linux-imx

/*****************************************************************************

 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets

 *

 * PPPoX    --- Generic PPP encapsulation socket family

 * PPPoL2TP --- PPP over L2TP (RFC 2661)

 *

 * Version: 2.0.0

 *

 * Authors: James Chapman (jchapman@katalix.com)

 *

 * Based on original work by Martijn van Oosterhout <kleptog@svana.org>

 *

 * License:

 *      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.

 *

 */

​

/* This driver handles only L2TP data frames; control frames are handled by a

 * userspace application.

 *

 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and

 * attaches it to a bound UDP socket with local tunnel_id / session_id and

 * peer tunnel_id / session_id set. Data can then be sent or received using

 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket

 * can be read or modified using ioctl() or [gs]etsockopt() calls.

 *

 * When a PPPoL2TP socket is connected with local and peer session_id values

 * zero, the socket is treated as a special tunnel management socket.

 *

 * Here's example userspace code to create a socket for sending/receiving data

 * over an L2TP session:-

 *

 *  struct sockaddr_pppol2tp sax;

 *  int fd;

 *  int session_fd;

 *

 *  fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP);

 *

 *  sax.sa_family = AF_PPPOX;

 *  sax.sa_protocol = PX_PROTO_OL2TP;

 *  sax.pppol2tp.fd = tunnel_fd;    // bound UDP socket

 *  sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr;

 *  sax.pppol2tp.addr.sin_port = addr->sin_port;

 *  sax.pppol2tp.addr.sin_family = AF_INET;

 *  sax.pppol2tp.s_tunnel  = tunnel_id;

 *  sax.pppol2tp.s_session = session_id;

 *  sax.pppol2tp.d_tunnel  = peer_tunnel_id;

 *  sax.pppol2tp.d_session = peer_session_id;

 *

 *  session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax));

 *

 * A pppd plugin that allows PPP traffic to be carried over L2TP using

 * this driver is available from the OpenL2TP project at

 * http://openl2tp.sourceforge.net.

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/module.h>

#include <linux/string.h>

#include <linux/list.h>

#include <linux/uaccess.h>

​

#include <linux/kernel.h>

#include <linux/spinlock.h>

#include <linux/kthread.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/errno.h>

#include <linux/jiffies.h>

​

#include <linux/netdevice.h>

#include <linux/net.h>

#include <linux/inetdevice.h>

#include <linux/skbuff.h>

#include <linux/init.h>

#include <linux/ip.h>

#include <linux/udp.h>

#include <linux/if_pppox.h>

#include <linux/if_pppol2tp.h>

#include <net/sock.h>

#include <linux/ppp_channel.h>

#include <linux/ppp_defs.h>

#include <linux/ppp-ioctl.h>

#include <linux/file.h>

#include <linux/hash.h>

#include <linux/sort.h>

#include <linux/proc_fs.h>

#include <linux/l2tp.h>