text: /***************************************************************************
   * Linux PPP over X - Generic PPP transport layer sockets
   * Linux PPP over Ethernet (PPPoE) Socket Implementation (RFC 2516) 
   *
   * This file supplies definitions required by the PPP over Ethernet driver
   * (pppox.c).  All version information wrt this file is located in pppox.c
   *
   * 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.
   *
   */
  
  #ifndef __LINUX_IF_PPPOX_H
  #define __LINUX_IF_PPPOX_H
  
  
  #include <linux/types.h>
  #include <asm/byteorder.h>
  
  #include <linux/socket.h>
  #include <linux/if_ether.h>
  #include <linux/if_pppol2tp.h>
  #include <linux/if_pppolac.h>
  #include <linux/if_pppopns.h>
  
  /* For user-space programs to pick up these definitions
   * which they wouldn't get otherwise without defining __KERNEL__
   */
  #ifndef AF_PPPOX
  #define AF_PPPOX	24
  #define PF_PPPOX	AF_PPPOX
  #endif /* !(AF_PPPOX) */
  
  /************************************************************************ 
   * PPPoE addressing definition 
   */ 
  typedef __be16 sid_t;
  struct pppoe_addr {
  	sid_t         sid;                    /* Session identifier */
  	unsigned char remote[ETH_ALEN];       /* Remote address */
  	char          dev[IFNAMSIZ];          /* Local device to use */
  }; 
   
  /************************************************************************ 
   * PPTP addressing definition
   */
  struct pptp_addr {
  	__u16		call_id;
  	struct in_addr	sin_addr;
  };
  
  /************************************************************************
   * Protocols supported by AF_PPPOX
   */
  #define PX_PROTO_OE    0 /* Currently just PPPoE */
  #define PX_PROTO_OL2TP 1 /* Now L2TP also */
  #define PX_PROTO_PPTP  2
  #define PX_PROTO_OLAC  3
  #define PX_PROTO_OPNS  4
  #define PX_MAX_PROTO   5
  
  struct sockaddr_pppox {
  	__kernel_sa_family_t sa_family;       /* address family, AF_PPPOX */
  	unsigned int    sa_protocol;          /* protocol identifier */
  	union {
  		struct pppoe_addr  pppoe;
  		struct pptp_addr   pptp;
  	} sa_addr;
  } __attribute__((packed));
  
  /* The use of the above union isn't viable because the size of this
   * struct must stay fixed over time -- applications use sizeof(struct
   * sockaddr_pppox) to fill it. We use a protocol specific sockaddr
   * type instead.
   */
  struct sockaddr_pppol2tp {
  	__kernel_sa_family_t sa_family; /* address family, AF_PPPOX */
  	unsigned int    sa_protocol;    /* protocol identifier */
  	struct pppol2tp_addr pppol2tp;
  } __attribute__((packed));
  
  struct sockaddr_pppol2tpin6 {
  	__kernel_sa_family_t sa_family; /* address family, AF_PPPOX */
  	unsigned int    sa_protocol;    /* protocol identifier */
  	struct pppol2tpin6_addr pppol2tp;
  } __attribute__((packed));
  
  /* The L2TPv3 protocol changes tunnel and session ids from 16 to 32
   * bits. So we need a different sockaddr structure.
   */
  struct sockaddr_pppol2tpv3 {
  	__kernel_sa_family_t sa_family; /* address family, AF_PPPOX */
  	unsigned int    sa_protocol;    /* protocol identifier */
  	struct pppol2tpv3_addr pppol2tp;
  } __attribute__((packed));
  
  struct sockaddr_pppol2tpv3in6 {
  	__kernel_sa_family_t sa_family; /* address family, AF_PPPOX */
  	unsigned int    sa_protocol;    /* protocol identifier */
  	struct pppol2tpv3in6_addr pppol2tp;
  } __attribute__((packed));
  
  /*********************************************************************
   *
   * ioctl interface for defining forwarding of connections
   *
   ********************************************************************/
  
  #define PPPOEIOCSFWD	_IOW(0xB1 ,0, size_t)
  #define PPPOEIOCDFWD	_IO(0xB1 ,1)
  /*#define PPPOEIOCGFWD	_IOWR(0xB1,2, size_t)*/
  
  /* Codes to identify message types */
  #define PADI_CODE	0x09
  #define PADO_CODE	0x07
  #define PADR_CODE	0x19
  #define PADS_CODE	0x65
  #define PADT_CODE	0xa7
  struct pppoe_tag {
  	__be16 tag_type;
  	__be16 tag_len;
  	char tag_data[0];
  } __attribute__ ((packed));
  
  /* Tag identifiers */
  #define PTT_EOL		__cpu_to_be16(0x0000)
  #define PTT_SRV_NAME	__cpu_to_be16(0x0101)
  #define PTT_AC_NAME	__cpu_to_be16(0x0102)
  #define PTT_HOST_UNIQ	__cpu_to_be16(0x0103)
  #define PTT_AC_COOKIE	__cpu_to_be16(0x0104)
  #define PTT_VENDOR 	__cpu_to_be16(0x0105)
  #define PTT_RELAY_SID	__cpu_to_be16(0x0110)
  #define PTT_SRV_ERR     __cpu_to_be16(0x0201)
  #define PTT_SYS_ERR  	__cpu_to_be16(0x0202)
  #define PTT_GEN_ERR  	__cpu_to_be16(0x0203)
  
  struct pppoe_hdr {
  #if defined(__LITTLE_ENDIAN_BITFIELD)
  	__u8 type : 4;
  	__u8 ver : 4;
  #elif defined(__BIG_ENDIAN_BITFIELD)
  	__u8 ver : 4;
  	__u8 type : 4;
  #else
  #error	"Please fix <asm/byteorder.h>"
  #endif
  	__u8 code;
  	__be16 sid;
  	__be16 length;
  	struct pppoe_tag tag[0];
  } __attribute__((packed));
  
  /* Length of entire PPPoE + PPP header */
  #define PPPOE_SES_HLEN	8
  
  
  #endif /* __LINUX_IF_PPPOX_H */
  