veth.c revision 612c337306f00dc8d396830212de51c475844791
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#include <linux/module.h> 21 22#define DRV_NAME "veth" 23#define DRV_VERSION "1.0" 24 25#define MIN_MTU 68 /* Min L3 MTU */ 26#define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */ 27 28struct pcpu_vstats { 29 u64 packets; 30 u64 bytes; 31 struct u64_stats_sync syncp; 32}; 33 34struct veth_priv { 35 struct net_device __rcu *peer; 36 atomic64_t dropped; 37}; 38 39/* 40 * ethtool interface 41 */ 42 43static struct { 44 const char string[ETH_GSTRING_LEN]; 45} ethtool_stats_keys[] = { 46 { "peer_ifindex" }, 47}; 48 49static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) 50{ 51 cmd->supported = 0; 52 cmd->advertising = 0; 53 ethtool_cmd_speed_set(cmd, SPEED_10000); 54 cmd->duplex = DUPLEX_FULL; 55 cmd->port = PORT_TP; 56 cmd->phy_address = 0; 57 cmd->transceiver = XCVR_INTERNAL; 58 cmd->autoneg = AUTONEG_DISABLE; 59 cmd->maxtxpkt = 0; 60 cmd->maxrxpkt = 0; 61 return 0; 62} 63 64static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) 65{ 66 strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); 67 strlcpy(info->version, DRV_VERSION, sizeof(info->version)); 68} 69 70static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf) 71{ 72 switch(stringset) { 73 case ETH_SS_STATS: 74 memcpy(buf, ðtool_stats_keys, sizeof(ethtool_stats_keys)); 75 break; 76 } 77} 78 79static int veth_get_sset_count(struct net_device *dev, int sset) 80{ 81 switch (sset) { 82 case ETH_SS_STATS: 83 return ARRAY_SIZE(ethtool_stats_keys); 84 default: 85 return -EOPNOTSUPP; 86 } 87} 88 89static void veth_get_ethtool_stats(struct net_device *dev, 90 struct ethtool_stats *stats, u64 *data) 91{ 92 struct veth_priv *priv = netdev_priv(dev); 93 struct net_device *peer = rtnl_dereference(priv->peer); 94 95 data[0] = peer ? peer->ifindex : 0; 96} 97 98static const struct ethtool_ops veth_ethtool_ops = { 99 .get_settings = veth_get_settings, 100 .get_drvinfo = veth_get_drvinfo, 101 .get_link = ethtool_op_get_link, 102 .get_strings = veth_get_strings, 103 .get_sset_count = veth_get_sset_count, 104 .get_ethtool_stats = veth_get_ethtool_stats, 105}; 106 107static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) 108{ 109 struct veth_priv *priv = netdev_priv(dev); 110 struct net_device *rcv; 111 int length = skb->len; 112 113 rcu_read_lock(); 114 rcv = rcu_dereference(priv->peer); 115 if (unlikely(!rcv)) { 116 kfree_skb(skb); 117 goto drop; 118 } 119 /* don't change ip_summed == CHECKSUM_PARTIAL, as that 120 * will cause bad checksum on forwarded packets 121 */ 122 if (skb->ip_summed == CHECKSUM_NONE && 123 rcv->features & NETIF_F_RXCSUM) 124 skb->ip_summed = CHECKSUM_UNNECESSARY; 125 126 if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) { 127 struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats); 128 129 u64_stats_update_begin(&stats->syncp); 130 stats->bytes += length; 131 stats->packets++; 132 u64_stats_update_end(&stats->syncp); 133 } else { 134drop: 135 atomic64_inc(&priv->dropped); 136 } 137 rcu_read_unlock(); 138 return NETDEV_TX_OK; 139} 140 141/* 142 * general routines 143 */ 144 145static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev) 146{ 147 struct veth_priv *priv = netdev_priv(dev); 148 int cpu; 149 150 result->packets = 0; 151 result->bytes = 0; 152 for_each_possible_cpu(cpu) { 153 struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu); 154 u64 packets, bytes; 155 unsigned int start; 156 157 do { 158 start = u64_stats_fetch_begin_bh(&stats->syncp); 159 packets = stats->packets; 160 bytes = stats->bytes; 161 } while (u64_stats_fetch_retry_bh(&stats->syncp, start)); 162 result->packets += packets; 163 result->bytes += bytes; 164 } 165 return atomic64_read(&priv->dropped); 166} 167 168static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev, 169 struct rtnl_link_stats64 *tot) 170{ 171 struct veth_priv *priv = netdev_priv(dev); 172 struct net_device *peer; 173 struct pcpu_vstats one; 174 175 tot->tx_dropped = veth_stats_one(&one, dev); 176 tot->tx_bytes = one.bytes; 177 tot->tx_packets = one.packets; 178 179 rcu_read_lock(); 180 peer = rcu_dereference(priv->peer); 181 if (peer) { 182 tot->rx_dropped = veth_stats_one(&one, peer); 183 tot->rx_bytes = one.bytes; 184 tot->rx_packets = one.packets; 185 } 186 rcu_read_unlock(); 187 188 return tot; 189} 190 191static int veth_open(struct net_device *dev) 192{ 193 struct veth_priv *priv = netdev_priv(dev); 194 struct net_device *peer = rtnl_dereference(priv->peer); 195 196 if (!peer) 197 return -ENOTCONN; 198 199 if (peer->flags & IFF_UP) { 200 netif_carrier_on(dev); 201 netif_carrier_on(peer); 202 } 203 return 0; 204} 205 206static int veth_close(struct net_device *dev) 207{ 208 struct veth_priv *priv = netdev_priv(dev); 209 struct net_device *peer = rtnl_dereference(priv->peer); 210 211 netif_carrier_off(dev); 212 if (peer) 213 netif_carrier_off(peer); 214 215 return 0; 216} 217 218static int is_valid_veth_mtu(int new_mtu) 219{ 220 return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU; 221} 222 223static int veth_change_mtu(struct net_device *dev, int new_mtu) 224{ 225 if (!is_valid_veth_mtu(new_mtu)) 226 return -EINVAL; 227 dev->mtu = new_mtu; 228 return 0; 229} 230 231static int veth_dev_init(struct net_device *dev) 232{ 233 dev->vstats = alloc_percpu(struct pcpu_vstats); 234 if (!dev->vstats) 235 return -ENOMEM; 236 237 return 0; 238} 239 240static void veth_dev_free(struct net_device *dev) 241{ 242 free_percpu(dev->vstats); 243 free_netdev(dev); 244} 245 246static const struct net_device_ops veth_netdev_ops = { 247 .ndo_init = veth_dev_init, 248 .ndo_open = veth_open, 249 .ndo_stop = veth_close, 250 .ndo_start_xmit = veth_xmit, 251 .ndo_change_mtu = veth_change_mtu, 252 .ndo_get_stats64 = veth_get_stats64, 253 .ndo_set_mac_address = eth_mac_addr, 254}; 255 256#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \ 257 NETIF_F_HW_CSUM | NETIF_F_RXCSUM | NETIF_F_HIGHDMA | \ 258 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \ 259 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX ) 260 261static void veth_setup(struct net_device *dev) 262{ 263 ether_setup(dev); 264 265 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 266 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 267 268 dev->netdev_ops = &veth_netdev_ops; 269 dev->ethtool_ops = &veth_ethtool_ops; 270 dev->features |= NETIF_F_LLTX; 271 dev->features |= VETH_FEATURES; 272 dev->vlan_features = dev->features; 273 dev->destructor = veth_dev_free; 274 275 dev->hw_features = VETH_FEATURES; 276} 277 278/* 279 * netlink interface 280 */ 281 282static int veth_validate(struct nlattr *tb[], struct nlattr *data[]) 283{ 284 if (tb[IFLA_ADDRESS]) { 285 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 286 return -EINVAL; 287 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 288 return -EADDRNOTAVAIL; 289 } 290 if (tb[IFLA_MTU]) { 291 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU]))) 292 return -EINVAL; 293 } 294 return 0; 295} 296 297static struct rtnl_link_ops veth_link_ops; 298 299static int veth_newlink(struct net *src_net, struct net_device *dev, 300 struct nlattr *tb[], struct nlattr *data[]) 301{ 302 int err; 303 struct net_device *peer; 304 struct veth_priv *priv; 305 char ifname[IFNAMSIZ]; 306 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp; 307 struct ifinfomsg *ifmp; 308 struct net *net; 309 310 /* 311 * create and register peer first 312 */ 313 if (data != NULL && data[VETH_INFO_PEER] != NULL) { 314 struct nlattr *nla_peer; 315 316 nla_peer = data[VETH_INFO_PEER]; 317 ifmp = nla_data(nla_peer); 318 err = nla_parse(peer_tb, IFLA_MAX, 319 nla_data(nla_peer) + sizeof(struct ifinfomsg), 320 nla_len(nla_peer) - sizeof(struct ifinfomsg), 321 ifla_policy); 322 if (err < 0) 323 return err; 324 325 err = veth_validate(peer_tb, NULL); 326 if (err < 0) 327 return err; 328 329 tbp = peer_tb; 330 } else { 331 ifmp = NULL; 332 tbp = tb; 333 } 334 335 if (tbp[IFLA_IFNAME]) 336 nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ); 337 else 338 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d"); 339 340 net = rtnl_link_get_net(src_net, tbp); 341 if (IS_ERR(net)) 342 return PTR_ERR(net); 343 344 peer = rtnl_create_link(net, ifname, &veth_link_ops, tbp); 345 if (IS_ERR(peer)) { 346 put_net(net); 347 return PTR_ERR(peer); 348 } 349 350 if (tbp[IFLA_ADDRESS] == NULL) 351 eth_hw_addr_random(peer); 352 353 if (ifmp && (dev->ifindex != 0)) 354 peer->ifindex = ifmp->ifi_index; 355 356 err = register_netdevice(peer); 357 put_net(net); 358 net = NULL; 359 if (err < 0) 360 goto err_register_peer; 361 362 netif_carrier_off(peer); 363 364 err = rtnl_configure_link(peer, ifmp); 365 if (err < 0) 366 goto err_configure_peer; 367 368 /* 369 * register dev last 370 * 371 * note, that since we've registered new device the dev's name 372 * should be re-allocated 373 */ 374 375 if (tb[IFLA_ADDRESS] == NULL) 376 eth_hw_addr_random(dev); 377 378 if (tb[IFLA_IFNAME]) 379 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ); 380 else 381 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d"); 382 383 err = register_netdevice(dev); 384 if (err < 0) 385 goto err_register_dev; 386 387 netif_carrier_off(dev); 388 389 /* 390 * tie the deviced together 391 */ 392 393 priv = netdev_priv(dev); 394 rcu_assign_pointer(priv->peer, peer); 395 396 priv = netdev_priv(peer); 397 rcu_assign_pointer(priv->peer, dev); 398 return 0; 399 400err_register_dev: 401 /* nothing to do */ 402err_configure_peer: 403 unregister_netdevice(peer); 404 return err; 405 406err_register_peer: 407 free_netdev(peer); 408 return err; 409} 410 411static void veth_dellink(struct net_device *dev, struct list_head *head) 412{ 413 struct veth_priv *priv; 414 struct net_device *peer; 415 416 priv = netdev_priv(dev); 417 peer = rtnl_dereference(priv->peer); 418 419 /* Note : dellink() is called from default_device_exit_batch(), 420 * before a rcu_synchronize() point. The devices are guaranteed 421 * not being freed before one RCU grace period. 422 */ 423 RCU_INIT_POINTER(priv->peer, NULL); 424 unregister_netdevice_queue(dev, head); 425 426 if (peer) { 427 priv = netdev_priv(peer); 428 RCU_INIT_POINTER(priv->peer, NULL); 429 unregister_netdevice_queue(peer, head); 430 } 431} 432 433static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = { 434 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) }, 435}; 436 437static size_t veth_get_size(const struct net_device *dev) 438{ 439 return nla_total_size(sizeof(u64)) + /* VETH_INFO_PEER */ 440 0; 441} 442 443static int veth_fill_info(struct sk_buff *skb, const struct net_device *dev) 444{ 445 struct veth_priv *priv = netdev_priv(dev); 446 struct net_device *peer = rtnl_dereference(priv->peer); 447 u64 peer_ifindex; 448 449 peer_ifindex = peer ? peer->ifindex : 0; 450 if (nla_put_u64(skb, VETH_INFO_PEER, peer_ifindex)) 451 return -EMSGSIZE; 452 453 return 0; 454} 455 456static struct rtnl_link_ops veth_link_ops = { 457 .kind = DRV_NAME, 458 .priv_size = sizeof(struct veth_priv), 459 .setup = veth_setup, 460 .validate = veth_validate, 461 .newlink = veth_newlink, 462 .dellink = veth_dellink, 463 .policy = veth_policy, 464 .maxtype = VETH_INFO_MAX, 465 .get_size = veth_get_size, 466 .fill_info = veth_fill_info, 467}; 468 469/* 470 * init/fini 471 */ 472 473static __init int veth_init(void) 474{ 475 return rtnl_link_register(&veth_link_ops); 476} 477 478static __exit void veth_exit(void) 479{ 480 rtnl_link_unregister(&veth_link_ops); 481} 482 483module_init(veth_init); 484module_exit(veth_exit); 485 486MODULE_DESCRIPTION("Virtual Ethernet Tunnel"); 487MODULE_LICENSE("GPL v2"); 488MODULE_ALIAS_RTNL_LINK(DRV_NAME); 489