1 files changed, 360 insertions, 0 deletions

diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
new file mode 100644
index 000000000..4b552873b
--- /dev/null
+++ b/net/l2tp/l2tp_eth.c
@@ -0,0 +1,360 @@
+/*
+ * 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 "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 struct lock_class_key l2tp_eth_tx_busylock;
+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);
+	dev->qdisc_tx_busylock = &l2tp_eth_tx_busylock;
+	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 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 defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
+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, NET_NAME_UNKNOWN,
+			   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;
+#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
+	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");