/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <pthread.h>
#include <strings.h>
#include <sip.h>

#include "sip_msg.h"
#include "sip_miscdefs.h"
#include "sip_hash.h"
#include "sip_dialog.h"
#include "sip_parse_generic.h"

#define	SIP_DLG_XCHG_FROM	0
#define	SIP_DLG_XCHG_TO		1

/*
 * Dialog state change callback function
 */
void (*sip_dlg_ulp_state_cb)(sip_dialog_t, sip_msg_t, int, int) = NULL;
void (*sip_ulp_dlg_del_cb)(sip_dialog_t, sip_msg_t, void *) = NULL;

boolean_t	sip_incomplete_dialog(sip_dialog_t);

/*
 * Exchange From/To header
 */
_sip_header_t *sip_dlg_xchg_from_to(sip_msg_t, int);

/*
 * Complete dialog hash table
 */
sip_hash_t sip_dialog_hash[SIP_HASH_SZ];

/*
 * Partial dialog hash table
 */
sip_hash_t sip_dialog_phash[SIP_HASH_SZ];

/*
 * Route set structure
 */
typedef struct sip_dlg_route_set_s  {
	char		*sip_dlg_route;
	sip_str_t	sip_dlg_ruri;
	boolean_t	sip_dlg_route_lr;
	struct sip_dlg_route_set_s *sip_dlg_route_next;
}sip_dlg_route_set_t;

sip_dialog_t		sip_seed_dialog(sip_conn_object_t, _sip_msg_t *,
			    boolean_t, int);
sip_dialog_t		sip_complete_dialog(_sip_msg_t *, _sip_dialog_t *);
int			sip_dialog_process(_sip_msg_t *, sip_dialog_t *);
void			sip_dialog_delete(_sip_dialog_t *);
void			sip_dialog_init();
sip_dialog_t		sip_dialog_find(_sip_msg_t *);
boolean_t		sip_dialog_match(void *, void *);
boolean_t		sip_dialog_free(void *, void *, int *);
sip_dialog_t		sip_update_dialog(sip_dialog_t, _sip_msg_t *);
char			*sip_dialog_req_uri(sip_dialog_t);

static void		sip_release_dialog_res(_sip_dialog_t *);
void			sip_dlg_self_destruct(void *);
static int		sip_dialog_get_route_set(_sip_dialog_t *, _sip_msg_t *,
			    int);
static void		sip_dialog_free_rset(sip_dlg_route_set_t *);

/*
 * Timer object for partial dialogs
 */
typedef struct sip_dialog_timer_obj_s {
	_sip_dialog_t	*dialog;
	void		(*func)(sip_dialog_t, sip_msg_t, void *);
} sip_dialog_timer_obj_t;

/*
 * To avoid duplication all over the place
 */
static void
sip_release_dialog_res(_sip_dialog_t *dialog)
{

	assert(dialog->sip_dlg_ref_cnt == 0);
	if (SIP_IS_TIMER_RUNNING(dialog->sip_dlg_timer))
		SIP_CANCEL_TIMER(dialog->sip_dlg_timer);
	if (dialog->sip_dlg_call_id != NULL)
		sip_free_header(dialog->sip_dlg_call_id);
	if (dialog->sip_dlg_local_uri_tag != NULL)
		sip_free_header(dialog->sip_dlg_local_uri_tag);
	if (dialog->sip_dlg_remote_uri_tag != NULL)
		sip_free_header(dialog->sip_dlg_remote_uri_tag);
	if (dialog->sip_dlg_remote_target != NULL)
		sip_free_header(dialog->sip_dlg_remote_target);
	if (dialog->sip_dlg_local_contact != NULL)
		sip_free_header(dialog->sip_dlg_local_contact);
	if (dialog->sip_dlg_new_local_contact != NULL)
		sip_free_header(dialog->sip_dlg_new_local_contact);
	if (dialog->sip_dlg_route_set != NULL)
		sip_free_header(dialog->sip_dlg_route_set);
	if (dialog->sip_dlg_event != NULL)
		sip_free_header(dialog->sip_dlg_event);
	if (dialog->sip_dlg_req_uri.sip_str_ptr != NULL) {
		free(dialog->sip_dlg_req_uri.sip_str_ptr);
		dialog->sip_dlg_req_uri.sip_str_ptr = NULL;
		dialog->sip_dlg_req_uri.sip_str_len = 0;
	}
	if (dialog->sip_dlg_rset.sip_str_ptr != NULL) {
		free(dialog->sip_dlg_rset.sip_str_ptr);
		dialog->sip_dlg_rset.sip_str_len = 0;
		dialog->sip_dlg_rset.sip_str_ptr = NULL;
	}
	(void) pthread_mutex_destroy(&dialog->sip_dlg_mutex);
	free(dialog);
}

/*
 * Get the route information from the 'value' and add it to the route
 * set.
 */
static sip_dlg_route_set_t *
sip_add_route_to_set(sip_hdr_value_t *value)
{
	int			vlen = 0;
	sip_dlg_route_set_t	*rset;
	char			*crlf;
	const sip_param_t	*uri_param;
	int			error;

	rset = calloc(1, sizeof (*rset));
	if (rset == NULL)
		return (NULL);
	rset->sip_dlg_route_next = NULL;
	vlen = value->sip_value_end - value->sip_value_start;

	/*
	 * check for CRLF
	 */
	crlf = value->sip_value_end - strlen(SIP_CRLF);
	while (crlf != NULL && strncmp(crlf, SIP_CRLF, strlen(SIP_CRLF)) == 0) {
		vlen -= strlen(SIP_CRLF);
		crlf -= strlen(SIP_CRLF);
	}
	rset->sip_dlg_route = calloc(1, vlen + 1);
	if (rset->sip_dlg_route == NULL) {
		free(rset);
		return (NULL);
	}
	/*
	 * loose routing
	 */
	rset->sip_dlg_route_lr = B_FALSE;
	(void) strncpy(rset->sip_dlg_route, value->sip_value_start, vlen);
	rset->sip_dlg_ruri.sip_str_ptr = rset->sip_dlg_route +
	    (value->cftr_uri.sip_str_ptr - value->sip_value_start);
	rset->sip_dlg_ruri.sip_str_len = value->cftr_uri.sip_str_len;
	rset->sip_dlg_route[vlen] = '\0';

	assert(value->sip_value_parsed_uri != NULL);
	/*
	 * Check if the 'lr' param is present for this route.
	 */
	uri_param = sip_get_uri_params(value->sip_value_parsed_uri, &error);
	if (error != 0) {
		free(rset->sip_dlg_route);
		free(rset);
		return (NULL);
	}
	if (uri_param != NULL) {
		rset->sip_dlg_route_lr = sip_is_param_present(uri_param, "lr",
		    strlen("lr"));
	}
	return (rset);
}

/*
 * Depending on the route-set, determine the request URI.
 */
char *
sip_dialog_req_uri(sip_dialog_t dialog)
{
	const sip_str_t		*req_uri;
	char			*uri;
	_sip_dialog_t		*_dialog;

	_dialog = (_sip_dialog_t *)dialog;
	if (_dialog->sip_dlg_route_set == NULL ||
	    _dialog->sip_dlg_req_uri.sip_str_ptr == NULL) {
		const struct sip_value	*val;

		val = sip_get_header_value(_dialog->sip_dlg_remote_target,
		    NULL);
		if (val == NULL)
			return (NULL);
		req_uri = &((sip_hdr_value_t *)val)->cftr_uri;
	} else {
		req_uri = &_dialog->sip_dlg_req_uri;
	}
	uri = (char *)malloc(req_uri->sip_str_len + 1);
	if (uri == NULL)
		return (NULL);
	(void) strncpy(uri, req_uri->sip_str_ptr, req_uri->sip_str_len);
	uri[req_uri->sip_str_len] = '\0';

	return (uri);
}

/*
 * Free the route set.
 */
void
sip_dialog_free_rset(sip_dlg_route_set_t *rset)
{
	sip_dlg_route_set_t	*next;

	while (rset != NULL) {
		next = rset->sip_dlg_route_next;
		rset->sip_dlg_route_next = NULL;
		free(rset->sip_dlg_route);
		free(rset);
		rset = next;
	}
}

/*
 * Recompute route-set
 */
static int
sip_dlg_recompute_rset(_sip_dialog_t *dialog, _sip_msg_t *sip_msg, int what)
{
	int ret;

	if (dialog->sip_dlg_route_set != NULL) {
		sip_free_header(dialog->sip_dlg_route_set);
		dialog->sip_dlg_route_set = NULL;
	}
	if (dialog->sip_dlg_req_uri.sip_str_ptr != NULL) {
		free(dialog->sip_dlg_req_uri.sip_str_ptr);
		dialog->sip_dlg_req_uri.sip_str_ptr = NULL;
		dialog->sip_dlg_req_uri.sip_str_len = 0;
	}
	if (dialog->sip_dlg_rset.sip_str_ptr != NULL) {
		free(dialog->sip_dlg_rset.sip_str_ptr);
		dialog->sip_dlg_rset.sip_str_ptr = NULL;
		dialog->sip_dlg_rset.sip_str_len = 0;
	}
	ret = sip_dialog_get_route_set(dialog, sip_msg, what);
	return (ret);
}

/*
 * If the route set is empty, the UAC MUST place the remote target URI
 * into the Request-URI.  The UAC MUST NOT add a Route header field to
 * the request.
 *
 * If the route set is not empty, and the first URI in the route set
 * contains the lr parameter (see Section 19.1.1), the UAC MUST place
 * the remote target URI into the Request-URI and MUST include a Route
 * header field containing the route set values in order, including all
 * parameters.
 *
 * If the route set is not empty, and its first URI does not contain the
 * lr parameter, the UAC MUST place the first URI from the route set
 * into the Request-URI, stripping any parameters that are not allowed
 * in a Request-URI.  The UAC MUST add a Route header field containing
 * the remainder of the route set values in order, including all
 * parameters.  The UAC MUST then place the remote target URI into the
 * Route header field as the last value.
 */
int
sip_dialog_set_route_hdr(_sip_dialog_t *dialog, sip_dlg_route_set_t *rset_head,
    int rcnt, int rlen)
{
	size_t			rset_len;
	_sip_header_t		*rhdr;
	char			*rset;
	char			*rp;
	char			*rsp;
	int			count;
	sip_dlg_route_set_t	*route;
	boolean_t		first = B_TRUE;
	const sip_str_t		*to_uri;
	char			*uri = NULL;
	int			rspl;
	int			rpl;

	assert(rcnt > 0);

	dialog->sip_dlg_rset.sip_str_len = rlen + rcnt - 1;
	dialog->sip_dlg_rset.sip_str_ptr = malloc(rlen + rcnt);
	if (dialog->sip_dlg_rset.sip_str_ptr == NULL)
		return (ENOMEM);
	rsp = dialog->sip_dlg_rset.sip_str_ptr;
	rspl = rlen + rcnt;
	route = rset_head;
	rset_len = rlen;
	if (!route->sip_dlg_route_lr) {
		const struct sip_value	*val;

		val = sip_get_header_value(dialog->sip_dlg_remote_target, NULL);
		to_uri = &((sip_hdr_value_t *)val)->cftr_uri;
		uri = (char *)malloc(to_uri->sip_str_len + 1);
		if (uri == NULL) {
			free(dialog->sip_dlg_rset.sip_str_ptr);
			dialog->sip_dlg_rset.sip_str_len = 0;
			dialog->sip_dlg_rset.sip_str_ptr = NULL;
			return (ENOMEM);
		}
		(void) strncpy(uri, to_uri->sip_str_ptr, to_uri->sip_str_len);
		uri[to_uri->sip_str_len] = '\0';
		rset_len = rlen - strlen(route->sip_dlg_route) + strlen(uri) +
		    SIP_SPACE_LEN + sizeof (char) + SIP_SPACE_LEN +
		    sizeof (char);
		count = snprintf(rsp, rspl, "%s", route->sip_dlg_route);
		dialog->sip_dlg_req_uri.sip_str_ptr = malloc(
		    route->sip_dlg_ruri.sip_str_len + 1);
		if (dialog->sip_dlg_req_uri.sip_str_ptr == NULL) {
			free(uri);
			free(dialog->sip_dlg_rset.sip_str_ptr);
			dialog->sip_dlg_rset.sip_str_len = 0;
			dialog->sip_dlg_rset.sip_str_ptr = NULL;
			return (ENOMEM);
		}
		(void) strncpy(dialog->sip_dlg_req_uri.sip_str_ptr, rsp +
		    (route->sip_dlg_ruri.sip_str_ptr - route->sip_dlg_route),
		    route->sip_dlg_ruri.sip_str_len);
		dialog->sip_dlg_req_uri.sip_str_ptr[
		    route->sip_dlg_ruri.sip_str_len] = '\0';
		dialog->sip_dlg_req_uri.sip_str_len =
		    route->sip_dlg_ruri.sip_str_len;

		rsp += count;
		rspl -= count;
		route = route->sip_dlg_route_next;
	}

	/*
	 * rcnt - 1 is for the number of COMMAs
	 */
	rset_len += strlen(SIP_ROUTE) + SIP_SPACE_LEN + sizeof (char) +
	    SIP_SPACE_LEN + rcnt - 1;
	rset = malloc(rset_len + 1);
	if (rset == NULL) {
		free(dialog->sip_dlg_rset.sip_str_ptr);
		dialog->sip_dlg_rset.sip_str_len = 0;
		dialog->sip_dlg_rset.sip_str_ptr = NULL;
		return (ENOMEM);
	}
	rhdr = sip_new_header(rset_len + strlen(SIP_CRLF));
	if (rhdr == NULL) {
		free(rset);
		free(dialog->sip_dlg_rset.sip_str_ptr);
		dialog->sip_dlg_rset.sip_str_len = 0;
		dialog->sip_dlg_rset.sip_str_ptr = NULL;
		return (ENOMEM);
	}

	rp = rset;
	rpl = rset_len + 1;
	count = snprintf(rp, rpl, "%s %c ", SIP_ROUTE, SIP_HCOLON);
	rp += count;
	rpl -= count;

	while (route != NULL) {
		if (first) {
			count = snprintf(rp, rpl, "%s", route->sip_dlg_route);
			rp += count;
			rpl -= count;
			first = B_FALSE;
			if (uri != NULL) {
				count = snprintf(rsp, rspl, "%c%s",
				    SIP_COMMA, route->sip_dlg_route);
			} else {
				count = snprintf(rsp, rspl, "%s",
				    route->sip_dlg_route);
			}
			rsp += count;
			rspl -= count;
		} else {
			count = snprintf(rp, rpl, "%c%s", SIP_COMMA,
			    route->sip_dlg_route);
			rp += count;
			rpl -= count;
			count = snprintf(rsp, rspl, "%c%s", SIP_COMMA,
			    route->sip_dlg_route);
			rsp += count;
			rspl -= count;
		}
		route = route->sip_dlg_route_next;
	}
	assert(rsp <= dialog->sip_dlg_rset.sip_str_ptr +
	    dialog->sip_dlg_rset.sip_str_len);
	dialog->sip_dlg_rset.sip_str_ptr[dialog->sip_dlg_rset.sip_str_len] =
	    '\0';
	if (uri != NULL) {
		if (first) {
			count = snprintf(rp, rpl, "%c %s %c", SIP_LAQUOT,
			    uri, SIP_RAQUOT);
		} else {
			count = snprintf(rp, rpl, "%c%c %s %c", SIP_COMMA,
			    SIP_LAQUOT, uri, SIP_RAQUOT);
		}
		rp += count;
		rpl -= count;
		free(uri);
	}
	assert(rp <= rset + rset_len);
	(void) snprintf(rhdr->sip_hdr_start, rset_len + strlen(SIP_CRLF) + 1,
	    "%s%s", rset, SIP_CRLF);
	free(rset);
	dialog->sip_dlg_route_set = (sip_header_t)rhdr;
	sip_dialog_free_rset(rset_head);
	return (0);
}

/*
 * UAC Behavior
 * The route set MUST be set to the list of URIs in the Record-Route
 * header field from the response, taken in reverse order and preserving
 * all URI parameters.
 *
 * UAS behavior
 * The route set MUST be set to the list of URIs in the Record-Route
 * header field from the request, taken in order and preserving all URI
 * parameters.
 */
static int
sip_dialog_get_route_set(_sip_dialog_t *dialog, _sip_msg_t *sip_msg, int what)
{
	sip_header_t		rrhdr;
	sip_hdr_value_t		*value;
	int			error;
	sip_dlg_route_set_t	*rset_head = NULL;
	sip_dlg_route_set_t	*rset_tail = NULL;
	sip_dlg_route_set_t	*rset;
	int			rset_cnt = 0;
	int			rset_len = 0;

	(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
	rrhdr = sip_search_for_header(sip_msg, SIP_RECORD_ROUTE, NULL);
	while (rrhdr != NULL) {
		(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
		value = (sip_hdr_value_t *)sip_get_header_value(rrhdr, &error);
		while (value != NULL && error == 0) {
			char	*crlf;

			if (value->sip_value_state == SIP_VALUE_BAD) {
				value = (sip_hdr_value_t *)sip_get_next_value(
				    (sip_header_value_t)value, &error);
				continue;
			}
			rset = sip_add_route_to_set(value);
			if (rset == NULL)
				goto r_error;
			/*
			 * Add one for COMMA
			 */
			rset_cnt++;
			rset_len += (value->sip_value_end -
			    value->sip_value_start);
			/*
			 * Check for CRLF
			 */
			crlf = value->sip_value_end - strlen(SIP_CRLF);
			while (crlf != NULL &&
			    strncmp(crlf, SIP_CRLF, strlen(SIP_CRLF)) == 0) {
				rset_len -= strlen(SIP_CRLF);
				crlf -= strlen(SIP_CRLF);
			}
			if (rset_head == NULL) {
				assert(rset_tail == NULL);
				rset_head = rset_tail = rset;
			} else if (what == SIP_UAS_DIALOG) {
				rset_tail->sip_dlg_route_next = rset;
				rset_tail = rset;
			} else if (what == SIP_UAC_DIALOG) {
				rset->sip_dlg_route_next = rset_head;
				rset_head = rset;
			} else {
				assert(0);
			}
			value = (sip_hdr_value_t *)sip_get_next_value(
			    (sip_header_value_t)value, &error);
		}
		(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
		rrhdr = sip_search_for_header(sip_msg, SIP_RECORD_ROUTE, rrhdr);
	}
	(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
	if (rset_cnt == 0)
		return (0);
	if (sip_dialog_set_route_hdr(dialog, rset_head, rset_cnt,
	    rset_len) != 0) {
		goto r_error;
	}
	return (0);
r_error:
	sip_dialog_free_rset(rset_head);
	return (ENOMEM);
}

/*
 * UAS behavior:
 * The remote sequence number MUST be set to the value of the sequence
 * number in the CSeq header field of the request.  The local sequence
 * number MUST be empty.  The call identifier component of the dialog ID
 * MUST be set to the value of the Call-ID in the request.  The local
 * tag component of the dialog ID MUST be set to the tag in the To field
 * in the response to the request (which always includes a tag), and the
 * remote tag component of the dialog ID MUST be set to the tag from the
 * From field in the request.  A UAS MUST be prepared to receive a
 * request without a tag in the From field, in which case the tag is
 * considered to have a value of null.
 * The remote URI MUST be set to the URI in the From field, and the
 * local URI MUST be set to the URI in the To field.
 * The remote target MUST be set to the URI from the Contact header field
 * of the request.
 *
 * UAC behavior:
 * The local sequence number MUST be set to the value of the sequence
 * number in the CSeq header field of the request.  The remote sequence
 * number MUST be empty (it is established when the remote UA sends a
 * request within the dialog).  The call identifier component of the
 * dialog ID MUST be set to the value of the Call-ID in the request.
 * The local tag component of the dialog ID MUST be set to the tag in
 * the From field in the request, and the remote tag component of the
 * dialog ID MUST be set to the tag in the To field of the response.  A
 * UAC MUST be prepared to receive a response without a tag in the To
 * field, in which case the tag is considered to have a value of null.
 * The remote URI MUST be set to the URI in the To field, and the local
 * URI MUST be set to the URI in the From field.
 * The remote target MUST be set to the URI from the Contact header field
 * of the response.
 */


/*
 * This is the routine that seeds a dialog.
 */
sip_dialog_t
sip_seed_dialog(sip_conn_object_t obj, _sip_msg_t *sip_msg,
    boolean_t dlg_on_fork, int dlg_type)
{
	_sip_dialog_t		*dialog;
	int			cseq;
	sip_header_t		fhdr = NULL;
	sip_header_t		thdr = NULL;
	sip_header_t		chdr;
	sip_header_t		cihdr;
	sip_header_t		evhdr = NULL;
	const struct sip_value	*value;
	sip_dialog_timer_obj_t	*tim_obj = NULL;
	const sip_str_t		*callid;
	sip_method_t		method;
	int			timer1 = sip_timer_T1;
	int			error;

	if (!sip_msg_is_request((sip_msg_t)sip_msg, &error))
		return (NULL);

	method = sip_get_request_method((sip_msg_t)sip_msg, &error);
	/*
	 * Only INVITE and SUBSCRIBE supported
	 */
	if (error != 0 || (method != INVITE && method != SUBSCRIBE))
		return (NULL);

	/*
	 * A request outside of a dialog MUST NOT contain a To tag
	 */
	if (sip_get_to_tag((sip_msg_t)sip_msg, NULL) != NULL)
		return (NULL);

	if (dlg_type == SIP_UAS_DIALOG) {
		thdr = sip_dlg_xchg_from_to((sip_msg_t)sip_msg,
		    SIP_DLG_XCHG_FROM);
		(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
	} else {
		(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
		fhdr = sip_search_for_header(sip_msg, SIP_FROM, NULL);
	}
	cihdr = sip_search_for_header(sip_msg, SIP_CALL_ID, NULL);
	chdr = sip_search_for_header(sip_msg, SIP_CONTACT, NULL);
	if (method == SUBSCRIBE)
		evhdr = sip_search_for_header(sip_msg, SIP_EVENT, NULL);
	(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
	if ((fhdr == NULL && thdr == NULL) || cihdr == NULL || chdr == NULL ||
	    (method == SUBSCRIBE && evhdr == NULL)) {
		if (thdr != NULL)
			sip_free_header(thdr);
		return (NULL);
	}

	/*
	 * Sanity check since we just store the headers in the dialog
	 */
	if (sip_get_from_tag((sip_msg_t)sip_msg, NULL) == NULL ||
	    sip_get_from_uri_str((sip_msg_t)sip_msg, NULL) == NULL ||
	    ((cseq = sip_get_callseq_num((sip_msg_t)sip_msg, NULL)) == -1) ||
	    (callid = sip_get_callid((sip_msg_t)sip_msg, NULL)) == NULL ||
	    sip_get_to_uri_str((sip_msg_t)sip_msg, NULL) == NULL ||
	    ((value = sip_get_header_value(chdr, NULL)) == NULL) ||
	    sip_get_contact_uri_str((sip_header_value_t)value, NULL) == NULL) {
		if (thdr != NULL)
			sip_free_header(thdr);
		return (NULL);
	}

	tim_obj = calloc(1, sizeof (sip_dialog_timer_obj_t));
	if (tim_obj == NULL) {
		if (thdr != NULL)
			sip_free_header(thdr);
		return (NULL);
	}
	dialog = calloc(1, sizeof (_sip_dialog_t));
	if (dialog == NULL) {
		if (thdr != NULL)
			sip_free_header(thdr);
		return (NULL);
	}
	/*
	 * We will take the TO header with the tag when we complete this
	 * dialog
	 */
	if (dlg_type == SIP_UAS_DIALOG) {
		dialog->sip_dlg_remote_uri_tag = thdr;
		/*
		 * We take the remote target from the incoming request on the
		 * UAS. For the UAC, we will take it from the response.
		 */
		if ((dialog->sip_dlg_remote_target = sip_dup_header(chdr)) ==
		    NULL) {
			goto dia_err;
		}
	} else {
		if ((dialog->sip_dlg_local_uri_tag = sip_dup_header(fhdr)) ==
		    NULL) {
			goto dia_err;
		}
		/*
		 * We take the local contact from the originating request on
		 * UAC. For the UAS, we will take it from the response.
		 */
		if ((dialog->sip_dlg_local_contact = sip_dup_header(chdr)) ==
		    NULL) {
			goto dia_err;
		} else {
			dialog->sip_dlg_new_local_contact = NULL;
		}
	}
	if ((dialog->sip_dlg_call_id = sip_dup_header(cihdr)) == NULL)
		goto dia_err;
	if (method == SUBSCRIBE) {
		dialog->sip_dlg_event = sip_dup_header(evhdr);
		if (dialog->sip_dlg_event == NULL) {
			goto dia_err;
		}
	}
	dialog->sip_dlg_rset.sip_str_ptr = NULL;
	dialog->sip_dlg_rset.sip_str_len = 0;
	dialog->sip_dlg_req_uri.sip_str_ptr = NULL;
	dialog->sip_dlg_req_uri.sip_str_len = 0;
	/*
	 * Get the route set from the request, if present
	 */
	if (dlg_type == SIP_UAS_DIALOG &&
	    sip_dialog_get_route_set(dialog, sip_msg, dlg_type) != 0) {
		goto dia_err;
	}
	if (dlg_type == SIP_UAC_DIALOG)
		dialog->sip_dlg_local_cseq = cseq;
	else
		dialog->sip_dlg_remote_cseq = cseq;
	dialog->sip_dlg_type = dlg_type;
	dialog->sip_dlg_on_fork = dlg_on_fork;
	dialog->sip_dlg_method = method;
	/*
	 * Set the partial dialog timer with the INVITE timeout val
	 */
	if (sip_conn_timer1 != NULL)
		timer1 = sip_conn_timer1(obj);
	SIP_INIT_TIMER(dialog->sip_dlg_timer, 64 * timer1);
	tim_obj->dialog = dialog;
	/*
	 * Since at the client we never pass the partial dialog, we need not
	 * invoke the callback when the partial dialog self-destructs.
	 */
	if (dlg_type == SIP_UAS_DIALOG)
		tim_obj->func = sip_ulp_dlg_del_cb;
	SIP_SCHED_TIMER(dialog->sip_dlg_timer, (void *)tim_obj,
	    sip_dlg_self_destruct);
	if (!SIP_IS_TIMER_RUNNING(dialog->sip_dlg_timer))
		goto dia_err;
	(void) pthread_mutex_init(&dialog->sip_dlg_mutex, NULL);

	if (dlg_type == SIP_UAC_DIALOG) {
		const sip_str_t	*local_tag;

		local_tag = sip_get_from_tag((sip_msg_t)sip_msg, NULL);
		assert(local_tag != NULL);
		sip_md5_hash(local_tag->sip_str_ptr, local_tag->sip_str_len,
		    callid->sip_str_ptr, callid->sip_str_len,
		    NULL, 0, NULL, 0, NULL, 0, NULL, 0,
		    (uchar_t *)dialog->sip_dlg_id);


		/*
		 * Add it to the partial hash table
		 */
		if (sip_hash_add(sip_dialog_phash, (void *)dialog,
		    SIP_DIGEST_TO_HASH(dialog->sip_dlg_id)) != 0) {
			goto dia_err;
		}
	}
	SIP_DLG_REFCNT_INCR(dialog);
	return ((sip_dialog_t)dialog);
dia_err:
	sip_release_dialog_res(dialog);
	if (SIP_IS_TIMER_RUNNING(dialog->sip_dlg_timer))
		SIP_CANCEL_TIMER(dialog->sip_dlg_timer);
	if (tim_obj != NULL)
		free(tim_obj);
	return (NULL);
}

/*
 * When creating a dialog from a NOTIFY request, we need to get the FROM
 * header for the dialog from the TO header of the NOTIFY.
 */
_sip_header_t *
sip_dlg_xchg_from_to(sip_msg_t sip_msg, int what)
{
	int			len;
	_sip_header_t		*newhdr;
	int			cnt;
	const struct sip_header	*hdr;
	int			hdrsize;
	int			error;

	hdr = sip_get_header(sip_msg, what == SIP_DLG_XCHG_FROM ? SIP_FROM :
	    SIP_TO, NULL, &error);
	if (error != 0 || hdr == NULL)
		return (NULL);
	if (sip_parse_goto_values((_sip_header_t *)hdr) != 0)
		return (NULL);
	len = hdr->sip_hdr_end - hdr->sip_hdr_current;
	if (what == SIP_DLG_XCHG_FROM) {
		hdrsize = len + strlen(SIP_TO) + SIP_SPACE_LEN + sizeof (char) +
		    SIP_SPACE_LEN;
	} else {
		hdrsize = len + strlen(SIP_FROM) + SIP_SPACE_LEN +
		    sizeof (char) + SIP_SPACE_LEN;
	}
	newhdr = sip_new_header(hdrsize);
	if (newhdr == NULL)
		return (NULL);
	if (what == SIP_DLG_XCHG_FROM) {
		cnt = snprintf(newhdr->sip_hdr_current, hdrsize + 1,
		    "%s %c ", SIP_TO, SIP_HCOLON);
	} else {
		cnt = snprintf(newhdr->sip_hdr_current, hdrsize + 1,
		    "%s %c ", SIP_FROM, SIP_HCOLON);
	}
	newhdr->sip_hdr_current += cnt;
	(void) strncpy(newhdr->sip_hdr_current, hdr->sip_hdr_current, len);
	newhdr->sip_hdr_current += len;
	assert(newhdr->sip_hdr_current == newhdr->sip_hdr_end);
	assert(hdr->sip_header_functions != NULL);

	/*
	 * FROM and TO have common parsing functions
	 */
	newhdr->sip_header_functions = hdr->sip_header_functions;
	newhdr->sip_hdr_current = newhdr->sip_hdr_start;

	return (newhdr);
}

/*
 * This is the response that completes the dialog that was created
 * in sip_seed_dialog().
 */
sip_dialog_t
sip_complete_dialog(_sip_msg_t *sip_msg, _sip_dialog_t *dialog)
{
	_sip_header_t		*thdr;
	_sip_header_t		*evhdr = NULL;
	_sip_header_t		*substate = NULL;
	sip_header_t		chdr = NULL;
	int			resp_code;
	const sip_str_t		*ttag;
	const sip_str_t		*remtag;
	const sip_str_t		*callid;
	const struct sip_value 	*val;
	sip_method_t		method;
	int			error = 0;
	int			prev_state;
	boolean_t		alloc_thdr = B_FALSE;

	if (sip_msg_is_request((sip_msg_t)sip_msg, &error) && error == 0)
		method = sip_get_request_method((sip_msg_t)sip_msg, &error);
	else
		method = sip_get_callseq_method((sip_msg_t)sip_msg, &error);
	if (error != 0 || dialog == NULL ||
	    (sip_msg_is_request((sip_msg_t)sip_msg, &error) &&
	    (dialog->sip_dlg_method == INVITE || method != NOTIFY))) {
		return (NULL);
	}
	if ((dialog->sip_dlg_type == SIP_UAC_DIALOG && method != NOTIFY &&
	    sip_get_callseq_num((sip_msg_t)sip_msg, NULL) !=
	    dialog->sip_dlg_local_cseq) ||
	    (dialog->sip_dlg_type == SIP_UAS_DIALOG && method != NOTIFY &&
	    sip_get_callseq_num((sip_msg_t)sip_msg, NULL) !=
	    dialog->sip_dlg_remote_cseq)) {
		return (NULL);
	}
	if (method == NOTIFY) {
		const sip_str_t	*sstate;

		thdr = sip_dlg_xchg_from_to((sip_msg_t)sip_msg,
		    SIP_DLG_XCHG_FROM);
		if (thdr == NULL)
			return (NULL);
		alloc_thdr = B_TRUE;
		(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
		chdr = sip_search_for_header(sip_msg, SIP_CONTACT, NULL);
		if (chdr == NULL) {
			(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
			sip_free_header(thdr);
			return (NULL);
		}
		evhdr = sip_search_for_header(sip_msg, SIP_EVENT, NULL);
		if (evhdr == NULL) {
			(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
			sip_free_header(thdr);
			return (NULL);
		}
		substate = sip_search_for_header(sip_msg,
		    SIP_SUBSCRIPTION_STATE, NULL);
		if (substate == NULL) {
			(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
			sip_free_header(thdr);
			return (NULL);
		}
		(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
		sstate = sip_get_substate((sip_msg_t)sip_msg, &error);
		if (sstate == NULL || error != 0) {
			sip_free_header(thdr);
			return (NULL);
		}
		if ((sstate->sip_str_len != strlen("pending") &&
		    sstate->sip_str_len != strlen("active")) ||
		    ((sstate->sip_str_len == strlen("pending") &&
		    strncasecmp(sstate->sip_str_ptr, "pending",
		    strlen("pending")) != 0) ||
		    (sstate->sip_str_len == strlen("active") &&
		    strncasecmp(sstate->sip_str_ptr, "active",
		    strlen("active")) != 0))) {
			sip_free_header(thdr);
			return (NULL);
		}
		ttag = sip_get_from_tag((sip_msg_t)sip_msg, NULL);
	} else {
		if (dialog->sip_dlg_type == SIP_UAS_DIALOG) {
			thdr = sip_dlg_xchg_from_to((sip_msg_t)sip_msg,
			    SIP_DLG_XCHG_TO);
			alloc_thdr = B_TRUE;
		} else {
			(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
			thdr = sip_search_for_header(sip_msg, SIP_TO, NULL);
			if (dialog->sip_dlg_remote_target == NULL) {
				chdr = sip_search_for_header(sip_msg,
				    SIP_CONTACT, NULL);
			}
			(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
		}
		if (thdr == NULL) {
			(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
			return (NULL);
		}
		ttag = sip_get_to_tag((sip_msg_t)sip_msg, NULL);
	}
	if (ttag == NULL) {
		if (alloc_thdr)
			sip_free_header(thdr);
		return (NULL);
	}
	prev_state = dialog->sip_dlg_state;

	if (method == NOTIFY) {
		int			error;
		const sip_str_t		*dlg_id_val = NULL;
		const sip_str_t		*event;
		const sip_str_t		*id_val = NULL;
		sip_header_value_t	ev_val;
		sip_hdr_value_t		*dlg_ev_val = NULL;

		event = sip_get_event((sip_msg_t)sip_msg, &error);
		if (event == NULL || error != 0) {
			sip_free_header(thdr);
			return (NULL);
		}
		ev_val = (sip_header_value_t)sip_get_header_value(evhdr,
		    &error);
		if (ev_val != NULL)
			id_val = sip_get_param_value(ev_val, "id", &error);
		if (error == 0) {
			dlg_ev_val = (sip_hdr_value_t *)sip_get_header_value(
			    dialog->sip_dlg_event, &error);
		}
		if (dlg_ev_val == NULL || error != 0) {
			sip_free_header(thdr);
			return (NULL);
		}
		dlg_id_val = sip_get_param_value((sip_header_value_t)dlg_ev_val,
		    "id", &error);
		if (error != 0 ||
		    dlg_ev_val->str_val_len != event->sip_str_len ||
		    strncmp(dlg_ev_val->str_val_ptr, event->sip_str_ptr,
		    event->sip_str_len != 0)) {
			sip_free_header(thdr);
			return (NULL);
		}
		if ((dlg_id_val == NULL && id_val != NULL) ||
		    (dlg_id_val != NULL && id_val == NULL)) {
			sip_free_header(thdr);
			return (NULL);
		} else if (dlg_id_val != NULL && id_val != NULL) {
			if (dlg_id_val->sip_str_len != id_val->sip_str_len ||
			    strncasecmp(dlg_id_val->sip_str_ptr,
			    id_val->sip_str_ptr, dlg_id_val->sip_str_len) !=
			    0) {
				sip_free_header(thdr);
				return (NULL);
			}
		}
		if (dialog->sip_dlg_type == SIP_UAC_DIALOG) {
			dialog->sip_dlg_remote_uri_tag = thdr;
			if ((dialog->sip_dlg_remote_target =
			    sip_dup_header(chdr)) == NULL) {
				sip_free_header(thdr);
				return (NULL);
			}
		} else {
			dialog->sip_dlg_local_uri_tag = thdr;
		}
		dialog->sip_dlg_state = SIP_DLG_CONFIRMED;
	} else {
		resp_code = sip_get_response_code((sip_msg_t)sip_msg, &error);
		(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
		assert(dialog->sip_dlg_state == SIP_DLG_NEW);
		if (dialog->sip_dlg_remote_target == NULL && chdr != NULL) {
			assert(dialog->sip_dlg_type == SIP_UAC_DIALOG);
			if ((dialog->sip_dlg_remote_target =
			    sip_dup_header(chdr)) == NULL) {
				(void) pthread_mutex_unlock(
				    &dialog->sip_dlg_mutex);
				if (alloc_thdr)
					sip_free_header(thdr);
				goto terminate_new_dlg;
			}
			if (sip_dialog_get_route_set(dialog, sip_msg,
			    dialog->sip_dlg_type) != 0) {
				(void) pthread_mutex_unlock(
				    &dialog->sip_dlg_mutex);
				if (alloc_thdr)
					sip_free_header(thdr);
				goto terminate_new_dlg;
			}
		}
		if (SIP_PROVISIONAL_RESP(resp_code)) {
			dialog->sip_dlg_state = SIP_DLG_EARLY;
		} else if (SIP_OK_RESP(resp_code)) {
			/*
			 * Per 12.1 the UAS must include the contact header
			 * for a dialog establishing response, so if we
			 * don't find one, we terminate it.
			 */
			if (dialog->sip_dlg_remote_target == NULL) {
				(void) pthread_mutex_unlock(
				    &dialog->sip_dlg_mutex);
				if (sip_ulp_dlg_del_cb != NULL) {
					sip_ulp_dlg_del_cb(dialog,
					    (sip_msg_t)sip_msg, NULL);
				}
				if (alloc_thdr)
					sip_free_header(thdr);
				goto terminate_new_dlg;
			}
			dialog->sip_dlg_state = SIP_DLG_CONFIRMED;
		} else {
			(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
			if (sip_ulp_dlg_del_cb != NULL) {
				sip_ulp_dlg_del_cb(dialog, (sip_msg_t)sip_msg,
				    NULL);
			}
			if (alloc_thdr)
				sip_free_header(thdr);
			goto terminate_new_dlg;
		}
		if (dialog->sip_dlg_type == SIP_UAS_DIALOG) {
			dialog->sip_dlg_local_uri_tag = thdr;
		} else {
			if ((dialog->sip_dlg_remote_uri_tag =
			    sip_dup_header(thdr)) == NULL) {
				(void) pthread_mutex_unlock(
				    &dialog->sip_dlg_mutex);
				goto terminate_new_dlg;
			}
		}
	}

	/*
	 * We take the local contact for UAS Dialog from the response (either
	 * NOTIFY for SUBSCRIBE request or from final response 2xx to INVITE
	 * request)
	 */
	if ((dialog->sip_dlg_type == SIP_UAS_DIALOG) && (dialog->sip_dlg_state
	    == SIP_DLG_CONFIRMED)) {
		if (chdr == NULL) {
			(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
			chdr = sip_search_for_header(sip_msg, SIP_CONTACT,
			    NULL);
			(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
		}
		if ((chdr == NULL) || ((dialog->sip_dlg_local_contact =
		    sip_dup_header(chdr)) == NULL)) {
			(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
			if (alloc_thdr)
				sip_free_header(thdr);
			goto terminate_new_dlg;
		}
	}

	/*
	 * Cancel the partial dialog timer
	 */
	if (SIP_IS_TIMER_RUNNING(dialog->sip_dlg_timer))
		SIP_CANCEL_TIMER(dialog->sip_dlg_timer);

	if (dialog->sip_dlg_type == SIP_UAC_DIALOG) {
		val =  sip_get_header_value(dialog->sip_dlg_local_uri_tag,
		    &error);
	} else {
		val =  sip_get_header_value(dialog->sip_dlg_remote_uri_tag,
		    &error);
	}
	assert(val != NULL && error == 0);
	remtag = sip_get_param_value((sip_header_value_t)val, "tag", &error);

	val = sip_get_header_value(dialog->sip_dlg_call_id, &error);
	callid = &((sip_hdr_value_t *)val)->str_val;

	/*
	 * Get an ID for this dialog
	 */
	if (dialog->sip_dlg_type == SIP_UAC_DIALOG) {
		sip_md5_hash(remtag->sip_str_ptr, remtag->sip_str_len,
		    ttag->sip_str_ptr, ttag->sip_str_len,
		    callid->sip_str_ptr, callid->sip_str_len,
		    NULL, 0, NULL, 0, NULL, 0, (uchar_t *)dialog->sip_dlg_id);
	} else {
		sip_md5_hash(ttag->sip_str_ptr, ttag->sip_str_len,
		    remtag->sip_str_ptr, remtag->sip_str_len,
		    callid->sip_str_ptr, callid->sip_str_len,
		    NULL, 0, NULL, 0, NULL, 0, (uchar_t *)dialog->sip_dlg_id);
	}

	SIP_DLG_REFCNT_INCR(dialog);
	(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);

	/*
	 * Add it to the hash table
	 */
	if (sip_hash_add(sip_dialog_hash, (void *)dialog,
	    SIP_DIGEST_TO_HASH(dialog->sip_dlg_id)) != 0) {
	terminate_new_dlg:
		/*
		 * So that sip_dialog_delete() does not try to remove
		 * this from the hash table.
		 */
		(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
		if (dialog->sip_dlg_type == SIP_UAS_DIALOG) {
			if (dialog->sip_dlg_local_uri_tag != NULL) {
				sip_free_header(dialog->sip_dlg_local_uri_tag);
				dialog->sip_dlg_local_uri_tag = NULL;
			}
		} else {
			if (dialog->sip_dlg_remote_uri_tag != NULL) {
				sip_free_header(dialog->sip_dlg_remote_uri_tag);
				dialog->sip_dlg_remote_uri_tag = NULL;
			}
		}
		(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
		sip_dialog_terminate(dialog, (sip_msg_t)sip_msg);
		return (NULL);
	}
	if (sip_dlg_ulp_state_cb != NULL) {
		sip_dlg_ulp_state_cb((sip_dialog_t)dialog,
		    (sip_msg_t)sip_msg, prev_state, dialog->sip_dlg_state);
	}
	return ((sip_dialog_t)dialog);
}

/*
 * Check if this dialog is a match.
 */
boolean_t
sip_dialog_match(void *obj, void *hindex)
{
	_sip_dialog_t	*dialog = (_sip_dialog_t *)obj;

	(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
	if (dialog->sip_dlg_state == SIP_DLG_DESTROYED) {
		(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
		return (B_FALSE);
	}
	if (bcmp(dialog->sip_dlg_id, hindex,
	    sizeof (dialog->sip_dlg_id)) == 0) {
		SIP_DLG_REFCNT_INCR(dialog);
		(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
		return (B_TRUE);
	}
	(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
	return (B_FALSE);
}

/*
 * Don't delete, just take it out of the hash
 */
boolean_t
sip_dialog_dontfree(void *obj, void *hindex, int *found)
{
	_sip_dialog_t	*dialog = (_sip_dialog_t *)obj;

	*found = 0;
	(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
	if (bcmp(dialog->sip_dlg_id, hindex, sizeof (dialog->sip_dlg_id))
	    == 0) {
		*found = 1;
		(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
		return (B_TRUE);
	}
	(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
	return (B_FALSE);
}

/*
 * Free resources associated with the dialog, the object will be removed
 * from the hash list by sip_hash_delete.
 */
boolean_t
sip_dialog_free(void *obj, void *hindex, int *found)
{
	_sip_dialog_t	*dialog = (_sip_dialog_t *)obj;

	*found = 0;
	(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
	if (bcmp(dialog->sip_dlg_id, hindex, sizeof (dialog->sip_dlg_id))
	    == 0) {
		*found = 1;
		assert(dialog->sip_dlg_state == SIP_DLG_DESTROYED);
		if (dialog->sip_dlg_ref_cnt != 0) {
			(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
			return (B_FALSE);
		}
		sip_release_dialog_res(dialog);
		return (B_TRUE);
	}
	(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
	return (B_FALSE);
}

/*
 * The UAS will receive the request from the transaction layer.  If the
 * request has a tag in the To header field, the UAS core computes the
 * dialog identifier corresponding to the request and compares it with
 * existing dialogs.  If there is a match, this is a mid-dialog request.
 */
sip_dialog_t
sip_dialog_find(_sip_msg_t *sip_msg)
{
	const sip_str_t	*localtag;
	const sip_str_t	*remtag;
	const sip_str_t	*callid;
	uint16_t	digest[8];
	_sip_dialog_t	*dialog;
	boolean_t	is_request;
	int		error;

	is_request = sip_msg_is_request((sip_msg_t)sip_msg, &error);
	if (error != 0)
		return (NULL);
	if (is_request) {
		localtag = sip_get_to_tag((sip_msg_t)sip_msg, &error);
		if (error == 0)
			remtag = sip_get_from_tag((sip_msg_t)sip_msg, &error);
	} else {
		remtag = sip_get_to_tag((sip_msg_t)sip_msg, &error);
		if (error == 0)
			localtag = sip_get_from_tag((sip_msg_t)sip_msg, &error);
	}
	if (error != 0)
		return (NULL);
	callid = sip_get_callid((sip_msg_t)sip_msg, &error);
	if (error != 0 || remtag == NULL || localtag == NULL ||
	    callid == NULL) {
		return (NULL);
	}
	sip_md5_hash(localtag->sip_str_ptr, localtag->sip_str_len,
	    remtag->sip_str_ptr, remtag->sip_str_len,
	    callid->sip_str_ptr, callid->sip_str_len,
	    NULL, 0, NULL, 0, NULL, 0, (uchar_t *)digest);

	dialog = (_sip_dialog_t *)sip_hash_find(sip_dialog_hash,
	    (void *)digest, SIP_DIGEST_TO_HASH(digest), sip_dialog_match);
	if (dialog == NULL) {
		sip_md5_hash(localtag->sip_str_ptr, localtag->sip_str_len,
		    NULL, 0, callid->sip_str_ptr, callid->sip_str_len,
		    NULL, 0, NULL, 0, NULL, 0, (uchar_t *)digest);
		dialog = (_sip_dialog_t *)sip_hash_find(sip_dialog_phash,
		    (void *)digest, SIP_DIGEST_TO_HASH(digest),
		    sip_dialog_match);
	}
	return ((sip_dialog_t)dialog);
}

/*
 * We keep this partial dialog for the duration of the INVITE
 * transaction timeout duration, i.e. Timer B.
 */
void
sip_dlg_self_destruct(void *args)
{
	sip_dialog_timer_obj_t	*tim_obj = (sip_dialog_timer_obj_t *)args;
	_sip_dialog_t		*dialog = (_sip_dialog_t *)tim_obj->dialog;
	int			index;

	(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
	assert(dialog->sip_dlg_state == SIP_DLG_NEW);
	dialog->sip_dlg_state = SIP_DLG_DESTROYED;
	if (dialog->sip_dlg_type == SIP_UAC_DIALOG) {
		index = SIP_DIGEST_TO_HASH(dialog->sip_dlg_id);
		(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
		sip_hash_delete(sip_dialog_phash, (void *)dialog->sip_dlg_id,
		    index, sip_dialog_dontfree);
	} else {
		(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
	}
	if (tim_obj->func != NULL)
		tim_obj->func(dialog, NULL, NULL);
	free(tim_obj);
	SIP_DLG_REFCNT_DECR(dialog);
}

/*
 * Terminate a dialog
 */
void
sip_dialog_terminate(_sip_dialog_t *dialog, sip_msg_t sip_msg)
{
	int	prev_state;

	(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
	prev_state = dialog->sip_dlg_state;
	dialog->sip_dlg_state = SIP_DLG_DESTROYED;
	(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
	if (sip_dlg_ulp_state_cb != NULL) {
		sip_dlg_ulp_state_cb((sip_dialog_t)dialog, sip_msg, prev_state,
		    dialog->sip_dlg_state);
	}
	SIP_DLG_REFCNT_DECR(dialog);
}

/*
 * Delete a dialog
 */
void
sip_dialog_delete(_sip_dialog_t *dialog)
{
	int	index;

	/*
	 * partial dialog, not in the hash table
	 */
	if (dialog->sip_dlg_local_uri_tag == NULL ||
	    dialog->sip_dlg_remote_uri_tag == NULL) {
		/*
		 * Cancel the partial dialog timer
		 */
		if (SIP_IS_TIMER_RUNNING(dialog->sip_dlg_timer))
			SIP_CANCEL_TIMER(dialog->sip_dlg_timer);
		sip_release_dialog_res(dialog);
		return;
	}
	index = SIP_DIGEST_TO_HASH(dialog->sip_dlg_id);
	sip_hash_delete(sip_dialog_hash, (void *)dialog->sip_dlg_id, index,
	    sip_dialog_free);
}

/*
 * Get the remote target from the CONTACT header from the 200 OK response
 */
static boolean_t
sip_get_rtarg(_sip_dialog_t *dialog, _sip_msg_t *sip_msg)
{
	sip_header_t	chdr;

	if (dialog->sip_dlg_remote_target != NULL)
		return (B_TRUE);

	(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
	chdr = sip_search_for_header(sip_msg, SIP_CONTACT, NULL);
	(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
	if (chdr == NULL)
		return (B_FALSE);
	if ((dialog->sip_dlg_remote_target = sip_dup_header(chdr)) == NULL)
		return (B_FALSE);

	return (B_TRUE);
}

/*
 * Process an incoming request/response
 */
/* ARGSUSED */
int
sip_dialog_process(_sip_msg_t *sip_msg, sip_dialog_t *sip_dialog)
{
	boolean_t	request;
	_sip_dialog_t	*_dialog;
	int		error;

	request = sip_msg_is_request((sip_msg_t)sip_msg, &error);
	if (error != 0)
		return (EINVAL);
	_dialog = (_sip_dialog_t *)*sip_dialog;
	if (request) {
		uint32_t	cseq;
		sip_method_t	method;

		cseq = sip_get_callseq_num((sip_msg_t)sip_msg, &error);
		if (error != 0)
			return (EINVAL);
		method = sip_get_callseq_method((sip_msg_t)sip_msg, &error);
		if (error != 0)
			return (EINVAL);
		if (sip_get_request_method((sip_msg_t)sip_msg, &error) !=
		    method) {
			return (EINVAL);
		}
		(void) pthread_mutex_lock(&_dialog->sip_dlg_mutex);
		/*
		 * Requests that do not change in any way the state
		 * of a dialog may be received within a dialog.
		 * They are processed as if they had been received
		 * outside the dialog.
		 * For dialogs that have been established with an
		 * INVITE, the only target refresh request defined is
		 * re-INVITE.
		 */
		if (_dialog->sip_dlg_method == INVITE &&
		    method == INVITE && _dialog->sip_dlg_remote_cseq != 0 &&
		    SIP_CSEQ_LT(cseq, _dialog->sip_dlg_remote_cseq)) {
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
			return (EPROTO);
		}
		/*
		 * Target-Refresh request
		 */
		if (_dialog->sip_dlg_method == INVITE && method == INVITE) {
			sip_header_t	chdr;
			sip_header_t	nchdr;

			(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
			chdr = sip_search_for_header(sip_msg, SIP_CONTACT,
			    NULL);
			(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);
			if (chdr != NULL &&
			    (nchdr = sip_dup_header(chdr)) != NULL) {
				if (_dialog->sip_dlg_remote_target != NULL) {
					sip_free_header(
					    _dialog->sip_dlg_remote_target);
				}
				_dialog->sip_dlg_remote_target = nchdr;
			}
		}
		_dialog->sip_dlg_remote_cseq = cseq;
		(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
	} else {
		int		resp_code;
		sip_method_t	method;
		int		error;

		resp_code = sip_get_response_code((sip_msg_t)sip_msg, &error);
		if (error == 0) {
			method = sip_get_callseq_method((sip_msg_t)sip_msg,
			    &error);
		}
		if (error != 0)
			return (error);

		(void) pthread_mutex_lock(&_dialog->sip_dlg_mutex);
		if (_dialog->sip_dlg_state == SIP_DLG_DESTROYED) {
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
			return (0);
		}
		assert(_dialog->sip_dlg_state == SIP_DLG_EARLY ||
		    _dialog->sip_dlg_state == SIP_DLG_CONFIRMED);
		/*
		 * Let the user delete the dialog if it is not a 1XX/2XX resp
		 * for an early INVITE dialog.
		 */
		if (SIP_OK_RESP(resp_code)) {
			if (method == INVITE) {
				if (!sip_get_rtarg(_dialog, sip_msg)) {
					(void) pthread_mutex_unlock(
					    &_dialog->sip_dlg_mutex);
					if (sip_ulp_dlg_del_cb != NULL) {
						sip_ulp_dlg_del_cb(
						    (sip_dialog_t)_dialog,
						    (sip_msg_t)sip_msg, NULL);
					}
					sip_dialog_terminate(_dialog,
					    (sip_msg_t)sip_msg);
					return (0);
				}
				if (_dialog->sip_dlg_state == SIP_DLG_EARLY) {
					_dialog->sip_dlg_state =
					    SIP_DLG_CONFIRMED;
					(void) pthread_mutex_unlock(
					    &_dialog->sip_dlg_mutex);
					(void) sip_dlg_recompute_rset(_dialog,
					    sip_msg, SIP_UAC_DIALOG);
					if (sip_dlg_ulp_state_cb != NULL) {
						sip_dlg_ulp_state_cb(
						    (sip_dialog_t)_dialog,
						    sip_msg, SIP_DLG_EARLY,
						    _dialog->sip_dlg_state);
					}
					return (0);
				} else if (_dialog->sip_dlg_new_local_contact
				    != NULL) {
					assert(_dialog->sip_dlg_local_contact
					    != NULL);
					sip_free_header(_dialog->
					    sip_dlg_local_contact);
					_dialog->sip_dlg_local_contact =
					    _dialog->sip_dlg_new_local_contact;
					_dialog->sip_dlg_new_local_contact =
					    NULL;
				}
			}
		}
		(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
	}
	return (0);
}

/*
 * Copy partial dialog to create a complete dialog
 */
_sip_dialog_t *
sip_copy_partial_dialog(_sip_dialog_t *dialog)
{
	_sip_dialog_t	*new_dlg;

	new_dlg =  calloc(1, sizeof (_sip_dialog_t));
	if (new_dlg == NULL)
		return (NULL);
	if (dialog->sip_dlg_req_uri.sip_str_ptr != NULL) {
		new_dlg->sip_dlg_req_uri.sip_str_ptr =
		    malloc(dialog->sip_dlg_req_uri.sip_str_len + 1);
		if (new_dlg->sip_dlg_req_uri.sip_str_ptr == NULL) {
			free(new_dlg);
			return (NULL);
		}
		(void) strncpy(new_dlg->sip_dlg_req_uri.sip_str_ptr,
		    dialog->sip_dlg_req_uri.sip_str_ptr,
		    dialog->sip_dlg_req_uri.sip_str_len);
		new_dlg->sip_dlg_req_uri.sip_str_ptr[
		    dialog->sip_dlg_req_uri.sip_str_len] = '\0';
		new_dlg->sip_dlg_req_uri.sip_str_len =
		    dialog->sip_dlg_req_uri.sip_str_len;
	}
	if (dialog->sip_dlg_route_set != NULL) {
		assert(dialog->sip_dlg_rset.sip_str_ptr != NULL);
		new_dlg->sip_dlg_rset.sip_str_ptr =
		    malloc(dialog->sip_dlg_rset.sip_str_len + 1);
		if (new_dlg->sip_dlg_rset.sip_str_ptr == NULL) {
			if (new_dlg->sip_dlg_req_uri.sip_str_ptr != NULL)
				free(new_dlg->sip_dlg_req_uri.sip_str_ptr);
			free(new_dlg);
			return (NULL);
		}
		(void) strncpy(new_dlg->sip_dlg_rset.sip_str_ptr,
		    dialog->sip_dlg_rset.sip_str_ptr,
		    dialog->sip_dlg_rset.sip_str_len);
		new_dlg->sip_dlg_rset.sip_str_ptr[
		    dialog->sip_dlg_rset.sip_str_len] = '\0';
		new_dlg->sip_dlg_rset.sip_str_len =
		    dialog->sip_dlg_rset.sip_str_len;

		new_dlg->sip_dlg_route_set =
		    sip_dup_header(dialog->sip_dlg_route_set);
		if (new_dlg->sip_dlg_route_set == NULL) {
			free(new_dlg->sip_dlg_rset.sip_str_ptr);
			if (new_dlg->sip_dlg_req_uri.sip_str_ptr != NULL)
				free(new_dlg->sip_dlg_req_uri.sip_str_ptr);
			free(new_dlg);
			return (NULL);
		}
	}
	if ((new_dlg->sip_dlg_local_uri_tag =
	    sip_dup_header(dialog->sip_dlg_local_uri_tag)) == NULL ||
	    (new_dlg->sip_dlg_remote_target =
	    sip_dup_header(dialog->sip_dlg_remote_target)) == NULL ||
	    (new_dlg->sip_dlg_local_contact =
	    sip_dup_header(dialog->sip_dlg_local_contact)) == NULL ||
	    (new_dlg->sip_dlg_call_id =
	    sip_dup_header(dialog->sip_dlg_call_id)) == NULL) {
		sip_release_dialog_res(new_dlg);
		return (NULL);
	}
	if (dialog->sip_dlg_event != NULL) {
		new_dlg->sip_dlg_event = sip_dup_header(dialog->sip_dlg_event);
		if (new_dlg->sip_dlg_event == NULL) {
			sip_release_dialog_res(new_dlg);
			return (NULL);
		}
	}
	new_dlg->sip_dlg_local_cseq = dialog->sip_dlg_local_cseq;
	new_dlg->sip_dlg_type = dialog->sip_dlg_type;
	new_dlg->sip_dlg_on_fork = B_FALSE;
	(void) pthread_mutex_init(&new_dlg->sip_dlg_mutex, NULL);

	return (new_dlg);
}

/*
 * Update the dialog using the response
 */
sip_dialog_t
sip_update_dialog(sip_dialog_t dialog, _sip_msg_t *sip_msg)
{
	_sip_dialog_t	*_dialog;
	boolean_t	isreq;
	sip_method_t	method;
	int		resp_code = 0;
	int		prev_state;
	boolean_t	decr_ref = B_FALSE;
	int		error;

	isreq = sip_msg_is_request((sip_msg_t)sip_msg, &error);
	if (error != 0)
		return (dialog);
	_dialog = (_sip_dialog_t *)dialog;
	(void) pthread_mutex_lock(&_dialog->sip_dlg_mutex);
	if (isreq) {
		method = sip_get_request_method((sip_msg_t)sip_msg, &error);
		if (error != 0 || _dialog->sip_dlg_method != SUBSCRIBE ||
		    method != NOTIFY) {
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
			return (dialog);
		}
	} else {
		resp_code = sip_get_response_code((sip_msg_t)sip_msg, &error);
		if (error != 0) {
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
			return (dialog);
		}
		method = sip_get_callseq_method((sip_msg_t)sip_msg, &error);
		if (error != 0) {
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
			return (dialog);
		}
	}
	prev_state = _dialog->sip_dlg_state;
	if (_dialog->sip_dlg_state == SIP_DLG_CONFIRMED) {
		(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
	} else if (_dialog->sip_dlg_state == SIP_DLG_EARLY) {
		/*
		 * Let the user delete the dialog if it is not a 1XX/2XX resp
		 * for an early dialog.
		 */
		assert(!isreq);
		if (SIP_OK_RESP(resp_code)) {
			_dialog->sip_dlg_state = SIP_DLG_CONFIRMED;
			/*
			 * If we recieved provisional response before we would
			 * not have captured local contact. So store it now.
			 */
			if (_dialog->sip_dlg_type == SIP_UAS_DIALOG && _dialog->
			    sip_dlg_method == INVITE && method == INVITE) {
				sip_header_t chdr;
				(void) pthread_mutex_lock(&sip_msg->
				    sip_msg_mutex);
				chdr = sip_search_for_header(sip_msg,
				    SIP_CONTACT, NULL);
				(void) pthread_mutex_unlock(&sip_msg->
				    sip_msg_mutex);
				if (chdr != NULL) {
					_dialog->sip_dlg_local_contact
					    = sip_dup_header(chdr);
					_dialog->sip_dlg_new_local_contact =
					    NULL;
				}
			}
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
			(void) sip_dlg_recompute_rset(_dialog, sip_msg,
			    SIP_UAS_DIALOG);
			if (sip_dlg_ulp_state_cb != NULL) {
				sip_dlg_ulp_state_cb(dialog, (sip_msg_t)sip_msg,
				    prev_state, dialog->sip_dlg_state);
			}
		} else {
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
		}
	} else if (_dialog->sip_dlg_state == SIP_DLG_NEW) {
		if (!isreq && _dialog->sip_dlg_method == SUBSCRIBE &&
		    SIP_PROVISIONAL_RESP(resp_code)) {
			(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
			return (dialog);
		}
		if (_dialog->sip_dlg_type == SIP_UAC_DIALOG) {
			_sip_dialog_t	*new_dlg;

			if (_dialog->sip_dlg_on_fork) {
				new_dlg = sip_copy_partial_dialog(_dialog);
				if (new_dlg == NULL) {
					(void) pthread_mutex_unlock(
					    &_dialog->sip_dlg_mutex);
					return (dialog);
				}
				/*
				 * This decr/incr dance is because the caller
				 * has incremented the ref on the partial
				 * dialog, we release it here and incr the
				 * ref on the new dialog which will be
				 * released by the caller.
				 */
				(void) pthread_mutex_unlock(
				    &_dialog->sip_dlg_mutex);
				SIP_DLG_REFCNT_DECR(_dialog);
				_dialog = new_dlg;
				(void) pthread_mutex_lock(
				    &_dialog->sip_dlg_mutex);
				SIP_DLG_REFCNT_INCR(_dialog);
			} else {
				int	index;

				/*
				 * take it out of the list so that further
				 * responses will not result in a dialog.
				 * We will have an extra refcount when we
				 * come back from sip_complete_dialog(), i.e.
				 * one when the partial dialog was created -
				 * in sip_seed_dialog(), one held by the caller
				 * and one that will be added by
				 * sip_complete_dialog(). We need to release
				 * the one added by the sip_seed_dialog(),
				 * since the one in sip_complete_dialog()
				 * is for the same purpose.
				 */
				if (SIP_IS_TIMER_RUNNING(
				    _dialog->sip_dlg_timer)) {
					SIP_CANCEL_TIMER(
					    _dialog->sip_dlg_timer);
				}
				index = SIP_DIGEST_TO_HASH(dialog->sip_dlg_id);
				(void) pthread_mutex_unlock(
				    &_dialog->sip_dlg_mutex);
				sip_hash_delete(sip_dialog_phash,
				    (void *)_dialog->sip_dlg_id,
				    index, sip_dialog_dontfree);
				(void) pthread_mutex_lock(
				    &_dialog->sip_dlg_mutex);
				decr_ref = B_TRUE;
			}
		} else {
			decr_ref = B_TRUE;
		}
		(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
		if ((dialog = sip_complete_dialog(sip_msg, _dialog)) ==
		    NULL) {
			if (_dialog->sip_dlg_type == SIP_UAC_DIALOG && decr_ref)
				SIP_DLG_REFCNT_DECR(_dialog);
			return (NULL);
		}
		if (decr_ref)
			SIP_DLG_REFCNT_DECR(_dialog);
	} else {
		(void) pthread_mutex_unlock(&_dialog->sip_dlg_mutex);
	}
	return (dialog);
}

/*
 * Initialize the hash table
 */
void
sip_dialog_init(void (*ulp_dlg_del) (sip_dialog_t, sip_msg_t, void *),
    void (*ulp_state_cb)(sip_dialog_t, sip_msg_t, int, int))
{
	int	cnt;

	for (cnt = 0; cnt < SIP_HASH_SZ; cnt++) {
		sip_dialog_hash[cnt].hash_count = 0;
		sip_dialog_hash[cnt].hash_head = NULL;
		sip_dialog_hash[cnt].hash_tail = NULL;
		(void) pthread_mutex_init(
		    &sip_dialog_hash[cnt].sip_hash_mutex, NULL);
		sip_dialog_phash[cnt].hash_count = 0;
		sip_dialog_phash[cnt].hash_head = NULL;
		sip_dialog_phash[cnt].hash_tail = NULL;
		(void) pthread_mutex_init(
		    &sip_dialog_phash[cnt].sip_hash_mutex, NULL);
	}
	if (ulp_dlg_del != NULL)
		sip_ulp_dlg_del_cb = ulp_dlg_del;

	if (ulp_state_cb != NULL)
		sip_dlg_ulp_state_cb = ulp_state_cb;
}

/*
 * Copy the new contact header of re-INVITE
 */
void
sip_dialog_add_new_contact(sip_dialog_t dialog, _sip_msg_t *sip_msg)
{
	sip_header_t chdr = NULL;
	sip_header_t nhdr = NULL;

	(void) pthread_mutex_lock(&sip_msg->sip_msg_mutex);
	chdr = sip_search_for_header(sip_msg, SIP_CONTACT, NULL);
	(void) pthread_mutex_unlock(&sip_msg->sip_msg_mutex);

	if (chdr == NULL)
		return;

	(void) pthread_mutex_lock(&dialog->sip_dlg_mutex);
	if (dialog->sip_dlg_method != INVITE || dialog->sip_dlg_state
	    != SIP_DLG_CONFIRMED) {
		(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
		return;
	}

	if (((nhdr = sip_dup_header(chdr)) != NULL)) {
		if (dialog->sip_dlg_new_local_contact != NULL)
			sip_free_header(dialog->sip_dlg_new_local_contact);
		dialog->sip_dlg_new_local_contact = nhdr;
	}
	(void) pthread_mutex_unlock(&dialog->sip_dlg_mutex);
}