ip에는 iphddr에 없는 struct in_addr ip_src, ip_dst가 존재한다.
struct in_addr의 구조는 다음과 같다.
struct in_addr {
union {
struct {
unsigned char s_b1,
s_b2,
s_b3,
s_b4;
} S_un_b;
struct {
unsigned short s_w1,
s_w2;
} S_un_w;
unsigned long S_addr;
} S_un;
};
출력 할때 xxx.xxx.xxx.xxx 와 같은 형태로 출력하려면 ip 구조체에 ip_src, ip_dst를 이용하면 된다.
/* Copyright (C) 1991,92,93,95,96,97,98,99,2000,2009 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef __NETINET_IP_H
#define __NETINET_IP_H 1
#include <features.h>
#include <sys/types.h>
#include <netinet/in.h>
__BEGIN_DECLS
struct timestamp
{
u_int8_t len;
u_int8_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
u_int32_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
u_int8_t tos;
u_int16_t tot_len;
u_int16_t id;
u_int16_t frag_off;
u_int8_t ttl;
u_int8_t protocol;
u_int16_t check;
u_int32_t saddr;
u_int32_t daddr;
/*The options start here. */
};
#ifdef __USE_BSD
/*
* 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
u_int8_t 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_int8_t ip_ttl; /* time to live */
u_int8_t ip_p; /* protocol */
u_short ip_sum; /* checksum */
struct in_addr ip_src, ip_dst; /* source and dest address */
};
/*
* Time stamp option structure.
*/
struct ip_timestamp
{
u_int8_t ipt_code; /* IPOPT_TS */
u_int8_t ipt_len; /* size of structure (variable) */
u_int8_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
u_int32_t data[9];
};
#endif /* __USE_BSD */
#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
/*
* Definitions for IP type of service (ip_tos)
*/
#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) (hopefully unused)
*/
#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
/*
* 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 */
출처 : http://blog.naver.com/hjs20613?Redirect=Log&logNo=140188632025
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