31         u64                     tx_bytes;
  32         u64                     rx_dropped;
  33         u64                     tx_dropped;
  34         struct u64_stats_sync   syncp;
  35 };
  36
  37 struct veth_priv {
  38         struct net_device *peer;
  39         struct veth_net_stats __percpu *stats;
  40 };
  41
  42 /*
  43  * ethtool interface
  44  */
  45
  46 static struct {
  47         const char string[ETH_GSTRING_LEN];
  48 } ethtool_stats_keys[] = {
  49         { "peer_ifindex" },
  50 };
  51
  52 static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
  53 {
  54         cmd->supported          = 0;
  55         cmd->advertising        = 0;
  56         ethtool_cmd_speed_set(cmd, SPEED_10000);
  57         cmd->duplex             = DUPLEX_FULL;
  58         cmd->port               = PORT_TP;
  59         cmd->phy_address        = 0;
  60         cmd->transceiver        = XCVR_INTERNAL;
  61         cmd->autoneg            = AUTONEG_DISABLE;
  62         cmd->maxtxpkt           = 0;
  63         cmd->maxrxpkt           = 0;
  64         return 0;
  65 }
  66
  67 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
  68 {
  69         strcpy(info->driver, DRV_NAME);
  70         strcpy(info->version, DRV_VERSION);
  71         strcpy(info->fw_version, "N/A");
  72 }
  73
  74 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
  75 {
  76         switch(stringset) {
  77         case ETH_SS_STATS:
  78                 memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
  79                 break;
  80         }
  81 }
  82
  83 static int veth_get_sset_count(struct net_device *dev, int sset)
  84 {
  85         switch (sset) {
  86         case ETH_SS_STATS:
  87                 return ARRAY_SIZE(ethtool_stats_keys);
  88         default:
  89                 return -EOPNOTSUPP;
  90         }
  91 }
  92
  93 static void veth_get_ethtool_stats(struct net_device *dev,
  94                 struct ethtool_stats *stats, u64 *data)
  95 {
  96         struct veth_priv *priv;
  97
  98         priv = netdev_priv(dev);
  99         data[0] = priv->peer->ifindex;
 100 }
 101
 102 static const struct ethtool_ops veth_ethtool_ops = {
 103         .get_settings           = veth_get_settings,
 104         .get_drvinfo            = veth_get_drvinfo,
 105         .get_link               = ethtool_op_get_link,
 106         .get_strings            = veth_get_strings,
 107         .get_sset_count         = veth_get_sset_count,
 108         .get_ethtool_stats      = veth_get_ethtool_stats,
 109 };
 110
 111 /*
 112  * xmit
 113  */
 114
 115 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 116 {
 117         struct net_device *rcv = NULL;
 118         struct veth_priv *priv, *rcv_priv;
 119         struct veth_net_stats *stats, *rcv_stats;
 120         int length;
 121
 122         priv = netdev_priv(dev);
 123         rcv = priv->peer;
 124         rcv_priv = netdev_priv(rcv);
 125
 126         stats = this_cpu_ptr(priv->stats);
 127         rcv_stats = this_cpu_ptr(rcv_priv->stats);
 128
 129         if (!(rcv->flags & IFF_UP))
 130                 goto tx_drop;
 131
 132         /* don't change ip_summed == CHECKSUM_PARTIAL, as that
 133            will cause bad checksum on forwarded packets */
 134         if (skb->ip_summed == CHECKSUM_NONE &&
 135             rcv->features & NETIF_F_RXCSUM)
 136                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 137
 138         length = skb->len;
 139         if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
 140                 goto rx_drop;
 141
 142         u64_stats_update_begin(&stats->syncp);
 143         stats->tx_bytes += length;
 144         stats->tx_packets++;
 145         u64_stats_update_end(&stats->syncp);
 146
 147         u64_stats_update_begin(&rcv_stats->syncp);
 148         rcv_stats->rx_bytes += length;
 149         rcv_stats->rx_packets++;
 150         u64_stats_update_end(&rcv_stats->syncp);
 151
 152         return NETDEV_TX_OK;
 153
 154 tx_drop:
 155         kfree_skb(skb);
 156         u64_stats_update_begin(&stats->syncp);
 157         stats->tx_dropped++;
 158         u64_stats_update_end(&stats->syncp);
 159         return NETDEV_TX_OK;
 160
 161 rx_drop:
 162         u64_stats_update_begin(&rcv_stats->syncp);
 163         rcv_stats->rx_dropped++;
 164         u64_stats_update_end(&rcv_stats->syncp);
 165         return NETDEV_TX_OK;
 166 }
 167
 168 /*
 169  * general routines
 170  */
 171
 172 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
 173                                                   struct rtnl_link_stats64 *tot)
 174 {
 175         struct veth_priv *priv = netdev_priv(dev);
 176         int cpu;
 177
 178         for_each_possible_cpu(cpu) {
 179                 struct veth_net_stats *stats = per_cpu_ptr(priv->stats, cpu);
 180                 u64 rx_packets, rx_bytes, rx_dropped;
 181                 u64 tx_packets, tx_bytes, tx_dropped;
 182                 unsigned int start;
 183
 184                 do {
 185                         start = u64_stats_fetch_begin_bh(&stats->syncp);
 186                         rx_packets = stats->rx_packets;
 187                         tx_packets = stats->tx_packets;
 188                         rx_bytes = stats->rx_bytes;
 189                         tx_bytes = stats->tx_bytes;
 190                         rx_dropped = stats->rx_dropped;
 191                         tx_dropped = stats->tx_dropped;
 192                 } while (u64_stats_fetch_retry_bh(&stats->syncp, start));
 193                 tot->rx_packets += rx_packets;
 194                 tot->tx_packets += tx_packets;
 195                 tot->rx_bytes   += rx_bytes;
 196                 tot->tx_bytes   += tx_bytes;
 197                 tot->rx_dropped += rx_dropped;
 198                 tot->tx_dropped += tx_dropped;
 199         }
 200
 201         return tot;
 202 }
 203
 204 static int veth_open(struct net_device *dev)
 205 {
 206         struct veth_priv *priv;
 207
 208         priv = netdev_priv(dev);
 209         if (priv->peer == NULL)
 210                 return -ENOTCONN;
 211
 212         if (priv->peer->flags & IFF_UP) {
 213                 netif_carrier_on(dev);
 214                 netif_carrier_on(priv->peer);
 215         }
 216         return 0;
 217 }
 218
 219 static int veth_close(struct net_device *dev)
 220 {
 221         struct veth_priv *priv = netdev_priv(dev);
 222
 223         netif_carrier_off(dev);
 224         netif_carrier_off(priv->peer);
 225
 226         return 0;
 227 }
 228
 229 static int is_valid_veth_mtu(int new_mtu)
 230 {
 231         return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
 232 }
 233
 234 static int veth_change_mtu(struct net_device *dev, int new_mtu)
 235 {
 236         if (!is_valid_veth_mtu(new_mtu))
 237                 return -EINVAL;
 238         dev->mtu = new_mtu;
 239         return 0;
 240 }
 241
 242 static int veth_dev_init(struct net_device *dev)
 243 {
 244         struct veth_net_stats __percpu *stats;
 245         struct veth_priv *priv;
 246
 247         stats = alloc_percpu(struct veth_net_stats);
 248         if (stats == NULL)
 249                 return -ENOMEM;
 250
 251         priv = netdev_priv(dev);
 252         priv->stats = stats;
 253         return 0;
 254 }
 255
 256 static void veth_dev_free(struct net_device *dev)
 257 {
 258         struct veth_priv *priv;
 259
 260         priv = netdev_priv(dev);
 261         free_percpu(priv->stats);
 262         free_netdev(dev);
 263 }
 264
 265 static const struct net_device_ops veth_netdev_ops = {
 266         .ndo_init            = veth_dev_init,
 267         .ndo_open            = veth_open,
 268         .ndo_stop            = veth_close,
 269         .ndo_start_xmit      = veth_xmit,
 270         .ndo_change_mtu      = veth_change_mtu,
 271         .ndo_get_stats64     = veth_get_stats64,
 272         .ndo_set_mac_address = eth_mac_addr,
 273 };
 274
 275 static void veth_setup(struct net_device *dev)
 276 {
 277         ether_setup(dev);
 278
 279         dev->netdev_ops = &veth_netdev_ops;
 280         dev->ethtool_ops = &veth_ethtool_ops;
 281         dev->features |= NETIF_F_LLTX;
 282         dev->destructor = veth_dev_free;
 283
 284         dev->hw_features = NETIF_F_NO_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
 285 }
 286
 287 /*
 288  * netlink interface
 289  */
 290
 291 static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
 292 {
 293         if (tb[IFLA_ADDRESS]) {
 294                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 295                         return -EINVAL;
 296                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 297                         return -EADDRNOTAVAIL;
 298         }
 299         if (tb[IFLA_MTU]) {
 300                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
 301                         return -EINVAL;
 302         }
 303         return 0;
 304 }
 305
 306 static struct rtnl_link_ops veth_link_ops;
 307
 308 static int veth_newlink(struct net *src_net, struct net_device *dev,
 309                          struct nlattr *tb[], struct nlattr *data[])
 310 {
 311         int err;
 312         struct net_device *peer;
 313         struct veth_priv *priv;
 314         char ifname[IFNAMSIZ];
 315         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
 316         struct ifinfomsg *ifmp;
 317         struct net *net;
 318
 319         /*
 320          * create and register peer first
 321          */
 322         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
 323                 struct nlattr *nla_peer;
 324
 325                 nla_peer = data[VETH_INFO_PEER];
 326                 ifmp = nla_data(nla_peer);
 327                 err = nla_parse(peer_tb, IFLA_MAX,
 328                                 nla_data(nla_peer) + sizeof(struct ifinfomsg),
 329                                 nla_len(nla_peer) - sizeof(struct ifinfomsg),
 330                                 ifla_policy);
 331                 if (err < 0)
 332                         return err;
 333
 334                 err = veth_validate(peer_tb, NULL);
 335                 if (err < 0)
 336                         return err;
 337
 338                 tbp = peer_tb;
 339         } else {
 340                 ifmp = NULL;
 341                 tbp = tb;
 342         }
 343
 344         if (tbp[IFLA_IFNAME])
 345                 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
 346         else
 347                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
 348
 349         net = rtnl_link_get_net(src_net, tbp);
 350         if (IS_ERR(net))
 351                 return PTR_ERR(net);
 352
 353         peer = rtnl_create_link(src_net, net, ifname, &veth_link_ops, tbp);
 354         if (IS_ERR(peer)) {
 355                 put_net(net);
 356                 return PTR_ERR(peer);
 357         }
 358
 359         if (tbp[IFLA_ADDRESS] == NULL)
 360                 random_ether_addr(peer->dev_addr);
 361
 362         err = register_netdevice(peer);
 363         put_net(net);
 364         net = NULL;
 365         if (err < 0)
 366                 goto err_register_peer;
 367
 368         netif_carrier_off(peer);
 369
 370         err = rtnl_configure_link(peer, ifmp);
 371         if (err < 0)
 372                 goto err_configure_peer;
 373
 374         /*
 375          * register dev last
 376          *
 377          * note, that since we've registered new device the dev's name
 378          * should be re-allocated
 379          */
 380
 381         if (tb[IFLA_ADDRESS] == NULL)
 382                 random_ether_addr(dev->dev_addr);
 383
 384         if (tb[IFLA_IFNAME])
 385                 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
 386         else
 387                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
 388
 389         if (strchr(dev->name, '%')) {
 390                 err = dev_alloc_name(dev, dev->name);
 391                 if (err < 0)
 392                         goto err_alloc_name;
 393         }
 394
 395         err = register_netdevice(dev);
 396         if (err < 0)
 397                 goto err_register_dev;
 398
 399         netif_carrier_off(dev);
 400
 401         /*
 402          * tie the deviced together
 403          */
 404
 405         priv = netdev_priv(dev);
 406         priv->peer = peer;
 407
 408         priv = netdev_priv(peer);
 409         priv->peer = dev;
 410         return 0;
 411
 412 err_register_dev:
 413         /* nothing to do */
 414 err_alloc_name:
 415 err_configure_peer:
 416         unregister_netdevice(peer);
 417         return err;
 418
 419 err_register_peer:
 420         free_netdev(peer);
 421         return err;
 422 }
 423
 424 static void veth_dellink(struct net_device *dev, struct list_head *head)
 425 {
 426         struct veth_priv *priv;
 427         struct net_device *peer;
 428
 429         priv = netdev_priv(dev);
 430         peer = priv->peer;
 431
 432         unregister_netdevice_queue(dev, head);
 433         unregister_netdevice_queue(peer, head);
 434 }
 435
 436 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];
 437
 438 static struct rtnl_link_ops veth_link_ops = {
 439         .kind           = DRV_NAME,
 440         .priv_size      = sizeof(struct veth_priv),
 441         .setup          = veth_setup,
 442         .validate       = veth_validate,
 443         .newlink        = veth_newlink,
 444         .dellink        = veth_dellink,
 445         .policy         = veth_policy,
 446         .maxtype        = VETH_INFO_MAX,
 447 };
 448
 449 /*
 450  * init/fini
 451  */
 452
 453 static __init int veth_init(void)
 454 {
 455         return rtnl_link_register(&veth_link_ops);
 456 }
 457
 458 static __exit void veth_exit(void)
 459 {
 460         rtnl_link_unregister(&veth_link_ops);
 461 }
 462
 463 module_init(veth_init);
 464 module_exit(veth_exit);
 465
 466 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
 467 MODULE_LICENSE("GPL v2");
 468 MODULE_ALIAS_RTNL_LINK(DRV_NAME);