ip.h

linux得一些常用命令,以及linux环境下的c编程

/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Definitions for the IP protocol.
 *
 * Version:	@(#)ip.h	1.0.2	04/28/93
 *
 * Authors:	Fred N. van Kempen, <[e-mail]>
 *
 *		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_IP_H
#define _LINUX_IP_H
#include <asm/byteorder.h>

/* SOL_IP socket options */

#define IPTOS_TOS_MASK		0x1E
#define IPTOS_TOS(tos)		((tos)&IPTOS_TOS_MASK)
#define	IPTOS_LOWDELAY		0x10
#define	IPTOS_THROUGHPUT	0x08
#define	IPTOS_RELIABILITY	0x04
#define	IPTOS_MINCOST		0x02

#define IPTOS_PREC_MASK		0xE0
#define IPTOS_PREC(tos)		((tos)&IPTOS_PREC_MASK)
#define IPTOS_PREC_NETCONTROL           0xe0
#define IPTOS_PREC_INTERNETCONTROL      0xc0
#define IPTOS_PREC_CRITIC_ECP           0xa0
#define IPTOS_PREC_FLASHOVERRIDE        0x80
#define IPTOS_PREC_FLASH                0x60
#define IPTOS_PREC_IMMEDIATE            0x40
#define IPTOS_PREC_PRIORITY             0x20
#define IPTOS_PREC_ROUTINE              0x00


/* IP options */
#define IPOPT_COPY		0x80
#define IPOPT_CLASS_MASK	0x60
#define IPOPT_NUMBER_MASK	0x1f

#define	IPOPT_COPIED(o)		((o)&IPOPT_COPY)
#define	IPOPT_CLASS(o)		((o)&IPOPT_CLASS_MASK)
#define	IPOPT_NUMBER(o)		((o)&IPOPT_NUMBER_MASK)

#define	IPOPT_CONTROL		0x00
#define	IPOPT_RESERVED1		0x20
#define	IPOPT_MEASUREMENT	0x40
#define	IPOPT_RESERVED2		0x60

#define IPOPT_END	(0 |IPOPT_CONTROL)
#define IPOPT_NOOP	(1 |IPOPT_CONTROL)
#define IPOPT_SEC	(2 |IPOPT_CONTROL|IPOPT_COPY)
#define IPOPT_LSRR	(3 |IPOPT_CONTROL|IPOPT_COPY)
#define IPOPT_TIMESTAMP	(4 |IPOPT_MEASUREMENT)
#define IPOPT_RR	(7 |IPOPT_CONTROL)
#define IPOPT_SID	(8 |IPOPT_CONTROL|IPOPT_COPY)
#define IPOPT_SSRR	(9 |IPOPT_CONTROL|IPOPT_COPY)
#define IPOPT_RA	(20|IPOPT_CONTROL|IPOPT_COPY)

#define IPVERSION	4
#define MAXTTL		255
#define IPDEFTTL	64

/* struct timestamp, struct route and MAX_ROUTES are removed.

   REASONS: it is clear that nobody used them because:
   - MAX_ROUTES value was wrong.
   - "struct route" was wrong.
   - "struct timestamp" had fatally misaligned bitfields and was completely unusable.
 */

#define IPOPT_OPTVAL 0
#define IPOPT_OLEN   1
#define IPOPT_OFFSET 2
#define IPOPT_MINOFF 4
#define MAX_IPOPTLEN 40
#define IPOPT_NOP IPOPT_NOOP
#define IPOPT_EOL IPOPT_END
#define IPOPT_TS  IPOPT_TIMESTAMP

#define	IPOPT_TS_TSONLY		0		/* timestamps only */
#define	IPOPT_TS_TSANDADDR	1		/* timestamps and addresses */
#define	IPOPT_TS_PRESPEC	3		/* specified modules only */

#ifdef __KERNEL__

struct ip_options {
  __u32		faddr;				/* Saved first hop address */
  unsigned char	optlen;
  unsigned char srr;
  unsigned char rr;
  unsigned char ts;
  unsigned char is_setbyuser:1,			/* Set by setsockopt?			*/
                is_data:1,			/* Options in __data, rather than skb	*/
                is_strictroute:1,		/* Strict source route			*/
                srr_is_hit:1,			/* Packet destination addr was our one	*/
                is_changed:1,			/* IP checksum more not valid		*/	
                rr_needaddr:1,			/* Need to record addr of outgoing dev	*/
                ts_needtime:1,			/* Need to record timestamp		*/
                ts_needaddr:1;			/* Need to record addr of outgoing dev  */
  unsigned char router_alert;
  unsigned char __pad1;
  unsigned char __pad2;
  unsigned char __data[0];
};

#define optlength(opt) (sizeof(struct ip_options) + opt->optlen)
#endif

struct iphdr {
#if defined(__LITTLE_ENDIAN_BITFIELD)
	__u8	ihl:4,
		version:4;
#elif defined (__BIG_ENDIAN_BITFIELD)
	__u8	version:4,
  		ihl:4;
#else
#error	"Please fix <asm/byteorder.h>"
#endif
	__u8	tos;
	__u16	tot_len;
	__u16	id;
	__u16	frag_off;
	__u8	ttl;
	__u8	protocol;
	__u16	check;
	__u32	saddr;
	__u32	daddr;
	/*The options start here. */
};

#endif	/* _LINUX_IP_H */