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/rtnetlink.h> 18 #include <net/dst.h> 19 #include <net/xfrm.h> 20 #include <linux/veth.h> 21 #include <linux/module.h> 22 23 #define DRV_NAME "veth" 24 #define DRV_VERSION "1.0" 25 26 #define MIN_MTU 68 /* Min L3 MTU */ 27 #define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */ 28 29 struct pcpu_vstats { 30 u64 packets; 31 u64 bytes; 32 struct u64_stats_sync syncp; 33 }; 34 35 struct veth_priv { 36 struct net_device __rcu *peer; 37 atomic64_t dropped; 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 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 68 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 69 } 70 71 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf) 72 { 73 switch(stringset) { 74 case ETH_SS_STATS: 75 memcpy(buf, ðtool_stats_keys, sizeof(ethtool_stats_keys)); 76 break; 77 } 78 } 79 80 static int veth_get_sset_count(struct net_device *dev, int sset) 81 { 82 switch (sset) { 83 case ETH_SS_STATS: 84 return ARRAY_SIZE(ethtool_stats_keys); 85 default: 86 return -EOPNOTSUPP; 87 } 88 } 89 90 static void veth_get_ethtool_stats(struct net_device *dev, 91 struct ethtool_stats *stats, u64 *data) 92 { 93 struct veth_priv *priv = netdev_priv(dev); 94 struct net_device *peer = rtnl_dereference(priv->peer); 95 96 data[0] = peer ? peer->ifindex : 0; 97 } 98 99 static const struct ethtool_ops veth_ethtool_ops = { 100 .get_settings = veth_get_settings, 101 .get_drvinfo = veth_get_drvinfo, 102 .get_link = ethtool_op_get_link, 103 .get_strings = veth_get_strings, 104 .get_sset_count = veth_get_sset_count, 105 .get_ethtool_stats = veth_get_ethtool_stats, 106 }; 107 108 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) 109 { 110 struct veth_priv *priv = netdev_priv(dev); 111 struct net_device *rcv; 112 int length = skb->len; 113 114 rcu_read_lock(); 115 rcv = rcu_dereference(priv->peer); 116 if (unlikely(!rcv)) { 117 kfree_skb(skb); 118 goto drop; 119 } 120 /* don't change ip_summed == CHECKSUM_PARTIAL, as that 121 * will cause bad checksum on forwarded packets 122 */ 123 if (skb->ip_summed == CHECKSUM_NONE && 124 rcv->features & NETIF_F_RXCSUM) 125 skb->ip_summed = CHECKSUM_UNNECESSARY; 126 127 if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) { 128 struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats); 129 130 u64_stats_update_begin(&stats->syncp); 131 stats->bytes += length; 132 stats->packets++; 133 u64_stats_update_end(&stats->syncp); 134 } else { 135 drop: 136 atomic64_inc(&priv->dropped); 137 } 138 rcu_read_unlock(); 139 return NETDEV_TX_OK; 140 } 141 142 /* 143 * general routines 144 */ 145 146 static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev) 147 { 148 struct veth_priv *priv = netdev_priv(dev); 149 int cpu; 150 151 result->packets = 0; 152 result->bytes = 0; 153 for_each_possible_cpu(cpu) { 154 struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu); 155 u64 packets, bytes; 156 unsigned int start; 157 158 do { 159 start = u64_stats_fetch_begin_irq(&stats->syncp); 160 packets = stats->packets; 161 bytes = stats->bytes; 162 } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); 163 result->packets += packets; 164 result->bytes += bytes; 165 } 166 return atomic64_read(&priv->dropped); 167 } 168 169 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev, 170 struct rtnl_link_stats64 *tot) 171 { 172 struct veth_priv *priv = netdev_priv(dev); 173 struct net_device *peer; 174 struct pcpu_vstats one; 175 176 tot->tx_dropped = veth_stats_one(&one, dev); 177 tot->tx_bytes = one.bytes; 178 tot->tx_packets = one.packets; 179 180 rcu_read_lock(); 181 peer = rcu_dereference(priv->peer); 182 if (peer) { 183 tot->rx_dropped = veth_stats_one(&one, peer); 184 tot->rx_bytes = one.bytes; 185 tot->rx_packets = one.packets; 186 } 187 rcu_read_unlock(); 188 189 return tot; 190 } 191 192 /* fake multicast ability */ 193 static void veth_set_multicast_list(struct net_device *dev) 194 { 195 } 196 197 static int veth_open(struct net_device *dev) 198 { 199 struct veth_priv *priv = netdev_priv(dev); 200 struct net_device *peer = rtnl_dereference(priv->peer); 201 202 if (!peer) 203 return -ENOTCONN; 204 205 if (peer->flags & IFF_UP) { 206 netif_carrier_on(dev); 207 netif_carrier_on(peer); 208 } 209 return 0; 210 } 211 212 static int veth_close(struct net_device *dev) 213 { 214 struct veth_priv *priv = netdev_priv(dev); 215 struct net_device *peer = rtnl_dereference(priv->peer); 216 217 netif_carrier_off(dev); 218 if (peer) 219 netif_carrier_off(peer); 220 221 return 0; 222 } 223 224 static int is_valid_veth_mtu(int new_mtu) 225 { 226 return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU; 227 } 228 229 static int veth_change_mtu(struct net_device *dev, int new_mtu) 230 { 231 if (!is_valid_veth_mtu(new_mtu)) 232 return -EINVAL; 233 dev->mtu = new_mtu; 234 return 0; 235 } 236 237 static int veth_dev_init(struct net_device *dev) 238 { 239 dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats); 240 if (!dev->vstats) 241 return -ENOMEM; 242 return 0; 243 } 244 245 static void veth_dev_free(struct net_device *dev) 246 { 247 free_percpu(dev->vstats); 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_stats64 = veth_get_stats64, 258 .ndo_set_rx_mode = veth_set_multicast_list, 259 .ndo_set_mac_address = eth_mac_addr, 260 }; 261 262 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \ 263 NETIF_F_HW_CSUM | NETIF_F_RXCSUM | NETIF_F_HIGHDMA | \ 264 NETIF_F_GSO_GRE | NETIF_F_GSO_UDP_TUNNEL | \ 265 NETIF_F_GSO_IPIP | NETIF_F_GSO_SIT | NETIF_F_UFO | \ 266 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \ 267 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX ) 268 269 static void veth_setup(struct net_device *dev) 270 { 271 ether_setup(dev); 272 273 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 274 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 275 276 dev->netdev_ops = &veth_netdev_ops; 277 dev->ethtool_ops = &veth_ethtool_ops; 278 dev->features |= NETIF_F_LLTX; 279 dev->features |= VETH_FEATURES; 280 dev->vlan_features = dev->features & 281 ~(NETIF_F_HW_VLAN_CTAG_TX | 282 NETIF_F_HW_VLAN_STAG_TX | 283 NETIF_F_HW_VLAN_CTAG_RX | 284 NETIF_F_HW_VLAN_STAG_RX); 285 dev->destructor = veth_dev_free; 286 287 dev->hw_features = VETH_FEATURES; 288 dev->hw_enc_features = VETH_FEATURES; 289 } 290 291 /* 292 * netlink interface 293 */ 294 295 static int veth_validate(struct nlattr *tb[], struct nlattr *data[]) 296 { 297 if (tb[IFLA_ADDRESS]) { 298 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 299 return -EINVAL; 300 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 301 return -EADDRNOTAVAIL; 302 } 303 if (tb[IFLA_MTU]) { 304 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU]))) 305 return -EINVAL; 306 } 307 return 0; 308 } 309 310 static struct rtnl_link_ops veth_link_ops; 311 312 static int veth_newlink(struct net *src_net, struct net_device *dev, 313 struct nlattr *tb[], struct nlattr *data[]) 314 { 315 int err; 316 struct net_device *peer; 317 struct veth_priv *priv; 318 char ifname[IFNAMSIZ]; 319 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp; 320 struct ifinfomsg *ifmp; 321 struct net *net; 322 323 /* 324 * create and register peer first 325 */ 326 if (data != NULL && data[VETH_INFO_PEER] != NULL) { 327 struct nlattr *nla_peer; 328 329 nla_peer = data[VETH_INFO_PEER]; 330 ifmp = nla_data(nla_peer); 331 err = rtnl_nla_parse_ifla(peer_tb, 332 nla_data(nla_peer) + sizeof(struct ifinfomsg), 333 nla_len(nla_peer) - sizeof(struct ifinfomsg)); 334 if (err < 0) 335 return err; 336 337 err = veth_validate(peer_tb, NULL); 338 if (err < 0) 339 return err; 340 341 tbp = peer_tb; 342 } else { 343 ifmp = NULL; 344 tbp = tb; 345 } 346 347 if (tbp[IFLA_IFNAME]) 348 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ); 349 else 350 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d"); 351 352 net = rtnl_link_get_net(src_net, tbp); 353 if (IS_ERR(net)) 354 return PTR_ERR(net); 355 356 peer = rtnl_create_link(net, ifname, &veth_link_ops, tbp); 357 if (IS_ERR(peer)) { 358 put_net(net); 359 return PTR_ERR(peer); 360 } 361 362 if (tbp[IFLA_ADDRESS] == NULL) 363 eth_hw_addr_random(peer); 364 365 if (ifmp && (dev->ifindex != 0)) 366 peer->ifindex = ifmp->ifi_index; 367 368 err = register_netdevice(peer); 369 put_net(net); 370 net = NULL; 371 if (err < 0) 372 goto err_register_peer; 373 374 netif_carrier_off(peer); 375 376 err = rtnl_configure_link(peer, ifmp); 377 if (err < 0) 378 goto err_configure_peer; 379 380 /* 381 * register dev last 382 * 383 * note, that since we've registered new device the dev's name 384 * should be re-allocated 385 */ 386 387 if (tb[IFLA_ADDRESS] == NULL) 388 eth_hw_addr_random(dev); 389 390 if (tb[IFLA_IFNAME]) 391 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ); 392 else 393 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d"); 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 rcu_assign_pointer(priv->peer, peer); 407 408 priv = netdev_priv(peer); 409 rcu_assign_pointer(priv->peer, dev); 410 return 0; 411 412 err_register_dev: 413 /* nothing to do */ 414 err_configure_peer: 415 unregister_netdevice(peer); 416 return err; 417 418 err_register_peer: 419 free_netdev(peer); 420 return err; 421 } 422 423 static void veth_dellink(struct net_device *dev, struct list_head *head) 424 { 425 struct veth_priv *priv; 426 struct net_device *peer; 427 428 priv = netdev_priv(dev); 429 peer = rtnl_dereference(priv->peer); 430 431 /* Note : dellink() is called from default_device_exit_batch(), 432 * before a rcu_synchronize() point. The devices are guaranteed 433 * not being freed before one RCU grace period. 434 */ 435 RCU_INIT_POINTER(priv->peer, NULL); 436 unregister_netdevice_queue(dev, head); 437 438 if (peer) { 439 priv = netdev_priv(peer); 440 RCU_INIT_POINTER(priv->peer, NULL); 441 unregister_netdevice_queue(peer, head); 442 } 443 } 444 445 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = { 446 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) }, 447 }; 448 449 static struct rtnl_link_ops veth_link_ops = { 450 .kind = DRV_NAME, 451 .priv_size = sizeof(struct veth_priv), 452 .setup = veth_setup, 453 .validate = veth_validate, 454 .newlink = veth_newlink, 455 .dellink = veth_dellink, 456 .policy = veth_policy, 457 .maxtype = VETH_INFO_MAX, 458 }; 459 460 /* 461 * init/fini 462 */ 463 464 static __init int veth_init(void) 465 { 466 return rtnl_link_register(&veth_link_ops); 467 } 468 469 static __exit void veth_exit(void) 470 { 471 rtnl_link_unregister(&veth_link_ops); 472 } 473 474 module_init(veth_init); 475 module_exit(veth_exit); 476 477 MODULE_DESCRIPTION("Virtual Ethernet Tunnel"); 478 MODULE_LICENSE("GPL v2"); 479 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 480