NetBSD/usr.sbin/tcpdump/print-ip.c

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/* $NetBSD: print-ip.c,v 1.4 1995/04/24 13:27:43 cgd Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994
* 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: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char rcsid[] =
"@(#) Header: print-ip.c,v 1.38 94/06/14 20:17:40 leres Exp (LBL)";
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#include <stdio.h>
#ifdef __STDC__
#include <stdlib.h>
#endif
#include <unistd.h>
#include "interface.h"
#include "addrtoname.h"
static void
igmp_print(register const u_char *bp, register int len,
register const u_char *bp2)
{
register const struct ip *ip;
register const u_char *ep;
ip = (const struct ip *)bp2;
ep = (const u_char *)snapend;
(void)printf("%s > %s: ",
ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
if (bp + 7 > ep) {
(void)printf("[|igmp]");
return;
}
switch (bp[0] & 0xf) {
case 1:
(void)printf("igmp query");
if (*(int *)&bp[4])
(void)printf(" [gaddr %s]", ipaddr_string(&bp[4]));
if (len != 8)
(void)printf(" [len %d]", len);
break;
case 2:
(void)printf("igmp report %s", ipaddr_string(&bp[4]));
if (len != 8)
(void)printf(" [len %d]", len);
break;
case 3:
(void)printf("igmp dvmrp %s", ipaddr_string(&bp[4]));
if (len < 8)
(void)printf(" [len %d]", len);
break;
default:
(void)printf("igmp-%d", bp[0] & 0xf);
break;
}
if ((bp[0] >> 4) != 1)
(void)printf(" [v%d]", bp[0] >> 4);
if (bp[1])
(void)printf(" [b1=0x%x]", bp[1]);
}
/*
* print the recorded route in an IP RR, LSRR or SSRR option.
*/
static void
ip_printroute(const char *type, register const u_char *cp, int length)
{
int ptr = cp[2] - 1;
int len;
printf(" %s{", type);
if ((length + 1) & 3)
printf(" [bad length %d]", length);
if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
printf(" [bad ptr %d]", cp[2]);
type = "";
for (len = 3; len < length; len += 4) {
if (ptr == len)
type = "#";
#ifdef TCPDUMP_ALIGN
{
struct in_addr addr;
bcopy((char *)&cp[len], (char *)&addr, sizeof(addr));
printf("%s%s", type, ipaddr_string(&addr));
}
#else
printf("%s%s", type, ipaddr_string(&cp[len]));
#endif
type = " ";
}
printf("%s}", ptr == len? "#" : "");
}
/*
* print IP options.
*/
static void
ip_optprint(register const u_char *cp, int length)
{
int len;
for (; length > 0; cp += len, length -= len) {
int tt = *cp;
len = (tt == IPOPT_NOP || tt == IPOPT_EOL) ? 1 : cp[1];
if (&cp[1] >= snapend || cp + len > snapend) {
printf("[|ip]");
return;
}
switch (tt) {
case IPOPT_EOL:
printf(" EOL");
if (length > 1)
printf("-%d", length - 1);
return;
case IPOPT_NOP:
printf(" NOP");
break;
case IPOPT_TS:
printf(" TS{%d}", len);
break;
case IPOPT_SECURITY:
printf(" SECURITY{%d}", len);
break;
case IPOPT_RR:
printf(" RR{%d}=", len);
ip_printroute("RR", cp, len);
break;
case IPOPT_SSRR:
ip_printroute("SSRR", cp, len);
break;
case IPOPT_LSRR:
ip_printroute("LSRR", cp, len);
break;
default:
printf(" IPOPT-%d{%d}", cp[0], len);
break;
}
}
}
/*
* compute an IP header checksum.
* don't modifiy the packet.
*/
static int
in_cksum(const struct ip *ip)
{
register const u_short *sp = (u_short *)ip;
register u_int32 sum = 0;
register int count;
/*
* No need for endian conversions.
*/
for (count = ip->ip_hl * 2; --count >= 0; )
sum += *sp++;
while (sum > 0xffff)
sum = (sum & 0xffff) + (sum >> 16);
sum = ~sum & 0xffff;
return (sum);
}
/*
* print an IP datagram.
*/
void
ip_print(register const u_char *bp, register int length)
{
register const struct ip *ip;
register int hlen;
register int len;
register int off;
register const u_char *cp;
ip = (const struct ip *)bp;
#ifdef TCPDUMP_ALIGN
/*
* The IP header is not word aligned, so copy into abuf.
* This will never happen with BPF. It does happen raw packet
* dumps from -r.
*/
if ((long)ip & (sizeof(long)-1)) {
static u_char *abuf;
if (abuf == 0)
abuf = (u_char *)malloc(snaplen);
bcopy((char *)ip, (char *)abuf, min(length, snaplen));
snapend += abuf - (u_char *)ip;
packetp = abuf;
ip = (struct ip *)abuf;
}
#endif
if ((u_char *)(ip + 1) > snapend) {
printf("[|ip]");
return;
}
if (length < sizeof (struct ip)) {
(void)printf("truncated-ip %d", length);
return;
}
hlen = ip->ip_hl * 4;
len = ntohs(ip->ip_len);
if (length < len)
(void)printf("truncated-ip - %d bytes missing!",
len - length);
len -= hlen;
/*
* If this is fragment zero, hand it to the next higher
* level protocol.
*/
off = ntohs(ip->ip_off);
if ((off & 0x1fff) == 0) {
cp = (const u_char *)ip + hlen;
switch (ip->ip_p) {
case IPPROTO_TCP:
tcp_print(cp, len, (const u_char *)ip);
break;
case IPPROTO_UDP:
udp_print(cp, len, (const u_char *)ip);
break;
case IPPROTO_ICMP:
icmp_print(cp, (const u_char *)ip);
break;
case IPPROTO_ND:
(void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
(void)printf(" nd %d", len);
break;
case IPPROTO_EGP:
egp_print(cp, len, (const u_char *)ip);
break;
#ifndef IPPROTO_OSPF
#define IPPROTO_OSPF 89
#endif
case IPPROTO_OSPF:
ospf_print(cp, len, (const u_char *)ip);
break;
#ifndef IPPROTO_IGMP
#define IPPROTO_IGMP 2
#endif
case IPPROTO_IGMP:
igmp_print(cp, len, (const u_char *)ip);
break;
#ifndef IPPROTO_ENCAP
#define IPPROTO_ENCAP 4
#endif
case IPPROTO_ENCAP:
/* ip-in-ip encapsulation */
if (vflag)
(void)printf("%s > %s: ",
ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
ip_print(cp, len);
if (! vflag) {
printf(" (encap)");
return;
}
break;
default:
(void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
(void)printf(" ip-proto-%d %d", ip->ip_p, len);
break;
}
}
/*
* for fragmented datagrams, print id:size@offset. On all
* but the last stick a "+". For unfragmented datagrams, note
* the don't fragment flag.
*/
if (off & 0x3fff) {
/*
* if this isn't the first frag, we're missing the
* next level protocol header. print the ip addr.
*/
if (off & 0x1fff)
(void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
(void)printf(" (frag %d:%d@%d%s)", ntohs(ip->ip_id), len,
(off & 0x1fff) * 8,
(off & IP_MF)? "+" : "");
} else if (off & IP_DF)
(void)printf(" (DF)");
if (ip->ip_tos)
(void)printf(" [tos 0x%x]", (int)ip->ip_tos);
if (ip->ip_ttl <= 1)
(void)printf(" [ttl %d]", (int)ip->ip_ttl);
if (vflag) {
int sum;
char *sep = "";
printf(" (");
if (ip->ip_ttl > 1) {
(void)printf("%sttl %d", sep, (int)ip->ip_ttl);
sep = ", ";
}
if ((off & 0x3fff) == 0) {
(void)printf("%sid %d", sep, (int)ntohs(ip->ip_id));
sep = ", ";
}
sum = in_cksum(ip);
if (sum != 0) {
(void)printf("%sbad cksum %x!", sep,
ntohs(ip->ip_sum));
sep = ", ";
}
if ((hlen -= sizeof(struct ip)) > 0) {
(void)printf("%soptlen=%d", sep, hlen);
ip_optprint((u_char *)(ip + 1), hlen);
}
printf(")");
}
}