veth.c revision 57a7744e09867ebcfa0ccf1d6d529caa7728d552
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 29struct pcpu_vstats { 30 u64 packets; 31 u64 bytes; 32 struct u64_stats_sync syncp; 33}; 34 35struct veth_priv { 36 struct net_device __rcu *peer; 37 atomic64_t dropped; 38}; 39 40/* 41 * ethtool interface 42 */ 43 44static struct { 45 const char string[ETH_GSTRING_LEN]; 46} ethtool_stats_keys[] = { 47 { "peer_ifindex" }, 48}; 49 50static 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 65static 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 71static 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 80static 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 90static 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 99static 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 108static 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 { 135drop: 136 atomic64_inc(&priv->dropped); 137 } 138 rcu_read_unlock(); 139 return NETDEV_TX_OK; 140} 141 142/* 143 * general routines 144 */ 145 146static 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 169static 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 */ 193static void veth_set_multicast_list(struct net_device *dev) 194{ 195} 196 197static 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 212static 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 224static int is_valid_veth_mtu(int new_mtu) 225{ 226 return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU; 227} 228 229static 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 237static 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 245static void veth_dev_free(struct net_device *dev) 246{ 247 free_percpu(dev->vstats); 248 free_netdev(dev); 249} 250 251static 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 269static 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 | NETIF_F_HW_VLAN_STAG_TX); 282 dev->destructor = veth_dev_free; 283 284 dev->hw_features = VETH_FEATURES; 285 dev->hw_enc_features = VETH_FEATURES; 286} 287 288/* 289 * netlink interface 290 */ 291 292static int veth_validate(struct nlattr *tb[], struct nlattr *data[]) 293{ 294 if (tb[IFLA_ADDRESS]) { 295 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 296 return -EINVAL; 297 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 298 return -EADDRNOTAVAIL; 299 } 300 if (tb[IFLA_MTU]) { 301 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU]))) 302 return -EINVAL; 303 } 304 return 0; 305} 306 307static struct rtnl_link_ops veth_link_ops; 308 309static int veth_newlink(struct net *src_net, struct net_device *dev, 310 struct nlattr *tb[], struct nlattr *data[]) 311{ 312 int err; 313 struct net_device *peer; 314 struct veth_priv *priv; 315 char ifname[IFNAMSIZ]; 316 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp; 317 struct ifinfomsg *ifmp; 318 struct net *net; 319 320 /* 321 * create and register peer first 322 */ 323 if (data != NULL && data[VETH_INFO_PEER] != NULL) { 324 struct nlattr *nla_peer; 325 326 nla_peer = data[VETH_INFO_PEER]; 327 ifmp = nla_data(nla_peer); 328 err = rtnl_nla_parse_ifla(peer_tb, 329 nla_data(nla_peer) + sizeof(struct ifinfomsg), 330 nla_len(nla_peer) - sizeof(struct ifinfomsg)); 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(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 eth_hw_addr_random(peer); 361 362 if (ifmp && (dev->ifindex != 0)) 363 peer->ifindex = ifmp->ifi_index; 364 365 err = register_netdevice(peer); 366 put_net(net); 367 net = NULL; 368 if (err < 0) 369 goto err_register_peer; 370 371 netif_carrier_off(peer); 372 373 err = rtnl_configure_link(peer, ifmp); 374 if (err < 0) 375 goto err_configure_peer; 376 377 /* 378 * register dev last 379 * 380 * note, that since we've registered new device the dev's name 381 * should be re-allocated 382 */ 383 384 if (tb[IFLA_ADDRESS] == NULL) 385 eth_hw_addr_random(dev); 386 387 if (tb[IFLA_IFNAME]) 388 nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ); 389 else 390 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d"); 391 392 err = register_netdevice(dev); 393 if (err < 0) 394 goto err_register_dev; 395 396 netif_carrier_off(dev); 397 398 /* 399 * tie the deviced together 400 */ 401 402 priv = netdev_priv(dev); 403 rcu_assign_pointer(priv->peer, peer); 404 405 priv = netdev_priv(peer); 406 rcu_assign_pointer(priv->peer, dev); 407 return 0; 408 409err_register_dev: 410 /* nothing to do */ 411err_configure_peer: 412 unregister_netdevice(peer); 413 return err; 414 415err_register_peer: 416 free_netdev(peer); 417 return err; 418} 419 420static void veth_dellink(struct net_device *dev, struct list_head *head) 421{ 422 struct veth_priv *priv; 423 struct net_device *peer; 424 425 priv = netdev_priv(dev); 426 peer = rtnl_dereference(priv->peer); 427 428 /* Note : dellink() is called from default_device_exit_batch(), 429 * before a rcu_synchronize() point. The devices are guaranteed 430 * not being freed before one RCU grace period. 431 */ 432 RCU_INIT_POINTER(priv->peer, NULL); 433 unregister_netdevice_queue(dev, head); 434 435 if (peer) { 436 priv = netdev_priv(peer); 437 RCU_INIT_POINTER(priv->peer, NULL); 438 unregister_netdevice_queue(peer, head); 439 } 440} 441 442static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = { 443 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) }, 444}; 445 446static struct rtnl_link_ops veth_link_ops = { 447 .kind = DRV_NAME, 448 .priv_size = sizeof(struct veth_priv), 449 .setup = veth_setup, 450 .validate = veth_validate, 451 .newlink = veth_newlink, 452 .dellink = veth_dellink, 453 .policy = veth_policy, 454 .maxtype = VETH_INFO_MAX, 455}; 456 457/* 458 * init/fini 459 */ 460 461static __init int veth_init(void) 462{ 463 return rtnl_link_register(&veth_link_ops); 464} 465 466static __exit void veth_exit(void) 467{ 468 rtnl_link_unregister(&veth_link_ops); 469} 470 471module_init(veth_init); 472module_exit(veth_exit); 473 474MODULE_DESCRIPTION("Virtual Ethernet Tunnel"); 475MODULE_LICENSE("GPL v2"); 476MODULE_ALIAS_RTNL_LINK(DRV_NAME); 477