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ed37a22318
tcpdump/print-ip.c
hannes ed37a22318 split BGP output to multiple lines; 
added support for Originator_ID, Cluster List Attributes;
reworked BGP Open Message Decoder do decode optional Capabilities;
fixed the NEXTHOP decoder of MP_REACH and MP_UNREACH to honor
 NH length based on AFI,SAFI
2002-07-14 14:14:50 +00:00

587 lines
12 KiB
C
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/*
* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
* 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 const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.106 2002-07-14 14:14:50 hannes Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "addrtoname.h"
#include "interface.h"
#include "extract.h" /* must come after interface.h */
#include "ip.h"
/* Compatibility */
#ifndef IPPROTO_ND
#define IPPROTO_ND 77
#endif
/*
* print the recorded route in an IP RR, LSRR or SSRR option.
*/
static void
ip_printroute(const char *type, register const u_char *cp, u_int length)
{
register u_int ptr = cp[2] - 1;
register u_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 = "#";
printf("%s%s", type, ipaddr_string(&cp[len]));
type = " ";
}
printf("%s}", ptr == len? "#" : "");
}
static void
ip_printts(register const u_char *cp, u_int length)
{
register u_int ptr = cp[2] - 1;
register u_int len = 0;
int hoplen;
char *type;
printf(" TS{");
hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
if ((length - 4) & (hoplen-1))
printf("[bad length %d]", length);
if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
printf("[bad ptr %d]", cp[2]);
switch (cp[3]&0xF) {
case IPOPT_TS_TSONLY:
printf("TSONLY");
break;
case IPOPT_TS_TSANDADDR:
printf("TS+ADDR");
break;
/*
* prespecified should really be 3, but some ones might send 2
* instead, and the IPOPT_TS_PRESPEC constant can apparently
* have both values, so we have to hard-code it here.
*/
case 2:
printf("PRESPEC2.0");
break;
case 3: /* IPOPT_TS_PRESPEC */
printf("PRESPEC");
break;
default:
printf("[bad ts type %d]", cp[3]&0xF);
goto done;
}
type = " ";
for (len = 4; len < length; len += hoplen) {
if (ptr == len)
type = " ^ ";
printf("%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]),
hoplen!=8 ? "" : ipaddr_string(&cp[len]));
type = " ";
}
done:
printf("%s", ptr == len ? " ^ " : "");
if (cp[3]>>4)
printf(" [%d hops not recorded]} ", cp[3]>>4);
else
printf("}");
}
/*
* print IP options.
*/
static void
ip_optprint(register const u_char *cp, u_int length)
{
register u_int len;
for (; length > 0; cp += len, length -= len) {
int tt = *cp;
if (tt == IPOPT_NOP || tt == IPOPT_EOL)
len = 1;
else {
if (&cp[1] >= snapend) {
printf("[|ip]");
return;
}
len = cp[1];
}
if (len <= 0) {
printf("[|ip op len %d]", len);
return;
}
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:
ip_printts(cp, len);
break;
#ifndef IPOPT_SECURITY
#define IPOPT_SECURITY 130
#endif /* IPOPT_SECURITY */
case IPOPT_SECURITY:
printf(" SECURITY{%d}", len);
break;
case IPOPT_RR:
ip_printroute("RR", cp, len);
break;
case IPOPT_SSRR:
ip_printroute("SSRR", cp, len);
break;
case IPOPT_LSRR:
ip_printroute("LSRR", cp, len);
break;
#ifndef IPOPT_RA
#define IPOPT_RA 148 /* router alert */
#endif
case IPOPT_RA:
printf(" RA");
if (len != 4)
printf("{%d}", len);
else if (cp[2] || cp[3])
printf("%d.%d", cp[2], cp[3]);
break;
default:
printf(" IPOPT-%d{%d}", cp[0], len);
break;
}
}
}
/*
* compute an IP header checksum.
* don't modifiy the packet.
*/
u_short
in_cksum(const u_short *addr, register u_int len, int csum)
{
int nleft = len;
const u_short *w = addr;
u_short answer;
int sum = csum;
/*
* Our algorithm is simple, using a 32 bit accumulator (sum),
* we add sequential 16 bit words to it, and at the end, fold
* back all the carry bits from the top 16 bits into the lower
* 16 bits.
*/
while (nleft > 1) {
sum += *w++;
nleft -= 2;
}
if (nleft == 1)
sum += htons(*(u_char *)w<<8);
/*
* add back carry outs from top 16 bits to low 16 bits
*/
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
answer = ~sum; /* truncate to 16 bits */
return (answer);
}
/*
* print an IP datagram.
*/
void
ip_print(register const u_char *bp, register u_int length)
{
register const struct ip *ip;
register u_int hlen, len, len0, off;
register const u_char *cp;
u_char nh;
int advance;
struct protoent *proto;
ip = (const struct ip *)bp;
#ifdef LBL_ALIGN
/*
* If the IP header is not aligned, copy into abuf.
*/
if ((long)ip & 3) {
static u_char *abuf = NULL;
static int didwarn = 0;
if (abuf == NULL) {
abuf = (u_char *)malloc(snaplen);
if (abuf == NULL)
error("ip_print: malloc");
}
memcpy((char *)abuf, (char *)ip, min(length, snaplen));
snapend += abuf - (u_char *)ip;
packetp = abuf;
ip = (struct ip *)abuf;
/* We really want libpcap to give us aligned packets */
if (!didwarn) {
warning("compensating for unaligned libpcap packets");
++didwarn;
}
}
#endif
if ((u_char *)(ip + 1) > snapend) {
printf("[|ip]");
return;
}
if (length < sizeof (struct ip)) {
(void)printf("truncated-ip %d", length);
return;
}
hlen = IP_HL(ip) * 4;
if (hlen < sizeof (struct ip)) {
(void)printf("bad-hlen %d", hlen);
return;
}
len = ntohs(ip->ip_len);
if (length < len)
(void)printf("truncated-ip - %d bytes missing! ",
len - length);
len -= hlen;
len0 = len;
printf("IP ");
if (vflag) {
if (ip->ip_tos) {
(void)printf("(tos 0x%x", (int)ip->ip_tos);
/* ECN bits */
if (ip->ip_tos & 0x03) {
switch (ip->ip_tos & 0x03) {
case 1:
(void)printf(",ECT(1)");
break;
case 2:
(void)printf(",ECT(0)");
break;
case 3:
(void)printf(",CE");
}
}
}
if (ip->ip_ttl >= 1)
(void)printf(", ttl %d", (int)ip->ip_ttl);
if ((off & 0x3fff) == 0)
(void)printf(", id %d", (int)ntohs(ip->ip_id));
(void)printf(", len %d) ", (int)ntohs(ip->ip_len));
}
/*
* 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;
nh = ip->ip_p;
#ifndef IPPROTO_SCTP
#define IPPROTO_SCTP 132
#endif
if (nh != IPPROTO_TCP && nh != IPPROTO_UDP &&
nh != IPPROTO_SCTP) {
(void)printf("%s > %s: ", ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
}
again:
switch (nh) {
#ifndef IPPROTO_AH
#define IPPROTO_AH 51
#endif
case IPPROTO_AH:
nh = *cp;
advance = ah_print(cp, (const u_char *)ip);
cp += advance;
len -= advance;
goto again;
#ifndef IPPROTO_ESP
#define IPPROTO_ESP 50
#endif
case IPPROTO_ESP:
{
int enh, padlen;
advance = esp_print(cp, (const u_char *)ip, &enh, &padlen);
cp += advance;
len -= advance + padlen;
if (enh < 0)
break;
nh = enh & 0xff;
goto again;
}
#ifndef IPPROTO_IPCOMP
#define IPPROTO_IPCOMP 108
#endif
case IPPROTO_IPCOMP:
{
int enh;
advance = ipcomp_print(cp, (const u_char *)ip, &enh);
cp += advance;
len -= advance;
if (enh < 0)
break;
nh = enh & 0xff;
goto again;
}
case IPPROTO_SCTP:
sctp_print(cp, (const u_char *)ip, len);
break;
case IPPROTO_TCP:
tcp_print(cp, len, (const u_char *)ip, (off &~ 0x6000));
break;
case IPPROTO_UDP:
udp_print(cp, len, (const u_char *)ip, (off &~ 0x6000));
break;
case IPPROTO_ICMP:
icmp_print(cp, len, (const u_char *)ip);
break;
#ifndef IPPROTO_IGRP
#define IPPROTO_IGRP 9
#endif
case IPPROTO_IGRP:
igrp_print(cp, len, (const u_char *)ip);
break;
case IPPROTO_ND:
(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);
break;
case 4:
/* DVMRP multicast tunnel (ip-in-ip encapsulation) */
ip_print(cp, len);
if (! vflag) {
printf(" (ipip-proto-4)");
return;
}
break;
#ifdef INET6
#ifndef IP6PROTO_ENCAP
#define IP6PROTO_ENCAP 41
#endif
case IP6PROTO_ENCAP:
/* ip6-in-ip encapsulation */
ip6_print(cp, len);
break;
#endif /*INET6*/
#ifndef IPPROTO_GRE
#define IPPROTO_GRE 47
#endif
case IPPROTO_GRE:
/* do it */
gre_print(cp, len);
break;
#ifndef IPPROTO_MOBILE
#define IPPROTO_MOBILE 55
#endif
case IPPROTO_MOBILE:
mobile_print(cp, len);
break;
#ifndef IPPROTO_PIM
#define IPPROTO_PIM 103
#endif
case IPPROTO_PIM:
pim_print(cp, len);
break;
#ifndef IPPROTO_VRRP
#define IPPROTO_VRRP 112
#endif
case IPPROTO_VRRP:
vrrp_print(cp, len, ip->ip_ttl);
break;
default:
if ((proto = getprotobynumber(nh)) != NULL)
(void)printf(" %s", proto->p_name);
else
(void)printf(" ip-proto-%d", nh);
printf(" %d", len);
break;
}
}
/* Ultra quiet now means that all this stuff should be suppressed */
/* res 3-Nov-98 */
if (qflag > 1) return;
/*
* for fragmented datagrams, print id:size@offset. On all
* but the last stick a "+". For unfragmented datagrams, note
* the don't fragment flag.
*/
len = len0; /* get the original length */
if (off & 0x3fff) {
/*
* if this isn't the first frag, we're missing the
* next level protocol header. print the ip addr
* and the protocol.
*/
if (off & 0x1fff) {
(void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
if ((proto = getprotobynumber(ip->ip_p)) != NULL)
(void)printf(" %s", proto->p_name);
else
(void)printf(" ip-proto-%d", ip->ip_p);
}
#ifndef IP_MF
#define IP_MF 0x2000
#endif /* IP_MF */
#ifndef IP_DF
#define IP_DF 0x4000
#endif /* IP_DF */
(void)printf(" (frag %d:%u@%d%s)", ntohs(ip->ip_id), len,
(off & 0x1fff) * 8,
(off & IP_MF)? "+" : "");
} else if (off & IP_DF)
(void)printf(" (DF)");
if (vflag) {
int sum;
char *sep = "";
if ((u_char *)ip + hlen <= snapend) {
sum = in_cksum((const u_short *)ip, hlen, 0);
if (sum != 0) {
(void)printf("%sbad cksum %x (->%x)!", sep,
ntohs(ip->ip_sum),
ntohs(ip->ip_sum)-sum);
sep = ", ";
}
}
if ((hlen -= sizeof(struct ip)) > 0) {
(void)printf("%soptlen=%d", sep, hlen);
ip_optprint((u_char *)(ip + 1), hlen);
}
}
}
void
ipN_print(register const u_char *bp, register u_int length)
{
struct ip *ip, hdr;
ip = (struct ip *)bp;
if (length < 4) {
(void)printf("truncated-ip %d", length);
return;
}
memcpy (&hdr, (char *)ip, 4);
switch (IP_V(&hdr)) {
case 4:
ip_print (bp, length);
return;
#ifdef INET6
case 6:
ip6_print (bp, length);
return;
#endif
default:
(void)printf("unknown ip %d", IP_V(&hdr));
return;
}
}
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