tcpdump/print-llc.c
guy 393ce0607f The control field of an LLC frame is 1 byte for a U frame and 2 bytes
for an S or I frame; have the LLC dissector pass the control field value
as an argument to the NetBEUI dissector, rather than having the NetBEUI
dissector extract the control field value itself, and have it pass a
pointer to the beginning of the LLC *payload* rather than to the control
field.

Keep the NetBEUI dissector from running past the end of the buffer.

Add support for the NetBEUI SESSION ALIVE frame.
2000-12-05 06:42:47 +00:00

247 lines
6.2 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 Matt Thomas, Digital Equipment Corporation
* with an awful lot of hacking by Jeffrey Mogul, DECWRL
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-llc.c,v 1.30 2000-12-05 06:42:48 guy 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 */
#include "llc.h"
static struct tok cmd2str[] = {
{ LLC_UI, "ui" },
{ LLC_TEST, "test" },
{ LLC_XID, "xid" },
{ LLC_UA, "ua" },
{ LLC_DISC, "disc" },
{ LLC_DM, "dm" },
{ LLC_SABME, "sabme" },
{ LLC_FRMR, "frmr" },
{ 0, NULL }
};
/*
* Returns non-zero IFF it succeeds in printing the header
*/
int
llc_print(const u_char *p, u_int length, u_int caplen,
const u_char *esrc, const u_char *edst)
{
struct llc llc;
register u_short et;
u_short control;
register int ret;
if (caplen < 3) {
(void)printf("[|llc]");
default_print((u_char *)p, caplen);
return(0);
}
/* Watch out for possible alignment problems */
memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
ipx_print(p, length);
return (1);
}
/* Cisco Discovery Protocol - SNAP & ether type 0x2000 */
if(llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP &&
llc.llcui == LLC_UI &&
llc.ethertype[0] == 0x20 && llc.ethertype[1] == 0x00 ) {
cdp_print( p, length, caplen, esrc, edst);
return (1);
}
if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
stp_print(p, length);
return (1);
}
if (llc.ssap == 0xf0 && llc.dsap == 0xf0) {
/*
* we don't actually have a full netbeui parser yet, but the
* smb parser can handle many smb-in-netbeui packets, which
* is very useful, so we call that
*/
/*
* Skip the DSAP and LSAP.
*/
p += 2;
length -= 2;
caplen -= 2;
/*
* OK, what type of LLC frame is this? The length
* of the control field depends on that - S or I
* frames have a two-byte control field, and U frames
* have a one-byte control field.
*/
if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
control = llc.llcu;
p += 1;
length -= 1;
caplen -= 1;
} else {
control = llc.llcis;
p += 2;
length -= 2;
caplen -= 2;
}
netbeui_print(control, p, p + min(caplen, length));
return (1);
}
if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
&& llc.llcui == LLC_UI) {
isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst);
return (1);
}
if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
&& llc.llcui == LLC_UI) {
if (caplen < sizeof(llc)) {
(void)printf("[|llc-snap]");
default_print((u_char *)p, caplen);
return (0);
}
if (vflag)
(void)printf("snap %s ", protoid_string(llc.llcpi));
caplen -= sizeof(llc);
length -= sizeof(llc);
p += sizeof(llc);
/* This is an encapsulated Ethernet packet */
et = EXTRACT_16BITS(&llc.ethertype[0]);
ret = ether_encap_print(et, p, length, caplen);
if (ret)
return (ret);
}
if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
if (eflag)
(void)printf("%s ", llcsap_string(llc.dsap));
else
(void)printf("%s > %s %s ",
etheraddr_string(esrc),
etheraddr_string(edst),
llcsap_string(llc.dsap));
} else {
if (eflag)
(void)printf("%s > %s ",
llcsap_string(llc.ssap & ~LLC_GSAP),
llcsap_string(llc.dsap));
else
(void)printf("%s %s > %s %s ",
etheraddr_string(esrc),
llcsap_string(llc.ssap & ~LLC_GSAP),
etheraddr_string(edst),
llcsap_string(llc.dsap));
}
if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
const char *m;
char f;
m = tok2str(cmd2str, "%02x", LLC_U_CMD(llc.llcu));
switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
case 0: f = 'C'; break;
case LLC_GSAP: f = 'R'; break;
case LLC_U_POLL: f = 'P'; break;
case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
default: f = '?'; break;
}
printf("%s/%c", m, f);
p += 3;
length -= 3;
caplen -= 3;
if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
if (*p == LLC_XID_FI) {
printf(": %02x %02x", p[1], p[2]);
p += 3;
length -= 3;
caplen -= 3;
}
}
if (!strcmp(m,"ui") && f=='C') {
/*
* we don't have a proper ipx decoder yet, but there
* is a partial one in the smb code
*/
ipx_netbios_print(p,p+min(caplen,length));
}
} else {
char f;
llc.llcis = ntohs(llc.llcis);
switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
case 0: f = 'C'; break;
case LLC_GSAP: f = 'R'; break;
case LLC_U_POLL: f = 'P'; break;
case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
default: f = '?'; break;
}
if ((llc.llcu & LLC_S_FMT) == LLC_S_FMT) {
static char *llc_s[] = { "rr", "rej", "rnr", "03" };
(void)printf("%s (r=%d,%c)",
llc_s[LLC_S_CMD(llc.llcis)],
LLC_IS_NR(llc.llcis),
f);
} else {
(void)printf("I (s=%d,r=%d,%c)",
LLC_I_NS(llc.llcis),
LLC_IS_NR(llc.llcis),
f);
}
p += 4;
length -= 4;
caplen -= 4;
}
(void)printf(" len=%d", length);
return(1);
}