ip.h revision 75115
175115Sfenner/* @(#) $Header: /tcpdump/master/tcpdump/ip.h,v 1.7 2000/10/03 09:17:40 guy Exp $ (LBL) */ 275115Sfenner/* 375115Sfenner * Copyright (c) 1982, 1986, 1993 475115Sfenner * The Regents of the University of California. All rights reserved. 575115Sfenner * 675115Sfenner * Redistribution and use in source and binary forms, with or without 775115Sfenner * modification, are permitted provided that the following conditions 875115Sfenner * are met: 975115Sfenner * 1. Redistributions of source code must retain the above copyright 1075115Sfenner * notice, this list of conditions and the following disclaimer. 1175115Sfenner * 2. Redistributions in binary form must reproduce the above copyright 1275115Sfenner * notice, this list of conditions and the following disclaimer in the 1375115Sfenner * documentation and/or other materials provided with the distribution. 1475115Sfenner * 3. All advertising materials mentioning features or use of this software 1575115Sfenner * must display the following acknowledgement: 1675115Sfenner * This product includes software developed by the University of 1775115Sfenner * California, Berkeley and its contributors. 1875115Sfenner * 4. Neither the name of the University nor the names of its contributors 1975115Sfenner * may be used to endorse or promote products derived from this software 2075115Sfenner * without specific prior written permission. 2175115Sfenner * 2275115Sfenner * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2375115Sfenner * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2475115Sfenner * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2575115Sfenner * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2675115Sfenner * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2775115Sfenner * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2875115Sfenner * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2975115Sfenner * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3075115Sfenner * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3175115Sfenner * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3275115Sfenner * SUCH DAMAGE. 3375115Sfenner * 3475115Sfenner * @(#)ip.h 8.2 (Berkeley) 6/1/94 3575115Sfenner */ 3675115Sfenner 3775115Sfenner/* 3875115Sfenner * Definitions for internet protocol version 4. 3975115Sfenner * Per RFC 791, September 1981. 4075115Sfenner */ 4175115Sfenner#define IPVERSION 4 4275115Sfenner 4375115Sfenner/* 4475115Sfenner * Structure of an internet header, naked of options. 4575115Sfenner * 4675115Sfenner * We declare ip_len and ip_off to be short, rather than u_short 4775115Sfenner * pragmatically since otherwise unsigned comparisons can result 4875115Sfenner * against negative integers quite easily, and fail in subtle ways. 4975115Sfenner */ 5075115Sfennerstruct ip { 5175115Sfenner u_int8_t ip_vhl; /* header length, version */ 5275115Sfenner#define IP_V(ip) (((ip)->ip_vhl & 0xf0) >> 4) 5375115Sfenner#define IP_HL(ip) ((ip)->ip_vhl & 0x0f) 5475115Sfenner u_int8_t ip_tos; /* type of service */ 5575115Sfenner u_int16_t ip_len; /* total length */ 5675115Sfenner u_int16_t ip_id; /* identification */ 5775115Sfenner u_int16_t ip_off; /* fragment offset field */ 5875115Sfenner#define IP_DF 0x4000 /* dont fragment flag */ 5975115Sfenner#define IP_MF 0x2000 /* more fragments flag */ 6075115Sfenner#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */ 6175115Sfenner u_int8_t ip_ttl; /* time to live */ 6275115Sfenner u_int8_t ip_p; /* protocol */ 6375115Sfenner u_int16_t ip_sum; /* checksum */ 6475115Sfenner struct in_addr ip_src,ip_dst; /* source and dest address */ 6575115Sfenner}; 6675115Sfenner 6775115Sfenner#define IP_MAXPACKET 65535 /* maximum packet size */ 6875115Sfenner 6975115Sfenner/* 7075115Sfenner * Definitions for IP type of service (ip_tos) 7175115Sfenner */ 7275115Sfenner#define IPTOS_LOWDELAY 0x10 7375115Sfenner#define IPTOS_THROUGHPUT 0x08 7475115Sfenner#define IPTOS_RELIABILITY 0x04 7575115Sfenner 7675115Sfenner/* 7775115Sfenner * Definitions for IP precedence (also in ip_tos) (hopefully unused) 7875115Sfenner */ 7975115Sfenner#define IPTOS_PREC_NETCONTROL 0xe0 8075115Sfenner#define IPTOS_PREC_INTERNETCONTROL 0xc0 8175115Sfenner#define IPTOS_PREC_CRITIC_ECP 0xa0 8275115Sfenner#define IPTOS_PREC_FLASHOVERRIDE 0x80 8375115Sfenner#define IPTOS_PREC_FLASH 0x60 8475115Sfenner#define IPTOS_PREC_IMMEDIATE 0x40 8575115Sfenner#define IPTOS_PREC_PRIORITY 0x20 8675115Sfenner#define IPTOS_PREC_ROUTINE 0x00 8775115Sfenner 8875115Sfenner/* 8975115Sfenner * Definitions for options. 9075115Sfenner */ 9175115Sfenner#define IPOPT_COPIED(o) ((o)&0x80) 9275115Sfenner#define IPOPT_CLASS(o) ((o)&0x60) 9375115Sfenner#define IPOPT_NUMBER(o) ((o)&0x1f) 9475115Sfenner 9575115Sfenner#define IPOPT_CONTROL 0x00 9675115Sfenner#define IPOPT_RESERVED1 0x20 9775115Sfenner#define IPOPT_DEBMEAS 0x40 9875115Sfenner#define IPOPT_RESERVED2 0x60 9975115Sfenner 10075115Sfenner#define IPOPT_EOL 0 /* end of option list */ 10175115Sfenner#define IPOPT_NOP 1 /* no operation */ 10275115Sfenner 10375115Sfenner#define IPOPT_RR 7 /* record packet route */ 10475115Sfenner#define IPOPT_TS 68 /* timestamp */ 10575115Sfenner#define IPOPT_SECURITY 130 /* provide s,c,h,tcc */ 10675115Sfenner#define IPOPT_LSRR 131 /* loose source route */ 10775115Sfenner#define IPOPT_SATID 136 /* satnet id */ 10875115Sfenner#define IPOPT_SSRR 137 /* strict source route */ 10975115Sfenner 11075115Sfenner/* 11175115Sfenner * Offsets to fields in options other than EOL and NOP. 11275115Sfenner */ 11375115Sfenner#define IPOPT_OPTVAL 0 /* option ID */ 11475115Sfenner#define IPOPT_OLEN 1 /* option length */ 11575115Sfenner#define IPOPT_OFFSET 2 /* offset within option */ 11675115Sfenner#define IPOPT_MINOFF 4 /* min value of above */ 11775115Sfenner 11875115Sfenner/* 11975115Sfenner * Time stamp option structure. 12075115Sfenner */ 12175115Sfennerstruct ip_timestamp { 12275115Sfenner u_int8_t ipt_code; /* IPOPT_TS */ 12375115Sfenner u_int8_t ipt_len; /* size of structure (variable) */ 12475115Sfenner u_int8_t ipt_ptr; /* index of current entry */ 12575115Sfenner u_int8_t ipt_oflwflg; /* flags, overflow counter */ 12675115Sfenner#define IPTS_OFLW(ip) (((ipt)->ipt_oflwflg & 0xf0) >> 4) 12775115Sfenner#define IPTS_FLG(ip) ((ipt)->ipt_oflwflg & 0x0f) 12875115Sfenner union ipt_timestamp { 12975115Sfenner u_int32_t ipt_time[1]; 13075115Sfenner struct ipt_ta { 13175115Sfenner struct in_addr ipt_addr; 13275115Sfenner u_int32_t ipt_time; 13375115Sfenner } ipt_ta[1]; 13475115Sfenner } ipt_timestamp; 13575115Sfenner}; 13675115Sfenner 13775115Sfenner/* flag bits for ipt_flg */ 13875115Sfenner#define IPOPT_TS_TSONLY 0 /* timestamps only */ 13975115Sfenner#define IPOPT_TS_TSANDADDR 1 /* timestamps and addresses */ 14075115Sfenner#define IPOPT_TS_PRESPEC 3 /* specified modules only */ 14175115Sfenner 14275115Sfenner/* bits for security (not byte swapped) */ 14375115Sfenner#define IPOPT_SECUR_UNCLASS 0x0000 14475115Sfenner#define IPOPT_SECUR_CONFID 0xf135 14575115Sfenner#define IPOPT_SECUR_EFTO 0x789a 14675115Sfenner#define IPOPT_SECUR_MMMM 0xbc4d 14775115Sfenner#define IPOPT_SECUR_RESTR 0xaf13 14875115Sfenner#define IPOPT_SECUR_SECRET 0xd788 14975115Sfenner#define IPOPT_SECUR_TOPSECRET 0x6bc5 15075115Sfenner 15175115Sfenner/* 15275115Sfenner * Internet implementation parameters. 15375115Sfenner */ 15475115Sfenner#define MAXTTL 255 /* maximum time to live (seconds) */ 15575115Sfenner#define IPDEFTTL 64 /* default ttl, from RFC 1340 */ 15675115Sfenner#define IPFRAGTTL 60 /* time to live for frags, slowhz */ 15775115Sfenner#define IPTTLDEC 1 /* subtracted when forwarding */ 15875115Sfenner 15975115Sfenner#define IP_MSS 576 /* default maximum segment size */ 160