wireshark/packet-isis.c

/* packet-isis-core.c
 * Routines for ISO/OSI network and transport protocol packet disassembly, core
 * bits.
 *
 * $Id: packet-isis.c,v 1.19 2001/03/30 10:51:50 guy Exp $
 * Stuart Stanley <stuarts@mxmail.net>
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@zing.org>
 * 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 <glib.h>
#include "packet.h"
#include "nlpid.h"
#include "packet-osi.h"
#include "packet-isis.h"
#include "packet-isis-lsp.h"
#include "packet-isis-hello.h"
#include "packet-isis-snp.h"


/* isis base header */
static int proto_isis               = -1;

static int hf_isis_irpd             = -1;
static int hf_isis_header_length    = -1;
static int hf_isis_version          = -1;
static int hf_isis_system_id_length = -1;
static int hf_isis_type             = -1;
static int hf_isis_version2         = -1;
static int hf_isis_reserved         = -1;
static int hf_isis_max_area_adr     = -1;

static gint ett_isis                = -1;

static const value_string isis_vals[] = {
  { ISIS_TYPE_L1_HELLO,  "L1 HELLO"},
  { ISIS_TYPE_L2_HELLO,  "L2 HELLO"},
  { ISIS_TYPE_PTP_HELLO, "P2P HELLO"},
  { ISIS_TYPE_L1_LSP,    "L1 LSP"},
  { ISIS_TYPE_L2_LSP,    "L2 LSP"},
  { ISIS_TYPE_L1_CSNP,   "L1 CSNP"},
  { ISIS_TYPE_L2_CSNP,   "L2 CSNP"},
  { ISIS_TYPE_L1_PSNP,   "L1 PSNP"},
  { ISIS_TYPE_L2_PSNP,   "L2 PSNP"},
  { 0,                   NULL}      };

/*
 * Name: dissect_isis_unknown()
 *
 * Description:
 *	There was some error in the protocol and we are in unknown space
 *	here.  Add a tree item to cover the error and go on.  Note
 *	that we make sure we don't go off the end of the bleedin packet here!
 *
 * Input
 * 	unt offset : Current offset into packet data.
 * 	int len : length of to dump.
 *	proto_tree * : tree of display data.  May be NULL.
 *	frame_data * fd : frame data
 *	char * : format text
 *
 * Output:
 *	void (may modify proto tree)
 */
void
isis_dissect_unknown(int offset,guint length,proto_tree *tree,frame_data *fd,
		char *fmat, ...){
	va_list	ap;

	if ( !IS_DATA_IN_FRAME(offset) ) {
		/* 
		 * big oops   They were off the end of the packet already.
		 * Just ignore this one.
		 */
		return;
	}
	if ( !BYTES_ARE_IN_FRAME(offset, length) ) {
		/* 
		 * length will take us past eop.  Truncate length.
		 */
		length = END_OF_FRAME;
	}

	va_start(ap, fmat);
	proto_tree_add_text_valist(tree, NullTVB, offset, length, fmat, ap);
	va_end(ap);
}
/*
 * Name: dissect_isis()
 * 
 * Description:
 *	Main entry area for isis de-mangling.  This will build the
 *	main isis tree data and call the sub-protocols as needed.
 *
 * Input:
 *	u_char * : packet data
 *	int : offset into packet where we are (packet_data[offset]== start
 *		of what we care about)
 *	frame_data * : frame data (whole packet with extra info)
 *	proto_tree * : tree of display data.  May be NULL.
 *
 * Output:
 *	void, but we will add to the proto_tree if it is not NULL.
 */
static void
dissect_isis(const u_char *pd, int offset, frame_data *fd, 
		proto_tree *tree) {
	isis_hdr_t *ihdr;
	proto_item *ti;
	proto_tree *isis_tree = NULL;
	int id_length;

	OLD_CHECK_DISPLAY_AS_DATA(proto_isis, pd, offset, fd, tree);

	if (check_col(fd, COL_PROTOCOL))
		col_set_str(fd, COL_PROTOCOL, "ISIS");

	if (!BYTES_ARE_IN_FRAME(offset, sizeof(*ihdr))) {
		isis_dissect_unknown(offset, sizeof(*ihdr), tree, fd,
			"not enough capture data for header (%d vs %d)",
			sizeof(*ihdr), END_OF_FRAME);
		return;
	}

	ihdr = (isis_hdr_t *) &pd[offset];

	if (ihdr->isis_version != ISIS_REQUIRED_VERSION){
		isis_dissect_unknown(offset, END_OF_FRAME, tree, fd,
			"Unknown ISIS version (%d vs %d)",
			ihdr->isis_version, ISIS_REQUIRED_VERSION );
		return;
	}
	
	
	if (tree) {
		ti = proto_tree_add_item(tree, proto_isis, NullTVB, offset, 
			END_OF_FRAME, FALSE );
		isis_tree = proto_item_add_subtree(ti, ett_isis);
		proto_tree_add_uint(isis_tree, hf_isis_irpd, NullTVB, offset, 1,
			ihdr->isis_irpd );
		proto_tree_add_uint(isis_tree, hf_isis_header_length, NullTVB,
			offset + 1, 1, ihdr->isis_header_length );
		proto_tree_add_uint(isis_tree, hf_isis_version, NullTVB,
			offset + 2, 1, ihdr->isis_version );
		proto_tree_add_uint(isis_tree, hf_isis_system_id_length, NullTVB,
			offset + 3, 1, ihdr->isis_system_id_len );
		proto_tree_add_uint_format(isis_tree, hf_isis_type, NullTVB,
			offset + 4, 1, ihdr->isis_type,
			"Type               : %s (R:%s%s%s)",
			val_to_str(ihdr->isis_type & ISIS_TYPE_MASK, isis_vals,
		   		   "Unknown (0x%x)"),
			(ihdr->isis_type & ISIS_R8_MASK) ? "1" : "0",
			(ihdr->isis_type & ISIS_R7_MASK) ? "1" : "0",
			(ihdr->isis_type & ISIS_R6_MASK) ? "1" : "0");
		proto_tree_add_uint(isis_tree, hf_isis_version2, NullTVB,
			offset + 5, 1, ihdr->isis_version2 );
		proto_tree_add_uint(isis_tree, hf_isis_reserved, NullTVB,
			offset + 6, 1, ihdr->isis_reserved );
		proto_tree_add_uint(isis_tree, hf_isis_max_area_adr, NullTVB,
			offset + 7, 1, ihdr->isis_max_area_adr );
	}


	/*
	 * Let us make sure we use the same names for all our decodes
	 * here.  First, dump the name into info column, and THEN
	 * dispatch the sub-type.
	 */
	if (check_col(fd, COL_INFO)) {
		col_add_str(fd, COL_INFO, val_to_str ( 
			ihdr->isis_type&ISIS_TYPE_MASK, isis_vals,
			"Unknown (0x%x)" ) );
	}

	/*
	 * Interpret the system ID length.
	 */
	id_length = ihdr->isis_system_id_len;
	if (id_length == 0)
		id_length = 6;	/* zero means 6-octet ID field length */
	else if (id_length == 255) {
		id_length = 0;	/* 255 means null ID field */
		/* XXX - what about the LAN ID? */
	}
	/* XXX - otherwise, must be in the range 1 through 8 */

	/*
	 * Advance offset (we are past the header).
	 */
	offset += sizeof(*ihdr);
	switch (ihdr->isis_type) {
	case ISIS_TYPE_L1_HELLO:
		isis_dissect_isis_hello(ISIS_TYPE_L1_HELLO, 
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_L2_HELLO:
		isis_dissect_isis_hello(ISIS_TYPE_L2_HELLO, 
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_PTP_HELLO:
		isis_dissect_isis_hello(ISIS_TYPE_PTP_HELLO, 
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_L1_LSP:
		isis_dissect_isis_lsp(ISIS_TYPE_L1_LSP,
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_L2_LSP:
		isis_dissect_isis_lsp(ISIS_TYPE_L2_LSP,
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_L1_CSNP:
		isis_dissect_isis_csnp(ISIS_TYPE_L1_CSNP, 
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_L2_CSNP:
		isis_dissect_isis_csnp(ISIS_TYPE_L2_CSNP,
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_L1_PSNP:
		isis_dissect_isis_psnp(ISIS_TYPE_L1_PSNP, 
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	case ISIS_TYPE_L2_PSNP:
		isis_dissect_isis_psnp(ISIS_TYPE_L2_PSNP,
			ihdr->isis_header_length, id_length,
			pd, offset, fd, isis_tree);
		break;
	default:
		isis_dissect_unknown(offset, END_OF_FRAME, tree, fd,
			"unknown ISIS packet type" );
	}
} /* dissect_isis */


/*
 * Name: proto_register_isis()
 *
 * Description:
 *	main register for isis protocol set.  We register some display
 *	formats and the protocol module variables.
 *
 * 	NOTE: this procedure to autolinked by the makefile process that
 *	builds register.c
 *
 * Input: 
 *	void
 *
 * Output:
 *	void
 */
void 
proto_register_isis(void) {
  static hf_register_info hf[] = {
    { &hf_isis_irpd,
      { "Intra Domain Routing Protocol Discriminator",	"isis.irpd",	
        FT_UINT8, BASE_HEX, VALS(nlpid_vals), 0x0, "" }},

    { &hf_isis_header_length,
      { "PDU Header Length  ", "isis.len", FT_UINT8, BASE_DEC, NULL, 0x0, "" }},

    { &hf_isis_version,
      { "Version (==1)      ", "isis.version", FT_UINT8, 
         BASE_DEC, NULL, 0x0, "" }},

    { &hf_isis_system_id_length,
      { "System ID Length   ", "isis.sysid_len",	
        FT_UINT8, BASE_DEC, NULL, 0x0, "" }},

    { &hf_isis_type, 
      { "PDU Type          :", "isis.type", FT_UINT8, BASE_DEC, 
        VALS(isis_vals), 0xff, "" }},

    { &hf_isis_version2, 
      { "Version2 (==1)     ", "isis.version2", FT_UINT8, BASE_DEC, NULL, 
        0x0, "" }},

    { &hf_isis_reserved,
      { "Reserved (==0)     ", "isis.reserved", FT_UINT8, BASE_DEC, NULL, 
        0x0, "" }},

    { &hf_isis_max_area_adr,
      { "Max.AREAs: (0==3)  ", "isis.max_area_adr", FT_UINT8, BASE_DEC, NULL, 
      0x0, "" }},

    };
    /*
     * Note, we pull in the unknown CLV handler here, since it
     * is used by all ISIS packet types.
    */
    static gint *ett[] = {
      &ett_isis,
    };

    proto_isis = proto_register_protocol(PROTO_STRING_ISIS, "ISIS", "isis");
    proto_register_field_array(proto_isis, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_isis(void)
{
    old_dissector_add("osinl", NLPID_ISO10589_ISIS, dissect_isis, proto_isis);
}