[linux.git] / net / l2tp / l2tp_ip.c

/*
 * L2TPv3 IP encapsulation support
 *
 * 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/icmp.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/random.h>
#include <linux/socket.h>
#include <linux/l2tp.h>
#include <linux/in.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 "l2tp_core.h"

struct l2tp_ip_sock {
	/* inet_sock has to be the first member of l2tp_ip_sock */
	struct inet_sock	inet;

	__u32			conn_id;
	__u32			peer_conn_id;

	__u64			tx_packets;
	__u64			tx_bytes;
	__u64			tx_errors;
	__u64			rx_packets;
	__u64			rx_bytes;
	__u64			rx_errors;
};

static DEFINE_RWLOCK(l2tp_ip_lock);
static struct hlist_head l2tp_ip_table;
static struct hlist_head l2tp_ip_bind_table;

static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
{
	return (struct l2tp_ip_sock *)sk;
}

static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
{
	struct hlist_node *node;
	struct sock *sk;

	sk_for_each_bound(sk, node, &l2tp_ip_bind_table) {
		struct inet_sock *inet = inet_sk(sk);
		struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);

		if (l2tp == NULL)
			continue;

		if ((l2tp->conn_id == tunnel_id) &&
		    net_eq(sock_net(sk), net) &&
		    !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
		    !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
			goto found;
	}

	sk = NULL;
found:
	return sk;
}

static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
{
	struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
	if (sk)
		sock_hold(sk);

	return sk;
}

/* When processing receive frames, there are two cases to
 * consider. Data frames consist of a non-zero session-id and an
 * optional cookie. Control frames consist of a regular L2TP header
 * preceded by 32-bits of zeros.
 *
 * L2TPv3 Session Header Over IP
 *
 *  0                   1                   2                   3
 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                           Session ID                          |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |               Cookie (optional, maximum 64 bits)...
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *                                                                 |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * L2TPv3 Control Message Header Over IP
 *
 *  0                   1                   2                   3
 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                      (32 bits of zeros)                       |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |T|L|x|x|S|x|x|x|x|x|x|x|  Ver  |             Length            |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                     Control Connection ID                     |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |               Ns              |               Nr              |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * All control frames are passed to userspace.
 */
static int l2tp_ip_recv(struct sk_buff *skb)
{
	struct sock *sk;
	u32 session_id;
	u32 tunnel_id;
	unsigned char *ptr, *optr;
	struct l2tp_session *session;
	struct l2tp_tunnel *tunnel = NULL;
	int length;
	int offset;

	/* Point to L2TP header */
	optr = ptr = skb->data;

	if (!pskb_may_pull(skb, 4))
		goto discard;

	session_id = ntohl(*((__be32 *) ptr));
	ptr += 4;

	/* RFC3931: L2TP/IP packets have the first 4 bytes containing
	 * the session_id. If it is 0, the packet is a L2TP control
	 * frame and the session_id value can be discarded.
	 */
	if (session_id == 0) {
		__skb_pull(skb, 4);
		goto pass_up;
	}

	/* Ok, this is a data packet. Lookup the session. */
	session = l2tp_session_find(&init_net, NULL, session_id);
	if (session == NULL)
		goto discard;

	tunnel = session->tunnel;
	if (tunnel == NULL)
		goto discard;

	/* Trace packet contents, if enabled */
	if (tunnel->debug & L2TP_MSG_DATA) {
		length = min(32u, skb->len);
		if (!pskb_may_pull(skb, length))
			goto discard;

		printk(KERN_DEBUG "%s: ip recv: ", tunnel->name);

		offset = 0;
		do {
			printk(" %02X", ptr[offset]);
		} while (++offset < length);

		printk("\n");
	}

	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);

	return 0;

pass_up:
	/* Get the tunnel_id from the L2TP header */
	if (!pskb_may_pull(skb, 12))
		goto discard;

	if ((skb->data[0] & 0xc0) != 0xc0)
		goto discard;

	tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
	tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
	if (tunnel != NULL)
		sk = tunnel->sock;
	else {
		struct iphdr *iph = (struct iphdr *) skb_network_header(skb);

		read_lock_bh(&l2tp_ip_lock);
		sk = __l2tp_ip_bind_lookup(&init_net, iph->daddr, 0, tunnel_id);
		read_unlock_bh(&l2tp_ip_lock);
	}

	if (sk == NULL)
		goto discard;

	sock_hold(sk);

	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
		goto discard_put;

	nf_reset(skb);

	return sk_receive_skb(sk, skb, 1);

discard_put:
	sock_put(sk);

discard:
	kfree_skb(skb);
	return 0;
}

static int l2tp_ip_open(struct sock *sk)
{
	/* Prevent autobind. We don't have ports. */
	inet_sk(sk)->inet_num = IPPROTO_L2TP;

	write_lock_bh(&l2tp_ip_lock);
	sk_add_node(sk, &l2tp_ip_table);
	write_unlock_bh(&l2tp_ip_lock);

	return 0;
}

static void l2tp_ip_close(struct sock *sk, long timeout)
{
	write_lock_bh(&l2tp_ip_lock);
	hlist_del_init(&sk->sk_bind_node);
	hlist_del_init(&sk->sk_node);
	write_unlock_bh(&l2tp_ip_lock);
	sk_common_release(sk);
}

static void l2tp_ip_destroy_sock(struct sock *sk)
{
	struct sk_buff *skb;

	while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
		kfree_skb(skb);

	sk_refcnt_debug_dec(sk);
}

static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
	struct inet_sock *inet = inet_sk(sk);
	struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
	int ret = -EINVAL;
	int chk_addr_ret;

	ret = -EADDRINUSE;
	read_lock_bh(&l2tp_ip_lock);
	if (__l2tp_ip_bind_lookup(&init_net, addr->l2tp_addr.s_addr, sk->sk_bound_dev_if, addr->l2tp_conn_id))
		goto out_in_use;

	read_unlock_bh(&l2tp_ip_lock);

	lock_sock(sk);
	if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
		goto out;

	chk_addr_ret = inet_addr_type(&init_net, addr->l2tp_addr.s_addr);
	ret = -EADDRNOTAVAIL;
	if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
	    chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
		goto out;

	inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
		inet->inet_saddr = 0;  /* Use device */
	sk_dst_reset(sk);

	l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;

	write_lock_bh(&l2tp_ip_lock);
	sk_add_bind_node(sk, &l2tp_ip_bind_table);
	sk_del_node_init(sk);
	write_unlock_bh(&l2tp_ip_lock);
	ret = 0;
out:
	release_sock(sk);

	return ret;

out_in_use:
	read_unlock_bh(&l2tp_ip_lock);

	return ret;
}

static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
	struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
	struct inet_sock *inet = inet_sk(sk);
	struct flowi4 *fl4;
	struct rtable *rt;
	__be32 saddr;
	int oif, rc;

	rc = -EINVAL;
	if (addr_len < sizeof(*lsa))
		goto out;

	rc = -EAFNOSUPPORT;
	if (lsa->l2tp_family != AF_INET)
		goto out;

	lock_sock(sk);

	sk_dst_reset(sk);

	oif = sk->sk_bound_dev_if;
	saddr = inet->inet_saddr;

	rc = -EINVAL;
	if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
		goto out;

	fl4 = &inet->cork.fl.u.ip4;
	rt = ip_route_connect(fl4, lsa->l2tp_addr.s_addr, saddr,
			      RT_CONN_FLAGS(sk), oif,
			      IPPROTO_L2TP,
			      0, 0, sk, true);
	if (IS_ERR(rt)) {
		rc = PTR_ERR(rt);
		if (rc == -ENETUNREACH)
			IP_INC_STATS_BH(&init_net, IPSTATS_MIB_OUTNOROUTES);
		goto out;
	}

	rc = -ENETUNREACH;
	if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
		ip_rt_put(rt);
		goto out;
	}

	l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;

	if (!inet->inet_saddr)
		inet->inet_saddr = fl4->saddr;
	if (!inet->inet_rcv_saddr)
		inet->inet_rcv_saddr = fl4->saddr;
	inet->inet_daddr = fl4->daddr;
	sk->sk_state = TCP_ESTABLISHED;
	inet->inet_id = jiffies;

	sk_dst_set(sk, &rt->dst);

	write_lock_bh(&l2tp_ip_lock);
	hlist_del_init(&sk->sk_bind_node);
	sk_add_bind_node(sk, &l2tp_ip_bind_table);
	write_unlock_bh(&l2tp_ip_lock);

	rc = 0;
out:
	release_sock(sk);
	return rc;
}

static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
			   int *uaddr_len, int peer)
{
	struct sock *sk		= sock->sk;
	struct inet_sock *inet	= inet_sk(sk);
	struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
	struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;

	memset(lsa, 0, sizeof(*lsa));
	lsa->l2tp_family = AF_INET;
	if (peer) {
		if (!inet->inet_dport)
			return -ENOTCONN;
		lsa->l2tp_conn_id = lsk->peer_conn_id;
		lsa->l2tp_addr.s_addr = inet->inet_daddr;
	} else {
		__be32 addr = inet->inet_rcv_saddr;
		if (!addr)
			addr = inet->inet_saddr;
		lsa->l2tp_conn_id = lsk->conn_id;
		lsa->l2tp_addr.s_addr = addr;
	}
	*uaddr_len = sizeof(*lsa);
	return 0;
}

static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
{
	int rc;

	/* Charge it to the socket, dropping if the queue is full. */
	rc = sock_queue_rcv_skb(sk, skb);
	if (rc < 0)
		goto drop;

	return 0;

drop:
	IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
	kfree_skb(skb);
	return -1;
}

/* Userspace will call sendmsg() on the tunnel socket to send L2TP
 * control frames.
 */
static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len)
{
	struct sk_buff *skb;
	int rc;
	struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk);
	struct inet_sock *inet = inet_sk(sk);
	struct rtable *rt = NULL;
	struct flowi4 *fl4;
	int connected = 0;
	__be32 daddr;

	lock_sock(sk);

	rc = -ENOTCONN;
	if (sock_flag(sk, SOCK_DEAD))
		goto out;

	/* Get and verify the address. */
	if (msg->msg_name) {
		struct sockaddr_l2tpip *lip = (struct sockaddr_l2tpip *) msg->msg_name;
		rc = -EINVAL;
		if (msg->msg_namelen < sizeof(*lip))
			goto out;

		if (lip->l2tp_family != AF_INET) {
			rc = -EAFNOSUPPORT;
			if (lip->l2tp_family != AF_UNSPEC)
				goto out;
		}

		daddr = lip->l2tp_addr.s_addr;
	} else {
		if (sk->sk_state != TCP_ESTABLISHED)
			return -EDESTADDRREQ;

		daddr = inet->inet_daddr;
		connected = 1;
	}

	/* Allocate a socket buffer */
	rc = -ENOMEM;
	skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
			   4 + len, 0, GFP_KERNEL);
	if (!skb)
		goto error;

	/* Reserve space for headers, putting IP header on 4-byte boundary. */
	skb_reserve(skb, 2 + NET_SKB_PAD);
	skb_reset_network_header(skb);
	skb_reserve(skb, sizeof(struct iphdr));
	skb_reset_transport_header(skb);

	/* Insert 0 session_id */
	*((__be32 *) skb_put(skb, 4)) = 0;

	/* Copy user data into skb */
	rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
	if (rc < 0) {
		kfree_skb(skb);
		goto error;
	}

	fl4 = &inet->cork.fl.u.ip4;
	if (connected)
		rt = (struct rtable *) __sk_dst_check(sk, 0);

	rcu_read_lock();
	if (rt == NULL) {
		const struct ip_options_rcu *inet_opt;

		inet_opt = rcu_dereference(inet->inet_opt);

		/* Use correct destination address if we have options. */
		if (inet_opt && inet_opt->opt.srr)
			daddr = inet_opt->opt.faddr;

		/* If this fails, retransmit mechanism of transport layer will
		 * keep trying until route appears or the connection times
		 * itself out.
		 */
		rt = ip_route_output_ports(sock_net(sk), fl4, sk,
					   daddr, inet->inet_saddr,
					   inet->inet_dport, inet->inet_sport,
					   sk->sk_protocol, RT_CONN_FLAGS(sk),
					   sk->sk_bound_dev_if);
		if (IS_ERR(rt))
			goto no_route;
		if (connected)
			sk_setup_caps(sk, &rt->dst);
		else
			dst_release(&rt->dst); /* safe since we hold rcu_read_lock */
	}

	/* We dont need to clone dst here, it is guaranteed to not disappear.
	 *  __dev_xmit_skb() might force a refcount if needed.
	 */
	skb_dst_set_noref(skb, &rt->dst);

	/* Queue the packet to IP for output */
	rc = ip_queue_xmit(skb, &inet->cork.fl);
	rcu_read_unlock();

error:
	/* Update stats */
	if (rc >= 0) {
		lsa->tx_packets++;
		lsa->tx_bytes += len;
		rc = len;
	} else {
		lsa->tx_errors++;
	}

out:
	release_sock(sk);
	return rc;

no_route:
	rcu_read_unlock();
	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
	kfree_skb(skb);
	rc = -EHOSTUNREACH;
	goto out;
}

static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
			   size_t len, int noblock, int flags, int *addr_len)
{
	struct inet_sock *inet = inet_sk(sk);
	struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
	size_t copied = 0;
	int err = -EOPNOTSUPP;
	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
	struct sk_buff *skb;

	if (flags & MSG_OOB)
		goto out;

	if (addr_len)
		*addr_len = sizeof(*sin);

	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb)
		goto out;

	copied = skb->len;
	if (len < copied) {
		msg->msg_flags |= MSG_TRUNC;
		copied = len;
	}

	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
	if (err)
		goto done;

	sock_recv_timestamp(msg, sk, skb);

	/* Copy the address. */
	if (sin) {
		sin->sin_family = AF_INET;
		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
		sin->sin_port = 0;
		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
	}
	if (inet->cmsg_flags)
		ip_cmsg_recv(msg, skb);
	if (flags & MSG_TRUNC)
		copied = skb->len;
done:
	skb_free_datagram(sk, skb);
out:
	if (err) {
		lsk->rx_errors++;
		return err;
	}

	lsk->rx_packets++;
	lsk->rx_bytes += copied;

	return copied;
}

static struct proto l2tp_ip_prot = {
	.name		   = "L2TP/IP",
	.owner		   = THIS_MODULE,
	.init		   = l2tp_ip_open,
	.close		   = l2tp_ip_close,
	.bind		   = l2tp_ip_bind,
	.connect	   = l2tp_ip_connect,
	.disconnect	   = udp_disconnect,
	.ioctl		   = udp_ioctl,
	.destroy	   = l2tp_ip_destroy_sock,
	.setsockopt	   = ip_setsockopt,
	.getsockopt	   = ip_getsockopt,
	.sendmsg	   = l2tp_ip_sendmsg,
	.recvmsg	   = l2tp_ip_recvmsg,
	.backlog_rcv	   = l2tp_ip_backlog_recv,
	.hash		   = inet_hash,
	.unhash		   = inet_unhash,
	.obj_size	   = sizeof(struct l2tp_ip_sock),
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_ip_setsockopt,
	.compat_getsockopt = compat_ip_getsockopt,
#endif
};

static const struct proto_ops l2tp_ip_ops = {
	.family		   = PF_INET,
	.owner		   = THIS_MODULE,
	.release	   = inet_release,
	.bind		   = inet_bind,
	.connect	   = inet_dgram_connect,
	.socketpair	   = sock_no_socketpair,
	.accept		   = sock_no_accept,
	.getname	   = l2tp_ip_getname,
	.poll		   = datagram_poll,
	.ioctl		   = inet_ioctl,
	.listen		   = sock_no_listen,
	.shutdown	   = inet_shutdown,
	.setsockopt	   = sock_common_setsockopt,
	.getsockopt	   = sock_common_getsockopt,
	.sendmsg	   = inet_sendmsg,
	.recvmsg	   = sock_common_recvmsg,
	.mmap		   = sock_no_mmap,
	.sendpage	   = sock_no_sendpage,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_sock_common_setsockopt,
	.compat_getsockopt = compat_sock_common_getsockopt,
#endif
};

static struct inet_protosw l2tp_ip_protosw = {
	.type		= SOCK_DGRAM,
	.protocol	= IPPROTO_L2TP,
	.prot		= &l2tp_ip_prot,
	.ops		= &l2tp_ip_ops,
	.no_check	= 0,
};

static struct net_protocol l2tp_ip_protocol __read_mostly = {
	.handler	= l2tp_ip_recv,
};

static int __init l2tp_ip_init(void)
{
	int err;

	printk(KERN_INFO "L2TP IP encapsulation support (L2TPv3)\n");

	err = proto_register(&l2tp_ip_prot, 1);
	if (err != 0)
		goto out;

	err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
	if (err)
		goto out1;

	inet_register_protosw(&l2tp_ip_protosw);
	return 0;

out1:
	proto_unregister(&l2tp_ip_prot);
out:
	return err;
}

static void __exit l2tp_ip_exit(void)
{
	inet_unregister_protosw(&l2tp_ip_protosw);
	inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
	proto_unregister(&l2tp_ip_prot);
}

module_init(l2tp_ip_init);
module_exit(l2tp_ip_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Chapman <[email protected]>");
MODULE_DESCRIPTION("L2TP over IP");
MODULE_VERSION("1.0");

/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
 * enums
 */
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);
Commit	Line	Data
0d76751f JC	1	/*
	2	* L2TPv3 IP encapsulation support
	3	*
	4	* Copyright (c) 2008,2009,2010 Katalix Systems Ltd
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/icmp.h>
	13	#include <linux/module.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/random.h>
	16	#include <linux/socket.h>
	17	#include <linux/l2tp.h>
	18	#include <linux/in.h>
	19	#include <net/sock.h>
	20	#include <net/ip.h>
	21	#include <net/icmp.h>
	22	#include <net/udp.h>
	23	#include <net/inet_common.h>
	24	#include <net/inet_hashtables.h>
	25	#include <net/tcp_states.h>
	26	#include <net/protocol.h>
	27	#include <net/xfrm.h>
	28
	29	#include "l2tp_core.h"
	30
	31	struct l2tp_ip_sock {
	32	/* inet_sock has to be the first member of l2tp_ip_sock */
	33	struct inet_sock inet;
	34
	35	__u32 conn_id;
	36	__u32 peer_conn_id;
	37
	38	__u64 tx_packets;
	39	__u64 tx_bytes;
	40	__u64 tx_errors;
	41	__u64 rx_packets;
	42	__u64 rx_bytes;
	43	__u64 rx_errors;
	44	};
	45
	46	static DEFINE_RWLOCK(l2tp_ip_lock);
	47	static struct hlist_head l2tp_ip_table;
	48	static struct hlist_head l2tp_ip_bind_table;
	49
	50	static inline struct l2tp_ip_sock l2tp_ip_sk(const struct sock sk)
	51	{
	52	return (struct l2tp_ip_sock *)sk;
	53	}
	54
	55	static struct sock __l2tp_ip_bind_lookup(struct net net, __be32 laddr, int dif, u32 tunnel_id)
	56	{
	57	struct hlist_node *node;
	58	struct sock *sk;
	59
	60	sk_for_each_bound(sk, node, &l2tp_ip_bind_table) {
	61	struct inet_sock *inet = inet_sk(sk);
	62	struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
	63
	64	if (l2tp == NULL)
65	continue;
66
67	if ((l2tp->conn_id == tunnel_id) &&
e83726b0	68	net_eq(sock_net(sk), net) &&
0d76751f JC	69	!(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
	70	!(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
	71	goto found;
	72	}
	73
	74	sk = NULL;
	75	found:
	76	return sk;
	77	}
	78
	79	static inline struct sock l2tp_ip_bind_lookup(struct net net, __be32 laddr, int dif, u32 tunnel_id)
	80	{
	81	struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
	82	if (sk)
	83	sock_hold(sk);
	84
	85	return sk;
	86	}
	87
	88	/* When processing receive frames, there are two cases to
	89	* consider. Data frames consist of a non-zero session-id and an
	90	* optional cookie. Control frames consist of a regular L2TP header
	91	* preceded by 32-bits of zeros.
	92	*
	93	* L2TPv3 Session Header Over IP
	94	*
	95	* 0 1 2 3
	96	* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	97	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	98	* \| Session ID \|
	99	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	100	* \| Cookie (optional, maximum 64 bits)...
	101	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	102	* \|
	103	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	104	*
	105	* L2TPv3 Control Message Header Over IP
	106	*
	107	* 0 1 2 3
	108	* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	109	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	110	* \| (32 bits of zeros) \|
	111	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	112	* \|T\|L\|x\|x\|S\|x\|x\|x\|x\|x\|x\|x\| Ver \| Length \|
	113	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	114	* \| Control Connection ID \|
	115	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	116	* \| Ns \| Nr \|
	117	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	118	*
	119	* All control frames are passed to userspace.
	120	*/
	121	static int l2tp_ip_recv(struct sk_buff *skb)
	122	{
	123	struct sock *sk;
	124	u32 session_id;
	125	u32 tunnel_id;
	126	unsigned char ptr, optr;
	127	struct l2tp_session *session;
	128	struct l2tp_tunnel *tunnel = NULL;
	129	int length;
	130	int offset;
	131
	132	/* Point to L2TP header */
133	optr = ptr = skb->data;
134
135	if (!pskb_may_pull(skb, 4))
136	goto discard;
137
138	session_id = ntohl(((__be32 ) ptr));
139	ptr += 4;
140
141	/* RFC3931: L2TP/IP packets have the first 4 bytes containing
142	* the session_id. If it is 0, the packet is a L2TP control
143	* frame and the session_id value can be discarded.
144	*/
145	if (session_id == 0) {
146	__skb_pull(skb, 4);
147	goto pass_up;
148	}
149
150	/* Ok, this is a data packet. Lookup the session. */
151	session = l2tp_session_find(&init_net, NULL, session_id);
152	if (session == NULL)
153	goto discard;
154
155	tunnel = session->tunnel;
156	if (tunnel == NULL)
157	goto discard;
158
159	/* Trace packet contents, if enabled */
160	if (tunnel->debug & L2TP_MSG_DATA) {
161	length = min(32u, skb->len);
162	if (!pskb_may_pull(skb, length))
163	goto discard;
164
165	printk(KERN_DEBUG "%s: ip recv: ", tunnel->name);
166
167	offset = 0;
168	do {
169	printk(" %02X", ptr[offset]);
170	} while (++offset < length);
171
172	printk("\n");
173	}
174
175	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);
176
177	return 0;
178
179	pass_up:
180	/* Get the tunnel_id from the L2TP header */
181	if (!pskb_may_pull(skb, 12))
182	goto discard;
183
184	if ((skb->data[0] & 0xc0) != 0xc0)
185	goto discard;
186
187	tunnel_id = ntohl((__be32 ) &skb->data[4]);
188	tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
189	if (tunnel != NULL)
190	sk = tunnel->sock;
191	else {
192	struct iphdr iph = (struct iphdr ) skb_network_header(skb);
193
194	read_lock_bh(&l2tp_ip_lock);
195	sk = __l2tp_ip_bind_lookup(&init_net, iph->daddr, 0, tunnel_id);
196	read_unlock_bh(&l2tp_ip_lock);
197	}
198
199	if (sk == NULL)
200	goto discard;
201
202	sock_hold(sk);
203
204	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
205	goto discard_put;
206
207	nf_reset(skb);
208
209	return sk_receive_skb(sk, skb, 1);
210
211	discard_put:
212	sock_put(sk);
213
214	discard:
215	kfree_skb(skb);
216	return 0;
217	}
218
219	static int l2tp_ip_open(struct sock *sk)
220	{
221	/* Prevent autobind. We don't have ports. */
222	inet_sk(sk)->inet_num = IPPROTO_L2TP;
223
224	write_lock_bh(&l2tp_ip_lock);
225	sk_add_node(sk, &l2tp_ip_table);
226	write_unlock_bh(&l2tp_ip_lock);
227
228	return 0;
229	}
230
231	static void l2tp_ip_close(struct sock *sk, long timeout)
232	{
233	write_lock_bh(&l2tp_ip_lock);
234	hlist_del_init(&sk->sk_bind_node);
235	hlist_del_init(&sk->sk_node);
236	write_unlock_bh(&l2tp_ip_lock);
237	sk_common_release(sk);
238	}
239
240	static void l2tp_ip_destroy_sock(struct sock *sk)
241	{
242	struct sk_buff *skb;
243
244	while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
245	kfree_skb(skb);
246
247	sk_refcnt_debug_dec(sk);
248	}
249
250	static int l2tp_ip_bind(struct sock sk, struct sockaddr uaddr, int addr_len)
251	{
252	struct inet_sock *inet = inet_sk(sk);
253	struct sockaddr_l2tpip addr = (struct sockaddr_l2tpip ) uaddr;
254	int ret = -EINVAL;
255	int chk_addr_ret;
256
257	ret = -EADDRINUSE;
258	read_lock_bh(&l2tp_ip_lock);
259	if (__l2tp_ip_bind_lookup(&init_net, addr->l2tp_addr.s_addr, sk->sk_bound_dev_if, addr->l2tp_conn_id))
260	goto out_in_use;
261
262	read_unlock_bh(&l2tp_ip_lock);
263
264	lock_sock(sk);
265	if (sk->sk_state != TCP_CLOSE \|\| addr_len < sizeof(struct sockaddr_l2tpip))
266	goto out;
267
268	chk_addr_ret = inet_addr_type(&init_net, addr->l2tp_addr.s_addr);
269	ret = -EADDRNOTAVAIL;
270	if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
271	chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
272	goto out;
273
274	inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
275	if (chk_addr_ret == RTN_MULTICAST \|\| chk_addr_ret == RTN_BROADCAST)
276	inet->inet_saddr = 0; /* Use device */
277	sk_dst_reset(sk);
278
279	l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;
280
281	write_lock_bh(&l2tp_ip_lock);
282	sk_add_bind_node(sk, &l2tp_ip_bind_table);
283	sk_del_node_init(sk);
284	write_unlock_bh(&l2tp_ip_lock);
285	ret = 0;
286	out:
287	release_sock(sk);
288
289	return ret;
290
291	out_in_use:
292	read_unlock_bh(&l2tp_ip_lock);
293
294	return ret;
295	}
296
297	static int l2tp_ip_connect(struct sock sk, struct sockaddr uaddr, int addr_len)
298	{
0d76751f	299	struct sockaddr_l2tpip lsa = (struct sockaddr_l2tpip ) uaddr;
2d7192d6	300	struct inet_sock *inet = inet_sk(sk);
fdbb0f07	301	struct flowi4 *fl4;
0d76751f JC	302	struct rtable *rt;
0d76751f JC	303	__be32 saddr;
2d7192d6	304	int oif, rc;
0d76751f JC	305
	306	rc = -EINVAL;
	307	if (addr_len < sizeof(*lsa))
	308	goto out;
	309
	310	rc = -EAFNOSUPPORT;
	311	if (lsa->l2tp_family != AF_INET)
	312	goto out;
	313
2f16270f DM	314	lock_sock(sk);
2f16270f DM	315
0d76751f JC	316	sk_dst_reset(sk);
	317
	318	oif = sk->sk_bound_dev_if;
	319	saddr = inet->inet_saddr;
	320
	321	rc = -EINVAL;
	322	if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
	323	goto out;
	324
fdbb0f07 DM	325	fl4 = &inet->cork.fl.u.ip4;
fdbb0f07 DM	326	rt = ip_route_connect(fl4, lsa->l2tp_addr.s_addr, saddr,
0d76751f JC	327	RT_CONN_FLAGS(sk), oif,
0d76751f JC	328	IPPROTO_L2TP,
abdf7e72	329	0, 0, sk, true);
b23dd4fe DM	330	if (IS_ERR(rt)) {
b23dd4fe DM	331	rc = PTR_ERR(rt);
0d76751f JC	332	if (rc == -ENETUNREACH)
	333	IP_INC_STATS_BH(&init_net, IPSTATS_MIB_OUTNOROUTES);
	334	goto out;
	335	}
	336
	337	rc = -ENETUNREACH;
	338	if (rt->rt_flags & (RTCF_MULTICAST \| RTCF_BROADCAST)) {
	339	ip_rt_put(rt);
	340	goto out;
	341	}
	342
	343	l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
	344
	345	if (!inet->inet_saddr)
fdbb0f07	346	inet->inet_saddr = fl4->saddr;
0d76751f	347	if (!inet->inet_rcv_saddr)
fdbb0f07 DM	348	inet->inet_rcv_saddr = fl4->saddr;
fdbb0f07 DM	349	inet->inet_daddr = fl4->daddr;
0d76751f JC	350	sk->sk_state = TCP_ESTABLISHED;
	351	inet->inet_id = jiffies;
	352
d8d1f30b	353	sk_dst_set(sk, &rt->dst);
0d76751f JC	354
	355	write_lock_bh(&l2tp_ip_lock);
	356	hlist_del_init(&sk->sk_bind_node);
	357	sk_add_bind_node(sk, &l2tp_ip_bind_table);
	358	write_unlock_bh(&l2tp_ip_lock);
	359
	360	rc = 0;
	361	out:
2f16270f	362	release_sock(sk);
0d76751f JC	363	return rc;
	364	}
	365
	366	static int l2tp_ip_getname(struct socket sock, struct sockaddr uaddr,
	367	int *uaddr_len, int peer)
	368	{
	369	struct sock *sk = sock->sk;
	370	struct inet_sock *inet = inet_sk(sk);
	371	struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
	372	struct sockaddr_l2tpip lsa = (struct sockaddr_l2tpip )uaddr;
	373
	374	memset(lsa, 0, sizeof(*lsa));
	375	lsa->l2tp_family = AF_INET;
	376	if (peer) {
	377	if (!inet->inet_dport)
	378	return -ENOTCONN;
	379	lsa->l2tp_conn_id = lsk->peer_conn_id;
	380	lsa->l2tp_addr.s_addr = inet->inet_daddr;
	381	} else {
	382	__be32 addr = inet->inet_rcv_saddr;
	383	if (!addr)
	384	addr = inet->inet_saddr;
	385	lsa->l2tp_conn_id = lsk->conn_id;
	386	lsa->l2tp_addr.s_addr = addr;
	387	}
	388	uaddr_len = sizeof(lsa);
	389	return 0;
	390	}
	391
	392	static int l2tp_ip_backlog_recv(struct sock sk, struct sk_buff skb)
	393	{
	394	int rc;
	395
0d76751f JC	396	/* Charge it to the socket, dropping if the queue is full. */
	397	rc = sock_queue_rcv_skb(sk, skb);
	398	if (rc < 0)
	399	goto drop;
	400
	401	return 0;
	402
	403	drop:
	404	IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
	405	kfree_skb(skb);
	406	return -1;
	407	}
	408
	409	/* Userspace will call sendmsg() on the tunnel socket to send L2TP
	410	* control frames.
	411	*/
	412	static int l2tp_ip_sendmsg(struct kiocb iocb, struct sock sk, struct msghdr *msg, size_t len)
	413	{
	414	struct sk_buff *skb;
	415	int rc;
	416	struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk);
	417	struct inet_sock *inet = inet_sk(sk);
0d76751f	418	struct rtable *rt = NULL;
fdbb0f07	419	struct flowi4 *fl4;
0d76751f JC	420	int connected = 0;
	421	__be32 daddr;
	422
2f16270f DM	423	lock_sock(sk);
	424
	425	rc = -ENOTCONN;
0d76751f	426	if (sock_flag(sk, SOCK_DEAD))
2f16270f	427	goto out;
0d76751f JC	428
	429	/* Get and verify the address. */
	430	if (msg->msg_name) {
	431	struct sockaddr_l2tpip lip = (struct sockaddr_l2tpip ) msg->msg_name;
2f16270f	432	rc = -EINVAL;
0d76751f	433	if (msg->msg_namelen < sizeof(*lip))
2f16270f	434	goto out;
0d76751f JC	435
0d76751f JC	436	if (lip->l2tp_family != AF_INET) {
2f16270f	437	rc = -EAFNOSUPPORT;
0d76751f	438	if (lip->l2tp_family != AF_UNSPEC)
2f16270f	439	goto out;
0d76751f JC	440	}
	441
	442	daddr = lip->l2tp_addr.s_addr;
	443	} else {
	444	if (sk->sk_state != TCP_ESTABLISHED)
	445	return -EDESTADDRREQ;
	446
	447	daddr = inet->inet_daddr;
	448	connected = 1;
	449	}
	450
	451	/* Allocate a socket buffer */
	452	rc = -ENOMEM;
	453	skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
	454	4 + len, 0, GFP_KERNEL);
	455	if (!skb)
	456	goto error;
	457
	458	/* Reserve space for headers, putting IP header on 4-byte boundary. */
	459	skb_reserve(skb, 2 + NET_SKB_PAD);
	460	skb_reset_network_header(skb);
	461	skb_reserve(skb, sizeof(struct iphdr));
	462	skb_reset_transport_header(skb);
	463
	464	/* Insert 0 session_id */
	465	((__be32 ) skb_put(skb, 4)) = 0;
	466
	467	/* Copy user data into skb */
	468	rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
	469	if (rc < 0) {
	470	kfree_skb(skb);
	471	goto error;
	472	}
	473
fdbb0f07	474	fl4 = &inet->cork.fl.u.ip4;
0d76751f JC	475	if (connected)
	476	rt = (struct rtable *) __sk_dst_check(sk, 0);
	477
081b1b1b	478	rcu_read_lock();
0d76751f	479	if (rt == NULL) {
081b1b1b	480	const struct ip_options_rcu *inet_opt;
f6d8bd05	481
778865a5	482	inet_opt = rcu_dereference(inet->inet_opt);
f6d8bd05	483
0d76751f	484	/* Use correct destination address if we have options. */
f6d8bd05 ED	485	if (inet_opt && inet_opt->opt.srr)
f6d8bd05 ED	486	daddr = inet_opt->opt.faddr;
0d76751f	487
78fbfd8a DM	488	/* If this fails, retransmit mechanism of transport layer will
	489	* keep trying until route appears or the connection times
	490	* itself out.
	491	*/
fdbb0f07	492	rt = ip_route_output_ports(sock_net(sk), fl4, sk,
78fbfd8a DM	493	daddr, inet->inet_saddr,
	494	inet->inet_dport, inet->inet_sport,
	495	sk->sk_protocol, RT_CONN_FLAGS(sk),
	496	sk->sk_bound_dev_if);
	497	if (IS_ERR(rt))
	498	goto no_route;
081b1b1b ED	499	if (connected)
	500	sk_setup_caps(sk, &rt->dst);
	501	else
	502	dst_release(&rt->dst); /* safe since we hold rcu_read_lock */
0d76751f	503	}
081b1b1b ED	504
	505	/* We dont need to clone dst here, it is guaranteed to not disappear.
	506	* __dev_xmit_skb() might force a refcount if needed.
	507	*/
	508	skb_dst_set_noref(skb, &rt->dst);
0d76751f JC	509
0d76751f JC	510	/* Queue the packet to IP for output */
d9d8da80	511	rc = ip_queue_xmit(skb, &inet->cork.fl);
081b1b1b	512	rcu_read_unlock();
0d76751f JC	513
	514	error:
	515	/* Update stats */
	516	if (rc >= 0) {
	517	lsa->tx_packets++;
	518	lsa->tx_bytes += len;
	519	rc = len;
	520	} else {
	521	lsa->tx_errors++;
	522	}
	523
2f16270f DM	524	out:
2f16270f DM	525	release_sock(sk);
0d76751f JC	526	return rc;
	527
	528	no_route:
081b1b1b	529	rcu_read_unlock();
0d76751f JC	530	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
0d76751f JC	531	kfree_skb(skb);
2f16270f DM	532	rc = -EHOSTUNREACH;
2f16270f DM	533	goto out;
0d76751f JC	534	}
	535
	536	static int l2tp_ip_recvmsg(struct kiocb iocb, struct sock sk, struct msghdr *msg,
	537	size_t len, int noblock, int flags, int *addr_len)
	538	{
	539	struct inet_sock *inet = inet_sk(sk);
	540	struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
	541	size_t copied = 0;
	542	int err = -EOPNOTSUPP;
	543	struct sockaddr_in sin = (struct sockaddr_in )msg->msg_name;
	544	struct sk_buff *skb;
	545
	546	if (flags & MSG_OOB)
	547	goto out;
	548
	549	if (addr_len)
	550	addr_len = sizeof(sin);
	551
	552	skb = skb_recv_datagram(sk, flags, noblock, &err);
	553	if (!skb)
	554	goto out;
	555
	556	copied = skb->len;
	557	if (len < copied) {
	558	msg->msg_flags \|= MSG_TRUNC;
	559	copied = len;
	560	}
	561
	562	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
	563	if (err)
	564	goto done;
	565
	566	sock_recv_timestamp(msg, sk, skb);
	567
	568	/* Copy the address. */
	569	if (sin) {
	570	sin->sin_family = AF_INET;
	571	sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
	572	sin->sin_port = 0;
	573	memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
	574	}
	575	if (inet->cmsg_flags)
	576	ip_cmsg_recv(msg, skb);
	577	if (flags & MSG_TRUNC)
	578	copied = skb->len;
	579	done:
	580	skb_free_datagram(sk, skb);
	581	out:
	582	if (err) {
	583	lsk->rx_errors++;
	584	return err;
	585	}
	586
	587	lsk->rx_packets++;
	588	lsk->rx_bytes += copied;
	589
	590	return copied;
	591	}
	592
fc130840	593	static struct proto l2tp_ip_prot = {
0d76751f JC	594	.name = "L2TP/IP",
	595	.owner = THIS_MODULE,
	596	.init = l2tp_ip_open,
	597	.close = l2tp_ip_close,
	598	.bind = l2tp_ip_bind,
	599	.connect = l2tp_ip_connect,
	600	.disconnect = udp_disconnect,
	601	.ioctl = udp_ioctl,
	602	.destroy = l2tp_ip_destroy_sock,
	603	.setsockopt = ip_setsockopt,
	604	.getsockopt = ip_getsockopt,
	605	.sendmsg = l2tp_ip_sendmsg,
	606	.recvmsg = l2tp_ip_recvmsg,
	607	.backlog_rcv = l2tp_ip_backlog_recv,
	608	.hash = inet_hash,
	609	.unhash = inet_unhash,
	610	.obj_size = sizeof(struct l2tp_ip_sock),
	611	#ifdef CONFIG_COMPAT
	612	.compat_setsockopt = compat_ip_setsockopt,
	613	.compat_getsockopt = compat_ip_getsockopt,
	614	#endif
	615	};
	616
	617	static const struct proto_ops l2tp_ip_ops = {
	618	.family = PF_INET,
	619	.owner = THIS_MODULE,
	620	.release = inet_release,
	621	.bind = inet_bind,
	622	.connect = inet_dgram_connect,
	623	.socketpair = sock_no_socketpair,
	624	.accept = sock_no_accept,
	625	.getname = l2tp_ip_getname,
	626	.poll = datagram_poll,
	627	.ioctl = inet_ioctl,
	628	.listen = sock_no_listen,
	629	.shutdown = inet_shutdown,
	630	.setsockopt = sock_common_setsockopt,
	631	.getsockopt = sock_common_getsockopt,
	632	.sendmsg = inet_sendmsg,
	633	.recvmsg = sock_common_recvmsg,
	634	.mmap = sock_no_mmap,
	635	.sendpage = sock_no_sendpage,
	636	#ifdef CONFIG_COMPAT
	637	.compat_setsockopt = compat_sock_common_setsockopt,
	638	.compat_getsockopt = compat_sock_common_getsockopt,
	639	#endif
	640	};
	641
	642	static struct inet_protosw l2tp_ip_protosw = {
	643	.type = SOCK_DGRAM,
	644	.protocol = IPPROTO_L2TP,
	645	.prot = &l2tp_ip_prot,
	646	.ops = &l2tp_ip_ops,
	647	.no_check = 0,
	648	};
	649
	650	static struct net_protocol l2tp_ip_protocol __read_mostly = {
	651	.handler = l2tp_ip_recv,
	652	};
	653
	654	static int __init l2tp_ip_init(void)
	655	{
	656	int err;
	657
658	printk(KERN_INFO "L2TP IP encapsulation support (L2TPv3)\n");
659
660	err = proto_register(&l2tp_ip_prot, 1);
661	if (err != 0)
662	goto out;
663
664	err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
665	if (err)
666	goto out1;
667
668	inet_register_protosw(&l2tp_ip_protosw);
669	return 0;
670
671	out1:
672	proto_unregister(&l2tp_ip_prot);
673	out:
674	return err;
675	}
676
677	static void __exit l2tp_ip_exit(void)
678	{
679	inet_unregister_protosw(&l2tp_ip_protosw);
680	inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
681	proto_unregister(&l2tp_ip_prot);
682	}
683
684	module_init(l2tp_ip_init);
685	module_exit(l2tp_ip_exit);
686
687	MODULE_LICENSE("GPL");
688	MODULE_AUTHOR("James Chapman <[email protected]>");
689	MODULE_DESCRIPTION("L2TP over IP");
690	MODULE_VERSION("1.0");
e8d34a88	691
e9c54999	692	/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
e8d34a88 MM	693	* enums
	694	*/
	695	MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);