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/* $OpenBSD: print-llc.c,v 1.23 2023/02/28 10:04:50 claudio Exp $ */
/*
* 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
*/
#include <sys/time.h>
#include <netinet/in.h>
#include <ctype.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include "interface.h"
#include "addrtoname.h"
#include "extract.h" /* must come after interface.h */
#include "ethertype.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;
u_short et;
#if 0
u_short control;
#endif
int ret;
if (caplen < 3) {
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);
}
#ifdef notyet
else if (p[0] == 0xf0 && p[1] == 0xf0)
netbios_print(p, length);
#endif
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)) {
printf("[|llc-snap]");
default_print((u_char *)p, caplen);
return (0);
}
/* Cisco Discovery Protocol - SNAP & ether type 0x2000 */
if (llc.ethertype[0] == 0x20 && llc.ethertype[1] == 0x00) {
cdp_print(p, length, caplen, 8);
return (1);
}
/* Shared Spanning Tree Protocol - SNAP & ether type 0x010b */
if (llc.ethertype[0] == 0x01 && llc.ethertype[1] == 0x0b) {
stp_print(p, length);
return (1);
}
if (vflag)
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]);
/*
* Some protocols have special handling if they are 802.3
* SNAP encapsulated vs vers II encapsulated. Handle
* those special protocols here, and hand the rest to
* print-ether.c so we don't have to duplicate
* all that code here.
*/
switch (et) {
case ETHERTYPE_ATALK:
atalk_print(p, length);
ret = 1;
break;
default:
ret = ether_encap_print(et, p, length, caplen);
break;
}
if (ret)
return (ret);
}
if (llc.ssap == LLCSAP_8021D && llc.dsap == LLCSAP_8021D) {
stp_print(p, length);
return (1);
}
#if 0
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);
}
#endif
if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
if (eflag)
printf("%s ", llcsap_string(llc.dsap));
else
printf("%s > %s %s ",
etheraddr_string(esrc),
etheraddr_string(edst),
llcsap_string(llc.dsap));
} else {
if (eflag)
printf("%s > %s ",
llcsap_string(llc.ssap & ~LLC_GSAP),
llcsap_string(llc.dsap));
else
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);
if (caplen < 6) {
default_print(p, caplen);
return (0);
}
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 0
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));
}
#endif
} else {
char f;
if (caplen < 4) {
default_print(p, caplen);
return (0);
}
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" };
printf("%s (r=%d,%c)",
llc_s[LLC_S_CMD(llc.llcis)],
LLC_IS_NR(llc.llcis),
f);
} else {
printf("I (s=%d,r=%d,%c)",
LLC_I_NS(llc.llcis),
LLC_IS_NR(llc.llcis),
f);
}
p += 4;
length -= 4;
caplen -= 4;
}
printf(" len=%d", length);
return(1);
}
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