linux-imx

/*

 * 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.

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <asm/ioctls.h>

#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;

};

​

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(const struct net *net, __be32 laddr,

                      __be32 raddr, int dif, u32 tunnel_id)

{

    struct sock *sk;

​

    sk_for_each_bound(sk, &l2tp_ip_bind_table) {

        const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);

        const struct inet_sock *inet = inet_sk(sk);

​

        if (!net_eq(sock_net(sk), net))

            continue;

​

        if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif)

            continue;

​

        if (inet->inet_rcv_saddr && laddr &&

            inet->inet_rcv_saddr != laddr)

            continue;

​

        if (inet->inet_daddr && raddr && inet->inet_daddr != raddr)

            continue;

​

        if (l2tp->conn_id != tunnel_id)

            continue;

​

        goto found;

    }

​

    sk = NULL;

found:

    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