/* packet-sip.c
 * Routines for the Session Initiation Protocol (SIP) dissection.
 * RFC 2543
 *
 * TODO: Pay attention to Content-Type: It might not always be SDP.
 *       hf_ display filters for headers of SIP extension RFCs: 
 *		Done for RFC 3265, RFC 3262
 *		Use hash table for list of headers
 *       Add sip msg body dissection based on Content-Type for:
 *                SDP, MIME, and other types
 *       Align SIP methods with recent Internet Drafts or RFC
 *               (SIP INFO, rfc2976 - done)
 *               (SIP SUBSCRIBE-NOTIFY - done)
 *               (SIP REFER - done)
 *               check for other
 *
 * Copyright 2000, Heikki Vatiainen <hessu@cs.tut.fi>
 * Copyright 2001, Jean-Francois Mule <jfm@cablelabs.com>
 *
 * $Id: packet-sip.c,v 1.39 2003/06/12 08:33:29 guy Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 1998 Gerald Combs
 *
 * Copied from packet-cops.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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

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

#define TCP_PORT_SIP 5060
#define UDP_PORT_SIP 5060

/* Initialize the protocol and registered fields */
static gint proto_sip = -1;
static gint hf_msg_hdr = -1;
static gint hf_Method = -1;
static gint hf_Status_Code = -1;

/* Initialize the subtree pointers */
static gint ett_sip = -1;
static gint ett_sip_reqresp = -1;
static gint ett_sip_hdr = -1;

static const char *sip_methods[] = {
        "<Invalid method>",      /* Pad so that the real methods start at index 1 */
        "ACK",
        "BYE",
        "CANCEL",
        "DO",
        "INFO",
        "INVITE",
        "MESSAGE",
        "NOTIFY",
        "OPTIONS",
        "PRACK",
        "QAUTH",
        "REFER",
        "REGISTER",
        "SPRACK",
        "SUBSCRIBE"
};

/* from RFC 3261 */
static const char *sip_headers[] = {
		"Unknown-header", /* Pad so that the real headers start at index 1 */
                "Accept",
                "Accept-Encoding",
                "Accept-Language",
                "Alert-Info",
                "Allow",
		"Allow-Events",
                "Authentication-Info",
                "Authorization",
                "Call-ID",
                "Call-Info",
                "Contact",
                "Content-Disposition",
                "Content-Encoding",
                "Content-Language",
                "Content-Length",
                "Content-Type",
                "CSeq",
                "Date",
                "Error-Info",
		"Event",
                "Expires",
                "From",
                "In-Reply-To",
                "Max-Forwards",
                "MIME-Version",
                "Min-Expires",
                "Organization",
                "Priority",
                "Proxy-Authenticate",
                "Proxy-Authorization",
                "Proxy-Require",
		"RAck",
		"RSeq",
                "Record-Route",
                "Reply-To",
                "Require",
                "Retry-After",
                "Route",
                "Server",
                "Subject",
		"Subscription-State",
                "Supported",
                "Timestamp",
                "To",
                "Unsupported",
                "User-Agent",
                "Via",
                "Warning",
                "WWW-Authenticate"
};


#define POS_ACCEPT 		1
#define POS_ACCEPT_ENCODING	2
#define POS_ACCEPT_LANGUAGE	3
#define POS_ALERT_INFO		4
#define POS_ALLOW		5
#define POS_ALLOW_EVENTS	6
#define POS_AUTHENTICATION_INFO	7
#define POS_AUTHORIZATION	8
#define POS_CALL_ID		9
#define POS_CALL_INFO		10
#define POS_CONTACT		11
#define POS_CONTENT_DISPOSITION	12
#define POS_CONTENT_ENCODING	13
#define POS_CONTENT_LANGUAGE	14
#define POS_CONTENT_LENGTH	15
#define POS_CONTENT_TYPE	16
#define POS_CSEQ		17
#define POS_DATE		18
#define POS_ERROR_INFO		19
#define POS_EVENT		20
#define POS_EXPIRES		21
#define POS_FROM		22
#define POS_IN_REPLY_TO		23
#define POS_MAX_FORWARDS	24
#define POS_MIME_VERSION	25
#define POS_MIN_EXPIRES		26
#define POS_ORGANIZATION	27
#define POS_PRIORITY		28
#define POS_PROXY_AUTHENTICATE	29
#define POS_PROXY_AUTHORIZATION	30
#define POS_PROXY_REQUIRE	31
#define POS_RACK		32
#define POS_RSEQ		33
#define POS_RECORD_ROUTE	34
#define POS_REPLY_TO		35
#define POS_REQUIRE		36
#define POS_RETRY_AFTER		37
#define POS_ROUTE		38
#define POS_SERVER		39
#define POS_SUBJECT		40
#define POS_SUBSCRIPTION_STATE	41
#define POS_SUPPORTED		42
#define POS_TIMESTAMP		43
#define POS_TO			44
#define POS_UNSUPPORTED		45
#define POS_USER_AGENT		46
#define POS_VIA			47
#define POS_WARNING		48
#define POS_WWW_AUTHENTICATE	49

static gint hf_header_array[] = {
		-1, /* "Unknown-header" - Pad so that the real headers start at index 1 */
                -1, /* "Accept" */
                -1, /* "Accept-Encoding" */
                -1, /* "Accept-Language" */
                -1, /* "Alert-Info" */
                -1, /* "Allow" */
		-1, /* "Allow-Events" - RFC 3265 */
                -1, /* "Authentication-Info" */
                -1, /* "Authorization" */
                -1, /* "Call-ID" */
                -1, /* "Call-Info" */
                -1, /* "Contact" */
                -1, /* "Content-Disposition" */
                -1, /* "Content-Encoding" */
                -1, /* "Content-Language" */
                -1, /* "Content-Length" */
                -1, /* "Content-Type" */
                -1, /* "CSeq" */
                -1, /* "Date" */
                -1, /* "Error-Info" */
                -1, /* "Expires" */
		-1, /* "Event" - RFC 3265 */
                -1, /* "From" */
                -1, /* "In-Reply-To" */
                -1, /* "Max-Forwards" */
                -1, /* "MIME-Version" */
                -1, /* "Min-Expires" */
                -1, /* "Organization" */
                -1, /* "Priority" */
                -1, /* "Proxy-Authenticate" */
                -1, /* "Proxy-Authorization" */
                -1, /* "Proxy-Require" */
		-1, /* "RAck" - RFC 3262 */
		-1, /* "RSeq" - RFC 3261 */
                -1, /* "Record-Route" */
                -1, /* "Reply-To" */
                -1, /* "Require" */
                -1, /* "Retry-After" */
                -1, /* "Route" */
                -1, /* "Server" */
                -1, /* "Subject" */
		-1, /* "Subscription-State" - RFC 3265 */
                -1, /* "Supported" */
                -1, /* "Timestamp" */
                -1, /* "To" */
                -1, /* "Unsupported" */
                -1, /* "User-Agent" */
                -1, /* "Via" */
                -1, /* "Warning" */
                -1  /* "WWW-Authenticate" */
};

/*
 * Type of line.  It's either a SIP Request-Line, a SIP Status-Line, or
 * another type of line.
 */
typedef enum {
	REQUEST_LINE,
	STATUS_LINE,
	OTHER_LINE
} line_type_t;

static gboolean dissect_sip_common(tvbuff_t *tvb, packet_info *pinfo,
    proto_tree *tree, gboolean is_heur);
static line_type_t sip_parse_line(tvbuff_t *tvb, gint eol, guint *token_1_len);
static gboolean sip_is_known_request(tvbuff_t *tvb, int meth_offset,
    guint meth_len);
static gint sip_get_msg_offset(tvbuff_t *tvb, int offset);
static gint sip_is_known_sip_header(tvbuff_t *tvb, int offset,
    guint header_len);
void dfilter_sip_request_line(tvbuff_t *tvb, proto_tree *tree, guint meth_len);
void dfilter_sip_status_line(tvbuff_t *tvb, proto_tree *tree);

static dissector_handle_t sdp_handle;
static dissector_handle_t data_handle;

#define SIP2_HDR "SIP/2.0"
#define SIP2_HDR_LEN (strlen (SIP2_HDR))

/* Code to actually dissect the packets */
static void
dissect_sip(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	dissect_sip_common(tvb, pinfo, tree, FALSE);
}

static gboolean
dissect_sip_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	return dissect_sip_common(tvb, pinfo, tree, TRUE);
}

static gboolean
dissect_sip_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
    gboolean is_heur)
{
        int offset;
        gint eol, next_offset, msg_offset;
	line_type_t line_type;
        tvbuff_t *next_tvb;
        gboolean is_known_request;
        char *descr;
        guint token_1_len;

        /*
         * Note that "tvb_find_line_end()" will return a value that
         * is not longer than what's in the buffer, so the
         * "tvb_get_ptr()" calls below won't throw exceptions.
         *
         * Note that "tvb_strneql()" doesn't throw exceptions, so
         * "sip_parse_line()" won't throw an exception.
         */
        offset = 0;
        eol = tvb_find_line_end(tvb, 0, -1, &next_offset, FALSE);
        line_type = sip_parse_line(tvb, eol, &token_1_len);
        if (line_type == OTHER_LINE) {
        	/*
        	 * This is neither a SIP request nor response.
        	 */
                if (is_heur) {
                        /*
                         * This is a heuristic dissector, which means we get
                         * all the UDP and TCP traffic not sent to a known
                         * dissector and not claimed by a heuristic dissector
                         * called before us!
                         *
                         * Therefore, we reject this as not being for us.
                         */
                	return FALSE;
                } else {
                	/*
                	 * Just dissect it as data.
                	 */
                	goto bad;
                }
        }

        if (check_col(pinfo->cinfo, COL_PROTOCOL))
                col_set_str(pinfo->cinfo, COL_PROTOCOL, "SIP");

        switch (line_type) {

        case REQUEST_LINE:
                is_known_request = sip_is_known_request(tvb, 0, token_1_len);
                descr = is_known_request ? "Request" : "Unknown request";
                if (check_col(pinfo->cinfo, COL_INFO)) {
                        col_add_fstr(pinfo->cinfo, COL_INFO, "%s: %s",
                             descr,
                             tvb_format_text(tvb, 0, eol - SIP2_HDR_LEN - 1));
                }
		break;

        case STATUS_LINE:
                descr = "Status";
                if (check_col(pinfo->cinfo, COL_INFO)) {
                        col_add_fstr(pinfo->cinfo, COL_INFO, "Status: %s",
                             tvb_format_text(tvb, SIP2_HDR_LEN + 1, eol - SIP2_HDR_LEN - 1));
                }
		break;

	case OTHER_LINE:
	default: /* Squelch compiler complaints */
	        descr = "Continuation";
                if (check_col(pinfo->cinfo, COL_INFO))
                        col_set_str(pinfo->cinfo, COL_INFO, "Continuation");
                break;
        }
        msg_offset = sip_get_msg_offset(tvb, offset);
        if (msg_offset < 0) {
                /*
                 * XXX - this may just mean that the entire SIP message
                 * didn't fit in this TCP segment.
                 */
                goto bad;
        }

        if (tree) {
                proto_item *ti, *th;
                proto_tree *sip_tree, *reqresp_tree, *hdr_tree;

                ti = proto_tree_add_item(tree, proto_sip, tvb, 0, -1, FALSE);
                sip_tree = proto_item_add_subtree(ti, ett_sip);

                ti = proto_tree_add_text(sip_tree, tvb, 0, next_offset,
                                         "%s line: %s", descr,
                                         tvb_format_text(tvb, 0, eol));
                reqresp_tree = proto_item_add_subtree(ti, ett_sip_reqresp);

		switch (line_type) {

                case REQUEST_LINE:
                        dfilter_sip_request_line(tvb, reqresp_tree, token_1_len);
                        break;

                case STATUS_LINE:
                        dfilter_sip_status_line(tvb, reqresp_tree);
                        break;

		case OTHER_LINE:
		        break;
                }

                offset = next_offset;
                th = proto_tree_add_item(sip_tree, hf_msg_hdr, tvb, offset, msg_offset - offset, FALSE);
                hdr_tree = proto_item_add_subtree(th, ett_sip_hdr);

                /* - 2 since we have a CRLF separating the message-body */
                while (msg_offset - 2 > (int) offset) {
                	gint line_end_offset;
                	gint colon_offset;
			gint header_len;
                        gint hf_index;
                        gint value_offset;
                        guchar c;
		        size_t value_len;
			char *value;

                        eol = tvb_find_line_end(tvb, offset, -1, &next_offset,
                            FALSE);
                        line_end_offset = offset + eol;
			colon_offset = tvb_find_guint8(tvb, offset, -1, ':');
			if (colon_offset == -1) {
				/*
				 * Malformed header - no colon after the
				 * name.
				 */
				proto_tree_add_text(hdr_tree, tvb, offset,
				    next_offset - offset, "%s",
				    tvb_format_text(tvb, offset, eol));
			} else {
				header_len = colon_offset - offset;
				hf_index = sip_is_known_sip_header(tvb,
				    offset, header_len);
			
				if (hf_index == -1) {
					proto_tree_add_text(hdr_tree, tvb,
					    offset, next_offset - offset, "%s",
					    tvb_format_text(tvb, offset, eol));
				} else {
					/*
					 * Skip whitespace after the colon.
					 */
					value_offset = colon_offset + 1;
					while (value_offset < line_end_offset
					    && ((c = tvb_get_guint8(tvb,
						    value_offset)) == ' '
					      || c == '\t'))
						value_offset++;
					/*
					 * Fetch the value.
					 */
					value_len = line_end_offset - value_offset;
					value = tvb_get_string(tvb, value_offset,
					    value_len);

					/*
					 * Add it to the protocol tree,
					 * but display the line as is.
					 */
					proto_tree_add_string_format(hdr_tree,
					    hf_header_array[hf_index], tvb,
					    offset, next_offset - offset,
					    value, "%s",
					    tvb_format_text(tvb, offset, eol));
					g_free(value);
				}
			} 
					    
                        offset = next_offset;
                }
                offset += 2;  /* Skip the CRLF mentioned above */
       }

        if (tvb_offset_exists(tvb, msg_offset)) {
                next_tvb = tvb_new_subset(tvb, msg_offset, -1, -1);
                call_dissector(sdp_handle, next_tvb, pinfo, tree);
        }

        return TRUE;

  bad:
        next_tvb = tvb_new_subset(tvb, offset, -1, -1);
        call_dissector(data_handle,next_tvb, pinfo, tree);

        return TRUE;
}

/* Display filter for SIP Request-Line */
void dfilter_sip_request_line(tvbuff_t *tvb, proto_tree *tree, guint meth_len)
{
	char	*string;

        /*
         * We know we have the entire method; otherwise, "sip_parse_line()"
         * would have returned OTHER_LINE.
         */
        string = tvb_get_string(tvb, 0, meth_len);
        proto_tree_add_string(tree, hf_Method, tvb, 0, meth_len, string);
        g_free(string);
}

/* Display filter for SIP Status-Line */
void dfilter_sip_status_line(tvbuff_t *tvb, proto_tree *tree)
{
	char string[3+1];

        /*
         * We know we have the entire status code; otherwise,
         * "sip_parse_line()" would have returned OTHER_LINE.
         * We also know that we have a version string followed by a
         * space at the beginning of the line, for the same reason.
         */
        tvb_memcpy(tvb, (guint8 *)string, SIP2_HDR_LEN + 1, 3);
        string[3] = '\0';
        proto_tree_add_string(tree, hf_Status_Code, tvb, SIP2_HDR_LEN + 1,
            3, string);
}

/* Returns the offset to the start of the optional message-body, or
 * -1 if not found.
 */
static gint sip_get_msg_offset(tvbuff_t *tvb, int offset)
{
        gint eol;

        while ((eol = tvb_find_guint8(tvb, offset, -1, '\r')) > 0
            && tvb_bytes_exist(tvb, eol, 4)) {
                if (tvb_get_guint8(tvb, eol + 1) == '\n' &&
                    tvb_get_guint8(tvb, eol + 2) == '\r' &&
                    tvb_get_guint8(tvb, eol + 3) == '\n')
                        return eol + 4;
                offset = eol + 2;
        }

        return -1;
}

/* From section 4.1 of RFC 2543:
 *
 * Request-Line  =  Method SP Request-URI SP SIP-Version CRLF
 *
 * From section 5.1 of RFC 2543:
 *
 * Status-Line  =  SIP-version SP Status-Code SP Reason-Phrase CRLF
 */
static line_type_t
sip_parse_line(tvbuff_t *tvb, gint eol, guint *token_1_lenp)
{
	gint space_offset;
	guint token_1_len;
	gint token_2_start;
	guint token_2_len;
	gint token_3_start;
	guint token_3_len;
	gint colon_pos;

	space_offset = tvb_find_guint8(tvb, 0, -1, ' ');
	if (space_offset <= 0) {
		/*
		 * Either there's no space in the line (which means
		 * the line is empty or doesn't have a token followed
		 * by a space; neither is valid for a request or status), or
		 * the first character in the line is a space (meaning
		 * the method is empty, which isn't valid for a request,
		 * or the SIP version is empty, which isn't valid for a
		 * status).
		 */
		return OTHER_LINE;
	}
	token_1_len = space_offset;
	token_2_start = space_offset + 1;
	space_offset = tvb_find_guint8(tvb, token_2_start, -1, ' ');
	if (space_offset == -1) {
		/*
		 * There's no space after the second token, so we don't
		 * have a third token.
		 */
		return OTHER_LINE;
	}
	token_2_len = space_offset - token_2_start;
	token_3_start = space_offset + 1;
	token_3_len = eol - token_3_start;
	
	*token_1_lenp = token_1_len;

	/*
	 * Is the first token a version string?
	 */
	if (token_1_len == SIP2_HDR_LEN &&
	    tvb_strneql(tvb, 0, SIP2_HDR, SIP2_HDR_LEN) == 0) {
		/*
		 * Yes, so this is either a Status-Line or something
		 * else other than a Request-Line.  To be a Status-Line,
		 * the second token must be a 3-digit number.
		 */
		if (token_2_len != 3) {
			/*
			 * We don't have 3-character status code.
			 */
			return OTHER_LINE;
		}
		if (!isdigit(tvb_get_guint8(tvb, token_2_start)) ||
		    !isdigit(tvb_get_guint8(tvb, token_2_start + 1)) ||
		    !isdigit(tvb_get_guint8(tvb, token_2_start + 2))) {
			/*
			 * 3 characters yes, 3 digits no.
			 */
			return OTHER_LINE;
		}
		return STATUS_LINE;
	} else {
		/*
		 * No, so this is either a Request-Line or something
		 * other than a Status-Line.  To be a Request-Line, the
		 * second token must be a URI and the third token must
		 * be a version string.
		 */
		if (token_2_len < 3) {
			/*
			 * We don't have a URI consisting of at least 3
			 * characters.
			 */
			return OTHER_LINE;
		}
		colon_pos = tvb_find_guint8(tvb, token_2_start + 1, -1, ':');
		if (colon_pos == -1) {
			/*
			 * There is no colon after the method, so the URI
			 * doesn't have a colon in it, so it's not valid.
			 */
			return OTHER_LINE;
		}
		if (colon_pos >= token_3_start) {
			/*
			 * The colon is in the version string, not the URI.
			 */
			return OTHER_LINE;
		}
		/* XXX - Check for a proper URI prefix? */
		if (token_3_len != SIP2_HDR_LEN ||
		    tvb_strneql(tvb, token_3_start, SIP2_HDR, SIP2_HDR_LEN) == -1) {
			/*
			 * The version string isn't an SIP version 2.0 version
			 * string.
			 */
			return OTHER_LINE;
		}
		return REQUEST_LINE;
	}
}

static gboolean sip_is_known_request(tvbuff_t *tvb, int meth_offset,
    guint meth_len)
{
        guint i;

        for (i = 1; i < array_length(sip_methods); i++) {
                if (meth_len == strlen(sip_methods[i]) &&
                    tvb_strneql(tvb, meth_offset, sip_methods[i], meth_len) == 0)
                        return TRUE;
        }

        return FALSE;
}

/* Returns index of method in sip_headers */
static gint sip_is_known_sip_header(tvbuff_t *tvb, int offset, guint header_len)
{
        guint i;

        for (i = 1; i < array_length(sip_headers); i++) {
                if (header_len == strlen(sip_headers[i]) &&
                    tvb_strneql(tvb, offset, sip_headers[i], header_len) == 0)
                        return i;
        }

        return -1;
}

/* Register the protocol with Ethereal */
void proto_register_sip(void)
{

        /* Setup list of header fields */
        static hf_register_info hf[] = {

                { &hf_msg_hdr,
                        { "Message Header",           "sip.msg_hdr",
                        FT_NONE, 0, NULL, 0,
                        "Message Header in SIP message", HFILL }
                },
                { &hf_Method,
		       { "Method", 		"sip.Method", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"SIP Method", HFILL }
		},
                { &hf_Status_Code,
		       { "Status-Code", 		"sip.Status-Code", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"SIP Status Code", HFILL }
		},
                { &hf_header_array[POS_ACCEPT],
		       { "Accept", 		"sip.Accept", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Accept Header", HFILL }
		},
                { &hf_header_array[POS_ACCEPT_ENCODING],
		       { "Accept-Encoding", 		"sip.Accept-Encoding", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Accept-Encoding Header", HFILL }
		},
                { &hf_header_array[POS_ACCEPT_LANGUAGE],
		       { "Accept-Language", 		"sip.Accept-Language", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Accept-Language Header", HFILL }
		},
                { &hf_header_array[POS_ALERT_INFO],
		       { "Alert-Info", 		"sip.Alert-Info", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Alert-Info Header", HFILL }
		},
                { &hf_header_array[POS_ALLOW],
		       { "Allow", 		"sip.Allow", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Allow Header", HFILL }
		},
                { &hf_header_array[POS_ALLOW_EVENTS],
		       { "Allow-Events", 		"sip.Allow-Events", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3265: Allow-Events Header", HFILL }
		},
                { &hf_header_array[POS_AUTHENTICATION_INFO],
		       { "Authentication-Info", 		"sip.Authentication-Info", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Authentication-Info Header", HFILL }
		},
                { &hf_header_array[POS_AUTHORIZATION],
		       { "Authorization", 		"sip.Authorization", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Authorization Header", HFILL }
		},
                { &hf_header_array[POS_CALL_ID],
		       { "Call-ID", 		"sip.Call-ID", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Call-ID Header", HFILL }
		},
                { &hf_header_array[POS_CALL_INFO],
		       { "Call-Info", 		"sip.Call-Info", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Call-Info Header", HFILL }
		},
                { &hf_header_array[POS_CONTACT],
		       { "Contact", 		"sip.Contact", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Contact Header", HFILL }
		},
                { &hf_header_array[POS_CONTENT_DISPOSITION],
		       { "Content-Disposition", 		"sip.Content-Disposition", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Content-Disposition Header", HFILL }
		},
                { &hf_header_array[POS_CONTENT_ENCODING],
		       { "Content-Encoding", 		"sip.Content-Encoding", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Content-Encoding Header", HFILL }
		},
                { &hf_header_array[POS_CONTENT_LANGUAGE],
		       { "Content-Language", 		"sip.Content-Language", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Content-Language Header", HFILL }
		},
                { &hf_header_array[POS_CONTENT_LENGTH],
		       { "Content-Length", 		"sip.Content-Length", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Content-Length Header", HFILL }
		},
                { &hf_header_array[POS_CONTENT_TYPE],
		       { "Content-Type", 		"sip.Content-Type", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Content-Type Header", HFILL }
		},
                { &hf_header_array[POS_CSEQ],
		       { "CSeq", 		"sip.CSeq", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: CSeq Header", HFILL }
		},
                { &hf_header_array[POS_DATE],
		       { "Date", 		"sip.Date", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Date Header", HFILL }
		},
                { &hf_header_array[POS_ERROR_INFO],
		       { "Error-Info", 		"sip.Error-Info", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Error-Info Header", HFILL }
		},
                { &hf_header_array[POS_EVENT],
		       { "Event", 		"sip.Event", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3265: Event Header", HFILL }
		},
                { &hf_header_array[POS_EXPIRES],
		       { "Expires", 		"sip.Expires", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Expires Header", HFILL }
		},
                { &hf_header_array[POS_FROM],
		       { "From", 		"sip.From", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: From Header", HFILL }
		},
                { &hf_header_array[POS_IN_REPLY_TO],
		       { "In-Reply-To", 		"sip.In-Reply-To", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: In-Reply-To Header", HFILL }
		},
                { &hf_header_array[POS_MAX_FORWARDS],
		       { "Max-Forwards", 		"sip.Max-Forwards", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Max-Forwards Header", HFILL }
		},
                { &hf_header_array[POS_MIME_VERSION],
		       { "MIME-Version", 		"sip.MIME-Version", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: MIME-Version Header", HFILL }
		},
                { &hf_header_array[POS_MIN_EXPIRES],
		       { "Min-Expires", 		"sip.Min-Expires", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Min-Expires Header", HFILL }
		},
                { &hf_header_array[POS_ORGANIZATION],
		       { "Organization", 		"sip.Organization", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Organization Header", HFILL }
		},
                { &hf_header_array[POS_PRIORITY],
		       { "Priority", 		"sip.Priority", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Priority Header", HFILL }
		},
                { &hf_header_array[POS_PROXY_AUTHENTICATE],
		       { "Proxy-Authenticate", 		"sip.Proxy-Authenticate", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Proxy-Authenticate Header", HFILL }
		},
                { &hf_header_array[POS_PROXY_AUTHORIZATION],
		       { "Proxy-Authorization", 		"sip.Proxy-Authorization", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Proxy-Authorization Header", HFILL }
		},
                { &hf_header_array[POS_RACK],
		       { "RAck", 		"sip.RAck", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3262: RAck Header", HFILL }
		},
                { &hf_header_array[POS_RSEQ],
		       { "RSeq", 		"sip.RSeq", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3262: RSeq Header", HFILL }
		},
                { &hf_header_array[POS_PROXY_REQUIRE],
		       { "Proxy-Require", 		"sip.Proxy-Require", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Proxy-Require Header", HFILL }
		},
                { &hf_header_array[POS_RECORD_ROUTE],
		       { "Record-Route", 		"sip.Record-Route", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Record-Route Header", HFILL }
		},
                { &hf_header_array[POS_REPLY_TO],
		       { "Reply-To", 		"sip.Reply-To", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Reply-To Header", HFILL }
		},
                { &hf_header_array[POS_REQUIRE],
		       { "Require", 		"sip.Require", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Require Header", HFILL }
		},
                { &hf_header_array[POS_RETRY_AFTER],
		       { "Retry-After", 		"sip.Retry-After", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Retry-After Header", HFILL }
		},
                { &hf_header_array[POS_ROUTE],
		       { "Route", 		"sip.Route", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Route Header", HFILL }
		},
                { &hf_header_array[POS_SERVER],
		       { "Server", 		"sip.Server", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Server Header", HFILL }
		},
                { &hf_header_array[POS_SUBJECT],
		       { "Subject", 		"sip.Subject", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Subject Header", HFILL }
		},
                { &hf_header_array[POS_SUBSCRIPTION_STATE],
		       { "Subscription-State", 		"sip.Subscription-State", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3265: Subscription-State Header", HFILL }
		},
                { &hf_header_array[POS_SUPPORTED],
		       { "Supported", 		"sip.Supported", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Supported Header", HFILL }
		},
                { &hf_header_array[POS_TIMESTAMP],
		       { "Timestamp", 		"sip.Timestamp", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Timestamp Header", HFILL }
		},
                { &hf_header_array[POS_TO],
		       { "To", 		"sip.To", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: To Header", HFILL }
		},
                { &hf_header_array[POS_UNSUPPORTED],
		       { "Unsupported", 		"sip.Unsupported", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Unsupported Header", HFILL }
		},
                { &hf_header_array[POS_USER_AGENT],
		       { "User-Agent", 		"sip.User-Agent", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: User-Agent Header", HFILL }
		},
                { &hf_header_array[POS_VIA],
		       { "Via", 		"sip.Via", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Via Header", HFILL }
		},
                { &hf_header_array[POS_WARNING],
		       { "Warning", 		"sip.Warning", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: Warning Header", HFILL }
		},
                { &hf_header_array[POS_WWW_AUTHENTICATE],
		       { "WWW-Authenticate", 		"sip.WWW-Authenticate", 
		       FT_STRING, BASE_NONE,NULL,0x0,
			"RFC 3261: WWW-Authenticate Header", HFILL }
		},
		
        };

        /* Setup protocol subtree array */
        static gint *ett[] = {
                &ett_sip,
                &ett_sip_reqresp,
                &ett_sip_hdr,
        };

        /* Register the protocol name and description */
        proto_sip = proto_register_protocol("Session Initiation Protocol",
            "SIP", "sip");

        /* Required function calls to register the header fields and subtrees used */
        proto_register_field_array(proto_sip, hf, array_length(hf));
        proto_register_subtree_array(ett, array_length(ett));
}

void
proto_reg_handoff_sip(void)
{
        dissector_handle_t sip_handle;

        sip_handle = create_dissector_handle(dissect_sip, proto_sip);
        dissector_add("tcp.port", TCP_PORT_SIP, sip_handle);
        dissector_add("udp.port", UDP_PORT_SIP, sip_handle);

        heur_dissector_add( "udp", dissect_sip_heur, proto_sip );
        heur_dissector_add( "tcp", dissect_sip_heur, proto_sip );

        /*
         * Get a handle for the SDP dissector.
         */
        sdp_handle = find_dissector("sdp");
        data_handle = find_dissector("data");
}