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print-chdlc.c
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print-chdlc.c
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/*
* Copyright (c) 1990, 1991, 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.
*/
/* \summary: Cisco HDLC printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "addrtoname.h"
#include "ethertype.h"
#include "extract.h"
#include "chdlc.h"
#include "nlpid.h"
static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int);
static const struct tok chdlc_cast_values[] = {
{ CHDLC_UNICAST, "unicast" },
{ CHDLC_BCAST, "bcast" },
{ 0, NULL}
};
/* Standard CHDLC printer */
void
chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
{
ndo->ndo_protocol = "chdlc";
ND_TCHECK_LEN(p, CHDLC_HDRLEN);
ndo->ndo_ll_hdr_len += CHDLC_HDRLEN;
chdlc_print(ndo, p, h->len);
}
void
chdlc_print(netdissect_options *ndo, const u_char *p, u_int length)
{
u_int proto;
ndo->ndo_protocol = "chdlc";
ND_ICHECK_U(length, <, CHDLC_HDRLEN);
proto = GET_BE_U_2(p + 2);
if (ndo->ndo_eflag) {
ND_PRINT("%s, ethertype %s (0x%04x), length %u: ",
tok2str(chdlc_cast_values, "0x%02x", GET_U_1(p)),
tok2str(ethertype_values, "Unknown", proto),
proto,
length);
}
length -= CHDLC_HDRLEN;
p += CHDLC_HDRLEN;
switch (proto) {
case ETHERTYPE_IP:
ip_print(ndo, p, length);
break;
case ETHERTYPE_IPV6:
ip6_print(ndo, p, length);
break;
case CHDLC_TYPE_SLARP:
chdlc_slarp_print(ndo, p, length);
break;
case ETHERTYPE_MPLS:
case ETHERTYPE_MPLS_MULTI:
mpls_print(ndo, p, length);
break;
case ETHERTYPE_ISO:
/* is the fudge byte set ? lets verify by spotting ISO headers */
ND_ICHECK_U(length, <, 2);
if (GET_U_1(p + 1) == NLPID_CLNP ||
GET_U_1(p + 1) == NLPID_ESIS ||
GET_U_1(p + 1) == NLPID_ISIS)
isoclns_print(ndo, p + 1, length - 1);
else
isoclns_print(ndo, p, length);
break;
default:
if (!ndo->ndo_eflag)
ND_PRINT("unknown CHDLC protocol (0x%04x)", proto);
break;
}
return;
invalid:
nd_print_invalid(ndo);
}
/*
* The fixed-length portion of a SLARP packet.
*/
struct cisco_slarp {
nd_uint32_t code;
#define SLARP_REQUEST 0
#define SLARP_REPLY 1
#define SLARP_KEEPALIVE 2
union {
struct {
uint8_t addr[4];
uint8_t mask[4];
} addr;
struct {
nd_uint32_t myseq;
nd_uint32_t yourseq;
nd_uint16_t rel;
} keep;
} un;
};
#define SLARP_MIN_LEN 14
#define SLARP_MAX_LEN 18
static void
chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length)
{
const struct cisco_slarp *slarp;
u_int sec,min,hrs,days;
ndo->ndo_protocol = "chdlc_slarp";
ND_PRINT("SLARP");
ND_ICHECK_U(length, <, SLARP_MIN_LEN);
ND_PRINT(" (length: %u), ",length);
slarp = (const struct cisco_slarp *)cp;
ND_TCHECK_LEN(slarp, SLARP_MIN_LEN);
switch (GET_BE_U_4(slarp->code)) {
case SLARP_REQUEST:
ND_PRINT("request");
/*
* At least according to William "Chops" Westfield's
* message in
*
* https://web.archive.org/web/20190725151313/www.nethelp.no/net/cisco-hdlc.txt
*
* the address and mask aren't used in requests -
* they're just zero.
*/
break;
case SLARP_REPLY:
ND_PRINT("reply %s/%s",
GET_IPADDR_STRING(slarp->un.addr.addr),
GET_IPADDR_STRING(slarp->un.addr.mask));
break;
case SLARP_KEEPALIVE:
ND_PRINT("keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
GET_BE_U_4(slarp->un.keep.myseq),
GET_BE_U_4(slarp->un.keep.yourseq),
GET_BE_U_2(slarp->un.keep.rel));
if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
cp += SLARP_MIN_LEN;
sec = GET_BE_U_4(cp) / 1000;
min = sec / 60; sec -= min * 60;
hrs = min / 60; min -= hrs * 60;
days = hrs / 24; hrs -= days * 24;
ND_PRINT(", link uptime=%ud%uh%um%us",days,hrs,min,sec);
}
break;
default:
ND_PRINT("0x%02x unknown", GET_BE_U_4(slarp->code));
if (ndo->ndo_vflag <= 1)
print_unknown_data(ndo,cp+4,"\n\t",length-4);
break;
}
if (SLARP_MAX_LEN < length && ndo->ndo_vflag)
ND_PRINT(", (trailing junk: %u bytes)", length - SLARP_MAX_LEN);
if (ndo->ndo_vflag > 1)
print_unknown_data(ndo,cp+4,"\n\t",length-4);
return;
invalid:
nd_print_invalid(ndo);
}