forked from osmocom/wireshark
![Guy Harris](/assets/img/avatar_default.png)
If the area address/address prefix is 13 octets long, use the 13th octet, not the 21st octet; the latter is *not* part of the area address/address prefix, and might either not be in the packet or might be some random other part of the packet. Add/expand comments while we're at it. Bug: 14744 Change-Id: I7b90318a72a49b67d8ec17952add528185fd064b Reviewed-on: https://code.wireshark.org/review/27848 Reviewed-by: Guy Harris <guy@alum.mit.edu>
306 lines
9.7 KiB
C
306 lines
9.7 KiB
C
/* osi-utils.c
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* Routines for ISO/OSI network and transport protocol packet disassembly
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* Main entrance point and common functions
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*
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* Laurent Deniel <laurent.deniel@free.fr>
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* Ralf Schneider <Ralf.Schneider@t-online.de>
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include "config.h"
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#include <stdio.h>
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#include <string.h>
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#include <glib.h>
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#include "tvbuff.h"
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#include "osi-utils.h"
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#include "address.h"
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#include "address_types.h"
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static void print_nsap_net_buf( const guint8 *, int, gchar *, int);
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static void print_area_buf ( const guint8 *, int, gchar *, int);
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static void print_address_prefix_buf ( const guint8 *, int, gchar *, int);
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/*
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* XXX - shouldn't there be a centralized routine for dissecting NSAPs?
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* See also "dissect_atm_nsap()" in epan/dissectors/packet-arp.c and
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* "dissect_nsap()" in epan/dissectors/packet-isup.c.
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*/
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gchar *
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print_nsap_net( tvbuff_t *tvb, const gint offset, int length )
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{
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gchar *cur;
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cur = (gchar *)wmem_alloc(wmem_packet_scope(), MAX_NSAP_LEN * 3 + 50);
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print_nsap_net_buf( tvb_get_ptr(tvb, offset, length), length, cur, MAX_NSAP_LEN * 3 + 50);
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return( cur );
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}
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static void
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print_nsap_net_buf( const guint8 *ad, int length, gchar *buf, int buf_len)
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{
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gchar *cur;
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/* to do : NSAP / NET decoding */
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if ( (length <= 0 ) || ( length > MAX_NSAP_LEN ) ) {
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g_strlcpy(buf, "<Invalid length of NSAP>", buf_len);
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return;
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}
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cur = buf;
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if ( ( length == RFC1237_NSAP_LEN ) || ( length == RFC1237_NSAP_LEN + 1 ) ) {
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print_area_buf(ad, RFC1237_FULLAREA_LEN, cur, buf_len);
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cur += strlen( cur );
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print_system_id_buf( ad + RFC1237_FULLAREA_LEN, RFC1237_SYSTEMID_LEN, cur, (int) (buf_len-(cur-buf)));
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cur += strlen( cur );
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "[%02x]",
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ad[ RFC1237_FULLAREA_LEN + RFC1237_SYSTEMID_LEN ] );
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if ( length == RFC1237_NSAP_LEN + 1 ) {
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g_snprintf(cur, (int) (buf_len-(cur-buf)), "-%02x", ad[ length -1 ] );
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}
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}
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else { /* probably format as standard */
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/* XXX - this is an NSAP, not an area address/address prefix */
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print_area_buf( ad, length, buf, buf_len);
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}
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} /* print_nsap */
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gchar *
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print_system_id(wmem_allocator_t* scope, const guint8 *ad, int length )
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{
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gchar *cur;
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cur = (gchar *)wmem_alloc(scope, MAX_SYSTEMID_LEN * 3 + 5);
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print_system_id_buf(ad, length, cur, MAX_SYSTEMID_LEN * 3 + 5);
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return( cur );
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}
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gchar *
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tvb_print_system_id( tvbuff_t *tvb, const gint offset, int length )
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{
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return( print_system_id(wmem_packet_scope(), tvb_get_ptr(tvb, offset, length), length) );
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}
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void
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print_system_id_buf( const guint8 *ad, int length, gchar *buf, int buf_len)
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{
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gchar *cur;
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int tmp;
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if ( ( length <= 0 ) || ( length > MAX_SYSTEMID_LEN ) ) {
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g_strlcpy(buf, "<Invalid length of SYSTEM ID>", buf_len);
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return;
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}
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cur = buf;
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if ( ( 6 == length ) || /* System-ID */
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( 7 == length ) || /* LAN-ID */
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( 8 == length )) { /* LSP-ID */
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cur += g_snprintf(cur, buf_len, "%02x%02x.%02x%02x.%02x%02x", ad[0], ad[1],
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ad[2], ad[3], ad[4], ad[5] );
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if ( ( 7 == length ) ||
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( 8 == length )) {
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), ".%02x", ad[6] );
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}
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if ( 8 == length ) {
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g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "-%02x", ad[7] );
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}
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}
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else {
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tmp = 0;
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while ( tmp < length / 4 ) { /* 16 / 4 == 4 > four Octets left to print */
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x.", ad[tmp++] );
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}
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if ( 1 == tmp ) { /* Special case for Designated IS */
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cur--;
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g_snprintf(cur, (gulong) (buf_len-(cur-buf)), ".%02x", ad[tmp] );
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}
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else {
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for ( ; tmp < length; ) { /* print the rest without dot */
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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}
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}
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}
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}
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gchar *
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print_area(tvbuff_t *tvb, const gint offset, int length)
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{
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gchar *cur;
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cur = (gchar *)wmem_alloc(wmem_packet_scope(), MAX_AREA_LEN * 3 + 20);
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print_area_buf(tvb_get_ptr(tvb, offset, length), length, cur, MAX_AREA_LEN * 3 + 20);
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return cur;
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}
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/*
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* Note: length is in units of half-octets.
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*/
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gchar *
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print_address_prefix(tvbuff_t *tvb, const gint offset, int length)
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{
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gchar *cur;
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cur = (gchar *)wmem_alloc(wmem_packet_scope(), MAX_AREA_LEN * 3 + 20);
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print_address_prefix_buf(tvb_get_ptr(tvb, offset, (length+1)/2), length, cur, MAX_AREA_LEN * 3 + 20);
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return cur;
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}
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/*
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* Note: length is in units of octets.
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*/
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static void
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print_area_buf(const guint8 *ad, int length, gchar *buf, int buf_len)
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{
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print_address_prefix_buf(ad, length*2, buf, buf_len);
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}
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/*
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* Note: length is in units of half-octets.
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*/
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static void
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print_address_prefix_buf(const guint8 *ad, int length, gchar *buf, int buf_len)
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{
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gchar *cur;
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int tmp = 0;
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/* to do : all real area decoding now: NET is assumed if id len is 1 more byte
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*/
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if (length <= 0 || length > MAX_AREA_LEN*2) {
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g_strlcpy(buf, "<Invalid length of AREA>", buf_len);
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return;
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}
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cur = buf;
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/* Check the AFI and length. */
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if ( ( ( NSAP_IDI_ISO_DCC_BIN == *ad )
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|| ( NSAP_IDI_ISO_6523_ICD_BIN == *ad )
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)
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&&
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( ( RFC1237_FULLAREA_LEN*2 == length )
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|| ( (RFC1237_FULLAREA_LEN + 1)*2 == length )
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)
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) { /* AFI is good and length is long enough */
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/* The AFI is either ISO DCC, binary or ISO 6523-ICD, binary,
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* and the area length corresponds either to the area length
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* for RFC 1237 (GOSIP) addresses or that length + 1.
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*
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* XXX - RFC 1237 doesn't mention ISO DCC, binary, as a valid
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* AFI; is that from GOSIP Version 1? If it's ISO DCC, binary,
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* the IDI is 3 digits, i.e. 1 1/2 octets.
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*/
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/* there used to be a check for (length > RFC1237_FULLAREA_LEN + 1) here,
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* in order to report an invalied length of AREA for DCC / ISO 6523 AFI,
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* but that can *never* be the case because the if() test above explicitly
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* tests for (length == RFC1237_FULLAREA_LEN) or (length == RFC1237_FULLAREA_LEN + 1)
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*/
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/* Show the one-octet AFI, the two-octet IDI, the one-octet DFI, the
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* 3-octet AA, and the 2 reserved octets.
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*/
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "[%02x|%02x:%02x][%02x|%02x:%02x:%02x|%02x:%02x]",
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ad[0], ad[1], ad[2], ad[3], ad[4],
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ad[5], ad[6], ad[7], ad[8] );
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/* Show the 2-octet RD and the 2-octet Area. */
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "[%02x:%02x|%02x:%02x]",
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ad[9], ad[10], ad[11], ad[12] );
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/* Show whatever the heck this is; it's not specified by RFC 1237,
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* but we also handle 14-octet areas. Is it the "Designated IS"
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* stuff mentioned below? (I didn't find anything in the IS-IS
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* spec about that.)
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*/
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if ( (RFC1237_FULLAREA_LEN + 1)*2 == length )
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g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "-[%02x]", ad[13] );
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}
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else {
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/* This doesn't look like a full RFC 1237 IS-IS area, so all we know
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* is that the first octet is an AFI. Print it separately from all
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* the other octets.
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*/
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if ( length == RFC1237_AREA_LEN*2 ) {
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/* XXX - RFC1237_AREA_LEN, which is 3 octets, doesn't seem to
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* correspond to anything in RFC 1237. Where did it come from?
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*/
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g_snprintf(buf, buf_len, "%02x.%02x%02x", ad[0], ad[1], ad[2] );
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return;
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}
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if ( length == 4*2 ) {
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g_snprintf(buf, buf_len, "%02x%02x%02x%02x", ad[0], ad[1], ad[2], ad[3] );
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return;
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}
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while ( tmp < length / 8 ) { /* 32/8==4 > four Octets left to print */
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x.", ad[tmp++] );
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}
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if ( 2 == tmp ) { /* Special case for Designated IS */
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cur--;
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g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "-%02x", ad[tmp] );
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}
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else {
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for ( ; tmp < length / 2; ) { /* print the rest without dot or dash */
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cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
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}
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/* Odd half-octet? */
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if (length & 1) {
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/* Yes - print it (it's the upper half-octet) */
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g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%x", (ad[tmp] & 0xF0)>>4 );
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}
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}
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}
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} /* print_address_prefix_buf */
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/******************************************************************************
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* OSI Address Type
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******************************************************************************/
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static int osi_address_type = -1;
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static int osi_address_to_str(const address* addr, gchar *buf, int buf_len)
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{
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print_nsap_net_buf((const guint8 *)addr->data, addr->len, buf, buf_len);
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return (int)strlen(buf)+1;
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}
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static int osi_address_str_len(const address* addr _U_)
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{
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return MAX_NSAP_LEN * 3 + 50;
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}
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int get_osi_address_type(void)
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{
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return osi_address_type;
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}
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void register_osi_address_type(void)
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{
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if (osi_address_type != -1)
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return;
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osi_address_type = address_type_dissector_register("AT_OSI", "OSI Address", osi_address_to_str, osi_address_str_len, NULL, NULL, NULL, NULL, NULL);
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}
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/*
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* Editor modelines
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*
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* Local Variables:
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* c-basic-offset: 2
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* ex: set shiftwidth=2 tabstop=8 expandtab:
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* :indentSize=2:tabSize=8:noTabs=true:
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*/
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