@@ -68,3 +68,27 @@ config L2TP_IP
To compile this driver as a module, choose M here. The module
will be called l2tp_ip.
+
+config L2TP_ETH
+ tristate "L2TP ethernet pseudowire support for L2TPv3"
+ depends on L2TP_V3
+ help
+ Support for carrying raw ethernet frames over L2TPv3.
+
+ From RFC 4719 <http://www.ietf.org/rfc/rfc4719.txt>.
+
+ The Layer 2 Tunneling Protocol, Version 3 (L2TPv3) can be
+ used as a control protocol and for data encapsulation to set
+ up Pseudowires for transporting layer 2 Packet Data Units
+ across an IP network [RFC3931].
+
+ This driver provides an ethernet virtual interface for each
+ L2TP ethernet pseudowire instance. Standard Linux tools may
+ be used to assign an IP address to the local virtual
+ interface, or add the interface to a bridge.
+
+ If you are using L2TPv3, you will almost certainly want to
+ enable this option.
+
+ To compile this driver as a module, choose M here. The module
+ will be called l2tp_eth.
@@ -8,3 +8,4 @@ obj-$(CONFIG_L2TP) += l2tp_core.o
obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_PPPOL2TP)) += l2tp_ppp.o
obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_IP)) += l2tp_ip.o
obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_V3)) += l2tp_netlink.o
+obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_ETH)) += l2tp_eth.o
new file mode 100644
@@ -0,0 +1,371 @@
+/*
+ * 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.
+ */
+
+#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 <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 "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;
+};
+
+/* 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;
+ rwlock_t l2tp_eth_lock;
+};
+
+static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
+{
+ BUG_ON(!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);
+ struct l2tp_session *session = priv->session;
+ __be32 sid = htonl(session->session_id);
+
+ priv->dev = dev;
+
+ /* Derive a MAC address for the new interface. We use the L2TP
+ * session's session-id to guarantee a system-wide unique
+ * address. This MAC is only visible within the L2TP session.
+ */
+ dev->dev_addr[0] = 0x02; /* IEEE 802 local */
+ dev->dev_addr[1] = 'L';
+ memcpy(&dev->dev_addr[2], &sid, 4);
+ memset(&dev->broadcast[0], 0xff, 6);
+
+ 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));
+
+ write_lock(&pn->l2tp_eth_lock);
+ list_del_init(&priv->list);
+ write_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;
+
+ l2tp_xmit_skb(session, skb, session->hdr_len);
+
+ dev->stats.tx_bytes += skb->len;
+ dev->stats.tx_packets++;
+
+ return 0;
+}
+
+static 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,
+};
+
+static void l2tp_eth_dev_setup(struct net_device *dev)
+{
+ ether_setup(dev);
+
+ 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;
+
+ if (session->debug & L2TP_MSG_DATA) {
+ unsigned int length;
+ int offset;
+ u8 *ptr = skb->data;
+
+ length = min(32u, skb->len);
+ if (!pskb_may_pull(skb, length))
+ goto error;
+
+ printk(KERN_DEBUG "%s: eth recv: ", session->name);
+
+ offset = 0;
+ do {
+ printk(" %02X", ptr[offset]);
+ } while (++offset < length);
+
+ printk("\n");
+ }
+
+ if (data_len < 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) {
+ dev->last_rx = jiffies;
+ dev->stats.rx_packets++;
+ dev->stats.rx_bytes += data_len;
+ } else
+ dev->stats.rx_errors++;
+
+ return;
+
+error:
+ dev->stats.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;
+ }
+ }
+}
+
+#ifdef CONFIG_PROC_FS
+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 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;
+ }
+
+ session = l2tp_session_find(net, tunnel, session_id);
+ if (session) {
+ rc = -EEXIST;
+ 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 (!session) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ dev = alloc_netdev(sizeof(*priv), name, l2tp_eth_dev_setup);
+ if (!dev) {
+ rc = -ENOMEM;
+ goto out_del_session;
+ }
+
+ dev_net_set(dev, net);
+ if (session->mtu == 0)
+ session->mtu = dev->mtu - session->hdr_len;
+ dev->mtu = session->mtu;
+ dev->needed_headroom += session->hdr_len;
+
+ 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;
+#ifdef CONFIG_PROC_FS
+ 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;
+
+ /* Must be done after register_netdev() */
+ strlcpy(session->ifname, dev->name, IFNAMSIZ);
+
+ dev_hold(dev);
+ pn = l2tp_eth_pernet(dev_net(dev));
+ write_lock(&pn->l2tp_eth_lock);
+ list_add(&priv->list, &pn->l2tp_eth_dev_list);
+ write_unlock(&pn->l2tp_eth_lock);
+
+ return 0;
+
+out_del_dev:
+ free_netdev(dev);
+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;
+ int err;
+
+ pn = kzalloc(sizeof(*pn), GFP_KERNEL);
+ if (!pn)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
+ rwlock_init(&pn->l2tp_eth_lock);
+
+ err = net_assign_generic(net, l2tp_eth_net_id, pn);
+ if (err)
+ goto out;
+
+ return 0;
+
+out:
+ kfree(pn);
+ return err;
+}
+
+static __net_exit void l2tp_eth_exit_net(struct net *net)
+{
+ struct l2tp_eth_net *pn;
+
+ pn = net_generic(net, l2tp_eth_net_id);
+ /*
+ * if someone has cached our net then
+ * further net_generic call will return NULL
+ */
+ net_assign_generic(net, l2tp_eth_net_id, NULL);
+ kfree(pn);
+}
+
+static __net_initdata struct pernet_operations l2tp_eth_net_ops = {
+ .init = l2tp_eth_init_net,
+ .exit = l2tp_eth_exit_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;
+
+ printk(KERN_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");