nexmon – Rev 1
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/*
* 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.
*/
#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.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(netdissect_options *, const u_char *, const u_char *, u_int);
static int print_report(netdissect_options *, const u_char *, const u_char *, u_int);
static int print_neighbors(netdissect_options *, const u_char *, const u_char *, u_int);
static int print_neighbors2(netdissect_options *, const u_char *, const u_char *, u_int);
static int print_prune(netdissect_options *, const u_char *);
static int print_graft(netdissect_options *, const u_char *);
static int print_graft_ack(netdissect_options *, const u_char *);
static uint32_t target_level;
void
dvmrp_print(netdissect_options *ndo,
register const u_char *bp, register u_int len)
{
register const u_char *ep;
register u_char type;
ep = (const u_char *)ndo->ndo_snapend;
if (bp >= ep)
return;
ND_TCHECK(bp[1]);
type = bp[1];
/* Skip IGMP header */
bp += 8;
len -= 8;
switch (type) {
case DVMRP_PROBE:
ND_PRINT((ndo, " Probe"));
if (ndo->ndo_vflag) {
if (print_probe(ndo, bp, ep, len) < 0)
goto trunc;
}
break;
case DVMRP_REPORT:
ND_PRINT((ndo, " Report"));
if (ndo->ndo_vflag > 1) {
if (print_report(ndo, bp, ep, len) < 0)
goto trunc;
}
break;
case DVMRP_ASK_NEIGHBORS:
ND_PRINT((ndo, " Ask-neighbors(old)"));
break;
case DVMRP_NEIGHBORS:
ND_PRINT((ndo, " Neighbors(old)"));
if (print_neighbors(ndo, bp, ep, len) < 0)
goto trunc;
break;
case DVMRP_ASK_NEIGHBORS2:
ND_PRINT((ndo, " Ask-neighbors2"));
break;
case DVMRP_NEIGHBORS2:
ND_PRINT((ndo, " Neighbors2"));
/*
* extract version and capabilities from IGMP group
* address field
*/
bp -= 4;
ND_TCHECK2(bp[0], 4);
target_level = (bp[0] << 24) | (bp[1] << 16) |
(bp[2] << 8) | bp[3];
bp += 4;
if (print_neighbors2(ndo, bp, ep, len) < 0)
goto trunc;
break;
case DVMRP_PRUNE:
ND_PRINT((ndo, " Prune"));
if (print_prune(ndo, bp) < 0)
goto trunc;
break;
case DVMRP_GRAFT:
ND_PRINT((ndo, " Graft"));
if (print_graft(ndo, bp) < 0)
goto trunc;
break;
case DVMRP_GRAFT_ACK:
ND_PRINT((ndo, " Graft-ACK"));
if (print_graft_ack(ndo, bp) < 0)
goto trunc;
break;
default:
ND_PRINT((ndo, " [type %d]", type));
break;
}
return;
trunc:
ND_PRINT((ndo, "[|dvmrp]"));
return;
}
static int
print_report(netdissect_options *ndo,
register const u_char *bp, register const u_char *ep,
register u_int len)
{
register uint32_t mask, origin;
register int metric, done;
register u_int i, width;
while (len > 0) {
if (len < 3) {
ND_PRINT((ndo, " [|]"));
return (0);
}
ND_TCHECK2(bp[0], 3);
mask = (uint32_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;
ND_PRINT((ndo, "\n\tMask %s", intoa(htonl(mask))));
bp += 3;
len -= 3;
do {
if (bp + width + 1 > ep) {
ND_PRINT((ndo, " [|]"));
return (0);
}
if (len < width + 1) {
ND_PRINT((ndo, "\n\t [Truncated Report]"));
return (0);
}
origin = 0;
for (i = 0; i < width; ++i) {
ND_TCHECK(*bp);
origin = origin << 8 | *bp++;
}
for ( ; i < 4; ++i)
origin <<= 8;
ND_TCHECK(*bp);
metric = *bp++;
done = metric & 0x80;
metric &= 0x7f;
ND_PRINT((ndo, "\n\t %s metric %d", intoa(htonl(origin)),
metric));
len -= width + 1;
} while (!done);
}
return (0);
trunc:
return (-1);
}
static int
print_probe(netdissect_options *ndo,
register const u_char *bp, register const u_char *ep,
register u_int len)
{
register uint32_t genid;
ND_TCHECK2(bp[0], 4);
if ((len < 4) || ((bp + 4) > ep)) {
/* { (ctags) */
ND_PRINT((ndo, " [|}"));
return (0);
}
genid = (bp[0] << 24) | (bp[1] << 16) | (bp[2] << 8) | bp[3];
bp += 4;
len -= 4;
ND_PRINT((ndo, ndo->ndo_vflag > 1 ? "\n\t" : " "));
ND_PRINT((ndo, "genid %u", genid));
if (ndo->ndo_vflag < 2)
return (0);
while ((len > 0) && (bp < ep)) {
ND_TCHECK2(bp[0], 4);
ND_PRINT((ndo, "\n\tneighbor %s", ipaddr_string(ndo, bp)));
bp += 4; len -= 4;
}
return (0);
trunc:
return (-1);
}
static int
print_neighbors(netdissect_options *ndo,
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) {
ND_TCHECK2(bp[0], 7);
laddr = bp;
bp += 4;
metric = *bp++;
thresh = *bp++;
ncount = *bp++;
len -= 7;
while (--ncount >= 0) {
ND_TCHECK2(bp[0], 4);
ND_PRINT((ndo, " [%s ->", ipaddr_string(ndo, laddr)));
ND_PRINT((ndo, " %s, (%d/%d)]",
ipaddr_string(ndo, bp), metric, thresh));
bp += 4;
len -= 4;
}
}
return (0);
trunc:
return (-1);
}
static int
print_neighbors2(netdissect_options *ndo,
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;
ND_PRINT((ndo, " (v %d.%d):",
(int)target_level & 0xff,
(int)(target_level >> 8) & 0xff));
while (len > 0 && bp < ep) {
ND_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) {
ND_PRINT((ndo, " [%s -> ", ipaddr_string(ndo, laddr)));
ND_PRINT((ndo, "%s (%d/%d", ipaddr_string(ndo, bp),
metric, thresh));
if (flags & DVMRP_NF_TUNNEL)
ND_PRINT((ndo, "/tunnel"));
if (flags & DVMRP_NF_SRCRT)
ND_PRINT((ndo, "/srcrt"));
if (flags & DVMRP_NF_QUERIER)
ND_PRINT((ndo, "/querier"));
if (flags & DVMRP_NF_DISABLED)
ND_PRINT((ndo, "/disabled"));
if (flags & DVMRP_NF_DOWN)
ND_PRINT((ndo, "/down"));
ND_PRINT((ndo, ")]"));
bp += 4;
len -= 4;
}
if (ncount != -1) {
ND_PRINT((ndo, " [|]"));
return (0);
}
}
return (0);
trunc:
return (-1);
}
static int
print_prune(netdissect_options *ndo,
register const u_char *bp)
{
ND_TCHECK2(bp[0], 12);
ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
bp += 8;
ND_PRINT((ndo, " timer "));
relts_print(ndo, EXTRACT_32BITS(bp));
return (0);
trunc:
return (-1);
}
static int
print_graft(netdissect_options *ndo,
register const u_char *bp)
{
ND_TCHECK2(bp[0], 8);
ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
return (0);
trunc:
return (-1);
}
static int
print_graft_ack(netdissect_options *ndo,
register const u_char *bp)
{
ND_TCHECK2(bp[0], 8);
ND_PRINT((ndo, " src %s grp %s", ipaddr_string(ndo, bp), ipaddr_string(ndo, bp + 4)));
return (0);
trunc:
return (-1);
}