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 unsigned requested_headroom; 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 ethtool_cmd_speed_set(cmd, 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 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 69 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 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, ðtool_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 = netdev_priv(dev); 95 struct net_device *peer = rtnl_dereference(priv->peer); 96 97 data[0] = peer ? peer->ifindex : 0; 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 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) 110 { 111 struct veth_priv *priv = netdev_priv(dev); 112 struct net_device *rcv; 113 int length = skb->len; 114 115 rcu_read_lock(); 116 rcv = rcu_dereference(priv->peer); 117 if (unlikely(!rcv)) { 118 kfree_skb(skb); 119 goto drop; 120 } 121 122 if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) { 123 struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats); 124 125 u64_stats_update_begin(&stats->syncp); 126 stats->bytes += length; 127 stats->packets++; 128 u64_stats_update_end(&stats->syncp); 129 } else { 130 drop: 131 atomic64_inc(&priv->dropped); 132 } 133 rcu_read_unlock(); 134 return NETDEV_TX_OK; 135 } 136 137 /* 138 * general routines 139 */ 140 141 static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev) 142 { 143 struct veth_priv *priv = netdev_priv(dev); 144 int cpu; 145 146 result->packets = 0; 147 result->bytes = 0; 148 for_each_possible_cpu(cpu) { 149 struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu); 150 u64 packets, bytes; 151 unsigned int start; 152 153 do { 154 start = u64_stats_fetch_begin_irq(&stats->syncp); 155 packets = stats->packets; 156 bytes = stats->bytes; 157 } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); 158 result->packets += packets; 159 result->bytes += bytes; 160 } 161 return atomic64_read(&priv->dropped); 162 } 163 164 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev, 165 struct rtnl_link_stats64 *tot) 166 { 167 struct veth_priv *priv = netdev_priv(dev); 168 struct net_device *peer; 169 struct pcpu_vstats one; 170 171 tot->tx_dropped = veth_stats_one(&one, dev); 172 tot->tx_bytes = one.bytes; 173 tot->tx_packets = one.packets; 174 175 rcu_read_lock(); 176 peer = rcu_dereference(priv->peer); 177 if (peer) { 178 tot->rx_dropped = veth_stats_one(&one, peer); 179 tot->rx_bytes = one.bytes; 180 tot->rx_packets = one.packets; 181 } 182 rcu_read_unlock(); 183 184 return tot; 185 } 186 187 /* fake multicast ability */ 188 static void veth_set_multicast_list(struct net_device *dev) 189 { 190 } 191 192 static int veth_open(struct net_device *dev) 193 { 194 struct veth_priv *priv = netdev_priv(dev); 195 struct net_device *peer = rtnl_dereference(priv->peer); 196 197 if (!peer) 198 return -ENOTCONN; 199 200 if (peer->flags & IFF_UP) { 201 netif_carrier_on(dev); 202 netif_carrier_on(peer); 203 } 204 return 0; 205 } 206 207 static int veth_close(struct net_device *dev) 208 { 209 struct veth_priv *priv = netdev_priv(dev); 210 struct net_device *peer = rtnl_dereference(priv->peer); 211 212 netif_carrier_off(dev); 213 if (peer) 214 netif_carrier_off(peer); 215 216 return 0; 217 } 218 219 static int is_valid_veth_mtu(int new_mtu) 220 { 221 return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU; 222 } 223 224 static int veth_change_mtu(struct net_device *dev, int new_mtu) 225 { 226 if (!is_valid_veth_mtu(new_mtu)) 227 return -EINVAL; 228 dev->mtu = new_mtu; 229 return 0; 230 } 231 232 static int veth_dev_init(struct net_device *dev) 233 { 234 dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats); 235 if (!dev->vstats) 236 return -ENOMEM; 237 return 0; 238 } 239 240 static void veth_dev_free(struct net_device *dev) 241 { 242 free_percpu(dev->vstats); 243 free_netdev(dev); 244 } 245 246 #ifdef CONFIG_NET_POLL_CONTROLLER 247 static void veth_poll_controller(struct net_device *dev) 248 { 249 /* veth only receives frames when its peer sends one 250 * Since it's a synchronous operation, we are guaranteed 251 * never to have pending data when we poll for it so 252 * there is nothing to do here. 253 * 254 * We need this though so netpoll recognizes us as an interface that 255 * supports polling, which enables bridge devices in virt setups to 256 * still use netconsole 257 */ 258 } 259 #endif /* CONFIG_NET_POLL_CONTROLLER */ 260 261 static int veth_get_iflink(const struct net_device *dev) 262 { 263 struct veth_priv *priv = netdev_priv(dev); 264 struct net_device *peer; 265 int iflink; 266 267 rcu_read_lock(); 268 peer = rcu_dereference(priv->peer); 269 iflink = peer ? peer->ifindex : 0; 270 rcu_read_unlock(); 271 272 return iflink; 273 } 274 275 static void veth_set_rx_headroom(struct net_device *dev, int new_hr) 276 { 277 struct veth_priv *peer_priv, *priv = netdev_priv(dev); 278 struct net_device *peer; 279 280 if (new_hr < 0) 281 new_hr = 0; 282 283 rcu_read_lock(); 284 peer = rcu_dereference(priv->peer); 285 if (unlikely(!peer)) 286 goto out; 287 288 peer_priv = netdev_priv(peer); 289 priv->requested_headroom = new_hr; 290 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom); 291 dev->needed_headroom = new_hr; 292 peer->needed_headroom = new_hr; 293 294 out: 295 rcu_read_unlock(); 296 } 297 298 static const struct net_device_ops veth_netdev_ops = { 299 .ndo_init = veth_dev_init, 300 .ndo_open = veth_open, 301 .ndo_stop = veth_close, 302 .ndo_start_xmit = veth_xmit, 303 .ndo_change_mtu = veth_change_mtu, 304 .ndo_get_stats64 = veth_get_stats64, 305 .ndo_set_rx_mode = veth_set_multicast_list, 306 .ndo_set_mac_address = eth_mac_addr, 307 #ifdef CONFIG_NET_POLL_CONTROLLER 308 .ndo_poll_controller = veth_poll_controller, 309 #endif 310 .ndo_get_iflink = veth_get_iflink, 311 .ndo_features_check = passthru_features_check, 312 .ndo_set_rx_headroom = veth_set_rx_headroom, 313 }; 314 315 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \ 316 NETIF_F_RXCSUM | NETIF_F_HIGHDMA | \ 317 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \ 318 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \ 319 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX ) 320 321 static void veth_setup(struct net_device *dev) 322 { 323 ether_setup(dev); 324 325 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 326 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 327 dev->priv_flags |= IFF_NO_QUEUE; 328 dev->priv_flags |= IFF_PHONY_HEADROOM; 329 330 dev->netdev_ops = &veth_netdev_ops; 331 dev->ethtool_ops = &veth_ethtool_ops; 332 dev->features |= NETIF_F_LLTX; 333 dev->features |= VETH_FEATURES; 334 dev->vlan_features = dev->features & 335 ~(NETIF_F_HW_VLAN_CTAG_TX | 336 NETIF_F_HW_VLAN_STAG_TX | 337 NETIF_F_HW_VLAN_CTAG_RX | 338 NETIF_F_HW_VLAN_STAG_RX); 339 dev->destructor = veth_dev_free; 340 341 dev->hw_features = VETH_FEATURES; 342 dev->hw_enc_features = VETH_FEATURES; 343 } 344 345 /* 346 * netlink interface 347 */ 348 349 static int veth_validate(struct nlattr *tb[], struct nlattr *data[]) 350 { 351 if (tb[IFLA_ADDRESS]) { 352 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 353 return -EINVAL; 354 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 355 return -EADDRNOTAVAIL; 356 } 357 if (tb[IFLA_MTU]) { 358 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU]))) 359 return -EINVAL; 360 } 361 return 0; 362 } 363 364 static struct rtnl_link_ops veth_link_ops; 365 366 static int veth_newlink(struct net *src_net, struct net_device *dev, 367 struct nlattr *tb[], struct nlattr *data[]) 368 { 369 int err; 370 struct net_device *peer; 371 struct veth_priv *priv; 372 char ifname[IFNAMSIZ]; 373 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp; 374 unsigned char name_assign_type; 375 struct ifinfomsg *ifmp; 376 struct net *net; 377 378 /* 379 * create and register peer first 380 */ 381 if (data != NULL && data[VETH_INFO_PEER] != NULL) { 382 struct nlattr *nla_peer; 383 384 nla_peer = data[VETH_INFO_PEER]; 385 ifmp = nla_data(nla_peer); 386 err = rtnl_nla_parse_ifla(peer_tb, 387 nla_data(nla_peer) + sizeof(struct ifinfomsg), 388 nla_len(nla_peer) - sizeof(struct ifinfomsg)); 389 if (err < 0) 390 return err; 391 392 err = veth_validate(peer_tb, NULL); 393 if (err < 0) 394 return err; 395 396 tbp = peer_tb; 397 } else { 398 ifmp = NULL; 399 tbp = tb; 400 } 401 402 if (tbp[IFLA_IFNAME]) { 403 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ); 404 name_assign_type = NET_NAME_USER; 405 } else { 406 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d"); 407 name_assign_type = NET_NAME_ENUM; 408 } 409 410 net = rtnl_link_get_net(src_net, tbp); 411 if (IS_ERR(net)) 412 return PTR_ERR(net); 413 414 peer = rtnl_create_link(net, ifname, name_assign_type, 415 &veth_link_ops, tbp); 416 if (IS_ERR(peer)) { 417 put_net(net); 418 return PTR_ERR(peer); 419 } 420 421 if (tbp[IFLA_ADDRESS] == NULL) 422 eth_hw_addr_random(peer); 423 424 if (ifmp && (dev->ifindex != 0)) 425 peer->ifindex = ifmp->ifi_index; 426 427 err = register_netdevice(peer); 428 put_net(net); 429 net = NULL; 430 if (err < 0) 431 goto err_register_peer; 432 433 netif_carrier_off(peer); 434 435 err = rtnl_configure_link(peer, ifmp); 436 if (err < 0) 437 goto err_configure_peer; 438 439 /* 440 * register dev last 441 * 442 * note, that since we've registered new device the dev's name 443 * should be re-allocated 444 */ 445 446 if (tb[IFLA_ADDRESS] == NULL) 447 eth_hw_addr_random(dev); 448 449 if (tb[IFLA_IFNAME]) 450 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ); 451 else 452 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d"); 453 454 err = register_netdevice(dev); 455 if (err < 0) 456 goto err_register_dev; 457 458 netif_carrier_off(dev); 459 460 /* 461 * tie the deviced together 462 */ 463 464 priv = netdev_priv(dev); 465 rcu_assign_pointer(priv->peer, peer); 466 467 priv = netdev_priv(peer); 468 rcu_assign_pointer(priv->peer, dev); 469 return 0; 470 471 err_register_dev: 472 /* nothing to do */ 473 err_configure_peer: 474 unregister_netdevice(peer); 475 return err; 476 477 err_register_peer: 478 free_netdev(peer); 479 return err; 480 } 481 482 static void veth_dellink(struct net_device *dev, struct list_head *head) 483 { 484 struct veth_priv *priv; 485 struct net_device *peer; 486 487 priv = netdev_priv(dev); 488 peer = rtnl_dereference(priv->peer); 489 490 /* Note : dellink() is called from default_device_exit_batch(), 491 * before a rcu_synchronize() point. The devices are guaranteed 492 * not being freed before one RCU grace period. 493 */ 494 RCU_INIT_POINTER(priv->peer, NULL); 495 unregister_netdevice_queue(dev, head); 496 497 if (peer) { 498 priv = netdev_priv(peer); 499 RCU_INIT_POINTER(priv->peer, NULL); 500 unregister_netdevice_queue(peer, head); 501 } 502 } 503 504 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = { 505 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) }, 506 }; 507 508 static struct net *veth_get_link_net(const struct net_device *dev) 509 { 510 struct veth_priv *priv = netdev_priv(dev); 511 struct net_device *peer = rtnl_dereference(priv->peer); 512 513 return peer ? dev_net(peer) : dev_net(dev); 514 } 515 516 static struct rtnl_link_ops veth_link_ops = { 517 .kind = DRV_NAME, 518 .priv_size = sizeof(struct veth_priv), 519 .setup = veth_setup, 520 .validate = veth_validate, 521 .newlink = veth_newlink, 522 .dellink = veth_dellink, 523 .policy = veth_policy, 524 .maxtype = VETH_INFO_MAX, 525 .get_link_net = veth_get_link_net, 526 }; 527 528 /* 529 * init/fini 530 */ 531 532 static __init int veth_init(void) 533 { 534 return rtnl_link_register(&veth_link_ops); 535 } 536 537 static __exit void veth_exit(void) 538 { 539 rtnl_link_unregister(&veth_link_ops); 540 } 541 542 module_init(veth_init); 543 module_exit(veth_exit); 544 545 MODULE_DESCRIPTION("Virtual Ethernet Tunnel"); 546 MODULE_LICENSE("GPL v2"); 547 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 548