mirror of
https://github.com/the-tcpdump-group/tcpdump.git
synced 2024-11-24 18:43:39 +08:00
259cb9ad02
Instead of checking that there are 8 bytes available at the beginning of an IGMP packet - which there might not be, e.g. with some DVMRP packets - do the checks as necessary before fetching values.
370 lines
8.1 KiB
C
370 lines
8.1 KiB
C
/*
|
|
* Copyright (c) 1995, 1996
|
|
* 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[] _U_ =
|
|
"@(#) $Header: /tcpdump/master/tcpdump/print-dvmrp.c,v 1.27 2003-11-19 09:42:04 guy Exp $ (LBL)";
|
|
#endif
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
#include <tcpdump-stdinc.h>
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
|
|
#include "interface.h"
|
|
#include "extract.h"
|
|
#include "addrtoname.h"
|
|
|
|
/*
|
|
* DVMRP message types and flag values shamelessly stolen from
|
|
* mrouted/dvmrp.h.
|
|
*/
|
|
#define DVMRP_PROBE 1 /* for finding neighbors */
|
|
#define DVMRP_REPORT 2 /* for reporting some or all routes */
|
|
#define DVMRP_ASK_NEIGHBORS 3 /* sent by mapper, asking for a list */
|
|
/* of this router's neighbors */
|
|
#define DVMRP_NEIGHBORS 4 /* response to such a request */
|
|
#define DVMRP_ASK_NEIGHBORS2 5 /* as above, want new format reply */
|
|
#define DVMRP_NEIGHBORS2 6
|
|
#define DVMRP_PRUNE 7 /* prune message */
|
|
#define DVMRP_GRAFT 8 /* graft message */
|
|
#define DVMRP_GRAFT_ACK 9 /* graft acknowledgement */
|
|
|
|
/*
|
|
* 'flags' byte values in DVMRP_NEIGHBORS2 reply.
|
|
*/
|
|
#define DVMRP_NF_TUNNEL 0x01 /* neighbors reached via tunnel */
|
|
#define DVMRP_NF_SRCRT 0x02 /* tunnel uses IP source routing */
|
|
#define DVMRP_NF_DOWN 0x10 /* kernel state of interface */
|
|
#define DVMRP_NF_DISABLED 0x20 /* administratively disabled */
|
|
#define DVMRP_NF_QUERIER 0x40 /* I am the subnet's querier */
|
|
|
|
static int print_probe(const u_char *, const u_char *, u_int);
|
|
static int print_report(const u_char *, const u_char *, u_int);
|
|
static int print_neighbors(const u_char *, const u_char *, u_int);
|
|
static int print_neighbors2(const u_char *, const u_char *, u_int);
|
|
static int print_prune(const u_char *);
|
|
static int print_graft(const u_char *);
|
|
static int print_graft_ack(const u_char *);
|
|
|
|
static u_int32_t target_level;
|
|
|
|
void
|
|
dvmrp_print(register const u_char *bp, register u_int len)
|
|
{
|
|
register const u_char *ep;
|
|
register u_char type;
|
|
|
|
ep = (const u_char *)snapend;
|
|
if (bp >= ep)
|
|
return;
|
|
|
|
TCHECK(bp[1]);
|
|
type = bp[1];
|
|
|
|
/* Skip IGMP header */
|
|
bp += 8;
|
|
len -= 8;
|
|
|
|
switch (type) {
|
|
|
|
case DVMRP_PROBE:
|
|
printf(" Probe");
|
|
if (vflag) {
|
|
if (print_probe(bp, ep, len) < 0)
|
|
goto trunc;
|
|
}
|
|
break;
|
|
|
|
case DVMRP_REPORT:
|
|
printf(" Report");
|
|
if (vflag > 1) {
|
|
if (print_report(bp, ep, len) < 0)
|
|
goto trunc;
|
|
}
|
|
break;
|
|
|
|
case DVMRP_ASK_NEIGHBORS:
|
|
printf(" Ask-neighbors(old)");
|
|
break;
|
|
|
|
case DVMRP_NEIGHBORS:
|
|
printf(" Neighbors(old)");
|
|
if (print_neighbors(bp, ep, len) < 0)
|
|
goto trunc;
|
|
break;
|
|
|
|
case DVMRP_ASK_NEIGHBORS2:
|
|
printf(" Ask-neighbors2");
|
|
break;
|
|
|
|
case DVMRP_NEIGHBORS2:
|
|
printf(" Neighbors2");
|
|
/*
|
|
* extract version and capabilities from IGMP group
|
|
* address field
|
|
*/
|
|
bp -= 4;
|
|
TCHECK2(bp[0], 4);
|
|
target_level = (bp[0] << 24) | (bp[1] << 16) |
|
|
(bp[2] << 8) | bp[3];
|
|
bp += 4;
|
|
if (print_neighbors2(bp, ep, len) < 0)
|
|
goto trunc;
|
|
break;
|
|
|
|
case DVMRP_PRUNE:
|
|
printf(" Prune");
|
|
if (print_prune(bp) < 0)
|
|
goto trunc;
|
|
break;
|
|
|
|
case DVMRP_GRAFT:
|
|
printf(" Graft");
|
|
if (print_graft(bp) < 0)
|
|
goto trunc;
|
|
break;
|
|
|
|
case DVMRP_GRAFT_ACK:
|
|
printf(" Graft-ACK");
|
|
if (print_graft_ack(bp) < 0)
|
|
goto trunc;
|
|
break;
|
|
|
|
default:
|
|
printf(" [type %d]", type);
|
|
break;
|
|
}
|
|
return;
|
|
|
|
trunc:
|
|
printf("[|dvmrp]");
|
|
return;
|
|
}
|
|
|
|
static int
|
|
print_report(register const u_char *bp, register const u_char *ep,
|
|
register u_int len)
|
|
{
|
|
register u_int32_t mask, origin;
|
|
register int metric, done;
|
|
register u_int i, width;
|
|
|
|
while (len > 0) {
|
|
if (len < 3) {
|
|
printf(" [|]");
|
|
return (0);
|
|
}
|
|
TCHECK2(bp[0], 3);
|
|
mask = (u_int32_t)0xff << 24 | bp[0] << 16 | bp[1] << 8 | bp[2];
|
|
width = 1;
|
|
if (bp[0])
|
|
width = 2;
|
|
if (bp[1])
|
|
width = 3;
|
|
if (bp[2])
|
|
width = 4;
|
|
|
|
printf("\n\tMask %s", intoa(htonl(mask)));
|
|
bp += 3;
|
|
len -= 3;
|
|
do {
|
|
if (bp + width + 1 > ep) {
|
|
printf(" [|]");
|
|
return (0);
|
|
}
|
|
if (len < width + 1) {
|
|
printf("\n\t [Truncated Report]");
|
|
return (0);
|
|
}
|
|
origin = 0;
|
|
for (i = 0; i < width; ++i) {
|
|
TCHECK(*bp);
|
|
origin = origin << 8 | *bp++;
|
|
}
|
|
for ( ; i < 4; ++i)
|
|
origin <<= 8;
|
|
|
|
TCHECK(*bp);
|
|
metric = *bp++;
|
|
done = metric & 0x80;
|
|
metric &= 0x7f;
|
|
printf("\n\t %s metric %d", intoa(htonl(origin)),
|
|
metric);
|
|
len -= width + 1;
|
|
} while (!done);
|
|
}
|
|
return (0);
|
|
trunc:
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
print_probe(register const u_char *bp, register const u_char *ep,
|
|
register u_int len)
|
|
{
|
|
register u_int32_t genid;
|
|
|
|
TCHECK2(bp[0], 4);
|
|
if ((len < 4) || ((bp + 4) > ep)) {
|
|
/* { (ctags) */
|
|
printf(" [|}");
|
|
return (0);
|
|
}
|
|
genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
|
|
bp += 4;
|
|
len -= 4;
|
|
if (vflag > 1)
|
|
printf("\n\t");
|
|
else
|
|
printf(" ");
|
|
printf("genid %u", genid);
|
|
if (vflag < 2)
|
|
return (0);
|
|
|
|
while ((len > 0) && (bp < ep)) {
|
|
TCHECK2(bp[0], 4);
|
|
printf("\n\tneighbor %s", ipaddr_string(bp));
|
|
bp += 4; len -= 4;
|
|
}
|
|
return (0);
|
|
trunc:
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
print_neighbors(register const u_char *bp, register const u_char *ep,
|
|
register u_int len)
|
|
{
|
|
const u_char *laddr;
|
|
register u_char metric;
|
|
register u_char thresh;
|
|
register int ncount;
|
|
|
|
while (len > 0 && bp < ep) {
|
|
TCHECK2(bp[0], 7);
|
|
laddr = bp;
|
|
bp += 4;
|
|
metric = *bp++;
|
|
thresh = *bp++;
|
|
ncount = *bp++;
|
|
len -= 7;
|
|
while (--ncount >= 0) {
|
|
TCHECK2(bp[0], 4);
|
|
printf(" [%s ->", ipaddr_string(laddr));
|
|
printf(" %s, (%d/%d)]",
|
|
ipaddr_string(bp), metric, thresh);
|
|
bp += 4;
|
|
len -= 4;
|
|
}
|
|
}
|
|
return (0);
|
|
trunc:
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
print_neighbors2(register const u_char *bp, register const u_char *ep,
|
|
register u_int len)
|
|
{
|
|
const u_char *laddr;
|
|
register u_char metric, thresh, flags;
|
|
register int ncount;
|
|
|
|
printf(" (v %d.%d):",
|
|
(int)target_level & 0xff,
|
|
(int)(target_level >> 8) & 0xff);
|
|
|
|
while (len > 0 && bp < ep) {
|
|
TCHECK2(bp[0], 8);
|
|
laddr = bp;
|
|
bp += 4;
|
|
metric = *bp++;
|
|
thresh = *bp++;
|
|
flags = *bp++;
|
|
ncount = *bp++;
|
|
len -= 8;
|
|
while (--ncount >= 0 && (len >= 4) && (bp + 4) <= ep) {
|
|
printf(" [%s -> ", ipaddr_string(laddr));
|
|
printf("%s (%d/%d", ipaddr_string(bp),
|
|
metric, thresh);
|
|
if (flags & DVMRP_NF_TUNNEL)
|
|
printf("/tunnel");
|
|
if (flags & DVMRP_NF_SRCRT)
|
|
printf("/srcrt");
|
|
if (flags & DVMRP_NF_QUERIER)
|
|
printf("/querier");
|
|
if (flags & DVMRP_NF_DISABLED)
|
|
printf("/disabled");
|
|
if (flags & DVMRP_NF_DOWN)
|
|
printf("/down");
|
|
printf(")]");
|
|
bp += 4;
|
|
len -= 4;
|
|
}
|
|
if (ncount != -1) {
|
|
printf(" [|]");
|
|
return (0);
|
|
}
|
|
}
|
|
return (0);
|
|
trunc:
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
print_prune(register const u_char *bp)
|
|
{
|
|
TCHECK2(bp[0], 12);
|
|
printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
|
|
bp += 8;
|
|
(void)printf(" timer ");
|
|
relts_print(EXTRACT_32BITS(bp));
|
|
return (0);
|
|
trunc:
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
print_graft(register const u_char *bp)
|
|
{
|
|
TCHECK2(bp[0], 8);
|
|
printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
|
|
return (0);
|
|
trunc:
|
|
return (-1);
|
|
}
|
|
|
|
static int
|
|
print_graft_ack(register const u_char *bp)
|
|
{
|
|
TCHECK2(bp[0], 8);
|
|
printf(" src %s grp %s", ipaddr_string(bp), ipaddr_string(bp + 4));
|
|
return (0);
|
|
trunc:
|
|
return (-1);
|
|
}
|