/* * drivers/net/veth.c * * Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc * * Author: Pavel Emelianov <xemul@openvz.org> * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com> * */ #include <linux/netdevice.h> #include <linux/slab.h> #include <linux/ethtool.h> #include <linux/etherdevice.h> #include <linux/u64_stats_sync.h> #include <net/rtnetlink.h> #include <net/dst.h> #include <net/xfrm.h> #include <linux/veth.h> #include <linux/module.h> #define DRV_NAME "veth" #define DRV_VERSION "1.0" #define MIN_MTU 68 /* Min L3 MTU */ #define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */ struct pcpu_vstats { u64 packets; u64 bytes; struct u64_stats_sync syncp; }; struct veth_priv { struct net_device __rcu *peer; atomic64_t dropped; unsigned requested_headroom; }; /* * ethtool interface */ static struct { const char string[ETH_GSTRING_LEN]; } ethtool_stats_keys[] = { { "peer_ifindex" }, }; static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd) { cmd->supported = 0; cmd->advertising = 0; ethtool_cmd_speed_set(cmd, SPEED_10000); cmd->duplex = DUPLEX_FULL; cmd->port = PORT_TP; cmd->phy_address = 0; cmd->transceiver = XCVR_INTERNAL; cmd->autoneg = AUTONEG_DISABLE; cmd->maxtxpkt = 0; cmd->maxrxpkt = 0; return 0; } static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) { strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); strlcpy(info->version, DRV_VERSION, sizeof(info->version)); } static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf) { switch(stringset) { case ETH_SS_STATS: memcpy(buf, ðtool_stats_keys, sizeof(ethtool_stats_keys)); break; } } static int veth_get_sset_count(struct net_device *dev, int sset) { switch (sset) { case ETH_SS_STATS: return ARRAY_SIZE(ethtool_stats_keys); default: return -EOPNOTSUPP; } } static void veth_get_ethtool_stats(struct net_device *dev, struct ethtool_stats *stats, u64 *data) { struct veth_priv *priv = netdev_priv(dev); struct net_device *peer = rtnl_dereference(priv->peer); data[0] = peer ? peer->ifindex : 0; } static const struct ethtool_ops veth_ethtool_ops = { .get_settings = veth_get_settings, .get_drvinfo = veth_get_drvinfo, .get_link = ethtool_op_get_link, .get_strings = veth_get_strings, .get_sset_count = veth_get_sset_count, .get_ethtool_stats = veth_get_ethtool_stats, }; static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); struct net_device *rcv; int length = skb->len; rcu_read_lock(); rcv = rcu_dereference(priv->peer); if (unlikely(!rcv)) { kfree_skb(skb); goto drop; } if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) { struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats); u64_stats_update_begin(&stats->syncp); stats->bytes += length; stats->packets++; u64_stats_update_end(&stats->syncp); } else { drop: atomic64_inc(&priv->dropped); } rcu_read_unlock(); return NETDEV_TX_OK; } /* * general routines */ static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); int cpu; result->packets = 0; result->bytes = 0; for_each_possible_cpu(cpu) { struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu); u64 packets, bytes; unsigned int start; do { start = u64_stats_fetch_begin_irq(&stats->syncp); packets = stats->packets; bytes = stats->bytes; } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); result->packets += packets; result->bytes += bytes; } return atomic64_read(&priv->dropped); } static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *tot) { struct veth_priv *priv = netdev_priv(dev); struct net_device *peer; struct pcpu_vstats one; tot->tx_dropped = veth_stats_one(&one, dev); tot->tx_bytes = one.bytes; tot->tx_packets = one.packets; rcu_read_lock(); peer = rcu_dereference(priv->peer); if (peer) { tot->rx_dropped = veth_stats_one(&one, peer); tot->rx_bytes = one.bytes; tot->rx_packets = one.packets; } rcu_read_unlock(); return tot; } /* fake multicast ability */ static void veth_set_multicast_list(struct net_device *dev) { } static int veth_open(struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); struct net_device *peer = rtnl_dereference(priv->peer); if (!peer) return -ENOTCONN; if (peer->flags & IFF_UP) { netif_carrier_on(dev); netif_carrier_on(peer); } return 0; } static int veth_close(struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); struct net_device *peer = rtnl_dereference(priv->peer); netif_carrier_off(dev); if (peer) netif_carrier_off(peer); return 0; } static int is_valid_veth_mtu(int new_mtu) { return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU; } static int veth_change_mtu(struct net_device *dev, int new_mtu) { if (!is_valid_veth_mtu(new_mtu)) return -EINVAL; dev->mtu = new_mtu; return 0; } static int veth_dev_init(struct net_device *dev) { dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats); if (!dev->vstats) return -ENOMEM; return 0; } static void veth_dev_free(struct net_device *dev) { free_percpu(dev->vstats); free_netdev(dev); } #ifdef CONFIG_NET_POLL_CONTROLLER static void veth_poll_controller(struct net_device *dev) { /* veth only receives frames when its peer sends one * Since it's a synchronous operation, we are guaranteed * never to have pending data when we poll for it so * there is nothing to do here. * * We need this though so netpoll recognizes us as an interface that * supports polling, which enables bridge devices in virt setups to * still use netconsole */ } #endif /* CONFIG_NET_POLL_CONTROLLER */ static int veth_get_iflink(const struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); struct net_device *peer; int iflink; rcu_read_lock(); peer = rcu_dereference(priv->peer); iflink = peer ? peer->ifindex : 0; rcu_read_unlock(); return iflink; } static void veth_set_rx_headroom(struct net_device *dev, int new_hr) { struct veth_priv *peer_priv, *priv = netdev_priv(dev); struct net_device *peer; if (new_hr < 0) new_hr = 0; rcu_read_lock(); peer = rcu_dereference(priv->peer); if (unlikely(!peer)) goto out; peer_priv = netdev_priv(peer); priv->requested_headroom = new_hr; new_hr = max(priv->requested_headroom, peer_priv->requested_headroom); dev->needed_headroom = new_hr; peer->needed_headroom = new_hr; out: rcu_read_unlock(); } static const struct net_device_ops veth_netdev_ops = { .ndo_init = veth_dev_init, .ndo_open = veth_open, .ndo_stop = veth_close, .ndo_start_xmit = veth_xmit, .ndo_change_mtu = veth_change_mtu, .ndo_get_stats64 = veth_get_stats64, .ndo_set_rx_mode = veth_set_multicast_list, .ndo_set_mac_address = eth_mac_addr, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = veth_poll_controller, #endif .ndo_get_iflink = veth_get_iflink, .ndo_features_check = passthru_features_check, .ndo_set_rx_headroom = veth_set_rx_headroom, }; #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \ NETIF_F_HW_CSUM | NETIF_F_RXCSUM | NETIF_F_HIGHDMA | \ NETIF_F_GSO_GRE | NETIF_F_GSO_UDP_TUNNEL | \ NETIF_F_GSO_IPIP | NETIF_F_GSO_SIT | NETIF_F_UFO | \ NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \ NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX ) static void veth_setup(struct net_device *dev) { ether_setup(dev); dev->priv_flags &= ~IFF_TX_SKB_SHARING; dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; dev->priv_flags |= IFF_NO_QUEUE; dev->priv_flags |= IFF_PHONY_HEADROOM; dev->netdev_ops = &veth_netdev_ops; dev->ethtool_ops = &veth_ethtool_ops; dev->features |= NETIF_F_LLTX; dev->features |= VETH_FEATURES; dev->vlan_features = dev->features & ~(NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_STAG_RX); dev->destructor = veth_dev_free; dev->hw_features = VETH_FEATURES; dev->hw_enc_features = VETH_FEATURES; } /* * netlink interface */ static int veth_validate(struct nlattr *tb[], struct nlattr *data[]) { if (tb[IFLA_ADDRESS]) { if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) return -EINVAL; if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) return -EADDRNOTAVAIL; } if (tb[IFLA_MTU]) { if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU]))) return -EINVAL; } return 0; } static struct rtnl_link_ops veth_link_ops; static int veth_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { int err; struct net_device *peer; struct veth_priv *priv; char ifname[IFNAMSIZ]; struct nlattr *peer_tb[IFLA_MAX + 1], **tbp; unsigned char name_assign_type; struct ifinfomsg *ifmp; struct net *net; /* * create and register peer first */ if (data != NULL && data[VETH_INFO_PEER] != NULL) { struct nlattr *nla_peer; nla_peer = data[VETH_INFO_PEER]; ifmp = nla_data(nla_peer); err = rtnl_nla_parse_ifla(peer_tb, nla_data(nla_peer) + sizeof(struct ifinfomsg), nla_len(nla_peer) - sizeof(struct ifinfomsg)); if (err < 0) return err; err = veth_validate(peer_tb, NULL); if (err < 0) return err; tbp = peer_tb; } else { ifmp = NULL; tbp = tb; } if (tbp[IFLA_IFNAME]) { nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ); name_assign_type = NET_NAME_USER; } else { snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d"); name_assign_type = NET_NAME_ENUM; } net = rtnl_link_get_net(src_net, tbp); if (IS_ERR(net)) return PTR_ERR(net); peer = rtnl_create_link(net, ifname, name_assign_type, &veth_link_ops, tbp); if (IS_ERR(peer)) { put_net(net); return PTR_ERR(peer); } if (tbp[IFLA_ADDRESS] == NULL) eth_hw_addr_random(peer); if (ifmp && (dev->ifindex != 0)) peer->ifindex = ifmp->ifi_index; err = register_netdevice(peer); put_net(net); net = NULL; if (err < 0) goto err_register_peer; netif_carrier_off(peer); err = rtnl_configure_link(peer, ifmp); if (err < 0) goto err_configure_peer; /* * register dev last * * note, that since we've registered new device the dev's name * should be re-allocated */ if (tb[IFLA_ADDRESS] == NULL) eth_hw_addr_random(dev); if (tb[IFLA_IFNAME]) nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ); else snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d"); err = register_netdevice(dev); if (err < 0) goto err_register_dev; netif_carrier_off(dev); /* * tie the deviced together */ priv = netdev_priv(dev); rcu_assign_pointer(priv->peer, peer); priv = netdev_priv(peer); rcu_assign_pointer(priv->peer, dev); return 0; err_register_dev: /* nothing to do */ err_configure_peer: unregister_netdevice(peer); return err; err_register_peer: free_netdev(peer); return err; } static void veth_dellink(struct net_device *dev, struct list_head *head) { struct veth_priv *priv; struct net_device *peer; priv = netdev_priv(dev); peer = rtnl_dereference(priv->peer); /* Note : dellink() is called from default_device_exit_batch(), * before a rcu_synchronize() point. The devices are guaranteed * not being freed before one RCU grace period. */ RCU_INIT_POINTER(priv->peer, NULL); unregister_netdevice_queue(dev, head); if (peer) { priv = netdev_priv(peer); RCU_INIT_POINTER(priv->peer, NULL); unregister_netdevice_queue(peer, head); } } static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = { [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) }, }; static struct net *veth_get_link_net(const struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); struct net_device *peer = rtnl_dereference(priv->peer); return peer ? dev_net(peer) : dev_net(dev); } static struct rtnl_link_ops veth_link_ops = { .kind = DRV_NAME, .priv_size = sizeof(struct veth_priv), .setup = veth_setup, .validate = veth_validate, .newlink = veth_newlink, .dellink = veth_dellink, .policy = veth_policy, .maxtype = VETH_INFO_MAX, .get_link_net = veth_get_link_net, }; /* * init/fini */ static __init int veth_init(void) { return rtnl_link_register(&veth_link_ops); } static __exit void veth_exit(void) { rtnl_link_unregister(&veth_link_ops); } module_init(veth_init); module_exit(veth_exit); MODULE_DESCRIPTION("Virtual Ethernet Tunnel"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS_RTNL_LINK(DRV_NAME);