tcpdump/print-lwres.c
Guy Harris d07e352f5a CVE-2016-7993/Clean up relative time stamp printing.
Have separate routines for signed and unsigned relative time stamps.
Have the routine for signed time stamps handle the case of -2^31, where
you can't negate it and have the result fit in a 32-bit signed integer.

There are currently no users of the signed relative time stamp routine,
but it's there in case anybody needs it (and is passing 32-bit
quantitites, so that there's a risk that a packet might contain -2^31 as
the time stamp).

Fixes an array overflow found with American Fuzzy Lop by Hanno Böck.
2017-01-18 09:16:38 +01:00

596 lines
14 KiB
C

/*
* Copyright (C) 2001 WIDE Project.
* 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.
* 3. Neither the name of the project 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 PROJECT 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 PROJECT 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.
*/
/* \summary: BIND9 Lightweight Resolver protocol printer */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <netdissect-stdinc.h>
#include "nameser.h"
#include <stdio.h>
#include <string.h>
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
/* BIND9 lib/lwres/include/lwres */
typedef uint32_t lwres_uint32_t;
typedef uint16_t lwres_uint16_t;
typedef uint8_t lwres_uint8_t;
struct lwres_lwpacket {
lwres_uint32_t length;
lwres_uint16_t version;
lwres_uint16_t pktflags;
lwres_uint32_t serial;
lwres_uint32_t opcode;
lwres_uint32_t result;
lwres_uint32_t recvlength;
lwres_uint16_t authtype;
lwres_uint16_t authlength;
};
#define LWRES_LWPACKETFLAG_RESPONSE 0x0001U /* if set, pkt is a response */
#define LWRES_LWPACKETVERSION_0 0
#define LWRES_FLAG_TRUSTNOTREQUIRED 0x00000001U
#define LWRES_FLAG_SECUREDATA 0x00000002U
/*
* no-op
*/
#define LWRES_OPCODE_NOOP 0x00000000U
typedef struct {
/* public */
lwres_uint16_t datalength;
/* data follows */
} lwres_nooprequest_t;
typedef struct {
/* public */
lwres_uint16_t datalength;
/* data follows */
} lwres_noopresponse_t;
/*
* get addresses by name
*/
#define LWRES_OPCODE_GETADDRSBYNAME 0x00010001U
typedef struct lwres_addr lwres_addr_t;
struct lwres_addr {
lwres_uint32_t family;
lwres_uint16_t length;
/* address folows */
};
typedef struct {
/* public */
lwres_uint32_t flags;
lwres_uint32_t addrtypes;
lwres_uint16_t namelen;
/* name follows */
} lwres_gabnrequest_t;
typedef struct {
/* public */
lwres_uint32_t flags;
lwres_uint16_t naliases;
lwres_uint16_t naddrs;
lwres_uint16_t realnamelen;
/* aliases follows */
/* addrs follows */
/* realname follows */
} lwres_gabnresponse_t;
/*
* get name by address
*/
#define LWRES_OPCODE_GETNAMEBYADDR 0x00010002U
typedef struct {
/* public */
lwres_uint32_t flags;
lwres_addr_t addr;
/* addr body follows */
} lwres_gnbarequest_t;
typedef struct {
/* public */
lwres_uint32_t flags;
lwres_uint16_t naliases;
lwres_uint16_t realnamelen;
/* aliases follows */
/* realname follows */
} lwres_gnbaresponse_t;
/*
* get rdata by name
*/
#define LWRES_OPCODE_GETRDATABYNAME 0x00010003U
typedef struct {
/* public */
lwres_uint32_t flags;
lwres_uint16_t rdclass;
lwres_uint16_t rdtype;
lwres_uint16_t namelen;
/* name follows */
} lwres_grbnrequest_t;
typedef struct {
/* public */
lwres_uint32_t flags;
lwres_uint16_t rdclass;
lwres_uint16_t rdtype;
lwres_uint32_t ttl;
lwres_uint16_t nrdatas;
lwres_uint16_t nsigs;
/* realname here (len + name) */
/* rdata here (len + name) */
/* signatures here (len + name) */
} lwres_grbnresponse_t;
#define LWRDATA_VALIDATED 0x00000001
#define LWRES_ADDRTYPE_V4 0x00000001U /* ipv4 */
#define LWRES_ADDRTYPE_V6 0x00000002U /* ipv6 */
#define LWRES_MAX_ALIASES 16 /* max # of aliases */
#define LWRES_MAX_ADDRS 64 /* max # of addrs */
static const struct tok opcode[] = {
{ LWRES_OPCODE_NOOP, "noop", },
{ LWRES_OPCODE_GETADDRSBYNAME, "getaddrsbyname", },
{ LWRES_OPCODE_GETNAMEBYADDR, "getnamebyaddr", },
{ LWRES_OPCODE_GETRDATABYNAME, "getrdatabyname", },
{ 0, NULL, },
};
/* print-domain.c */
extern const struct tok ns_type2str[];
extern const struct tok ns_class2str[];
static int
lwres_printname(netdissect_options *ndo,
size_t l, const char *p0)
{
const char *p;
size_t i;
p = p0;
/* + 1 for terminating \0 */
if (p + l + 1 > (const char *)ndo->ndo_snapend)
goto trunc;
ND_PRINT((ndo, " "));
for (i = 0; i < l; i++)
safeputchar(ndo, *p++);
p++; /* skip terminating \0 */
return p - p0;
trunc:
return -1;
}
static int
lwres_printnamelen(netdissect_options *ndo,
const char *p)
{
uint16_t l;
int advance;
if (p + 2 > (const char *)ndo->ndo_snapend)
goto trunc;
l = EXTRACT_16BITS(p);
advance = lwres_printname(ndo, l, p + 2);
if (advance < 0)
goto trunc;
return 2 + advance;
trunc:
return -1;
}
static int
lwres_printbinlen(netdissect_options *ndo,
const char *p0)
{
const char *p;
uint16_t l;
int i;
p = p0;
if (p + 2 > (const char *)ndo->ndo_snapend)
goto trunc;
l = EXTRACT_16BITS(p);
if (p + 2 + l > (const char *)ndo->ndo_snapend)
goto trunc;
p += 2;
for (i = 0; i < l; i++)
ND_PRINT((ndo, "%02x", *p++));
return p - p0;
trunc:
return -1;
}
static int
lwres_printaddr(netdissect_options *ndo,
const lwres_addr_t *ap)
{
uint16_t l;
const char *p;
int i;
ND_TCHECK(ap->length);
l = EXTRACT_16BITS(&ap->length);
/* XXX ap points to packed struct */
p = (const char *)&ap->length + sizeof(ap->length);
ND_TCHECK2(*p, l);
switch (EXTRACT_32BITS(&ap->family)) {
case 1: /* IPv4 */
if (l < 4)
return -1;
ND_PRINT((ndo, " %s", ipaddr_string(ndo, p)));
p += sizeof(struct in_addr);
break;
case 2: /* IPv6 */
if (l < 16)
return -1;
ND_PRINT((ndo, " %s", ip6addr_string(ndo, p)));
p += sizeof(struct in6_addr);
break;
default:
ND_PRINT((ndo, " %u/", EXTRACT_32BITS(&ap->family)));
for (i = 0; i < l; i++)
ND_PRINT((ndo, "%02x", *p++));
}
return p - (const char *)ap;
trunc:
return -1;
}
void
lwres_print(netdissect_options *ndo,
register const u_char *bp, u_int length)
{
const struct lwres_lwpacket *np;
uint32_t v;
const char *s;
int response;
int advance;
int unsupported = 0;
np = (const struct lwres_lwpacket *)bp;
ND_TCHECK(np->authlength);
ND_PRINT((ndo, " lwres"));
v = EXTRACT_16BITS(&np->version);
if (ndo->ndo_vflag || v != LWRES_LWPACKETVERSION_0)
ND_PRINT((ndo, " v%u", v));
if (v != LWRES_LWPACKETVERSION_0) {
s = (const char *)np + EXTRACT_32BITS(&np->length);
goto tail;
}
response = EXTRACT_16BITS(&np->pktflags) & LWRES_LWPACKETFLAG_RESPONSE;
/* opcode and pktflags */
v = EXTRACT_32BITS(&np->opcode);
s = tok2str(opcode, "#0x%x", v);
ND_PRINT((ndo, " %s%s", s, response ? "" : "?"));
/* pktflags */
v = EXTRACT_16BITS(&np->pktflags);
if (v & ~LWRES_LWPACKETFLAG_RESPONSE)
ND_PRINT((ndo, "[0x%x]", v));
if (ndo->ndo_vflag > 1) {
ND_PRINT((ndo, " (")); /*)*/
ND_PRINT((ndo, "serial:0x%x", EXTRACT_32BITS(&np->serial)));
ND_PRINT((ndo, " result:0x%x", EXTRACT_32BITS(&np->result)));
ND_PRINT((ndo, " recvlen:%u", EXTRACT_32BITS(&np->recvlength)));
/* BIND910: not used */
if (ndo->ndo_vflag > 2) {
ND_PRINT((ndo, " authtype:0x%x", EXTRACT_16BITS(&np->authtype)));
ND_PRINT((ndo, " authlen:%u", EXTRACT_16BITS(&np->authlength)));
}
/*(*/
ND_PRINT((ndo, ")"));
}
/* per-opcode content */
if (!response) {
/*
* queries
*/
const lwres_gabnrequest_t *gabn;
const lwres_gnbarequest_t *gnba;
const lwres_grbnrequest_t *grbn;
uint32_t l;
gabn = NULL;
gnba = NULL;
grbn = NULL;
switch (EXTRACT_32BITS(&np->opcode)) {
case LWRES_OPCODE_NOOP:
break;
case LWRES_OPCODE_GETADDRSBYNAME:
gabn = (const lwres_gabnrequest_t *)(np + 1);
ND_TCHECK(gabn->namelen);
/* XXX gabn points to packed struct */
s = (const char *)&gabn->namelen +
sizeof(gabn->namelen);
l = EXTRACT_16BITS(&gabn->namelen);
/* BIND910: not used */
if (ndo->ndo_vflag > 2) {
ND_PRINT((ndo, " flags:0x%x",
EXTRACT_32BITS(&gabn->flags)));
}
v = EXTRACT_32BITS(&gabn->addrtypes);
switch (v & (LWRES_ADDRTYPE_V4 | LWRES_ADDRTYPE_V6)) {
case LWRES_ADDRTYPE_V4:
ND_PRINT((ndo, " IPv4"));
break;
case LWRES_ADDRTYPE_V6:
ND_PRINT((ndo, " IPv6"));
break;
case LWRES_ADDRTYPE_V4 | LWRES_ADDRTYPE_V6:
ND_PRINT((ndo, " IPv4/6"));
break;
}
if (v & ~(LWRES_ADDRTYPE_V4 | LWRES_ADDRTYPE_V6))
ND_PRINT((ndo, "[0x%x]", v));
advance = lwres_printname(ndo, l, s);
if (advance < 0)
goto trunc;
s += advance;
break;
case LWRES_OPCODE_GETNAMEBYADDR:
gnba = (const lwres_gnbarequest_t *)(np + 1);
ND_TCHECK(gnba->addr);
/* BIND910: not used */
if (ndo->ndo_vflag > 2) {
ND_PRINT((ndo, " flags:0x%x",
EXTRACT_32BITS(&gnba->flags)));
}
s = (const char *)&gnba->addr;
advance = lwres_printaddr(ndo, &gnba->addr);
if (advance < 0)
goto trunc;
s += advance;
break;
case LWRES_OPCODE_GETRDATABYNAME:
/* XXX no trace, not tested */
grbn = (const lwres_grbnrequest_t *)(np + 1);
ND_TCHECK(grbn->namelen);
/* BIND910: not used */
if (ndo->ndo_vflag > 2) {
ND_PRINT((ndo, " flags:0x%x",
EXTRACT_32BITS(&grbn->flags)));
}
ND_PRINT((ndo, " %s", tok2str(ns_type2str, "Type%d",
EXTRACT_16BITS(&grbn->rdtype))));
if (EXTRACT_16BITS(&grbn->rdclass) != C_IN) {
ND_PRINT((ndo, " %s", tok2str(ns_class2str, "Class%d",
EXTRACT_16BITS(&grbn->rdclass))));
}
/* XXX grbn points to packed struct */
s = (const char *)&grbn->namelen +
sizeof(grbn->namelen);
l = EXTRACT_16BITS(&grbn->namelen);
advance = lwres_printname(ndo, l, s);
if (advance < 0)
goto trunc;
s += advance;
break;
default:
unsupported++;
break;
}
} else {
/*
* responses
*/
const lwres_gabnresponse_t *gabn;
const lwres_gnbaresponse_t *gnba;
const lwres_grbnresponse_t *grbn;
uint32_t l, na;
uint32_t i;
gabn = NULL;
gnba = NULL;
grbn = NULL;
switch (EXTRACT_32BITS(&np->opcode)) {
case LWRES_OPCODE_NOOP:
break;
case LWRES_OPCODE_GETADDRSBYNAME:
gabn = (const lwres_gabnresponse_t *)(np + 1);
ND_TCHECK(gabn->realnamelen);
/* XXX gabn points to packed struct */
s = (const char *)&gabn->realnamelen +
sizeof(gabn->realnamelen);
l = EXTRACT_16BITS(&gabn->realnamelen);
/* BIND910: not used */
if (ndo->ndo_vflag > 2) {
ND_PRINT((ndo, " flags:0x%x",
EXTRACT_32BITS(&gabn->flags)));
}
ND_PRINT((ndo, " %u/%u", EXTRACT_16BITS(&gabn->naliases),
EXTRACT_16BITS(&gabn->naddrs)));
advance = lwres_printname(ndo, l, s);
if (advance < 0)
goto trunc;
s += advance;
/* aliases */
na = EXTRACT_16BITS(&gabn->naliases);
for (i = 0; i < na; i++) {
advance = lwres_printnamelen(ndo, s);
if (advance < 0)
goto trunc;
s += advance;
}
/* addrs */
na = EXTRACT_16BITS(&gabn->naddrs);
for (i = 0; i < na; i++) {
advance = lwres_printaddr(ndo, (const lwres_addr_t *)s);
if (advance < 0)
goto trunc;
s += advance;
}
break;
case LWRES_OPCODE_GETNAMEBYADDR:
gnba = (const lwres_gnbaresponse_t *)(np + 1);
ND_TCHECK(gnba->realnamelen);
/* XXX gnba points to packed struct */
s = (const char *)&gnba->realnamelen +
sizeof(gnba->realnamelen);
l = EXTRACT_16BITS(&gnba->realnamelen);
/* BIND910: not used */
if (ndo->ndo_vflag > 2) {
ND_PRINT((ndo, " flags:0x%x",
EXTRACT_32BITS(&gnba->flags)));
}
ND_PRINT((ndo, " %u", EXTRACT_16BITS(&gnba->naliases)));
advance = lwres_printname(ndo, l, s);
if (advance < 0)
goto trunc;
s += advance;
/* aliases */
na = EXTRACT_16BITS(&gnba->naliases);
for (i = 0; i < na; i++) {
advance = lwres_printnamelen(ndo, s);
if (advance < 0)
goto trunc;
s += advance;
}
break;
case LWRES_OPCODE_GETRDATABYNAME:
/* XXX no trace, not tested */
grbn = (const lwres_grbnresponse_t *)(np + 1);
ND_TCHECK(grbn->nsigs);
/* BIND910: not used */
if (ndo->ndo_vflag > 2) {
ND_PRINT((ndo, " flags:0x%x",
EXTRACT_32BITS(&grbn->flags)));
}
ND_PRINT((ndo, " %s", tok2str(ns_type2str, "Type%d",
EXTRACT_16BITS(&grbn->rdtype))));
if (EXTRACT_16BITS(&grbn->rdclass) != C_IN) {
ND_PRINT((ndo, " %s", tok2str(ns_class2str, "Class%d",
EXTRACT_16BITS(&grbn->rdclass))));
}
ND_PRINT((ndo, " TTL "));
unsigned_relts_print(ndo, EXTRACT_32BITS(&grbn->ttl));
ND_PRINT((ndo, " %u/%u", EXTRACT_16BITS(&grbn->nrdatas),
EXTRACT_16BITS(&grbn->nsigs)));
/* XXX grbn points to packed struct */
s = (const char *)&grbn->nsigs+ sizeof(grbn->nsigs);
advance = lwres_printnamelen(ndo, s);
if (advance < 0)
goto trunc;
s += advance;
/* rdatas */
na = EXTRACT_16BITS(&grbn->nrdatas);
for (i = 0; i < na; i++) {
/* XXX should decode resource data */
advance = lwres_printbinlen(ndo, s);
if (advance < 0)
goto trunc;
s += advance;
}
/* sigs */
na = EXTRACT_16BITS(&grbn->nsigs);
for (i = 0; i < na; i++) {
/* XXX how should we print it? */
advance = lwres_printbinlen(ndo, s);
if (advance < 0)
goto trunc;
s += advance;
}
break;
default:
unsupported++;
break;
}
}
tail:
/* length mismatch */
if (EXTRACT_32BITS(&np->length) != length) {
ND_PRINT((ndo, " [len: %u != %u]", EXTRACT_32BITS(&np->length),
length));
}
if (!unsupported && s < (const char *)np + EXTRACT_32BITS(&np->length))
ND_PRINT((ndo, "[extra]"));
return;
trunc:
ND_PRINT((ndo, "[|lwres]"));
}