/* packet-9P.c
 * Routines for 9P dissection
 * Copyright 2005, Nils O. Selaasdal
 *
 * $Id: packet-9p.c 32367 2010-04-03 21:55:23Z wmeier $
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * File permission bits decoding taken from packet-nfs.c
 *
 * 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

#include <stdlib.h>
#include <string.h>

#include <glib.h>

#include <epan/packet.h>
#include <epan/strutil.h>

#define NINEPORT 564

/*Message types for 9P */
/*See man 5 intro on Plan 9 - or;
	http://www.cs.bell-labs.com/sys/man/5/INDEX.html
*/
enum {
	TVERSION	= 100,
	RVERSION	= 101,
	TAUTH 		= 102,
	RAUTH 		= 103,
	TATTACH		= 104,
	RATTACH		= 105,
	TERROR		= 106,	/* Not used */
	RERROR		= 107,
	TFLUSH		= 108,
	RFLUSH		= 109,
	TWALK		= 110,
	RWALK		= 111,
	TOPEN = 112,
	ROPEN,
	TCREATE = 114,
	RCREATE,
	TREAD = 116,
	RREAD,
	TWRITE = 118,
	RWRITE,
	TCLUNK = 120,
	RCLUNK,
	TREMOVE = 122,
	RREMOVE,
	TSTAT = 124,
	RSTAT,
	TWSTAT = 126,
	RWSTAT
};
/* File open modes */
#define P9_OREAD 	   0x0 
#define P9_OWRITE 	   0x1 
#define P9_ORDWR  	   0x2 
#define P9_OEXEC	   0x3
#define P9_MODEMASK	   0x3 
#define P9_OTRUNC	  0x10 
#define P9_ORCLOSE	  0x40 

/* stat mode flags */
#define DMDIR		0x80000000 /* Directory */
#define DMAPPEND	0x40000000 /* Append only */
#define DMEXCL		0x20000000 /* Exclusive use */
#define DMMOUNT		0x10000000 /* Mounted channel */
#define DMAUTH		0x08000000 /* Authentication */
#define DMTMP		0x04000000 /* Temporary */

#define QTDIR		0x80	/* Directory */
#define QTAPPEND	0x40	/* Append only */
#define QTEXCL		0x20	/* Exclusive use */
#define QTMOUNT		0x10	/* Mounted channel */
#define QTAUTH		0x08	/* Authentication */
#define QTTMP		0x04	/* Temporary */
#define QTFILE		0x00	/* plain file ?? */

/* Initialize the protocol and registered fields */
static int proto_9P = -1;
static int hf_9P_msgsz = -1;
static int hf_9P_msgtype = -1;
static int hf_9P_tag = -1;
static int hf_9P_oldtag = -1;
static int hf_9P_parmsz = -1;
static int hf_9P_maxsize = -1;
static int hf_9P_fid = -1;
static int hf_9P_nqid = -1;
static int hf_9P_mode = -1;
static int hf_9P_mode_rwx = -1;
static int hf_9P_mode_t = -1;
static int hf_9P_mode_c = -1;
static int hf_9P_iounit = -1;
static int hf_9P_count = -1;
static int hf_9P_offset = -1;
static int hf_9P_perm = -1;
static int hf_9P_qidtype = -1;
static int hf_9P_qidvers = -1;
static int hf_9P_qidpath = -1;
static int hf_9P_stattype = -1;
static int hf_9P_statmode = -1;
static int hf_9P_atime = -1;
static int hf_9P_mtime = -1;
static int hf_9P_length = -1;
static int hf_9P_dev = -1;
static int hf_9P_wname = -1;
static int hf_9P_version = -1;
static int hf_9P_afid = -1;
static int hf_9P_uname = -1;
static int hf_9P_aname = -1;
static int hf_9P_ename = -1;
static int hf_9P_name = -1;
static int hf_9P_filename = -1;
static int hf_9P_sdlen = -1;
static int hf_9P_uid = -1;
static int hf_9P_gid = -1;
static int hf_9P_muid = -1;
static int hf_9P_nwalk = -1;
static int hf_9P_newfid = -1;

/*handle for dissecting data in 9P msgs*/
static dissector_handle_t data_handle;

/* subtree pointers */
static gint ett_9P = -1;
static gint ett_9P_omode = -1;
static gint ett_9P_dm = -1;
static gint ett_9P_wname = -1;
static gint ett_9P_aname = -1;
static gint ett_9P_ename = -1;
static gint ett_9P_uname = -1;
static gint ett_9P_uid = -1;
static gint ett_9P_gid = -1;
static gint ett_9P_muid = -1;
static gint ett_9P_filename = -1;
static gint ett_9P_version = -1;
static gint ett_9P_qid = -1;
static gint ett_9P_qidtype = -1;

/*9P Msg types to name mapping */
static const value_string ninep_msg_type[] = 
{	{TVERSION,	"Tversion"},
	{RVERSION,	"Rversion"},
	{TAUTH,		"Tauth"},
	{RAUTH,		"Rauth"},
	{TATTACH,	"Tattach"},
	{RATTACH,	"Rattach"},
	{RERROR,	"Rerror"},
	{TFLUSH,	"Tflush"},
	{RFLUSH,	"Rflush"},
	{TWALK, 	"Twalk"},
	{RWALK,		"Rwalk"},
	{TOPEN, 	"Topen"},
	{ROPEN,		"Ropen"},
	{TCREATE, 	"Tcreate"},
	{RCREATE,	"Rcreate"},
	{TREAD,		"Tread"},
	{RREAD,		"Rread"},
	{TWRITE, 	"Twrite"},
	{RWRITE,	"Rwrite"},
	{TCLUNK, 	"Tclunk"},
	{RCLUNK,	"Rclunk"},
	{TREMOVE, 	"Tremove"},
	{RREMOVE,	"Rremove"},
	{TSTAT,		"Tstat"},
	{RSTAT,		"Rstat"},
	{TWSTAT,	"Twstat"},
	{RWSTAT,	"Rwstat"},
	{0,		NULL},
};
/* Open/Create modes */
static const value_string ninep_mode_vals[] = 
{
	{P9_OREAD,	"Read Access"},
	{P9_OWRITE,	"Write Access"},
	{P9_ORDWR,	"Read/Write Access "},
	{P9_OEXEC,	"Execute Access"},
	{0,		NULL}
};

static void dissect_9P_mode(tvbuff_t * tvb,  proto_item * tree,int offset);
static void dissect_9P_dm(tvbuff_t * tvb,  proto_item * tree,int offset,int iscreate);
static void dissect_9P_qid(tvbuff_t * tvb,  proto_tree * tree,int offset);

/* Dissect 9P messages*/
static void dissect_9P(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
{
	guint32 ninesz,tmp,i;
	guint16 tmp16;
	guint8 ninemsg;
	guint offset = 0;
	const char *mname;
	gint len,reportedlen;
	tvbuff_t *next_tvb;
	proto_item *ti;
	proto_tree *ninep_tree,*tmp_tree;
	nstime_t tv;

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "9P");
	col_clear(pinfo->cinfo, COL_INFO);

	ninesz = tvb_get_letohl(tvb, offset);
	ninemsg = tvb_get_guint8(tvb, offset + 4);

	mname = val_to_str(ninemsg, ninep_msg_type,"Unknown");
	
	if(strcmp(mname,"Unknown") == 0) {
		col_add_fstr(pinfo->cinfo, COL_INFO, "9P Data Continuation(?) (Tag %u)",(guint)ninemsg);

		return;
	}

	col_append_fstr(pinfo->cinfo, COL_INFO, "%s Tag=%u",mname,(guint)tvb_get_letohs(tvb,offset+5));

	if (!tree) /*not much more of one line summary interrest yet.. */
		return;

	ti = proto_tree_add_item(tree, proto_9P, tvb, 0, -1, FALSE);
	ninep_tree = proto_item_add_subtree(ti, ett_9P);
	proto_tree_add_item(ninep_tree, hf_9P_msgsz, tvb, offset, 4, TRUE);
	offset+=4;

	proto_tree_add_item(ninep_tree, hf_9P_msgtype, tvb, offset, 1, TRUE);
	++offset;
	proto_tree_add_item(ninep_tree, hf_9P_tag, tvb, offset, 2, TRUE);
	offset += 2;

	switch(ninemsg) {
	case RVERSION:
	case TVERSION:
		proto_tree_add_item(ninep_tree, hf_9P_maxsize, tvb, offset, 4, TRUE);
		offset +=4;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_version, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_version);	
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += 2;
		break;
	case TAUTH:
		proto_tree_add_item(ninep_tree, hf_9P_afid, tvb, offset, 4, TRUE);
		offset +=4;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_uname, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_uname);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_aname, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_aname);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset +=2;
		break;
	case RAUTH:
		dissect_9P_qid(tvb,ninep_tree,offset);
		offset += 13;
		break;
	case RERROR:
		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_ename, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_ename);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset +=2;

		break;
	case TFLUSH:
		proto_tree_add_item(ninep_tree, hf_9P_oldtag, tvb, offset, 2, TRUE);
		break;
	case RFLUSH:
		break;
	case TATTACH:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		offset +=4;

		proto_tree_add_item(ninep_tree, hf_9P_afid, tvb, offset, 4, TRUE);
		offset +=4;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_uname, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_uname);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16 + 2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_aname, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_aname);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;
		break;
	case RATTACH:
		dissect_9P_qid(tvb,ninep_tree,offset);
		offset += 13;
		break;
	case TWALK:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		offset +=4;

		proto_tree_add_item(ninep_tree, hf_9P_newfid, tvb, offset, 4, TRUE);
		offset +=4;
		
		tmp16 = tvb_get_letohs(tvb,offset);
		proto_tree_add_item(ninep_tree, hf_9P_nwalk, tvb, offset, 2, TRUE);
		offset +=2;
		/* I can't imagine anyone having a directory depth more than 25,
		   Limit to 10 times that to be sure, 2^16 is too much */
		if(tmp16 > 250) {
			tmp16 = 250;
			tmp_tree = proto_tree_add_text(ninep_tree, tvb, 0, 0, "Only first 250 items shown");
    			PROTO_ITEM_SET_GENERATED(tmp_tree);
		}

		for(i = 0 ; i < tmp16; i++) {
			guint16 tmplen;
			proto_item *wname;
			proto_tree *wname_tree;
			
			tmplen = tvb_get_letohs(tvb,offset);
			wname = proto_tree_add_item(ninep_tree, hf_9P_wname, tvb, offset+2, tmplen, TRUE);
			wname_tree = proto_item_add_subtree(wname,ett_9P_wname);
			proto_tree_add_item(wname_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);

			offset += tmplen + 2;
		}

		break;
	case RWALK:
		tmp16 = tvb_get_letohs(tvb,offset);
		proto_tree_add_item(ninep_tree, hf_9P_nqid, tvb, offset, 2, TRUE);
		offset +=2;
		/* I can't imagine anyone having a directory depth more than 25,
		   Limit to 10 times that to be sure, 2^16 is too much */
		if(tmp16 > 250) {
			tmp16 = 250;
			tmp_tree = proto_tree_add_text(ninep_tree, tvb, 0, 0, "Only first 250 items shown");
    			PROTO_ITEM_SET_GENERATED(tmp_tree);
		}

		for(i = 0; i < tmp16; i++) {
			dissect_9P_qid(tvb,ninep_tree,offset);
			offset += 13;
		}	
		break;	
	case TOPEN:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		offset +=4;
		ti = proto_tree_add_item(ninep_tree, hf_9P_mode, tvb, offset, 1, TRUE);
		dissect_9P_mode(tvb,ti,offset);
		break;
	case ROPEN:
		dissect_9P_qid(tvb,ninep_tree,offset);
		offset += 13;
		proto_tree_add_item(ninep_tree, hf_9P_iounit, tvb, offset, 4, TRUE);
		break;
	case TCREATE:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		offset +=4;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_name, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_filename);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16 + 2;

		ti = proto_tree_add_item(ninep_tree, hf_9P_perm, tvb, offset, 4, TRUE);
		dissect_9P_dm(tvb,ti,offset,1);
		offset +=4;

		ti = proto_tree_add_item(ninep_tree, hf_9P_mode, tvb, offset, 1, TRUE);
		dissect_9P_mode(tvb,ti,offset);

		break;
	case RCREATE:
		dissect_9P_qid(tvb,ninep_tree,offset);
		offset += 13;
		proto_tree_add_item(ninep_tree, hf_9P_iounit, tvb, offset, 4, TRUE);
		break;
	case TREAD:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		offset +=4;

		proto_tree_add_item(ninep_tree, hf_9P_offset, tvb, offset, 8, TRUE);
		offset +=8;

		proto_tree_add_item(ninep_tree, hf_9P_count, tvb, offset, 4, TRUE);
		break;	
	case RREAD:
		tmp = tvb_get_letohl(tvb,offset);
		proto_tree_add_item(ninep_tree, hf_9P_count, tvb, offset, 4, TRUE);
		offset += 4;

		len = tvb_reported_length_remaining(tvb, offset);
		reportedlen = ((gint)tmp&0xffff) > len ? len : (gint)tmp&0xffff;
		next_tvb = tvb_new_subset(tvb, offset, len, reportedlen);
		call_dissector(data_handle,next_tvb, pinfo, tree);
		break;
	case TWRITE:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		offset +=4;

		proto_tree_add_item(ninep_tree, hf_9P_offset, tvb, offset, 8, TRUE);
		offset +=8;

		tmp = tvb_get_letohl(tvb,offset);
		proto_tree_add_item(ninep_tree, hf_9P_count, tvb, offset, 4, TRUE);
		offset += 4;
		len = tvb_reported_length_remaining(tvb, offset);
		reportedlen = ((gint)tmp&0xffff) > len ? len : (gint)tmp&0xffff;
		next_tvb = tvb_new_subset(tvb, offset, len, reportedlen);
		call_dissector(data_handle,next_tvb, pinfo, tree);
		break;
	case RWRITE:
		proto_tree_add_item(ninep_tree, hf_9P_count, tvb, offset, 4, TRUE);
		break;
	case TCLUNK:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);

		break;
	case RCLUNK:
		break;
	case TREMOVE:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);

		break;
	case RREMOVE:
		break;
	case TSTAT:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		break;
	case RSTAT:
		proto_tree_add_item(ninep_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset +=2;

		proto_tree_add_item(ninep_tree, hf_9P_sdlen, tvb, offset, 2, TRUE);
		offset +=2;

		proto_tree_add_item(ninep_tree, hf_9P_stattype, tvb, offset, 2, TRUE);
		offset +=2;

		proto_tree_add_item(ninep_tree, hf_9P_dev, tvb, offset, 4, TRUE);
		offset +=4;

		dissect_9P_qid(tvb,ninep_tree,offset);
		offset += 13;

		ti = proto_tree_add_item(ninep_tree, hf_9P_statmode, tvb, offset, 4, TRUE);
		dissect_9P_dm(tvb,ti,offset,0);
		offset +=4;

		tv.secs = tvb_get_letohl(tvb,offset);
		tv.nsecs = 0;
		proto_tree_add_time(ninep_tree, hf_9P_atime, tvb, offset, 4, &tv);
		offset +=4;

		tv.secs = tvb_get_letohl(tvb,offset);
		tv.nsecs = 0;
		proto_tree_add_time(ninep_tree, hf_9P_mtime, tvb, offset, 4, &tv);
		offset +=4;

		proto_tree_add_item(ninep_tree, hf_9P_length, tvb, offset, 8, TRUE);
		offset +=8;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_filename, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_filename);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_uid, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_uid);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_gid, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_gid);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_muid, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_muid);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;
		break;
	case TWSTAT:
		proto_tree_add_item(ninep_tree, hf_9P_fid, tvb, offset, 4, TRUE);
		offset += 4;

		proto_tree_add_item(ninep_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset +=2;

		proto_tree_add_item(ninep_tree, hf_9P_sdlen, tvb, offset, 2, TRUE);
		offset +=2;

		proto_tree_add_item(ninep_tree, hf_9P_stattype, tvb, offset, 2, TRUE);
		offset +=2;

		proto_tree_add_item(ninep_tree, hf_9P_dev, tvb, offset, 4, TRUE);
		offset +=4;

		dissect_9P_qid(tvb,ninep_tree,offset);
		offset += 13;

		ti = proto_tree_add_item(ninep_tree, hf_9P_statmode, tvb, offset, 4, TRUE);
		dissect_9P_dm(tvb,ti,offset,0);
		offset +=4;

		tv.secs = tvb_get_letohl(tvb,offset);
		tv.nsecs = 0;
		proto_tree_add_time(ninep_tree, hf_9P_atime, tvb, offset, 4, &tv);
		offset +=4;

		tv.secs = tvb_get_letohl(tvb,offset);
		tv.nsecs = 0;
		proto_tree_add_time(ninep_tree, hf_9P_mtime, tvb, offset, 4, &tv);
		offset +=4;

		proto_tree_add_item(ninep_tree, hf_9P_length, tvb, offset, 8, TRUE);
		offset +=8;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_filename, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_filename);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_uid, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_uid);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_gid, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_gid);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;

		tmp16 = tvb_get_letohs(tvb,offset);
		ti = proto_tree_add_item(ninep_tree, hf_9P_muid, tvb, offset+2, tmp16, TRUE);
		tmp_tree = proto_item_add_subtree(ti,ett_9P_muid);
		proto_tree_add_item(tmp_tree, hf_9P_parmsz, tvb, offset, 2, TRUE);
		offset += tmp16+2;
		break;
	}
}
/* dissect 9P open mode flags */
static void dissect_9P_mode(tvbuff_t * tvb,  proto_item * item,int offset)
{
	proto_item *mode_tree;
	guint8 mode;

	mode = tvb_get_guint8(tvb,offset);
	mode_tree = proto_item_add_subtree(item, ett_9P_omode);
	if(!mode_tree)
		return;
	proto_tree_add_boolean(mode_tree, hf_9P_mode_c, tvb, offset, 1, mode);
	proto_tree_add_boolean(mode_tree, hf_9P_mode_t, tvb, offset, 1, mode);
	proto_tree_add_item(mode_tree, hf_9P_mode_rwx, tvb, offset, 1, mode);
}

/* dissect 9P Qid */
static void dissect_9P_qid(tvbuff_t * tvb,  proto_tree * tree,int offset)
{
	proto_item *qid_item,*qidtype_item;
	proto_tree *qid_tree,*qidtype_tree;
	guint64 path;
	guint32 vers;
	guint8 type;

	if(!tree)
		return;
	
	type = tvb_get_guint8(tvb,offset);
	vers = tvb_get_letohs(tvb,offset+1);
	path = tvb_get_letoh64(tvb,offset+1+4);

	qid_item = proto_tree_add_text(tree,tvb,offset,13,"Qid type=0x%02x vers=%d path=%" G_GINT64_MODIFIER "u",type,vers,path);
	qid_tree = proto_item_add_subtree(qid_item,ett_9P_qid);

	qidtype_item = proto_tree_add_item(qid_tree, hf_9P_qidtype, tvb, offset, 1, TRUE);
	qidtype_tree = proto_item_add_subtree(qidtype_item,ett_9P_qidtype);

	proto_tree_add_text(qidtype_tree, tvb, offset, 1, "%s",
	decode_boolean_bitfield(type,    QTDIR, 8, "Directory", "not a Directory"));
	proto_tree_add_text(qidtype_tree, tvb, offset, 1, "%s",
	decode_boolean_bitfield(type,    QTAPPEND, 8, "Append only", "not Append only"));
	proto_tree_add_text(qidtype_tree, tvb, offset, 1, "%s",
	decode_boolean_bitfield(type,    QTEXCL, 8, "Exclusive use", "not Exclusive use"));
	proto_tree_add_text(qidtype_tree, tvb, offset, 1, "%s",
	decode_boolean_bitfield(type,    QTMOUNT, 8, "Mounted channel", "not a Mounted channel"));
	proto_tree_add_text(qidtype_tree, tvb, offset, 1, "%s",
	decode_boolean_bitfield(type,    QTAUTH, 8, "Authentication file", "not an Authentication file"));
	proto_tree_add_text(qidtype_tree, tvb, offset, 1, "%s",
	decode_boolean_bitfield(type,    QTTMP, 8, "Temporary file (not backed up)", "not a Temporary file"));

	proto_tree_add_item(qid_tree, hf_9P_qidvers, tvb, offset+1, 4, TRUE);
	proto_tree_add_item(qid_tree, hf_9P_qidpath, tvb, offset+1+4, 8, TRUE);
}

/*dissect 9P stat mode and create perm flags */
static void dissect_9P_dm(tvbuff_t * tvb,  proto_item * item,int offset,int iscreate)
{
	proto_item *mode_tree;
	guint32 dm;


	dm = tvb_get_letohl(tvb,offset);
	mode_tree = proto_item_add_subtree(item, ett_9P_dm);
	if(!mode_tree)
		return;

	proto_tree_add_text(mode_tree, tvb, offset, 1, "%s",
	decode_boolean_bitfield(dm,    DMDIR, 32, "Directory", "not a Directory"));
	if(!iscreate) { /* Not applicable to Tcreate (?) */
		proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
		decode_boolean_bitfield(dm,    DMAPPEND, 32, "Append only", "not Append only"));
		proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
		decode_boolean_bitfield(dm,    DMEXCL, 32, "Exclusive use", "not Exclusive use"));
		proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
		decode_boolean_bitfield(dm,    DMMOUNT, 32, "Mounted channel", "not a Mounted channel"));
		proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
		decode_boolean_bitfield(dm,    DMAUTH, 32, "Authentication file", "not an Authentication file"));
		proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
		decode_boolean_bitfield(dm,    DMTMP, 32, "Temporary file (not backed up)", "not a Temporary file"));
	}

	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,    0400, 32, "Read permission for owner", "no Read permission for owner"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,    0200, 32, "Write permission for owner", "no Write permission for owner"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,    0100, 32, "Execute permission for owner", "no Execute permission for owner"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,     040, 32, "Read permission for group", "no Read permission for group"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,     020, 32, "Write permission for group", "no Write permission for group"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,     010, 32, "Execute permission for group", "no Execute permission for group"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,      04, 32, "Read permission for others", "no Read permission for others"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,      02, 32, "Write permission for others", "no Write permission for others"));
	proto_tree_add_text(mode_tree, tvb, offset, 4, "%s",
	decode_boolean_bitfield(dm,      01, 32, "Execute permission for others", "no Execute permission for others"));
}

/* Register 9P with Wireshark */
void proto_register_9P(void)
{
	static hf_register_info hf[] = {
		{&hf_9P_msgsz,
		 {"Msg length", "9p.msglen", FT_UINT32, BASE_DEC, NULL, 0x0,
		  "9P Message Length", HFILL}},
		{&hf_9P_msgtype,
		 {"Msg Type", "9p.msgtype", FT_UINT8, BASE_DEC, VALS(ninep_msg_type), 0x0,
		  "Message Type", HFILL}},
		{&hf_9P_tag,
		 {"Tag", "9p.tag", FT_UINT16, BASE_DEC, NULL, 0x0,
		  "9P Tag", HFILL}},
		{&hf_9P_oldtag,
		 {"Old tag", "9p.oldtag", FT_UINT16, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_parmsz,
		 {"Param length", "9p.paramsz", FT_UINT16, BASE_DEC, NULL, 0x0,
		  "Parameter length", HFILL}},
		{&hf_9P_maxsize,
		 {"Max msg size", "9p.maxsize", FT_UINT32, BASE_DEC, NULL, 0x0,
		  "Max message size", HFILL}},
		{&hf_9P_fid,
		 {"Fid", "9p.fid", FT_UINT32, BASE_DEC, NULL, 0x0,
		  "File ID", HFILL}},
		{&hf_9P_nqid,
		 {"Nr Qids", "9p.nqid", FT_UINT16, BASE_DEC, NULL, 0x0,
		  "Number of Qid results", HFILL}},
		{&hf_9P_mode,
		 {"Mode", "9p.mode", FT_UINT8, BASE_HEX, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_mode_rwx,
		 {"Open/Create Mode", "9p.mode.rwx", FT_UINT8, BASE_DEC,VALS(ninep_mode_vals),P9_MODEMASK,
		  NULL, HFILL}},
		{&hf_9P_mode_t,
		 {"Trunc", "9p.mode.trunc", FT_BOOLEAN, 8, TFS(&tfs_set_notset), P9_OTRUNC,
		  "Truncate", HFILL}},
		{&hf_9P_mode_c,
		 {"Remove on close", "9p.mode.orclose", FT_BOOLEAN, 8, TFS(&tfs_set_notset), P9_ORCLOSE,
		  NULL, HFILL}},
		{&hf_9P_iounit,
		 {"I/O Unit", "9p.iounit", FT_UINT32, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_count,
		 {"Count", "9p.count", FT_UINT32, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_offset,
		 {"Offset", "9p.offset", FT_UINT64, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_perm,
		 {"Permissions", "9p.perm", FT_UINT32, BASE_OCT, NULL, 0x0,
		  "Permission bits", HFILL}},
		{&hf_9P_qidpath,
		 {"Qid path", "9p.qidpath", FT_UINT64, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_qidvers,
		 {"Qid version", "9p.qidvers", FT_UINT32, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_qidtype,
		 {"Qid type", "9p.qidtype", FT_UINT8, BASE_HEX, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_statmode,
		 {"Mode", "9p.statmode", FT_UINT32, BASE_OCT, NULL, 0x0,
		  "File mode flags", HFILL}},
		{&hf_9P_stattype,
		 {"Type", "9p.stattype", FT_UINT16, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_atime,
		 {"Atime", "9p.atime", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0,
		  "Access Time", HFILL}},
		{&hf_9P_mtime,
		 {"Mtime", "9p.mtime", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x0,
		  "Modified Time", HFILL}},
		{&hf_9P_length,
		 {"Length", "9p.length", FT_UINT64, BASE_DEC, NULL, 0x0,
		  "File Length", HFILL}},
		{&hf_9P_dev,
		 {"Dev", "9p.dev", FT_UINT32, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_wname,
		 {"Wname", "9p.wname", FT_STRING, BASE_NONE, NULL, 0x0,
		  "Path Name Element", HFILL}},
		{&hf_9P_version,
		 {"Version", "9p.version", FT_STRING, BASE_NONE, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_afid,
		 {"Afid", "9p.fid", FT_UINT32, BASE_DEC, NULL, 0x0,
		  "Authenticating FID", HFILL}},
		{&hf_9P_uname,
		 {"Uname", "9p.uname", FT_STRING, BASE_NONE, NULL, 0x0,
		  "User Name", HFILL}},
		{&hf_9P_aname,
		 {"Aname", "9p.aname", FT_STRING, BASE_NONE, NULL, 0x0,
		  "Access Name", HFILL}},
		{&hf_9P_ename,
		 {"Ename", "9p.ename", FT_STRING, BASE_NONE, NULL, 0x0,
		  "Error", HFILL}},
		{&hf_9P_name,
		 {"Name", "9p.name", FT_STRING, BASE_NONE, NULL, 0x0,
		  "Name of file", HFILL}},
		{&hf_9P_sdlen,
		 {"Stat data length", "9p.sdlen", FT_UINT16, BASE_DEC, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_filename,
		 {"File name", "9p.filename", FT_STRING, BASE_NONE, NULL, 0x0,
		  NULL, HFILL}},
		{&hf_9P_uid,
		 {"Uid", "9p.uid", FT_STRING, BASE_NONE, NULL, 0x0,
		  "User id", HFILL}},
		{&hf_9P_gid,
		 {"Gid", "9p.gid", FT_STRING, BASE_NONE, NULL, 0x0,
		  "Group id", HFILL}},
		{&hf_9P_muid,
		 {"Muid", "9p.muid", FT_STRING, BASE_NONE, NULL, 0x0,
		  "Last modifiers uid", HFILL}},
		{&hf_9P_newfid,
		 {"New fid", "9p.newfid", FT_UINT32, BASE_DEC, NULL, 0x0,
		  "New file ID", HFILL}},
		{&hf_9P_nwalk,
		 {"Nr Walks", "9p.nwalk", FT_UINT32, BASE_DEC, NULL, 0x0,
		  "Nr of walk items", HFILL}}

	};

	static gint *ett[] = {
		&ett_9P,
		&ett_9P_omode,
		&ett_9P_dm,
		&ett_9P_wname,
		&ett_9P_aname,
		&ett_9P_ename,
		&ett_9P_uname,
		&ett_9P_uid,
		&ett_9P_gid,
		&ett_9P_muid,
		&ett_9P_filename,
		&ett_9P_version,
		&ett_9P_qid,
		&ett_9P_qidtype,
	};

	proto_9P = proto_register_protocol("Plan 9 9P", "9P", "9p");

	proto_register_field_array(proto_9P, hf, array_length(hf));

	proto_register_subtree_array(ett, array_length(ett));
}

void proto_reg_handoff_9P(void)
{
	dissector_handle_t ninep_handle;

	data_handle = find_dissector("data");

	ninep_handle = create_dissector_handle(dissect_9P, proto_9P);

	dissector_add("tcp.port", NINEPORT, ninep_handle);
}


