3 files changed, 372 insertions, 0 deletions

diff --git a/net/l2tp/Kconfig b/net/l2tp/Kconfig
index 0a11ccf2d95b..a292270c0abe 100644
--- a/net/l2tp/Kconfig
+++ b/net/l2tp/Kconfig
@@ -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.
diff --git a/net/l2tp/Makefile b/net/l2tp/Makefile
index 2c4a14b673ab..bddbf04f0ed3 100644
--- a/net/l2tp/Makefile
+++ b/net/l2tp/Makefile
@@ -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
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
new file mode 100644
index 000000000000..755c29729b6f
--- /dev/null
+++ b/net/l2tp/l2tp_eth.c
@@ -0,0 +1,347 @@
+/*
+ * 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 <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;
+};
+
+/* 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;
+        random_ether_addr(dev->dev_addr);
+        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));
+
+        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;
+
+        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;
+                }
+        }
+}
+
+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;
+
+        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));
+        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);
+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);
+        spin_lock_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");