| /* |
| * L2TPv3 ethernet pseudowire driver |
| * |
| * Copyright (c) 2008,2009,2010 Katalix Systems Ltd |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/socket.h> |
| #include <linux/hash.h> |
| #include <linux/l2tp.h> |
| #include <linux/in.h> |
| #include <linux/etherdevice.h> |
| #include <linux/spinlock.h> |
| #include <net/sock.h> |
| #include <net/ip.h> |
| #include <net/icmp.h> |
| #include <net/udp.h> |
| #include <net/inet_common.h> |
| #include <net/inet_hashtables.h> |
| #include <net/tcp_states.h> |
| #include <net/protocol.h> |
| #include <net/xfrm.h> |
| #include <net/net_namespace.h> |
| #include <net/netns/generic.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| #include <linux/udp.h> |
| |
| #include "l2tp_core.h" |
| |
| /* Default device name. May be overridden by name specified by user */ |
| #define L2TP_ETH_DEV_NAME "l2tpeth%d" |
| |
| /* via netdev_priv() */ |
| struct l2tp_eth { |
| struct net_device *dev; |
| struct sock *tunnel_sock; |
| struct l2tp_session *session; |
| struct list_head list; |
| atomic_long_t tx_bytes; |
| atomic_long_t tx_packets; |
| atomic_long_t tx_dropped; |
| atomic_long_t rx_bytes; |
| atomic_long_t rx_packets; |
| atomic_long_t rx_errors; |
| }; |
| |
| /* via l2tp_session_priv() */ |
| struct l2tp_eth_sess { |
| struct net_device *dev; |
| }; |
| |
| /* per-net private data for this module */ |
| static unsigned int l2tp_eth_net_id; |
| struct l2tp_eth_net { |
| struct list_head l2tp_eth_dev_list; |
| spinlock_t l2tp_eth_lock; |
| }; |
| |
| static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net) |
| { |
| return net_generic(net, l2tp_eth_net_id); |
| } |
| |
| static int l2tp_eth_dev_init(struct net_device *dev) |
| { |
| struct l2tp_eth *priv = netdev_priv(dev); |
| |
| priv->dev = dev; |
| eth_hw_addr_random(dev); |
| eth_broadcast_addr(dev->broadcast); |
| netdev_lockdep_set_classes(dev); |
| |
| return 0; |
| } |
| |
| static void l2tp_eth_dev_uninit(struct net_device *dev) |
| { |
| struct l2tp_eth *priv = netdev_priv(dev); |
| struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev)); |
| |
| spin_lock(&pn->l2tp_eth_lock); |
| list_del_init(&priv->list); |
| spin_unlock(&pn->l2tp_eth_lock); |
| dev_put(dev); |
| } |
| |
| static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct l2tp_eth *priv = netdev_priv(dev); |
| struct l2tp_session *session = priv->session; |
| unsigned int len = skb->len; |
| int ret = l2tp_xmit_skb(session, skb, session->hdr_len); |
| |
| if (likely(ret == NET_XMIT_SUCCESS)) { |
| atomic_long_add(len, &priv->tx_bytes); |
| atomic_long_inc(&priv->tx_packets); |
| } else { |
| atomic_long_inc(&priv->tx_dropped); |
| } |
| return NETDEV_TX_OK; |
| } |
| |
| static struct rtnl_link_stats64 *l2tp_eth_get_stats64(struct net_device *dev, |
| struct rtnl_link_stats64 *stats) |
| { |
| struct l2tp_eth *priv = netdev_priv(dev); |
| |
| stats->tx_bytes = atomic_long_read(&priv->tx_bytes); |
| stats->tx_packets = atomic_long_read(&priv->tx_packets); |
| stats->tx_dropped = atomic_long_read(&priv->tx_dropped); |
| stats->rx_bytes = atomic_long_read(&priv->rx_bytes); |
| stats->rx_packets = atomic_long_read(&priv->rx_packets); |
| stats->rx_errors = atomic_long_read(&priv->rx_errors); |
| return stats; |
| } |
| |
| |
| static const struct net_device_ops l2tp_eth_netdev_ops = { |
| .ndo_init = l2tp_eth_dev_init, |
| .ndo_uninit = l2tp_eth_dev_uninit, |
| .ndo_start_xmit = l2tp_eth_dev_xmit, |
| .ndo_get_stats64 = l2tp_eth_get_stats64, |
| .ndo_set_mac_address = eth_mac_addr, |
| }; |
| |
| static void l2tp_eth_dev_setup(struct net_device *dev) |
| { |
| ether_setup(dev); |
| dev->priv_flags &= ~IFF_TX_SKB_SHARING; |
| dev->features |= NETIF_F_LLTX; |
| dev->netdev_ops = &l2tp_eth_netdev_ops; |
| dev->destructor = free_netdev; |
| } |
| |
| static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) |
| { |
| struct l2tp_eth_sess *spriv = l2tp_session_priv(session); |
| struct net_device *dev = spriv->dev; |
| struct l2tp_eth *priv = netdev_priv(dev); |
| |
| if (session->debug & L2TP_MSG_DATA) { |
| unsigned int length; |
| |
| length = min(32u, skb->len); |
| if (!pskb_may_pull(skb, length)) |
| goto error; |
| |
| pr_debug("%s: eth recv\n", session->name); |
| print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); |
| } |
| |
| if (!pskb_may_pull(skb, ETH_HLEN)) |
| goto error; |
| |
| secpath_reset(skb); |
| |
| /* checksums verified by L2TP */ |
| skb->ip_summed = CHECKSUM_NONE; |
| |
| skb_dst_drop(skb); |
| nf_reset(skb); |
| |
| if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { |
| atomic_long_inc(&priv->rx_packets); |
| atomic_long_add(data_len, &priv->rx_bytes); |
| } else { |
| atomic_long_inc(&priv->rx_errors); |
| } |
| return; |
| |
| error: |
| atomic_long_inc(&priv->rx_errors); |
| kfree_skb(skb); |
| } |
| |
| static void l2tp_eth_delete(struct l2tp_session *session) |
| { |
| struct l2tp_eth_sess *spriv; |
| struct net_device *dev; |
| |
| if (session) { |
| spriv = l2tp_session_priv(session); |
| dev = spriv->dev; |
| if (dev) { |
| unregister_netdev(dev); |
| spriv->dev = NULL; |
| module_put(THIS_MODULE); |
| } |
| } |
| } |
| |
| #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) |
| static void l2tp_eth_show(struct seq_file *m, void *arg) |
| { |
| struct l2tp_session *session = arg; |
| struct l2tp_eth_sess *spriv = l2tp_session_priv(session); |
| struct net_device *dev = spriv->dev; |
| |
| seq_printf(m, " interface %s\n", dev->name); |
| } |
| #endif |
| |
| static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel, |
| struct l2tp_session *session, |
| struct net_device *dev) |
| { |
| unsigned int overhead = 0; |
| struct dst_entry *dst; |
| u32 l3_overhead = 0; |
| |
| /* if the encap is UDP, account for UDP header size */ |
| if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { |
| overhead += sizeof(struct udphdr); |
| dev->needed_headroom += sizeof(struct udphdr); |
| } |
| if (session->mtu != 0) { |
| dev->mtu = session->mtu; |
| dev->needed_headroom += session->hdr_len; |
| return; |
| } |
| l3_overhead = kernel_sock_ip_overhead(tunnel->sock); |
| if (l3_overhead == 0) { |
| /* L3 Overhead couldn't be identified, this could be |
| * because tunnel->sock was NULL or the socket's |
| * address family was not IPv4 or IPv6, |
| * dev mtu stays at 1500. |
| */ |
| return; |
| } |
| /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr |
| * UDP overhead, if any, was already factored in above. |
| */ |
| overhead += session->hdr_len + ETH_HLEN + l3_overhead; |
| |
| /* If PMTU discovery was enabled, use discovered MTU on L2TP device */ |
| dst = sk_dst_get(tunnel->sock); |
| if (dst) { |
| /* dst_mtu will use PMTU if found, else fallback to intf MTU */ |
| u32 pmtu = dst_mtu(dst); |
| |
| if (pmtu != 0) |
| dev->mtu = pmtu; |
| dst_release(dst); |
| } |
| session->mtu = dev->mtu - overhead; |
| dev->mtu = session->mtu; |
| dev->needed_headroom += session->hdr_len; |
| } |
| |
| static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) |
| { |
| struct net_device *dev; |
| char name[IFNAMSIZ]; |
| struct l2tp_tunnel *tunnel; |
| struct l2tp_session *session; |
| struct l2tp_eth *priv; |
| struct l2tp_eth_sess *spriv; |
| int rc; |
| struct l2tp_eth_net *pn; |
| |
| tunnel = l2tp_tunnel_find(net, tunnel_id); |
| if (!tunnel) { |
| rc = -ENODEV; |
| goto out; |
| } |
| |
| if (cfg->ifname) { |
| dev = dev_get_by_name(net, cfg->ifname); |
| if (dev) { |
| dev_put(dev); |
| rc = -EEXIST; |
| goto out; |
| } |
| strlcpy(name, cfg->ifname, IFNAMSIZ); |
| } else |
| strcpy(name, L2TP_ETH_DEV_NAME); |
| |
| session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, |
| peer_session_id, cfg); |
| if (IS_ERR(session)) { |
| rc = PTR_ERR(session); |
| goto out; |
| } |
| |
| dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, |
| l2tp_eth_dev_setup); |
| if (!dev) { |
| rc = -ENOMEM; |
| goto out_del_session; |
| } |
| |
| dev_net_set(dev, net); |
| l2tp_eth_adjust_mtu(tunnel, session, dev); |
| |
| priv = netdev_priv(dev); |
| priv->dev = dev; |
| priv->session = session; |
| INIT_LIST_HEAD(&priv->list); |
| |
| priv->tunnel_sock = tunnel->sock; |
| session->recv_skb = l2tp_eth_dev_recv; |
| session->session_close = l2tp_eth_delete; |
| #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) |
| session->show = l2tp_eth_show; |
| #endif |
| |
| spriv = l2tp_session_priv(session); |
| spriv->dev = dev; |
| |
| rc = register_netdev(dev); |
| if (rc < 0) |
| goto out_del_dev; |
| |
| __module_get(THIS_MODULE); |
| /* Must be done after register_netdev() */ |
| strlcpy(session->ifname, dev->name, IFNAMSIZ); |
| |
| dev_hold(dev); |
| pn = l2tp_eth_pernet(dev_net(dev)); |
| spin_lock(&pn->l2tp_eth_lock); |
| list_add(&priv->list, &pn->l2tp_eth_dev_list); |
| spin_unlock(&pn->l2tp_eth_lock); |
| |
| return 0; |
| |
| out_del_dev: |
| free_netdev(dev); |
| spriv->dev = NULL; |
| out_del_session: |
| l2tp_session_delete(session); |
| out: |
| return rc; |
| } |
| |
| static __net_init int l2tp_eth_init_net(struct net *net) |
| { |
| struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id); |
| |
| INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); |
| spin_lock_init(&pn->l2tp_eth_lock); |
| |
| return 0; |
| } |
| |
| static struct pernet_operations l2tp_eth_net_ops = { |
| .init = l2tp_eth_init_net, |
| .id = &l2tp_eth_net_id, |
| .size = sizeof(struct l2tp_eth_net), |
| }; |
| |
| |
| static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { |
| .session_create = l2tp_eth_create, |
| .session_delete = l2tp_session_delete, |
| }; |
| |
| |
| static int __init l2tp_eth_init(void) |
| { |
| int err = 0; |
| |
| err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); |
| if (err) |
| goto out; |
| |
| err = register_pernet_device(&l2tp_eth_net_ops); |
| if (err) |
| goto out_unreg; |
| |
| pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); |
| |
| return 0; |
| |
| out_unreg: |
| l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); |
| out: |
| return err; |
| } |
| |
| static void __exit l2tp_eth_exit(void) |
| { |
| unregister_pernet_device(&l2tp_eth_net_ops); |
| l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); |
| } |
| |
| module_init(l2tp_eth_init); |
| module_exit(l2tp_eth_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); |
| MODULE_DESCRIPTION("L2TP ethernet pseudowire driver"); |
| MODULE_VERSION("1.0"); |
| MODULE_ALIAS_L2TP_PWTYPE(5); |