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 <asm/types.h>
  #include <endian.h>
  #include <byteswap.h>
  
  #ifdef  __KERNEL__
  #include <linux/if_ether.h>
  #include <linux/if.h>
  #include <linux/netdevice.h>
  #include <linux/sched.h>
  #include <asm/semaphore.h>
  #include <linux/ppp_channel.h>
  #endif /* __KERNEL__ */
  #include <linux/if_pppol2tp.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 __u16 sid_t; 
  struct pppoe_addr{ 
         sid_t           sid;                    /* Session identifier */ 
         unsigned char   remote[ETH_ALEN];       /* Remote address */ 
         char            dev[IFNAMSIZ];          /* Local device to use */ 
  }; 
   
  /************************************************************************ 
   * Protocols supported by AF_PPPOX 
   */ 
  #define PX_PROTO_OE    0 /* Currently just PPPoE */
  #define PX_PROTO_OL2TP 1 /* Now L2TP also */
  #define PX_MAX_PROTO   2	
  
  /* The use of a union isn't viable because the size of this struct
   * must stay fixed over time -- applications use sizeof(struct
   * sockaddr_pppox) to fill it. Use protocol specific sockaddr types
   * instead.
   */ 
  struct sockaddr_pppox { 
         sa_family_t     sa_family;            /* address family, AF_PPPOX */ 
         unsigned int    sa_protocol;          /* protocol identifier */ 
         union{ 
                 struct pppoe_addr       pppoe; 
         }sa_addr; 
  }__attribute__ ((packed)); /* deprecated */ 
  
  /* Must be binary-compatible with sockaddr_pppox for backwards compatabilty */
  struct sockaddr_pppoe { 
  	sa_family_t     sa_family;	/* address family, AF_PPPOX */ 
  	unsigned int    sa_protocol;    /* protocol identifier */ 
  	struct pppoe_addr pppoe; 
  }__attribute__ ((packed)); 
  
  struct sockaddr_pppol2tp { 
  	sa_family_t     sa_family;      /* address family, AF_PPPOX */ 
  	unsigned int    sa_protocol;    /* protocol identifier */ 
  	struct pppol2tp_addr pppol2tp; 
  }__attribute__ ((packed)); 
  
  /*********************************************************************
   *
   * ioctl interface for defining forwarding of connections
   *
   ********************************************************************/
  
  #define PPPOEIOCSFWD	_IOW(0xB1 ,0, sizeof(struct sockaddr_pppox))
  #define PPPOEIOCDFWD	_IO(0xB1 ,1)
  /*#define PPPOEIOCGFWD	_IOWR(0xB1,2, sizeof(struct sockaddr_pppox))*/
  
  /* 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 {
  	__u16 tag_type;
  	__u16 tag_len;
  	char tag_data[0];
  } __attribute ((packed));
  
  /* Tag identifiers */
  #define PTT_EOL		htons(0x0000)
  #define PTT_SRV_NAME	htons(0x0101)
  #define PTT_AC_NAME	htons(0x0102)
  #define PTT_HOST_UNIQ	htons(0x0103)
  #define PTT_AC_COOKIE	htons(0x0104)
  #define PTT_VENDOR 	htons(0x0105)
  #define PTT_RELAY_SID	htons(0x0110)
  #define PTT_SRV_ERR     htons(0x0201)
  #define PTT_SYS_ERR  	htons(0x0202)
  #define PTT_GEN_ERR  	htons(0x0203)
  
  struct pppoe_hdr {
  #if (__BYTE_ORDER == __LITTLE_ENDIAN)
  	__u8 ver : 4;
  	__u8 type : 4;
  #elif (__BYTE_ORDER == __BIG_ENDIAN)
  	__u8 type : 4;
  	__u8 ver : 4;
  #else
  #error	"Adjust your <endian.h> defines"
  #endif
  	__u8 code;
  	__u16 sid;
  	__u16 length;
  	struct pppoe_tag tag[0];
  } __attribute__ ((packed));
  
  #ifdef __KERNEL__
  
  struct pppox_proto {
  	int (*create)(struct socket *sock);
  	int (*ioctl)(struct socket *sock, unsigned int cmd,
  		     unsigned long arg);
  };
  
  extern int register_pppox_proto(int proto_num, struct pppox_proto *pp);
  extern void unregister_pppox_proto(int proto_num);
  extern void pppox_unbind_sock(struct sock *sk);/* delete ppp-channel binding */
  extern int pppox_channel_ioctl(struct ppp_channel *pc, unsigned int cmd,
  			       unsigned long arg);
  
  /* PPPoX socket states */
  enum {
      PPPOX_NONE		= 0,  /* initial state */
      PPPOX_CONNECTED	= 1,  /* connection established ==TCP_ESTABLISHED */
      PPPOX_BOUND		= 2,  /* bound to ppp device */
      PPPOX_RELAY		= 4,  /* forwarding is enabled */
      PPPOX_ZOMBIE	= 8,  /* dead, but still bound to ppp device */
      PPPOX_DEAD		= 16  /* dead, useless, please clean me up!*/
  };
  
  extern struct ppp_channel_ops pppoe_chan_ops;
  
  extern int pppox_proto_init(struct net_proto *np);
  
  #endif /* __KERNEL__ */
  
  #endif /* !(__LINUX_IF_PPPOX_H) */
  