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mirror of https://git.FreeBSD.org/src.git synced 2024-12-15 10:17:20 +00:00
freebsd/contrib/tcpdump/print-cdp.c

263 lines
6.0 KiB
C

/*
* Copyright (c) 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.
*
* Code by Gert Doering, SpaceNet GmbH, gert@space.net
*
* Reference documentation:
* http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-cdp.c,v 1.11 2001/09/17 21:57:56 fenner Exp $";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <ctype.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include "interface.h"
#include "addrtoname.h"
#include "extract.h" /* must come after interface.h */
static int cdp_print_addr(const u_char *, int);
static int cdp_print_prefixes(const u_char *, int);
void
cdp_print(const u_char *p, u_int length, u_int caplen,
const u_char *esrc, const u_char *edst)
{
u_int i;
int type, len;
/* Cisco Discovery Protocol */
if (caplen < 4) {
(void)printf("[|cdp]");
return;
}
i = 0; /* CDP data starts at offset 0 */
printf("CDP v%u, ttl=%us", p[i], p[i + 1]);
i += 4; /* skip version, TTL and chksum */
while (i < length) {
if (i + 4 > caplen)
goto trunc;
type = (p[i] << 8) + p[i + 1];
len = (p[i + 2] << 8) + p[i + 3];
if (vflag > 1)
printf("\n\t");
if (vflag)
printf(" %02x/%02x", type, len);
if (i + len > caplen)
goto trunc;
switch (type) {
case 0x00:
printf(" Goodbye");
break;
case 0x01:
printf(" DevID '%.*s'", len - 4, p + i + 4);
break;
case 0x02:
printf(" Addr");
if (cdp_print_addr(p + i + 4, len - 4) < 0)
goto trunc;
break;
case 0x03:
printf(" PortID '%.*s'", len - 4, p + i + 4);
break;
case 0x04:
printf(" CAP 0x%02x", (unsigned) p[i + 7]);
break;
case 0x05:
if (vflag > 1)
printf(" Version:\n%.*s", len - 4, p + i + 4);
else
printf(" Version: (suppressed)");
break;
case 0x06:
printf(" Platform: '%.*s'", len - 4, p + i + 4);
break;
case 0x07:
if (cdp_print_prefixes(p + i + 4, len - 4) < 0)
goto trunc;
break;
case 0x09: /* guess - not documented */
printf(" VTP Management Domain: '%.*s'", len - 4,
p + i + 4);
break;
case 0x0a: /* guess - not documented */
printf(" Native VLAN ID: %d",
(p[i + 4] << 8) + p[i + 4 + 1] - 1);
break;
case 0x0b: /* guess - not documented */
printf(" Duplex: %s", p[i + 4] ? "full": "half");
break;
default:
printf(" unknown field type %02x, len %d", type, len);
break;
}
/* avoid infinite loop */
if (len == 0)
break;
i += len;
}
return;
trunc:
printf("[|cdp]");
}
/*
* Protocol type values.
*
* PT_NLPID means that the protocol type field contains an OSI NLPID.
*
* PT_IEEE_802_2 means that the protocol type field contains an IEEE 802.2
* LLC header that specifies that the payload is for that protocol.
*/
#define PT_NLPID 1 /* OSI NLPID */
#define PT_IEEE_802_2 2 /* IEEE 802.2 LLC header */
static int
cdp_print_addr(const u_char * p, int l)
{
int pt, pl, al, num;
const u_char *endp = p + l;
#ifdef INET6
static u_char prot_ipv6[] = {
0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd
};
#endif
num = EXTRACT_32BITS(p);
p += 4;
printf(" (%d): ", num);
while (p < endp && num >= 0) {
if (p + 2 > endp)
goto trunc;
pt = p[0]; /* type of "protocol" field */
pl = p[1]; /* length of "protocol" field */
p += 2;
if (p + pl + 2 > endp)
goto trunc;
al = EXTRACT_16BITS(&p[pl]); /* address length */
if (pt == PT_NLPID && pl == 1 && *p == 0xcc && al == 4) {
/*
* IPv4: protocol type = NLPID, protocol length = 1
* (1-byte NLPID), protocol = 0xcc (NLPID for IPv4),
* address length = 4
*/
p += 3;
if (p + 4 > endp)
goto trunc;
printf("IPv4 %u.%u.%u.%u", p[0], p[1], p[2], p[3]);
p += 4;
}
#ifdef INET6
else if (pt == PT_IEEE_802_2 && pl == 8 &&
memcmp(p, prot_ipv6, 8) == 0 && al == 16) {
/*
* IPv6: protocol type = IEEE 802.2 header,
* protocol length = 8 (size of LLC+SNAP header),
* protocol = LLC+SNAP header with the IPv6
* Ethertype, address length = 16
*/
p += 10;
if (p + al > endp)
goto trunc;
printf("IPv6 %s", ip6addr_string(p));
p += al;
}
#endif
else {
/*
* Generic case: just print raw data
*/
if (p + pl > endp)
goto trunc;
printf("pt=0x%02x, pl=%d, pb=", *(p - 2), pl);
while (pl-- > 0)
printf(" %02x", *p++);
if (p + 2 > endp)
goto trunc;
al = (*p << 8) + *(p + 1);
printf(", al=%d, a=", al);
p += 2;
if (p + al > endp)
goto trunc;
while (al-- > 0)
printf(" %02x", *p++);
}
num--;
if (num)
printf(" ");
}
return 0;
trunc:
return -1;
}
static int
cdp_print_prefixes(const u_char * p, int l)
{
if (l % 5)
goto trunc;
printf(" IPv4 Prefixes (%d):", l / 5);
while (l > 0) {
printf(" %u.%u.%u.%u/%u", p[0], p[1], p[2], p[3], p[4]);
l -= 5;
p += 5;
}
return 0;
trunc:
return -1;
}