/* Copyright (C) 1991-2025 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef __NETINET_IP_H
#define __NETINET_IP_H 1

#include <features.h>
#include <sys/types.h>

#include <netinet/in.h>

__BEGIN_DECLS

struct timestamp
  {
    uint8_t len;
    uint8_t ptr;
#if __BYTE_ORDER == __LITTLE_ENDIAN
    unsigned int flags:4;
    unsigned int overflow:4;
#elif __BYTE_ORDER == __BIG_ENDIAN
    unsigned int overflow:4;
    unsigned int flags:4;
#else
# error	"Please fix <bits/endian.h>"
#endif
    uint32_t data[9];
  };

struct iphdr
  {
#if __BYTE_ORDER == __LITTLE_ENDIAN
    unsigned int ihl:4;
    unsigned int version:4;
#elif __BYTE_ORDER == __BIG_ENDIAN
    unsigned int version:4;
    unsigned int ihl:4;
#else
# error	"Please fix <bits/endian.h>"
#endif
    uint8_t tos;
    uint16_t tot_len;
    uint16_t id;
    uint16_t frag_off;
    uint8_t ttl;
    uint8_t protocol;
    uint16_t check;
    uint32_t saddr;
    uint32_t daddr;
    /*The options start here. */
  };

#ifdef __USE_MISC
/*
 * 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.
 * 4. 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	8.1 (Berkeley) 6/10/93
 */

/*
 * Definitions for internet protocol version 4.
 * Per RFC 791, September 1981.
 */

/*
 * Structure of an internet header, naked of options.
 */
struct ip
  {
#if __BYTE_ORDER == __LITTLE_ENDIAN
    unsigned int ip_hl:4;		/* header length */
    unsigned int ip_v:4;		/* version */
#endif
#if __BYTE_ORDER == __BIG_ENDIAN
    unsigned int ip_v:4;		/* version */
    unsigned int ip_hl:4;		/* header length */
#endif
    uint8_t ip_tos;			/* type of service */
    unsigned short ip_len;		/* total length */
    unsigned short ip_id;		/* identification */
    unsigned 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 */
    uint8_t ip_ttl;			/* time to live */
    uint8_t ip_p;			/* protocol */
    unsigned short ip_sum;		/* checksum */
    struct in_addr ip_src, ip_dst;	/* source and dest address */
  };

/*
 * Time stamp option structure.
 */
struct ip_timestamp
  {
    uint8_t ipt_code;			/* IPOPT_TS */
    uint8_t ipt_len;			/* size of structure (variable) */
    uint8_t ipt_ptr;			/* index of current entry */
#if __BYTE_ORDER == __LITTLE_ENDIAN
    unsigned int ipt_flg:4;		/* flags, see below */
    unsigned int ipt_oflw:4;		/* overflow counter */
#endif
#if __BYTE_ORDER == __BIG_ENDIAN
    unsigned int ipt_oflw:4;		/* overflow counter */
    unsigned int ipt_flg:4;		/* flags, see below */
#endif
    uint32_t data[9];
  };
#endif /* __USE_MISC */

#define	IPVERSION	4               /* IP version number */
#define	IP_MAXPACKET	65535		/* maximum packet size */

/*
 * Definitions for Explicit Congestion Notification (ECN)
 *
 * Taken from RFC-3168, Section 5.
 */

#define	IPTOS_ECN_MASK		0x03
#define	IPTOS_ECN(x)		((x) & IPTOS_ECN_MASK)
#define	IPTOS_ECN_NOT_ECT	0x00
#define	IPTOS_ECN_ECT1		0x01
#define	IPTOS_ECN_ECT0		0x02
#define	IPTOS_ECN_CE		0x03

/*
 * Definitions for IP differentiated services code points (DSCP)
 *
 * Taken from RFC-2597, Section 6 and RFC-2598, Section 2.3.
 */

#define	IPTOS_DSCP_MASK		0xfc
#define	IPTOS_DSCP(x)		((x) & IPTOS_DSCP_MASK)
#define	IPTOS_DSCP_AF11		0x28
#define	IPTOS_DSCP_AF12		0x30
#define	IPTOS_DSCP_AF13		0x38
#define	IPTOS_DSCP_AF21		0x48
#define	IPTOS_DSCP_AF22		0x50
#define	IPTOS_DSCP_AF23		0x58
#define	IPTOS_DSCP_AF31		0x68
#define	IPTOS_DSCP_AF32		0x70
#define	IPTOS_DSCP_AF33		0x78
#define	IPTOS_DSCP_AF41		0x88
#define	IPTOS_DSCP_AF42		0x90
#define	IPTOS_DSCP_AF43		0x98
#define	IPTOS_DSCP_EF		0xb8

/*
 * Voice-Admit DSCP code point from RFC-5865, Section 4.
 */
#define	IPTOS_DSCP_VA		0xb0

/*
 * Lower-Effort Per-Hop Behavior DSCP code point from RFC-8622, Section 12.
 */
#define	IPTOS_DSCP_LE		0x04

/*
 * In RFC 2474, Section 4.2.2.1, the Class Selector Codepoints subsume
 * the old ToS Precedence values.
 */

#define	IPTOS_CLASS_MASK		0xe0
#define	IPTOS_CLASS(class)		((class) & IPTOS_CLASS_MASK)
#define	IPTOS_CLASS_CS0			0x00
#define	IPTOS_CLASS_CS1			0x20
#define	IPTOS_CLASS_CS2			0x40
#define	IPTOS_CLASS_CS3			0x60
#define	IPTOS_CLASS_CS4			0x80
#define	IPTOS_CLASS_CS5			0xa0
#define	IPTOS_CLASS_CS6			0xc0
#define	IPTOS_CLASS_CS7			0xe0

#define	IPTOS_CLASS_DEFAULT		IPTOS_CLASS_CS0

/*
 * Definitions for IP type of service (ip_tos) [deprecated; use DSCP
 * and CS definitions above instead.]
 */
#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_LOWCOST		0x02
#define	IPTOS_MINCOST		IPTOS_LOWCOST

/*
 * Definitions for IP precedence (also in ip_tos) [also deprecated.]
 */
#define	IPTOS_PREC_MASK			IPTOS_CLASS_MASK
#define	IPTOS_PREC(tos)			IPTOS_CLASS(tos)
#define	IPTOS_PREC_NETCONTROL		IPTOS_CLASS_CS7
#define	IPTOS_PREC_INTERNETCONTROL	IPTOS_CLASS_CS6
#define	IPTOS_PREC_CRITIC_ECP		IPTOS_CLASS_CS5
#define	IPTOS_PREC_FLASHOVERRIDE	IPTOS_CLASS_CS4
#define	IPTOS_PREC_FLASH		IPTOS_CLASS_CS3
#define	IPTOS_PREC_IMMEDIATE		IPTOS_CLASS_CS2
#define	IPTOS_PREC_PRIORITY		IPTOS_CLASS_CS1
#define	IPTOS_PREC_ROUTINE		IPTOS_CLASS_CS0

/*
 * Definitions for 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_DEBMEAS		0x40
#define	IPOPT_MEASUREMENT       IPOPT_DEBMEAS
#define	IPOPT_RESERVED2		0x60

#define	IPOPT_EOL		0		/* end of option list */
#define	IPOPT_END		IPOPT_EOL
#define	IPOPT_NOP		1		/* no operation */
#define	IPOPT_NOOP		IPOPT_NOP

#define	IPOPT_RR		7		/* record packet route */
#define	IPOPT_TS		68		/* timestamp */
#define	IPOPT_TIMESTAMP		IPOPT_TS
#define	IPOPT_SECURITY		130		/* provide s,c,h,tcc */
#define	IPOPT_SEC		IPOPT_SECURITY
#define	IPOPT_LSRR		131		/* loose source route */
#define	IPOPT_SATID		136		/* satnet id */
#define	IPOPT_SID		IPOPT_SATID
#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 */

#define	MAX_IPOPTLEN		40

/* 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 */

__END_DECLS

#endif /* netinet/ip.h */
