nexmon – Rev 1
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/*
* Copyright (c) 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.
*
* Initial contribution from Francis Dupont (francis.dupont@inria.fr)
*/
#define NETDISSECT_REWORKED
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include "interface.h"
#include "extract.h" /* must come after interface.h */
/* Cisco IGRP definitions */
/* IGRP Header */
struct igrphdr {
uint8_t ig_vop; /* protocol version number / opcode */
#define IGRP_V(x) (((x) & 0xf0) >> 4)
#define IGRP_OP(x) ((x) & 0x0f)
uint8_t ig_ed; /* edition number */
uint16_t ig_as; /* autonomous system number */
uint16_t ig_ni; /* number of subnet in local net */
uint16_t ig_ns; /* number of networks in AS */
uint16_t ig_nx; /* number of networks ouside AS */
uint16_t ig_sum; /* checksum of IGRP header & data */
};
#define IGRP_UPDATE 1
#define IGRP_REQUEST 2
/* IGRP routing entry */
struct igrprte {
uint8_t igr_net[3]; /* 3 significant octets of IP address */
uint8_t igr_dly[3]; /* delay in tens of microseconds */
uint8_t igr_bw[3]; /* bandwidth in units of 1 kb/s */
uint8_t igr_mtu[2]; /* MTU in octets */
uint8_t igr_rel; /* percent packets successfully tx/rx */
uint8_t igr_ld; /* percent of channel occupied */
uint8_t igr_hct; /* hop count */
};
#define IGRP_RTE_SIZE 14 /* don't believe sizeof ! */
static void
igrp_entry_print(netdissect_options *ndo, register struct igrprte *igr,
register int is_interior, register int is_exterior)
{
register u_int delay, bandwidth;
u_int metric, mtu;
if (is_interior)
ND_PRINT((ndo, " *.%d.%d.%d", igr->igr_net[0],
igr->igr_net[1], igr->igr_net[2]));
else if (is_exterior)
ND_PRINT((ndo, " X%d.%d.%d.0", igr->igr_net[0],
igr->igr_net[1], igr->igr_net[2]));
else
ND_PRINT((ndo, " %d.%d.%d.0", igr->igr_net[0],
igr->igr_net[1], igr->igr_net[2]));
delay = EXTRACT_24BITS(igr->igr_dly);
bandwidth = EXTRACT_24BITS(igr->igr_bw);
metric = bandwidth + delay;
if (metric > 0xffffff)
metric = 0xffffff;
mtu = EXTRACT_16BITS(igr->igr_mtu);
ND_PRINT((ndo, " d=%d b=%d r=%d l=%d M=%d mtu=%d in %d hops",
10 * delay, bandwidth == 0 ? 0 : 10000000 / bandwidth,
igr->igr_rel, igr->igr_ld, metric,
mtu, igr->igr_hct));
}
static const struct tok op2str[] = {
{ IGRP_UPDATE, "update" },
{ IGRP_REQUEST, "request" },
{ 0, NULL }
};
void
igrp_print(netdissect_options *ndo, register const u_char *bp, u_int length)
{
register struct igrphdr *hdr;
register u_char *cp;
u_int nint, nsys, next;
hdr = (struct igrphdr *)bp;
cp = (u_char *)(hdr + 1);
ND_PRINT((ndo, "igrp:"));
/* Header */
ND_TCHECK(*hdr);
nint = EXTRACT_16BITS(&hdr->ig_ni);
nsys = EXTRACT_16BITS(&hdr->ig_ns);
next = EXTRACT_16BITS(&hdr->ig_nx);
ND_PRINT((ndo, " %s V%d edit=%d AS=%d (%d/%d/%d)",
tok2str(op2str, "op-#%d", IGRP_OP(hdr->ig_vop)),
IGRP_V(hdr->ig_vop),
hdr->ig_ed,
EXTRACT_16BITS(&hdr->ig_as),
nint,
nsys,
next));
length -= sizeof(*hdr);
while (length >= IGRP_RTE_SIZE) {
if (nint > 0) {
ND_TCHECK2(*cp, IGRP_RTE_SIZE);
igrp_entry_print(ndo, (struct igrprte *)cp, 1, 0);
--nint;
} else if (nsys > 0) {
ND_TCHECK2(*cp, IGRP_RTE_SIZE);
igrp_entry_print(ndo, (struct igrprte *)cp, 0, 0);
--nsys;
} else if (next > 0) {
ND_TCHECK2(*cp, IGRP_RTE_SIZE);
igrp_entry_print(ndo, (struct igrprte *)cp, 0, 1);
--next;
} else {
ND_PRINT((ndo, " [extra bytes %d]", length));
break;
}
cp += IGRP_RTE_SIZE;
length -= IGRP_RTE_SIZE;
}
if (nint == 0 && nsys == 0 && next == 0)
return;
trunc:
ND_PRINT((ndo, " [|igrp]"));
}