wireshark/packet-ipx.c

/* packet-ipx.c
 * Routines for NetWare's IPX
 * Gilbert Ramirez <gram@verdict.uthscsa.edu>
 *
 * $Id: packet-ipx.c,v 1.38 1999/11/30 09:01:55 guy Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@unicom.net>
 * 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 <glib.h>
#include "packet.h"
#include "packet-ipx.h"
#include "packet-ncp.h"
#include "resolv.h"

/* The information in this module (IPX, SPX, NCP) comes from:
	NetWare LAN Analysis, Second Edition
	Laura A. Chappell and Dan E. Hakes
	(c) 1994 Novell, Inc.
	Novell Press, San Jose.
	ISBN: 0-7821-1362-1

  And from the ncpfs source code by Volker Lendecke

*/
	
static int proto_ipx = -1;
static int hf_ipx_checksum = -1;
static int hf_ipx_len = -1;
static int hf_ipx_hops = -1;
static int hf_ipx_packet_type = -1;
static int hf_ipx_dnet = -1;
static int hf_ipx_dnode = -1;
static int hf_ipx_dsocket = -1;
static int hf_ipx_snet = -1;
static int hf_ipx_snode = -1;
static int hf_ipx_ssocket = -1;

static gint ett_ipx = -1;

static int proto_spx = -1;
static int hf_spx_connection_control = -1;
static int hf_spx_datastream_type = -1;
static int hf_spx_src_id = -1;
static int hf_spx_dst_id = -1;
static int hf_spx_seq_nr = -1;
static int hf_spx_ack_nr = -1;
static int hf_spx_all_nr = -1;

static gint ett_spx = -1;

static int proto_ipxrip = -1;
static int hf_ipxrip_request = -1;
static int hf_ipxrip_response = -1;

static gint ett_ipxrip = -1;

static int proto_sap = -1;
static int hf_sap_request = -1;
static int hf_sap_response = -1;

static gint ett_ipxsap = -1;
static gint ett_ipxsap_server = -1;

static void
dissect_spx(const u_char *pd, int offset, frame_data *fd, proto_tree *tree);

static void
dissect_ipxrip(const u_char *pd, int offset, frame_data *fd, proto_tree *tree);

static void
dissect_ipxsap(const u_char *pd, int offset, frame_data *fd, proto_tree *tree);

typedef	void	(dissect_func_t)(const u_char *, int, frame_data *, proto_tree *);

struct port_info {
	guint16	port;
	dissect_func_t *func;
	char	*text;
};

struct conn_info {
	guint8	ctrl;
	char	*text;
};

struct server_info {
	guint16	type;
	char	*text;
};

/* ================================================================= */
/* IPX                                                               */
/* ================================================================= */

#define IPX_SOCKET_NCP			0x0451
#define IPX_SOCKET_SAP			0x0452
#define IPX_SOCKET_IPXRIP		0x0453
#define IPX_SOCKET_NETBIOS		0x0455
#define IPX_SOCKET_DIAGNOSTIC		0x0456
#define IPX_SOCKET_SERIALIZATION	0x0457
#define IPX_SOCKET_NWLINK_SMB_NAMEQUERY	0x0551
#define IPX_SOCKET_NWLINK_SMB_DGRAM	0x0553
#define IPX_SOCKET_NWLINK_SMB_BROWSE	0x0555 /* ? not sure on this
	but I guessed based on the content of the packet I saw */
#define IPX_SOCKET_ATTACHMATE_GW	0x055d
#define IPX_SOCKET_IPX_MESSAGE		0x4001
#define IPX_SOCKET_ADSM                 0x8522 /* www.tivoli.com */
#define IPX_SOCKET_SNMP_AGENT           0x900F /* RFC 1906 */
#define IPX_SOCKET_SNMP_SINK            0x9010 /* RFC 1906 */
#define IPX_SOCKET_TCP_TUNNEL           0x9091 /* RFC 1791 */
#define IPX_SOCKET_UDP_TUNNEL           0x9092 /* RFC 1791 */

static struct port_info	ports[] = {
	{ IPX_SOCKET_NCP,			dissect_ncp,
				"NCP" },
	{ IPX_SOCKET_SAP,			dissect_ipxsap,
				"SAP" },
	{ IPX_SOCKET_IPXRIP,			dissect_ipxrip,
				"RIP" },
	{ IPX_SOCKET_NETBIOS,			NULL,
				"NetBIOS" },
	{ IPX_SOCKET_DIAGNOSTIC,		NULL,
				"Diagnostic" },
	{ IPX_SOCKET_SERIALIZATION,		NULL,
				"Serialization" },
	{ IPX_SOCKET_NWLINK_SMB_NAMEQUERY,	NULL,
				"NWLink SMB Name Query" },
	{ IPX_SOCKET_NWLINK_SMB_DGRAM,		dissect_nwlink_dg,
				"NWLink SMB Datagram" },
	{ IPX_SOCKET_NWLINK_SMB_BROWSE,	NULL,
				"NWLink SMB Browse" },
	{ IPX_SOCKET_ATTACHMATE_GW,		NULL,
				"Attachmate Gateway" },
	{ IPX_SOCKET_IPX_MESSAGE,		NULL,
				"IPX Message" },
	{ IPX_SOCKET_SNMP_AGENT, NULL, "SNMP Agent" },
	{ IPX_SOCKET_SNMP_SINK,	NULL, "SNMP Sink" },
	{ IPX_SOCKET_UDP_TUNNEL, NULL, "UDP Tunnel" },
	{ IPX_SOCKET_TCP_TUNNEL, NULL, "TCP Tunnel" },
	{ IPX_SOCKET_TCP_TUNNEL, NULL, "TCP Tunnel" },
	{ IPX_SOCKET_ADSM, NULL, "ADSM" },
	{ 0x0000,				NULL,
				NULL }
};

static char*
port_text(guint16 port) {
	int i=0;

	while (ports[i].text != NULL) {
		if (ports[i].port == port) {
			return ports[i].text;
		}
		i++;
	}
	return "Unknown";
}

static dissect_func_t*
port_func(guint16 port) {
	int i=0;

	while (ports[i].text != NULL) {
		if (ports[i].port == port) {
			return ports[i].func;
		}
		i++;
	}
	return NULL;
}

/*
 * From:
 *
 *	http://alr.base2co.com:457/netguide/dipxD.ipx_packet_struct.html
 *
 * which is part of SCO's "Network Programmer's Guide and Reference".
 *
 * It calls type 20 "NetBIOS name packet".  Microsoft Network Monitor
 * calls it "WAN Broadcast"; it's also used for SMB browser announcements,
 * i.e. NetBIOS (broadcast) datagrams.
 */
#define IPX_PACKET_TYPE_IPX		0
#define IPX_PACKET_TYPE_RIP		1
#define	IPX_PACKET_TYPE_ECHO		2
#define	IPX_PACKET_TYPE_ERROR		3
#define IPX_PACKET_TYPE_PEP		4
#define IPX_PACKET_TYPE_SPX		5
#define IPX_PACKET_TYPE_NCP		17
#define IPX_PACKET_TYPE_WANBCAST	20	/* propagated NetBIOS packet? */

static const value_string ipx_packet_type_vals[] = {
	{ IPX_PACKET_TYPE_IPX,		"IPX" },
	{ IPX_PACKET_TYPE_RIP,		"RIP" },
	{ IPX_PACKET_TYPE_ECHO,		"Echo" },
	{ IPX_PACKET_TYPE_ERROR,	"Error" },
	{ IPX_PACKET_TYPE_PEP,		"PEP" }, /* Packet Exchange Packet */
	{ IPX_PACKET_TYPE_SPX,		"SPX" },
	{ 16,				"Experimental Protocol" },
	{ IPX_PACKET_TYPE_NCP,		"NCP" },
	{ 18,				"Experimental Protocol" },
	{ 19,				"Experimental Protocol" },
	{ IPX_PACKET_TYPE_WANBCAST,	"NetBIOS Broadcast" },
	{ 21,				"Experimental Protocol" },
	{ 22,				"Experimental Protocol" },
	{ 23,				"Experimental Protocol" },
	{ 24,				"Experimental Protocol" },
	{ 25,				"Experimental Protocol" },
	{ 26,				"Experimental Protocol" },
	{ 27,				"Experimental Protocol" },
	{ 28,				"Experimental Protocol" },
	{ 29,				"Experimental Protocol" },
	{ 30,				"Experimental Protocol" },
	{ 31,				"Experimental Protocol" },
	{ 0,				NULL }
};

gchar*
ipxnet_to_string(const guint8 *ad)
{
	guint32	addr = pntohl(ad);
	return ipxnet_to_str_punct(addr, ' ');
}

/* We use a different representation of hardware addresses
 * than ether_to_str(); we don't put punctuation between the hex
 * digits.
 */

gchar*
ipx_addr_to_str(guint32 net, const guint8 *ad)
{
	static gchar	str[3][8+1+MAXNAMELEN+1]; /* 8 digits, 1 period, NAME, 1 null */
	static gchar	*cur;
	char		*name;

	if (cur == &str[0][0]) {
		cur = &str[1][0];
	} else if (cur == &str[1][0]) {
		cur = &str[2][0];
	} else {
		cur = &str[0][0];
	}

	name = get_ether_name_if_known(ad);

	if (name) {
		sprintf(cur, "%s.%s", get_ipxnet_name(net), name);
	}
	else {
		sprintf(cur, "%s.%s", get_ipxnet_name(net), ether_to_str_punct(ad, '\0'));
	}
	return cur;
}

gchar *
ipxnet_to_str_punct(const guint32 ad, char punct) {
  static gchar  str[3][12];
  static gchar *cur;
  gchar        *p;
  int          i;
  guint32      octet;
  static const gchar hex_digits[16] = "0123456789ABCDEF";
  static const guint32  octet_mask[4] =
	  { 0xff000000 , 0x00ff0000, 0x0000ff00, 0x000000ff };

  if (cur == &str[0][0]) {
    cur = &str[1][0];
  } else if (cur == &str[1][0]) {  
    cur = &str[2][0];
  } else {  
    cur = &str[0][0];
  }
  p = &cur[12];
  *--p = '\0';
  i = 3;
  for (;;) {
    octet = (ad & octet_mask[i]) >> ((3 - i) * 8);
    *--p = hex_digits[octet&0xF];
    octet >>= 4;
    *--p = hex_digits[octet&0xF];
    if (i == 0)
      break;
    if (punct)
      *--p = punct;
    i--;
  }
  return p;
}

void
dissect_ipx(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {

	proto_tree	*ipx_tree;
	proto_item	*ti;
	guint8		ipx_type, ipx_hops;
	guint16		ipx_checksum, ipx_length;
	int		len;
	guint8		*ipx_snode, *ipx_dnode, *ipx_snet, *ipx_dnet;

	guint16		ipx_dsocket, ipx_ssocket;
	dissect_func_t	*dissect;
	guint32		ipx_dnet_val, ipx_snet_val;

	/* Calculate here for use in pinfo and in tree */
	ipx_dnet = (guint8*)&pd[offset+6];
	ipx_snet = (guint8*)&pd[offset+18];
	ipx_dnet_val = pntohl(ipx_dnet);
	ipx_snet_val = pntohl(ipx_snet);
	ipx_dsocket = pntohs(&pd[offset+16]);
	ipx_ssocket = pntohs(&pd[offset+28]);
	ipx_dnode = (guint8*)&pd[offset+10];
	ipx_snode = (guint8*)&pd[offset+22];
	ipx_type = pd[offset+5];
	ipx_length = pntohs(&pd[offset+2]);

	/* Length of IPX datagram plus headers above it. */
	len = ipx_length + offset;

	/* Set the payload and captured-payload lengths to the minima of
	   (the IPX length plus the length of the headers above it) and
	   the frame lengths. */
	if (pi.len > len)
		pi.len = len;
	if (pi.captured_len > len)
		pi.captured_len = len;

	SET_ADDRESS(&pi.net_src, AT_IPX, 10, &pd[offset+18]);
	SET_ADDRESS(&pi.src, AT_IPX, 10, &pd[offset+18]);
	SET_ADDRESS(&pi.net_dst, AT_IPX, 10, &pd[offset+6]);
	SET_ADDRESS(&pi.dst, AT_IPX, 10, &pd[offset+6]);

	if (check_col(fd, COL_PROTOCOL))
		col_add_str(fd, COL_PROTOCOL, "IPX");
	if (check_col(fd, COL_INFO))
		col_add_fstr(fd, COL_INFO, "%s (0x%04X)", port_text(ipx_dsocket),
				ipx_dsocket);

	if (tree) {
		ipx_checksum = pntohs(&pd[offset]);
		ipx_hops = pd[offset+4];

		ti = proto_tree_add_item(tree, proto_ipx, offset, 30, NULL);
		ipx_tree = proto_item_add_subtree(ti, ett_ipx);
		proto_tree_add_item(ipx_tree, hf_ipx_checksum, offset, 2, ipx_checksum);
		proto_tree_add_item_format(ipx_tree, hf_ipx_len, offset+2, 2, ipx_length,
			"Length: %d bytes", ipx_length);
		proto_tree_add_item_format(ipx_tree, hf_ipx_hops, offset+4, 1, ipx_hops,
			"Transport Control: %d hops", ipx_hops);
		proto_tree_add_item(ipx_tree, hf_ipx_packet_type, offset+5, 1, ipx_type);
		proto_tree_add_item(ipx_tree, hf_ipx_dnet, offset+6, 4, ipx_dnet_val);
		proto_tree_add_item(ipx_tree, hf_ipx_dnode, offset+10, 6, ipx_dnode);
		proto_tree_add_item_format(ipx_tree, hf_ipx_dsocket, offset+16, 2,
			ipx_dsocket, "Destination Socket: %s (0x%04X)",
			port_text(ipx_dsocket), ipx_dsocket);
		proto_tree_add_item(ipx_tree, hf_ipx_snet, offset+18, 4, ipx_snet_val);
		proto_tree_add_item(ipx_tree, hf_ipx_snode, offset+22, 6, ipx_snode);
		proto_tree_add_item_format(ipx_tree, hf_ipx_ssocket, offset+28, 2,
			ipx_ssocket, "Source Socket: %s (0x%04X)", port_text(ipx_ssocket),
			ipx_ssocket);
	}
	offset += 30;

	switch (ipx_type) {
		case IPX_PACKET_TYPE_SPX:
			dissect_spx(pd, offset, fd, tree);
			break;

		case IPX_PACKET_TYPE_NCP:
			/* Is the destination node 00:00:00:00:00:01 ? */
			if (pntohl(ipx_dnode) == 0 && pntohs(ipx_dnode + 4) == 1)
				nw_server_address = pntohl(ipx_dnet);

			/* Is the source node 00:00:00:00:00:01 ? */
			else if (pntohl(ipx_snode) == 0 && pntohs(ipx_snode + 4) == 1)
				nw_server_address = pntohl(ipx_snet);
			else
				nw_server_address = 0;

			dissect_ncp(pd, offset, fd, tree);
			break;

		case IPX_PACKET_TYPE_WANBCAST:
		case IPX_PACKET_TYPE_PEP:
			if (ipx_dsocket == IPX_SOCKET_NETBIOS) {
				dissect_nbipx(pd, offset, fd, tree);
				break;
			}
			/* else fall through */

		case 0: /* IPX, fall through to default */
			/* XXX - should type 0's be dissected as NBIPX
			   if they're aimed at the NetBIOS socket? */
		default:
			dissect = port_func(ipx_dsocket);
			if (dissect) {
				dissect(pd, offset, fd, tree);
			}
			else {
				dissect = port_func(ipx_ssocket);
				if (dissect) {
					dissect(pd, offset, fd, tree);
				}
				else {
					dissect_data(pd, offset, fd, tree);
				}
			}
			break;
	}
}


/* ================================================================= */
/* SPX                                                               */
/* ================================================================= */
static char*
spx_conn_ctrl(u_char ctrl)
{
	int i=0;

	static struct conn_info	conns[] = {
		{ 0x10, "End-of-Message" },
		{ 0x20, "Attention" },
		{ 0x40, "Acknowledgment Required"},
		{ 0x80, "System Packet"},
		{ 0x00, NULL }
	};

	while (conns[i].text != NULL) {
		if (conns[i].ctrl == ctrl) {
			return conns[i].text;
		}
		i++;
	}
	return "Unknown";
}

static char*
spx_datastream(u_char type)
{
	switch (type) {
		case 0xfe:
			return "End-of-Connection";
		case 0xff:
			return "End-of-Connection Acknowledgment";
		default:
			return "Client-Defined";
	}
}

static void
dissect_spx(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
	proto_tree	*spx_tree;
	proto_item	*ti;

	if (check_col(fd, COL_PROTOCOL))
		col_add_str(fd, COL_PROTOCOL, "SPX");
	if (check_col(fd, COL_INFO))
		col_add_str(fd, COL_INFO, "SPX");

	if (tree) {
		ti = proto_tree_add_item(tree, proto_spx, offset, 12, NULL);
		spx_tree = proto_item_add_subtree(ti, ett_spx);

		proto_tree_add_item_format(spx_tree, hf_spx_connection_control,
					   offset,      1,
					   pd[offset],
					   "Connection Control: %s (0x%02X)",
					   spx_conn_ctrl(pd[offset]), 
					   pd[offset]);

		proto_tree_add_item_format(spx_tree, hf_spx_datastream_type,
					   offset+1,     1,
					   pd[offset+1],
					   "Datastream Type: %s (0x%02X)",
					   spx_datastream(pd[offset+1]), 
					   pd[offset+1]);

		proto_tree_add_item(spx_tree, hf_spx_src_id, 
				    offset+2,     2,
				    pntohs( &pd[offset+2] ));

		proto_tree_add_item(spx_tree, hf_spx_dst_id,
				    offset+4,     2,
				    pntohs( &pd[offset+4] ));

		proto_tree_add_item(spx_tree, hf_spx_seq_nr, 
				    offset+6,     2,
				    pntohs( &pd[offset+6] ) );

		proto_tree_add_item(spx_tree, hf_spx_ack_nr,
				    offset+8,     2,
				    pntohs( &pd[offset+8] ) );

		proto_tree_add_item(spx_tree, hf_spx_all_nr,
				    offset+10,     2,
				    pntohs( &pd[offset+10] ) );

		offset += 12;
		dissect_data(pd, offset, fd, tree);
	}
}

/* ================================================================= */
/* IPX RIP                                                           */
/* ================================================================= */
static void
dissect_ipxrip(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
	proto_tree	*rip_tree;
	proto_item	*ti;
	guint16		operation;
	struct ipx_rt_def route;
	int		cursor;

	char		*rip_type[2] = { "Request", "Response" };

	operation = pntohs(&pd[offset]) - 1;

	if (check_col(fd, COL_PROTOCOL))
	 col_add_str(fd, COL_PROTOCOL, "IPX RIP");
	if (check_col(fd, COL_PROTOCOL)) {
	 if (operation < 2) {
		 col_add_str(fd, COL_INFO, rip_type[operation]);
	 }
	 else {
		 col_add_str(fd, COL_INFO, "Unknown Packet Type");
	 }
	}

	if (tree) {
		ti = proto_tree_add_item(tree, proto_ipxrip, offset, END_OF_FRAME, NULL);
		rip_tree = proto_item_add_subtree(ti, ett_ipxrip);

		if (operation < 2) {
			proto_tree_add_text(rip_tree, offset, 2,
			"RIP packet type: %s", rip_type[operation]);

			if (operation == 0) {
			  proto_tree_add_item_hidden(rip_tree, 
						     hf_ipxrip_request, 
						     offset, 2, 1);
			} else {
			  proto_tree_add_item_hidden(rip_tree, 
						     hf_ipxrip_response, 
						     offset, 2, 1);
			}

		}
		else {
			proto_tree_add_text(rip_tree, offset, 2, "Unknown RIP packet type");
		}

		for (cursor = offset + 2; cursor < fd->cap_len; cursor += 8) {
			memcpy(&route.network, &pd[cursor], 4);
			route.hops = pntohs(&pd[cursor+4]);
			route.ticks = pntohs(&pd[cursor+6]);

			if (operation == IPX_RIP_REQUEST - 1) {
				proto_tree_add_text(rip_tree, cursor,      8,
					"Route Vector: %s, %d hop%s, %d tick%s",
					ipxnet_to_string((guint8*)&route.network),
					route.hops,  route.hops  == 1 ? "" : "s",
					route.ticks, route.ticks == 1 ? "" : "s");
			}
			else {
				proto_tree_add_text(rip_tree, cursor,      8,
					"Route Vector: %s, %d hop%s, %d tick%s (%d ms)",
					ipxnet_to_string((guint8*)&route.network),
					route.hops,  route.hops  == 1 ? "" : "s",
					route.ticks, route.ticks == 1 ? "" : "s",
					route.ticks * 1000 / 18);
			}
		}
	}
}



/* ================================================================= */
/* SAP																 */
/* ================================================================= */
static char*
server_type(guint16 type)
{
	int i=0;

	/* some of these are from ncpfs, others are from the book */
	static struct server_info	servers[] = {
		{ 0x0001,	"User" },
		{ 0x0002,	"User Group" },
		{ 0x0003,	"Print Queue" },
		{ 0x0004,	"File server" },
		{ 0x0005,	"Job server" },
		{ 0x0007,	"Print server" },
		{ 0x0008,	"Archive server" },
		{ 0x0009,	"Archive server" },
		{ 0x000a,	"Job queue" },
		{ 0x000b,	"Administration" },
		{ 0x0021,	"NAS SNA gateway" },
		{ 0x0024,	"Remote bridge" },
		{ 0x0026,	"Bridge server" },
		{ 0x0027,	"TCP/IP gateway" },
		{ 0x002d,	"Time Synchronization VAP" },
		{ 0x002e,	"Archive Server Dynamic SAP" },
		{ 0x0047,	"Advertising print server" },
		{ 0x004b,	"Btrieve VAP 5.0" },
		{ 0x004c,	"SQL VAP" },
		{ 0x0050,	"Btrieve VAP" },
		{ 0x0053,	"Print Queue VAP" },
		{ 0x007a,	"TES NetWare for VMS" },
		{ 0x0098,	"NetWare access server" },
		{ 0x009a,	"Named Pipes server" },
		{ 0x009e,	"Portable NetWare Unix" },
		{ 0x0107,	"NetWare 386" },
		{ 0x0111,	"Test server" },
		{ 0x0133,	"NetWare Name Service" },
		{ 0x0166,	"NetWare management" },
		{ 0x023f,	"SMS Testing and Development" },
		{ 0x026a,	"NetWare management" },
		{ 0x026b,	"Time synchronization" },
		{ 0x027b,	"NetWare Management Agent" },
		{ 0x0278,	"NetWare Directory server" },
		{ 0x030c,	"HP LaserJet / Quick Silver" },
		{ 0x0355,	"Arcada Software" },
		{ 0x0361,	"NETINELO" },
		{ 0x037e,	"Powerchute UPS Monitoring" },
		{ 0x03e1,	"UnixWare Application Server" },
		{ 0x044c,	"Archive" },
		{ 0x055d,	"Attachmate SNA gateway" },
		{ 0x0610,	"Adaptec SCSI Management" },
		{ 0x0640,	"NT Server-RPC/GW for NW/Win95 User Level Sec" },
		{ 0x064e,	"NT Server-IIS" },
		{ 0x0810,	"ELAN License Server Demo" },
		{ 0x8002,	"Intel NetPort Print Server" },

/* For any unidentified ones, I found a really big list of them at: */
/*    http://www.inpnet.org/cnpweb/saplist.txt */
/*    http://www.isi.edu/in-notes/iana/assignments/novell-sap-numbers */

		{ 0x0000,	NULL }
	};

	while (servers[i].text != NULL) {
		if (servers[i].type == type) {
			return servers[i].text;
		}
		i++;
	}
	return "Unknown";
}

static void
dissect_ipxsap(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {

	proto_tree	*sap_tree, *s_tree;
	proto_item	*ti;
	int		cursor;
	struct sap_query query;
	struct sap_server_ident server;

	char		*sap_type[4] = { "General Query", "General Response",
		"Nearest Query", "Nearest Response" };

	query.query_type = pntohs(&pd[offset]);
	query.server_type = pntohs(&pd[offset+2]);

	if (check_col(fd, COL_PROTOCOL))
		col_add_str(fd, COL_PROTOCOL, "SAP");
	if (check_col(fd, COL_INFO)) {
		if (query.query_type >= 1 && query.query_type <= 4) {
			col_add_str(fd, COL_INFO, sap_type[query.query_type - 1]);
		}
		else {
			col_add_str(fd, COL_INFO, "Unknown Packet Type");
		}
	}

	if (tree) {
		ti = proto_tree_add_item(tree, proto_sap, offset, END_OF_FRAME, NULL);
		sap_tree = proto_item_add_subtree(ti, ett_ipxsap);

		if (query.query_type >= 1 && query.query_type <= 4) {
			proto_tree_add_text(sap_tree, offset, 2, sap_type[query.query_type - 1]);
			if ((query.query_type - 1) % 2) {
			  proto_tree_add_item_hidden(sap_tree, 
						     hf_sap_response, 
						     offset, 2, 1);
			} else {
			  proto_tree_add_item_hidden(sap_tree, 
						     hf_sap_request, 
						     offset, 2, 1);
			}
		}
		else {
			proto_tree_add_text(sap_tree, offset, 2,
					"Unknown SAP Packet Type %d", query.query_type);
		}

		if (query.query_type == IPX_SAP_GENERAL_RESPONSE ||
				query.query_type == IPX_SAP_NEAREST_RESPONSE) { /* responses */

			for (cursor = offset + 2; (cursor + 64) <= fd->cap_len; cursor += 64) {
				server.server_type = pntohs(&pd[cursor]);
				memcpy(server.server_name, &pd[cursor+2], 48);
				memcpy(&server.server_network, &pd[cursor+50], 4);
				memcpy(&server.server_node, &pd[cursor+54], 6);
				server.server_port = pntohs(&pd[cursor+60]);
				server.intermediate_network = pntohs(&pd[cursor+62]);

				ti = proto_tree_add_text(sap_tree, cursor+2, 48,
					"Server Name: %s", server.server_name);
				s_tree = proto_item_add_subtree(ti, ett_ipxsap_server);

				proto_tree_add_text(s_tree, cursor, 2, "Server Type: %s (0x%04X)",
						server_type(server.server_type), server.server_type);
				proto_tree_add_text(s_tree, cursor+50, 4, "Network: %s",
						ipxnet_to_string((guint8*)&pd[cursor+50]));
				proto_tree_add_text(s_tree, cursor+54, 6, "Node: %s",
						ether_to_str((guint8*)&pd[cursor+54]));
				proto_tree_add_text(s_tree, cursor+60, 2, "Socket: %s (0x%04X)",
						port_text(server.server_port), server.server_port);
				proto_tree_add_text(s_tree, cursor+62, 2,
						"Intermediate Networks: %d",
						server.intermediate_network);
			}
		}
		else {  /* queries */
			proto_tree_add_text(sap_tree, offset+2, 2, "Server Type: %s (0x%04X)",
					server_type(query.server_type), query.server_type);
		}
	}
}


void
proto_register_ipx(void)
{
	static hf_register_info hf_ipx[] = {
		{ &hf_ipx_checksum,
		{ "Checksum",		"ipx.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
			"" }},

		{ &hf_ipx_len,
		{ "Length",		"ipx.len", FT_UINT16, BASE_DEC, NULL, 0x0,
			"" }},

		{ &hf_ipx_hops,
		{ "Transport Control (Hops)", "ipx.hops", FT_UINT8, BASE_DEC, NULL, 0x0,
			"" }},

		{ &hf_ipx_packet_type,
		{ "Packet Type",	"ipx.packet_type", FT_UINT8, BASE_HEX, VALS(ipx_packet_type_vals),
			0x0,
			"" }},

		{ &hf_ipx_dnet,
		{ "Destination Network","ipx.dst.net", FT_IPXNET, BASE_NONE, NULL, 0x0,
			"" }},

		{ &hf_ipx_dnode,
		{ "Destination Node",	"ipx.dst.node", FT_ETHER, BASE_NONE, NULL, 0x0,
			"" }},

		{ &hf_ipx_dsocket,
		{ "Destination Socket",	"ipx.dst.socket", FT_UINT16, BASE_HEX, NULL, 0x0,
			"" }},

		{ &hf_ipx_snet,
		{ "Source Network","ipx.src.net", FT_IPXNET, BASE_NONE, NULL, 0x0,
			"" }},

		{ &hf_ipx_snode,
		{ "Source Node",	"ipx.src.node", FT_ETHER, BASE_NONE, NULL, 0x0,
			"" }},

		{ &hf_ipx_ssocket,
		{ "Source Socket",	"ipx.src.socket", FT_UINT16, BASE_HEX, NULL, 0x0,
			"" }},
	};

	static hf_register_info hf_spx[] = {
		{ &hf_spx_connection_control,
		{ "Connection Control",		"spx.ctl", 
		  FT_UINT8,	BASE_HEX,	NULL,	0x0,
		  "" }},

		{ &hf_spx_datastream_type,
		{ "Datastream type",	       	"spx.type", 
		  FT_UINT8,	BASE_HEX,	NULL,	0x0,
		  "" }},

		{ &hf_spx_src_id,
		{ "Source Connection ID",	"spx.src", 
		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
		  "" }},

		{ &hf_spx_dst_id,
		{ "Destination Connection ID",	"spx.dst", 
		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
		  "" }},

		{ &hf_spx_seq_nr,
		{ "Sequence Number",		"spx.seq", 
		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
		  "" }},

		{ &hf_spx_ack_nr,
		{ "Acknowledgment Number",	"spx.ack", 
		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
		  "" }},

		{ &hf_spx_all_nr,
		{ "Allocation Number",		"spx.alloc", 
		  FT_UINT16,	BASE_DEC,	NULL,	0x0,
		  "" }}
	};

	static hf_register_info hf_ipxrip[] = {
		{ &hf_ipxrip_request,
		{ "Request",			"ipxrip.request", 
		  FT_BOOLEAN,	BASE_NONE,	NULL,	0x0,
		  "TRUE if IPX RIP request" }},

		{ &hf_ipxrip_response,
		{ "Response",			"ipxrip.response", 
		  FT_BOOLEAN,	BASE_NONE,	NULL,	0x0,
		  "TRUE if IPX RIP response" }}
	};

	static hf_register_info hf_sap[] = {
		{ &hf_sap_request,
		{ "Request",			"sap.request", 
		  FT_BOOLEAN,	BASE_NONE,	NULL,	0x0,
		  "TRUE if SAP request" }},

		{ &hf_sap_response,
		{ "Response",			"sap.response", 
		  FT_BOOLEAN,	BASE_NONE,	NULL,	0x0,
		  "TRUE if SAP response" }}
	};
	static gint *ett[] = {
		&ett_ipx,
		&ett_spx,
		&ett_ipxrip,
		&ett_ipxsap,
		&ett_ipxsap_server,
	};

	proto_ipx = proto_register_protocol ("Internetwork Packet eXchange", "ipx");
	proto_register_field_array(proto_ipx, hf_ipx, array_length(hf_ipx));

	proto_spx = proto_register_protocol ("Sequenced Packet eXchange", "spx");
	proto_register_field_array(proto_spx, hf_spx, array_length(hf_spx));

	proto_ipxrip = proto_register_protocol ("IPX Routing Information Protocol", "ipxrip");
	proto_register_field_array(proto_ipxrip, hf_ipxrip, array_length(hf_ipxrip));

	proto_sap = proto_register_protocol ("Service Advertisement Protocol", "sap");
	proto_register_field_array(proto_sap, hf_sap, array_length(hf_sap));

	proto_register_subtree_array(ett, array_length(ett));
}