* Copyright (c) 1982, 1986, 1993

/*
* 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
*/

#ifndef netdissect_ip_h
#define netdissect_ip_h

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

/*
* Structure of an internet header, naked of options.
*
* We declare ip_len and ip_off to be short, rather than u_short
* pragmatically since otherwise unsigned comparisons can result
* against negative integers quite easily, and fail in subtle ways.
*/
struct ip {
nd_uint8_t ip_vhl; /* header length, version */
#define IP_V(ip) ((GET_U_1((ip)->ip_vhl) & 0xf0) >> 4)
#define IP_HL(ip) (GET_U_1((ip)->ip_vhl) & 0x0f)
nd_uint8_t ip_tos; /* type of service */
nd_uint16_t ip_len; /* total length */
nd_uint16_t ip_id; /* identification */
nd_uint16_t ip_off; /* fragment offset field */
#define IP_DF 0x4000 /* don't fragment flag */
#define IP_MF 0x2000 /* more fragments flag */
#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
nd_uint8_t ip_ttl; /* time to live */
nd_uint8_t ip_p; /* protocol */
nd_uint16_t ip_sum; /* checksum */
nd_ipv4 ip_src,ip_dst; /* source and dest address */
};

#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

/*
* Definitions for IP precedence (also in ip_tos) (hopefully unused)
*/
#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

/*
* 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_RFC1393 82 /* traceroute RFC 1393 */
#define IPOPT_SECURITY 130 /* provide s,c,h,tcc */
#define IPOPT_LSRR 131 /* loose source route */
#define IPOPT_SSRR 137 /* strict source route */
#define IPOPT_RA 148 /* router-alert, rfc2113 */

/*
* 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 {
nd_uint8_t ipt_code; /* IPOPT_TS */
nd_uint8_t ipt_len; /* size of structure (variable) */
nd_uint8_t ipt_ptr; /* index of current entry */
nd_uint8_t ipt_oflwflg; /* flags, overflow counter */
#define IPTS_OFLW(ip) (((ipt)->ipt_oflwflg & 0xf0) >> 4)
#define IPTS_FLG(ip) ((ipt)->ipt_oflwflg & 0x0f)
union ipt_timestamp {
nd_uint32_t ipt_time[1];
struct ipt_ta {
nd_ipv4 ipt_addr;
nd_uint32_t ipt_time;
} 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 */
#endif /* netdissect_ip_h */