ip.h

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/*
 * 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, <waltje@uWalt.NL.Mugnet.ORG>
 *
 *              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 */

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