mirrors/tcpdump
0
0
Fork 0
mirror of https://github.com/the-tcpdump-group/tcpdump.git synced 2024-11-24 18:43:39 +08:00
Code Issues Packages Projects Releases Wiki Activity
5c46e9a6cc
tcpdump/print-domain.c
itojun 16ce7b4be2 avoid segfault (NULL pointer deref)
2001-01-01 04:22:56 +00:00

707 lines
15 KiB
C
Raw Blame History

/*
* 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-domain.c,v 1.63 2001-01-01 04:22:56 itojun Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <netinet/in.h>
#ifdef NOERROR
#undef NOERROR /* Solaris sucks */
#endif
#ifdef NOERROR
#undef T_UNSPEC /* SINIX does too */
#endif
#include "nameser.h"
#include <stdio.h>
#include <string.h>
#include "interface.h"
#include "addrtoname.h"
#include "extract.h" /* must come after interface.h */
/* Compatibility */
#ifndef T_TXT
#define T_TXT 16 /* text strings */
#endif
#ifndef T_RP
#define T_RP 17 /* responsible person */
#endif
#ifndef T_AFSDB
#define T_AFSDB 18 /* AFS cell database */
#endif
#ifndef T_X25
#define T_X25 19 /* X_25 calling address */
#endif
#ifndef T_ISDN
#define T_ISDN 20 /* ISDN calling address */
#endif
#ifndef T_RT
#define T_RT 21 /* router */
#endif
#ifndef T_NSAP
#define T_NSAP 22 /* NSAP address */
#endif
#ifndef T_NSAP_PTR
#define T_NSAP_PTR 23 /* reverse NSAP lookup (deprecated) */
#endif
#ifndef T_SIG
#define T_SIG 24 /* security signature */
#endif
#ifndef T_KEY
#define T_KEY 25 /* security key */
#endif
#ifndef T_PX
#define T_PX 26 /* X.400 mail mapping */
#endif
#ifndef T_GPOS
#define T_GPOS 27 /* geographical position (withdrawn) */
#endif
#ifndef T_AAAA
#define T_AAAA 28 /* IP6 Address */
#endif
#ifndef T_LOC
#define T_LOC 29 /* Location Information */
#endif
#ifndef T_NXT
#define T_NXT 30 /* Next Valid Name in Zone */
#endif
#ifndef T_EID
#define T_EID 31 /* Endpoint identifier */
#endif
#ifndef T_NIMLOC
#define T_NIMLOC 32 /* Nimrod locator */
#endif
#ifndef T_SRV
#define T_SRV 33 /* Server selection */
#endif
#ifndef T_ATMA
#define T_ATMA 34 /* ATM Address */
#endif
#ifndef T_NAPTR
#define T_NAPTR 35 /* Naming Authority PoinTeR */
#endif
#ifndef T_A6
#define T_A6 38 /* IP6 address */
#endif
#ifndef T_DNAME
#define T_DNAME 39 /* non-terminal redirection */
#endif
#ifndef T_OPT
#define T_OPT 41 /* EDNS0 option (meta-RR) */
#endif
#ifndef T_UNSPEC
#define T_UNSPEC 103 /* Unspecified format (binary data) */
#endif
#ifndef T_UNSPECA
#define T_UNSPECA 104 /* "unspecified ascii". Ugly MIT hack */
#endif
#ifndef C_CHAOS
#define C_CHAOS 3 /* for chaos net (MIT) */
#endif
#ifndef C_HS
#define C_HS 4 /* for Hesiod name server (MIT) (XXX) */
#endif
static char *ns_ops[] = {
"", " inv_q", " stat", " op3", " notify", " op5", " op6", " op7",
" op8", " updataA", " updateD", " updateDA",
" updateM", " updateMA", " zoneInit", " zoneRef",
};
static char *ns_resp[] = {
"", " FormErr", " ServFail", " NXDomain",
" NotImp", " Refused", " Resp6", " Resp7",
" Resp8", " Resp9", " Resp10", " Resp11",
" Resp12", " Resp13", " Resp14", " NoChange",
};
/* skip over a domain name */
static const u_char *
ns_nskip(register const u_char *cp, register const u_char *bp)
{
register u_char i;
if (((i = *cp++) & INDIR_MASK) == INDIR_MASK)
return (cp + 1);
if (cp >= snapend)
return(NULL);
while (i && cp < snapend) {
if ((i & INDIR_MASK) == EDNS0_MASK) {
int bitlen, bytelen;
if ((i & ~INDIR_MASK) != EDNS0_ELT_BITLABEL)
return(NULL); /* unknown ELT */
if ((bitlen = *cp++) == 0)
bitlen = 256;
bytelen = (bitlen + 7) / 8;
cp += bytelen;
} else
cp += i;
if (cp >= snapend)
return(NULL);
i = *cp++;
}
return (cp);
}
/* print a <domain-name> */
static const u_char *
blabel_print(const u_char *cp)
{
int bitlen, slen, b;
int truncated = 0;
const u_char *bitp, *lim;
char tc;
if (cp >= snapend)
return(NULL);
if ((bitlen = *cp) == 0)
bitlen = 256;
slen = (bitlen + 3) / 4;
if ((lim = cp + 1 + slen) > snapend) {
truncated = 1;
lim = snapend;
}
/* print the bit string as a hex string */
printf("\\[x");
for (bitp = cp + 1, b = bitlen; bitp < lim && b > 7; b -= 8, bitp++)
printf("%02x", *bitp);
if (bitp == lim)
printf("...");
else if (b > 4) {
tc = *bitp++;
printf("%02x", tc & (0xff << (8 - b)));
} else if (b > 0) {
tc = *bitp++;
printf("%1x", ((tc >> 4) & 0x0f) & (0x0f << (4 - b)));
}
printf("/%d]", bitlen);
return(truncated ? NULL : lim);
}
static int
labellen(const u_char *cp)
{
register u_int i;
if (cp >= snapend)
return(-1);
i = *cp;
if ((i & INDIR_MASK) == EDNS0_MASK) {
int bitlen, elt;
if ((elt = (i & ~INDIR_MASK)) != EDNS0_ELT_BITLABEL)
return(-1);
if (cp + 1 >= snapend)
return(-1);
if ((bitlen = *(cp + 1)) == 0)
bitlen = 256;
return(((bitlen + 7) / 8) + 1);
} else
return(i);
}
static const u_char *
ns_nprint(register const u_char *cp, register const u_char *bp)
{
register u_int i, l;
register const u_char *rp;
register int compress = 0;
int chars_processed;
int elt;
int data_size = snapend - bp;
if ((l = labellen(cp)) < 0)
return(NULL);
if (cp >= snapend)
return(NULL);
chars_processed = 1;
if (((i = *cp++) & INDIR_MASK) != INDIR_MASK) {
compress = 0;
rp = cp + l;
}
if (i != 0)
while (i && cp < snapend) {
if ((i & INDIR_MASK) == INDIR_MASK) {
if (!compress) {
rp = cp + 1;
compress = 1;
}
cp = bp + (((i << 8) | *cp) & 0x3fff);
if (cp >= snapend)
return(NULL);
if ((l = labellen(cp)) < 0)
return(NULL);
i = *cp++;
chars_processed++;
/*
* If we've looked at every character in
* the message, this pointer will make
* us look at some character again,
* which means we're looping.
*/
if (chars_processed >= data_size) {
printf("<LOOP>");
return (NULL);
}
continue;
}
if ((i & INDIR_MASK) == EDNS0_MASK) {
elt = (i & ~INDIR_MASK);
switch(elt) {
case EDNS0_ELT_BITLABEL:
blabel_print(cp);
break;
default:
/* unknown ELT */
printf("<ELT %d>", elt);
return(NULL);
}
} else {
if (fn_printn(cp, l, snapend))
break;
}
cp += l;
chars_processed += l;
putchar('.');
if (cp >= snapend || (l = labellen(cp)) < 0)
return(NULL);
i = *cp++;
chars_processed++;
if (!compress)
rp += l + 1;
}
else
putchar('.');
return (rp);
}
/* print a <character-string> */
static const u_char *
ns_cprint(register const u_char *cp, register const u_char *bp)
{
register u_int i;
if (cp >= snapend)
return NULL;
i = *cp++;
(void)fn_printn(cp, i, snapend);
return (cp + i);
}
static struct tok type2str[] = {
{ T_A, "A" },
{ T_NS, "NS" },
{ T_MD, "MD" },
{ T_MF, "MF" },
{ T_CNAME, "CNAME" },
{ T_SOA, "SOA" },
{ T_MB, "MB" },
{ T_MG, "MG" },
{ T_MR, "MR" },
{ T_NULL, "NULL" },
{ T_WKS, "WKS" },
{ T_PTR, "PTR" },
{ T_HINFO, "HINFO" },
{ T_MINFO, "MINFO" },
{ T_MX, "MX" },
{ T_TXT, "TXT" },
{ T_RP, "RP" },
{ T_AFSDB, "AFSDB" },
{ T_X25, "X25" },
{ T_ISDN, "ISDN" },
{ T_RT, "RT" },
{ T_NSAP, "NSAP" },
{ T_NSAP_PTR, "NSAP_PTR" },
{ T_SIG, "SIG" },
{ T_KEY, "KEY" },
{ T_PX, "PX" },
{ T_GPOS, "GPOS" },
{ T_AAAA, "AAAA" },
{ T_LOC, "LOC " },
{ T_NXT, "NXT " },
{ T_EID, "EID " },
{ T_NIMLOC, "NIMLOC " },
{ T_SRV, "SRV " },
{ T_ATMA, "ATMA " },
{ T_NAPTR, "NAPTR " },
{ T_A6, "A6 " },
{ T_DNAME, "DNAME " },
{ T_OPT, "OPT " },
{ T_UINFO, "UINFO" },
{ T_UID, "UID" },
{ T_GID, "GID" },
{ T_UNSPEC, "UNSPEC" },
{ T_UNSPECA, "UNSPECA" },
{ T_AXFR, "AXFR" },
{ T_MAILB, "MAILB" },
{ T_MAILA, "MAILA" },
{ T_ANY, "ANY" },
{ 0, NULL }
};
static struct tok class2str[] = {
{ C_IN, "IN" }, /* Not used */
{ C_CHAOS, "CHAOS)" },
{ C_HS, "HS" },
{ C_ANY, "ANY" },
{ 0, NULL }
};
/* print a query */
static const u_char *
ns_qprint(register const u_char *cp, register const u_char *bp)
{
register const u_char *np = cp;
register u_int i;
cp = ns_nskip(cp, bp);
if (cp + 4 > snapend || cp == NULL)
return(NULL);
/* print the qtype and qclass (if it's not IN) */
i = *cp++ << 8;
i |= *cp++;
printf(" %s", tok2str(type2str, "Type%d", i));
i = *cp++ << 8;
i |= *cp++;
if (i != C_IN)
printf(" %s", tok2str(class2str, "(Class %d)", i));
fputs("? ", stdout);
cp = ns_nprint(np, bp);
return(cp ? cp + 4 : NULL);
}
/* print a reply */
static const u_char *
ns_rprint(register const u_char *cp, register const u_char *bp)
{
register u_int class;
register u_short typ, len;
register const u_char *rp;
if (vflag) {
putchar(' ');
if ((cp = ns_nprint(cp, bp)) == NULL)
return NULL;
} else
cp = ns_nskip(cp, bp);
if (cp + 10 > snapend || cp == NULL)
return (snapend);
/* print the type/qtype and class (if it's not IN) */
typ = *cp++ << 8;
typ |= *cp++;
class = *cp++ << 8;
class |= *cp++;
if (class != C_IN && typ != T_OPT)
printf(" %s", tok2str(class2str, "(Class %d)", class));
/* ignore ttl */
cp += 4;
len = *cp++ << 8;
len |= *cp++;
rp = cp + len;
printf(" %s", tok2str(type2str, "Type%d", typ));
if (rp > snapend)
return(NULL);
switch (typ) {
case T_A:
if (cp + sizeof(struct in_addr) > snapend)
return(NULL);
printf(" %s", ipaddr_string(cp));
break;
case T_NS:
case T_CNAME:
case T_PTR:
#ifdef T_DNAME
case T_DNAME:
#endif
putchar(' ');
if (ns_nprint(cp, bp) == NULL)
return(NULL);
break;
case T_SOA:
if (!vflag)
break;
putchar(' ');
if ((cp = ns_nprint(cp, bp)) == NULL)
return(NULL);
putchar(' ');
if ((cp = ns_nprint(cp, bp)) == NULL)
return(NULL);
if (cp + 5 * 4 > snapend)
return(NULL);
printf(" %u", EXTRACT_32BITS(cp));
cp += 4;
printf(" %u", EXTRACT_32BITS(cp));
cp += 4;
printf(" %u", EXTRACT_32BITS(cp));
cp += 4;
printf(" %u", EXTRACT_32BITS(cp));
cp += 4;
printf(" %u", EXTRACT_32BITS(cp));
cp += 4;
break;
case T_MX:
putchar(' ');
if (cp + 2 > snapend)
return(NULL);
if (ns_nprint(cp + 2, bp) == NULL)
return(NULL);
printf(" %d", EXTRACT_16BITS(cp));
break;
case T_TXT:
putchar(' ');
(void)ns_cprint(cp, bp);
break;
#ifdef INET6
case T_AAAA:
if (cp + sizeof(struct in6_addr) > snapend)
return(NULL);
printf(" %s", ip6addr_string(cp));
break;
case T_A6:
{
struct in6_addr a;
int pbit, pbyte;
pbit = *cp;
pbyte = (pbit & ~7) / 8;
if (pbit > 128) {
printf(" %u(bad plen)", pbit);
break;
} else if (pbit < 128) {
memset(&a, 0, sizeof(a));
memcpy(&a.s6_addr[pbyte], cp + 1, sizeof(a) - pbyte);
printf(" %u %s", pbit, ip6addr_string(&a));
}
if (pbit > 0) {
putchar(' ');
if (ns_nprint(cp + 1 + sizeof(a) - pbyte, bp) == NULL)
return(NULL);
}
break;
}
#endif /*INET6*/
case T_OPT:
printf(" UDPsize=%u", class);
break;
case T_UNSPECA: /* One long string */
if (cp + len > snapend)
return(NULL);
fn_printn(cp, len, snapend);
break;
}
return (rp); /* XXX This isn't always right */
}
void
ns_print(register const u_char *bp, u_int length)
{
register const HEADER *np;
register int qdcount, ancount, nscount, arcount;
register const u_char *cp;
np = (const HEADER *)bp;
/* get the byte-order right */
qdcount = ntohs(np->qdcount);
ancount = ntohs(np->ancount);
nscount = ntohs(np->nscount);
arcount = ntohs(np->arcount);
if (DNS_QR(np)) {
/* this is a response */
printf(" %d%s%s%s%s%s%s",
ntohs(np->id),
ns_ops[DNS_OPCODE(np)],
ns_resp[DNS_RCODE(np)],
DNS_AA(np)? "*" : "",
DNS_RA(np)? "" : "-",
DNS_TC(np)? "|" : "",
DNS_CD(np)? "%" : "");
if (qdcount != 1)
printf(" [%dq]", qdcount);
/* Print QUESTION section on -vv */
if (vflag > 1) {
fputs(" q:", stdout);
if ((cp = ns_qprint((const u_char *)(np + 1), bp))
== NULL)
goto trunc;
} else {
if ((cp = ns_nskip((const u_char *)(np + 1), bp))
== NULL)
goto trunc;
cp += 4;
}
printf(" %d/%d/%d", ancount, nscount, arcount);
if (ancount--) {
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
while (ancount-- && cp < snapend) {
putchar(',');
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
}
}
/* Print NS and AR sections on -vv */
if (vflag > 1) {
if (nscount-- && cp < snapend) {
fputs(" ns:", stdout);
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
while (nscount-- && cp < snapend) {
putchar(',');
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
}
}
if (arcount-- && cp < snapend) {
fputs(" ar:", stdout);
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
while (arcount-- && cp < snapend) {
putchar(',');
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
}
}
}
}
else {
/* this is a request */
printf(" %d%s%s%s", ntohs(np->id), ns_ops[DNS_OPCODE(np)],
DNS_RD(np) ? "+" : "",
DNS_AD(np) ? "$" : "");
/* any weirdness? */
if (*(((u_short *)np)+1) & htons(0x6cf))
printf(" [b2&3=0x%x]", ntohs(*(((u_short *)np)+1)));
if (DNS_OPCODE(np) == IQUERY) {
if (qdcount)
printf(" [%dq]", qdcount);
if (ancount != 1)
printf(" [%da]", ancount);
}
else {
if (ancount)
printf(" [%da]", ancount);
if (qdcount != 1)
printf(" [%dq]", qdcount);
}
if (nscount)
printf(" [%dn]", nscount);
if (arcount)
printf(" [%dau]", arcount);
if (qdcount--) {
cp = ns_qprint((const u_char *)(np + 1),
(const u_char *)np);
if (!cp)
goto trunc;
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
while (qdcount-- && cp < snapend) {
cp = ns_qprint((const u_char *)cp,
(const u_char *)np);
if (!cp)
goto trunc;
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
}
}
/* Print remaining sections on -vv */
if (vflag > 1) {
if (ancount--) {
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
while (ancount-- && cp < snapend) {
putchar(',');
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
}
}
if (nscount-- && cp < snapend) {
fputs(" ns:", stdout);
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
while (nscount-- && cp < snapend) {
putchar(',');
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
}
}
if (arcount-- && cp < snapend) {
fputs(" ar:", stdout);
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
while (arcount-- && cp < snapend) {
putchar(',');
if ((cp = ns_rprint(cp, bp)) == NULL)
goto trunc;
}
}
}
}
printf(" (%d)", length);
return;
trunc:
printf("[|domain]");
return;
}
Reference in New Issue View Git Blame Copy Permalink