ip.h

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/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1982, 1986, 1993
 *      The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)ip.h        8.2 (Berkeley) 6/1/94
 * $FreeBSD$
 */
 
#ifndef _NETINET_IP_H_
#define _NETINET_IP_H_
 
#include <sys/cdefs.h>
 
/*
 * Definitions for internet protocol version 4.
 *
 * Per RFC 791, September 1981.
 */
#define IPVERSION       4
 
/*
 * Structure of an internet header, naked of options.
 */
struct ip {
#if BYTE_ORDER == LITTLE_ENDIAN
        u_char  ip_hl:4,                /* header length */
                ip_v:4;                 /* version */
#endif
#if BYTE_ORDER == BIG_ENDIAN
        u_char  ip_v:4,                 /* version */
                ip_hl:4;                /* header length */
#endif
        u_char  ip_tos;                 /* type of service */
        u_short ip_len;                 /* total length */
        u_short ip_id;                  /* identification */
        u_short ip_off;                 /* fragment offset field */
#define IP_RF 0x8000                    /* reserved fragment flag */
#define IP_DF 0x4000                    /* dont fragment flag */
#define IP_MF 0x2000                    /* more fragments flag */
#define IP_OFFMASK 0x1fff               /* mask for fragmenting bits */
        u_char  ip_ttl;                 /* time to live */
        u_char  ip_p;                   /* protocol */
        u_short ip_sum;                 /* checksum */
        struct  in_addr ip_src,ip_dst;  /* source and dest address */
} __packed __aligned(2);
 
#define IP_MAXPACKET    65535           /* maximum packet size */
 
/*
 * Definitions for IP type of service (ip_tos).
 */
#define IPTOS_LOWDELAY          0x10
#define IPTOS_THROUGHPUT        0x08
#define IPTOS_RELIABILITY       0x04
#define IPTOS_MINCOST           IPTOS_DSCP_CS0
 
/*
 * Definitions for IP precedence (also in ip_tos) (deprecated).
 */
#define IPTOS_PREC_NETCONTROL           IPTOS_DSCP_CS7
#define IPTOS_PREC_INTERNETCONTROL      IPTOS_DSCP_CS6
#define IPTOS_PREC_CRITIC_ECP           IPTOS_DSCP_CS5
#define IPTOS_PREC_FLASHOVERRIDE        IPTOS_DSCP_CS4
#define IPTOS_PREC_FLASH                IPTOS_DSCP_CS3
#define IPTOS_PREC_IMMEDIATE            IPTOS_DSCP_CS2
#define IPTOS_PREC_PRIORITY             IPTOS_DSCP_CS1
#define IPTOS_PREC_ROUTINE              IPTOS_DSCP_CS0
 
/*
 * Offset of Diffserv decimal value to convert it to tos value .
 */
#define IPTOS_DSCP_OFFSET               2
 
/*
 * Definitions for DiffServ Codepoints as per RFC2474 and RFC5865.
 */
#define IPTOS_DSCP_CS0          0x00
#define IPTOS_DSCP_CS1          0x20
#define IPTOS_DSCP_AF11         0x28
#define IPTOS_DSCP_AF12         0x30
#define IPTOS_DSCP_AF13         0x38
#define IPTOS_DSCP_CS2          0x40
#define IPTOS_DSCP_AF21         0x48
#define IPTOS_DSCP_AF22         0x50
#define IPTOS_DSCP_AF23         0x58
#define IPTOS_DSCP_CS3          0x60
#define IPTOS_DSCP_AF31         0x68
#define IPTOS_DSCP_AF32         0x70
#define IPTOS_DSCP_AF33         0x78
#define IPTOS_DSCP_CS4          0x80
#define IPTOS_DSCP_AF41         0x88
#define IPTOS_DSCP_AF42         0x90
#define IPTOS_DSCP_AF43         0x98
#define IPTOS_DSCP_CS5          0xa0
#define IPTOS_DSCP_VA           0xb0
#define IPTOS_DSCP_EF           0xb8
#define IPTOS_DSCP_CS6          0xc0
#define IPTOS_DSCP_CS7          0xe0
 
/*
 * ECN (Explicit Congestion Notification) codepoints in RFC3168 mapped to the
 * lower 2 bits of the TOS field.
 */
#define IPTOS_ECN_NOTECT        0x00    /* not-ECT */
#define IPTOS_ECN_ECT1          0x01    /* ECN-capable transport (1) */
#define IPTOS_ECN_ECT0          0x02    /* ECN-capable transport (0) */
#define IPTOS_ECN_CE            0x03    /* congestion experienced */
#define IPTOS_ECN_MASK          0x03    /* ECN field mask */
 
/*
 * Definitions for options.
 */
#define IPOPT_COPIED(o)         ((o)&0x80)
#define IPOPT_CLASS(o)          ((o)&0x60)
#define IPOPT_NUMBER(o)         ((o)&0x1f)
 
#define IPOPT_CONTROL           0x00
#define IPOPT_RESERVED1         0x20
#define IPOPT_DEBMEAS           0x40
#define IPOPT_RESERVED2         0x60
 
#define IPOPT_EOL               0               /* end of option list */
#define IPOPT_NOP               1               /* no operation */
 
#define IPOPT_RR                7               /* record packet route */
#define IPOPT_TS                68              /* timestamp */
#define IPOPT_SECURITY          130             /* provide s,c,h,tcc */
#define IPOPT_LSRR              131             /* loose source route */
#define IPOPT_ESO               133             /* extended security */
#define IPOPT_CIPSO             134             /* commercial security */
#define IPOPT_SATID             136             /* satnet id */
#define IPOPT_SSRR              137             /* strict source route */
#define IPOPT_RA                148             /* router alert */
 
/*
 * Offsets to fields in options other than EOL and NOP.
 */
#define IPOPT_OPTVAL            0               /* option ID */
#define IPOPT_OLEN              1               /* option length */
#define IPOPT_OFFSET            2               /* offset within option */
#define IPOPT_MINOFF            4               /* min value of above */
 
/*
 * Time stamp option structure.
 */
struct  ip_timestamp {
        u_char  ipt_code;               /* IPOPT_TS */
        u_char  ipt_len;                /* size of structure (variable) */
        u_char  ipt_ptr;                /* index of current entry */
#if BYTE_ORDER == LITTLE_ENDIAN
        u_char  ipt_flg:4,              /* flags, see below */
                ipt_oflw:4;             /* overflow counter */
#endif
#if BYTE_ORDER == BIG_ENDIAN
        u_char  ipt_oflw:4,             /* overflow counter */
                ipt_flg:4;              /* flags, see below */
#endif
        union ipt_timestamp {
                uint32_t        ipt_time[1];    /* network format */
                struct  ipt_ta {
                        struct in_addr ipt_addr;
                        uint32_t ipt_time;      /* network format */
                } ipt_ta[1];
        } ipt_timestamp;
};
 
/* Flag bits for ipt_flg. */
#define IPOPT_TS_TSONLY         0               /* timestamps only */
#define IPOPT_TS_TSANDADDR      1               /* timestamps and addresses */
#define IPOPT_TS_PRESPEC        3               /* specified modules only */
 
/* Bits for security (not byte swapped). */
#define IPOPT_SECUR_UNCLASS     0x0000
#define IPOPT_SECUR_CONFID      0xf135
#define IPOPT_SECUR_EFTO        0x789a
#define IPOPT_SECUR_MMMM        0xbc4d
#define IPOPT_SECUR_RESTR       0xaf13
#define IPOPT_SECUR_SECRET      0xd788
#define IPOPT_SECUR_TOPSECRET   0x6bc5
 
/*
 * Internet implementation parameters.
 */
#define MAXTTL          255             /* maximum time to live (seconds) */
#define IPDEFTTL        64              /* default ttl, from RFC 1340 */
#define IPFRAGTTL       60              /* time to live for frags, slowhz */
#define IPTTLDEC        1               /* subtracted when forwarding */
#define IP_MSS          576             /* default maximum segment size */
 
/*
 * This is the real IPv4 pseudo header, used for computing the TCP and UDP
 * checksums. For the Internet checksum, struct ipovly can be used instead.
 * For stronger checksums, the real thing must be used.
 */
struct ippseudo {
        struct  in_addr ippseudo_src;   /* source internet address */
        struct  in_addr ippseudo_dst;   /* destination internet address */
        u_char          ippseudo_pad;   /* pad, must be zero */
        u_char          ippseudo_p;     /* protocol */
        u_short         ippseudo_len;   /* protocol length */
};
#endif