* Routines for ISO/OSI network and transport protocol packet disassembly
* Main entrance point and common functions
*
- * $Id: packet-osi.c,v 1.47 2001/11/25 22:51:13 hagbard Exp $
- * Laurent Deniel <deniel@worldnet.fr>
+ * $Id: packet-osi.c,v 1.63 2003/09/20 03:31:25 guy Exp $
+ * Laurent Deniel <laurent.deniel@free.fr>
* Ralf Schneider <Ralf.Schneider@t-online.de>
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
- *
+ *
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
- *
+ *
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
- *
+ *
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
-#ifdef HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
-
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <glib.h>
-#include "packet.h"
+#include <epan/packet.h>
#include "llcsaps.h"
#include "aftypes.h"
#include "nlpid.h"
#include "ppptypes.h"
+#include "chdlctypes.h"
#include "packet-osi.h"
#include "packet-isis.h"
#include "packet-esis.h"
cksum_status_t
-calc_checksum( tvbuff_t *tvb, int offset, u_int len, u_int checksum) {
+calc_checksum( tvbuff_t *tvb, int offset, guint len, guint checksum) {
const gchar *buffer;
guint available_len;
const guint8 *p;
guint32 c0, c1;
- u_int seglen;
- u_int i;
+ guint seglen;
+ guint i;
if ( 0 == checksum )
return( NO_CKSUM );
len -= seglen;
}
if (c0 != 0 || c1 != 0)
- return( CKSUM_NOT_OK ); /* XXX - what should the checksum be? */
+ return( CKSUM_NOT_OK ); /* XXX - what should the checksum field be? */
else
return( CKSUM_OK );
}
+cksum_status_t
+check_and_get_checksum( tvbuff_t *tvb, int offset, guint len, guint checksum, int offset_check, guint16* result) {
+ const gchar *buffer;
+ guint available_len;
+ const guint8 *p;
+ guint8 discard = 0;
+ guint32 c0, c1, factor;
+ guint seglen, initlen = len;
+ guint i;
+ int block, x, y;
+
+ if ( 0 == checksum )
+ return( NO_CKSUM );
+
+ available_len = tvb_length_remaining( tvb, offset );
+ offset_check -= offset;
+ if ( ( available_len < len ) || ( offset_check < 0 ) || ( (guint)(offset_check+2) > len ) )
+ return( DATA_MISSING );
+
+ buffer = tvb_get_ptr( tvb, offset, len );
+ block = offset_check / 5803;
+
+ /*
+ * The maximum values of c0 and c1 will occur if all bytes have the
+ * value 255; if so, then c0 will be len*255 and c1 will be
+ * (len*255 + (len-1)*255 + ... + 255), which is
+ * (len + (len - 1) + ... + 1)*255, or 255*(len*(len + 1))/2.
+ * This means it can overflow if "len" is 5804 or greater.
+ *
+ * (A+B) mod 255 = ((A mod 255) + (B mod 255) mod 255, so
+ * we can solve this by taking c0 and c1 mod 255 every
+ * 5803 bytes.
+ */
+ p = buffer;
+ c0 = 0;
+ c1 = 0;
+
+ while (len != 0) {
+ seglen = len;
+ if ( block-- == 0 ) {
+ seglen = offset_check % 5803;
+ discard = 1;
+ } else if ( seglen > 5803 )
+ seglen = 5803;
+ for (i = 0; i < seglen; i++) {
+ c0 = c0 + *(p++);
+ c1 += c0;
+ }
+ if ( discard ) {
+ /*
+ * This works even if (offset_check % 5803) == 5802
+ */
+ p += 2;
+ c1 += 2*c0;
+ len -= 2;
+ discard = 0;
+ }
+
+ c0 = c0 % 255;
+ c1 = c1 % 255;
+
+ len -= seglen;
+ }
+
+ factor = ( initlen - offset_check ) * c0;
+ x = factor - c0 - c1;
+ y = c1 - factor - 1;
+
+ /*
+ * This algorithm uses the 8 bits one's complement arithmetic.
+ * Therefore, we must correct an effect produced
+ * by the "standard" arithmetic (two's complement)
+ */
+
+ if (x < 0 ) x--;
+ if (y > 0 ) y++;
+
+ x %= 255;
+ y %= 255;
+
+ if (x == 0) x = 0xFF;
+ if (y == 0) y = 0x01;
+
+ *result = ( x << 8 ) | ( y & 0xFF );
+
+ if (*result != checksum)
+ return( CKSUM_NOT_OK ); /* XXX - what should the checksum field be? */
+ else
+ return( CKSUM_OK );
+}
+
+
+
/* main entry point */
+/*
+ * These assume the NLPID is a secondary protocol identifier, not an
+ * initial protocol identifier.
+ *
+ * This is an issue only if, in any packet where an NLPID appears, it's
+ * an initial protocol identifier *AND* it can have the value 1, which
+ * means T.70 for an IPI and X.29 for an SPI.
+ */
const value_string nlpid_vals[] = {
{ NLPID_NULL, "NULL" },
- { NLPID_T_70, "T.70" },
+ { NLPID_SPI_X_29, "X.29" },
{ NLPID_X_633, "X.633" },
{ NLPID_Q_931, "Q.931" },
{ NLPID_Q_2931, "Q.2931" },
{ NLPID_ISO11577, "ISO 11577" },
{ NLPID_COMPRESSED, "Data compression protocol" },
{ NLPID_IP, "IP" },
+ { NLPID_SNDCF, "SubNetwork Dependent Convergence Function"},
{ NLPID_IP6, "IPv6" },
{ NLPID_PPP, "PPP" },
{ 0, NULL },
};
-dissector_table_t osinl_subdissector_table;
-static dissector_handle_t data_handle;
+static dissector_table_t osinl_subdissector_table;
+static dissector_handle_t data_handle, ppp_handle;
-static void dissect_osi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+static void dissect_osi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
guint8 nlpid;
+ tvbuff_t *new_tvb;
pinfo->current_proto = "OSI";
/* ESIS (X.25) is not currently decoded */
case NLPID_ISO9542X25_ESIS:
- if (check_col(pinfo->fd, COL_PROTOCOL)) {
- col_set_str(pinfo->fd, COL_PROTOCOL, "ESIS (X.25)");
+ if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "ESIS (X.25)");
}
call_dissector(data_handle,tvb, pinfo, tree);
break;
case NLPID_ISO10747_IDRP:
- if (check_col(pinfo->fd, COL_PROTOCOL)) {
- col_set_str(pinfo->fd, COL_PROTOCOL, "IDRP");
+ if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "IDRP");
}
call_dissector(data_handle,tvb, pinfo, tree);
break;
+ case NLPID_PPP:
+ /* XXX - we should put the NLPID into the protocol tree.
+ We should also probably have a subdissector table for
+ those protocols whose PDUs *aren't* defined to begin
+ with an NLPID. */
+ new_tvb = tvb_new_subset(tvb, 1, -1, -1);
+ call_dissector(ppp_handle, new_tvb, pinfo, tree);
+ break;
default:
- if (check_col(pinfo->fd, COL_PROTOCOL)) {
- col_set_str(pinfo->fd, COL_PROTOCOL, "ISO");
+ if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "ISO");
}
- if (check_col(pinfo->fd, COL_INFO)) {
- col_add_fstr(pinfo->fd, COL_INFO, "Unknown ISO protocol (%02x)", nlpid);
+ if (check_col(pinfo->cinfo, COL_INFO)) {
+ col_add_fstr(pinfo->cinfo, COL_INFO, "Unknown ISO protocol (%02x)", nlpid);
}
call_dissector(data_handle,tvb, pinfo, tree);
break;
/* There's no "OSI" protocol *per se*, but we do register a
dissector table so various protocols running at the
network layer can register themselves. */
- osinl_subdissector_table = register_dissector_table("osinl");
+ osinl_subdissector_table = register_dissector_table("osinl",
+ "OSI NLPID", FT_UINT8, BASE_HEX);
}
void
proto_reg_handoff_osi(void)
{
- dissector_add("llc.dsap", SAP_OSINL, dissect_osi, -1);
- dissector_add("ppp.protocol", PPP_OSI, dissect_osi, -1);
- dissector_add("null.type", BSD_AF_ISO, dissect_osi, -1);
+ dissector_handle_t osi_handle;
+
+ osi_handle = create_dissector_handle(dissect_osi, -1);
+ dissector_add("llc.dsap", SAP_OSINL1, osi_handle);
+ dissector_add("llc.dsap", SAP_OSINL2, osi_handle);
+ dissector_add("llc.dsap", SAP_OSINL3, osi_handle);
+ dissector_add("llc.dsap", SAP_OSINL4, osi_handle);
+ dissector_add("llc.dsap", SAP_OSINL5, osi_handle);
+ dissector_add("ppp.protocol", PPP_OSI, osi_handle);
+ dissector_add("chdlctype", CHDLCTYPE_OSI, osi_handle);
+ dissector_add("null.type", BSD_AF_ISO, osi_handle);
+ dissector_add("gre.proto", SAP_OSINL5, osi_handle);
data_handle = find_dissector("data");
+ ppp_handle = find_dissector("ppp");
}
git.samba.org / obnox / wireshark / wip.git / blobdiff