![Guy Harris](/assets/img/avatar_default.png)
snprintf(), sensibly, takes a size_t argument specifying the size of the buffer. g_snprintf(), bogusly, takes a gulong argument specifying the size of the buffer, so we had to do casts to avoid narrowing complaints, but we're just using snprintf() now (as we require C11 or later), and don't need the casts any more.
306 lines
9.6 KiB
C
306 lines
9.6 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( wmem_allocator_t *scope, 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(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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(void) 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 += snprintf(cur, 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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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( wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, int length )
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{
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return( print_system_id(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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(void) 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 += 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 += snprintf(cur, buf_len-(cur-buf), ".%02x", ad[6] );
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}
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if ( 8 == length ) {
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snprintf(cur, 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 += snprintf(cur, buf_len-(cur-buf), "%02x", ad[tmp++] );
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cur += snprintf(cur, buf_len-(cur-buf), "%02x", ad[tmp++] );
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cur += snprintf(cur, buf_len-(cur-buf), "%02x", ad[tmp++] );
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cur += snprintf(cur, 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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snprintf(cur, 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 += snprintf(cur, 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(wmem_allocator_t *scope, 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(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(wmem_allocator_t *scope, 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(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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(void) 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 += snprintf(cur, 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 += snprintf(cur, 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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snprintf(cur, 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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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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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 += snprintf(cur, buf_len-(cur-buf), "%02x", ad[tmp++] );
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cur += snprintf(cur, buf_len-(cur-buf), "%02x", ad[tmp++] );
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cur += snprintf(cur, buf_len-(cur-buf), "%02x", ad[tmp++] );
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cur += snprintf(cur, 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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snprintf(cur, 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 += snprintf(cur, 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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snprintf(cur, 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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