sip_dialog.h

一个开源的sip源代码

/* $Id: sip_dialog.h 979 2007-02-19 16:55:42Z bennylp $ */
/* 
 * Copyright (C) 2003-2007 Benny Prijono <[e-mail]>
 *
 * 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 
 */
#ifndef __PJSIP_SIP_DIALOG_H__
#define __PJSIP_SIP_DIALOG_H__


/**
 * @file dialog.h
 * @brief SIP Dialog abstraction
 */

#include <pjsip/sip_msg.h>
#include <pjsip/sip_auth.h>
#include <pjsip/sip_errno.h>
#include <pjsip/sip_transport.h>
#include <pj/sock.h>
#include <pj/assert.h>


/**
 * @defgroup PJSIP_DIALOG Base Dialog
 * @ingroup PJSIP_UA
 * @brief The base dialog framework to support dialog usages.
 * @{
 *
 * The base dialog framework provides management for base dialog
 * properties such as <b>From</b> header, <b>To</b> header, <b>CSeq</b>
 * sequencing, <b>Call-ID</b> header, <b>Contact</b> header management, 
 * dialog <b>route-set</b> management, and common <b>authentication</b>. 
 * This basic dialog functionality will be shared by all <b>dialog
 * usages</b> of a particular dialog.
 *
 * More detailed information is explained in
 * <A HREF="/docs.htm">PJSIP Developer's Guide</A>
 * PDF document, and readers are encouraged to read the document to
 * get the concept behind dialog, dialog usages, and INVITE sessions.
 *
 * Application MUST initialize the user agent layer module by calling
 * #pjsip_ua_init_module() before using any of the dialog API, and link
 * the application with with <b>pjsip-core</b> library.
 */

PJ_BEGIN_DECL


/**
 * This structure is used to describe dialog's participants, which in this
 * case is local party (i.e. us) and remote party.
 */
typedef struct pjsip_dlg_party
{
    pjsip_fromto_hdr	*info;	    /**< From/To header, inc tag.	*/
    pj_str_t		 info_str;  /**< String rep of info header.	*/
    pj_uint32_t		 tag_hval;  /**< Hashed value of the tag.	*/
    pjsip_contact_hdr	*contact;   /**< Contact header.		*/
    pj_int32_t		 first_cseq;/**< First CSeq seen.		*/
    pj_int32_t		 cseq;	    /**< Next sequence number.		*/
} pjsip_dlg_party;


/**
 * Dialog state.
 */
typedef enum pjsip_dialog_state
{
    /** Dialog is not established. */
    PJSIP_DIALOG_STATE_NULL,

    /** Dialog has been established (probably early) */
    PJSIP_DIALOG_STATE_ESTABLISHED
} pjsip_dialog_state;

/**
 * This structure describes the dialog structure. Application MUST NOT
 * try to SET the values here directly, but instead it MUST use the
 * appropriate dialog API. The dialog declaration only needs to be made 
 * visible because other PJSIP modules need to see it (e.g. INVITE session,
 * the event framework, etc.).
 *
 * Application MAY READ the dialog contents directly after it acquires
 * dialog lock.
 *
 * To acquire dialog lock, use #pjsip_dlg_inc_lock(), and to release it,
 * use #pjsip_dlg_dec_lock(). DO NOT USE pj_mutex_lock()/pj_mutex_unlock()
 * on the dialog's mutex directly, because this will not protect against
 * dialog being destroyed.
 */
struct pjsip_dialog
{
    /** The dialog set list. */
    PJ_DECL_LIST_MEMBER(pjsip_dialog);

    /* Dialog's system properties. */
    char		obj_name[PJ_MAX_OBJ_NAME];  /**< Standard id.	    */
    pj_pool_t	       *pool;	    /**< Dialog's pool.			    */
    pj_mutex_t	       *mutex_;	    /**< Dialog's mutex. Do not call!!
					 Use pjsip_dlg_inc_lock() instead!  */
    pjsip_user_agent   *ua;	    /**< User agent instance.		    */
    pjsip_endpoint     *endpt;	    /**< Endpoint instance.		    */

    /** The dialog set which this dialog belongs (opaque type). */
    void	       *dlg_set;

    /* Dialog's session properties. */
    pjsip_dialog_state	state;	    /**< Dialog state.			    */
    pjsip_uri	       *target;	    /**< Current target.		    */
    pjsip_hdr	        inv_hdr;    /**< Headers from hparam in dest URL    */
    pjsip_dlg_party     local;	    /**< Local party info.		    */
    pjsip_dlg_party     remote;	    /**< Remote party info.		    */
    pjsip_role_e	role;	    /**< Initial role.			    */
    pj_bool_t		uac_has_2xx;/**< UAC has received 2xx response?	    */
    pj_bool_t		secure;	    /**< Use secure transport?		    */
    pjsip_cid_hdr      *call_id;    /**< Call-ID header.		    */
    pjsip_route_hdr	route_set;  /**< Route set.			    */
    pjsip_auth_clt_sess	auth_sess;  /**< Client authentication session.	    */

    /** Session counter. */
    int			sess_count; /**< Number of sessions.		    */

    /** Transaction counter. */
    int			tsx_count;  /**< Number of pending transactions.    */

    /** Transport selector. */
    pjsip_tpselector	tp_sel;

    /* Dialog usages. */
    unsigned		usage_cnt;  /**< Number of registered usages.	    */
    pjsip_module       *usage[PJSIP_MAX_MODULE]; /**< Array of usages, 
					 priority sorted		    */

    /** Module specific data. */
    void	       *mod_data[PJSIP_MAX_MODULE]; /**< Module data.	    */
};


/**
 * This utility function returns PJ_TRUE if the specified method is a
 * dialog creating request. This method property is used to determine
 * whether Contact header should be included in outgoing request.
 *
 * @param m		The SIP method.
 *
 * @return		PJ_TRUE if the method creates a dialog.
 */
PJ_DECL(pj_bool_t) pjsip_method_creates_dialog(const pjsip_method *m);

/**
 * Create a new dialog and return the instance in p_dlg parameter. 
 * After creating  the dialog, application can add modules as dialog usages
 * by calling  #pjsip_dlg_add_usage(). 
 *
 * If the request has To tag parameter, dialog's local tag will be initialized 
 * from this value. Otherwise a globally unique id generator will be invoked to
 * create dialog's local tag.
 *
 * This function also initializes the dialog's route set based on the 
 * Record-Route headers in the request, if present.
 *
 * Note that initially, the session count in the dialog will be initialized 
 * to zero.
 *
 * @param ua		    The user agent module instance.
 * @param local_uri	    Dialog local URI (i.e. From header).
 * @param local_contact_uri Optional dialog local Contact URI. 
 *			    If this argument is NULL, the Contact will be
 *			    taken from the local URI.
 * @param remote_uri	    Dialog remote URI (i.e. To header).
 * @param target	    Optional initial remote target. If this argument
 *			    is NULL, the initial target will be set to
 *			    remote URI.
 * @param p_dlg		    Pointer to receive the dialog.
 *
 * @return		    PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_dlg_create_uac( pjsip_user_agent *ua,
					   const pj_str_t *local_uri,
					   const pj_str_t *local_contact_uri,
					   const pj_str_t *remote_uri,
					   const pj_str_t *target,
					   pjsip_dialog **p_dlg);


/**
 * Initialize UAS dialog from the information found in the incoming request 
 * that creates a dialog (such as INVITE, REFER, or SUBSCRIBE), and set the 
 * local Contact to contact. If contact is not specified, the local contact 
 * is initialized from the URI in the To header in the request. 
 *
 * This function will also create UAS transaction for the incoming request,
 * and associate the transaction to the rdata. Application can query the
 * transaction used to handle this request by calling #pjsip_rdata_get_tsx()
 * after this function returns.
 *
 * Note that initially, the session count in the dialog will be initialized 
 * to zero.
 *
 *
 * @param ua		    The user agent module instance.
 * @param rdata		    The incoming request that creates the dialog,
 *			    such as INVITE, SUBSCRIBE, or REFER.
 * @param contact	    Optional URI to be used as local Contact. If
 *			    this argument is NULL, the local contact will be
 *			    initialized from the value of To header in the
 *			    request.
 * @param p_dlg		    Pointer to receive the dialog.
 *
 * @return		    PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_dlg_create_uas(  pjsip_user_agent *ua,
					    pjsip_rx_data *rdata,
					    const pj_str_t *contact,
					    pjsip_dialog **p_dlg);


/**
 * Lock/bind dialog to a specific transport/listener. This is optional,
 * as normally transport will be selected automatically based on the 
 * destination of messages upon resolver completion. When the dialog is 
 * explicitly bound to the specific transport/listener, all transactions
 * originated by this dialog will use the specified transport/listener
 * when sending outgoing requests.
 *
 * Note that this doesn't affect the Contact header generated by this
 * dialog. Application must manually update the Contact header if
 * necessary, to adjust the address according to the transport being
 * selected.
 *
 * @param dlg	    The dialog instance.
 * @param sel	    Transport selector containing the specification of
 *		    transport or listener to be used by this dialog
 *		    to send requests.
 *
 * @return	    PJ_SUCCESS on success, or the appropriate error code.
 */
PJ_DECL(pj_status_t) pjsip_dlg_set_transport(pjsip_dialog *dlg,
					     const pjsip_tpselector *sel);


/**
 * Create a new (forked) dialog on receipt on forked response in rdata. 
 * The new dialog will be created from original_dlg, except that it will have
 * new remote tag as copied from the To header in the response. Upon return, 
 * the new_dlg will have been registered to the user agent. Applications just 
 * need to add modules as dialog's usages.
 *
 * Note that initially, the session count in the dialog will be initialized 
 * to zero.
 *
 * @param original_dlg	    The original UAC dialog.
 * @param rdata		    The incoming forked response message.
 * @param new_dlg	    Pointer to receive the new dialog.
 *
 * @return		    PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pjsip_dlg_fork(const pjsip_dialog *original_dlg,
				    const pjsip_rx_data *rdata,
				    pjsip_dialog **new_dlg );

/**
 * Forcefully terminate the dialog. Application can only call this function
 * when there is no session associated to the dialog. If there are sessions
 * that use this dialog, this function will refuse to terminate the dialog.
 * For this case, application MUST call the appropriate termination function 
 * for each dialog session (e.g. #pjsip_inv_terminate() to terminate INVITE
 * session).
 *
 * @param dlg		    The dialog.
 *
 * @return		    PJ_SUCCESS if dialog has been terminated.
 */
PJ_DECL(pj_status_t) pjsip_dlg_terminate( pjsip_dialog *dlg );


/**
 * Set dialog's initial route set to route_set list. This can only be called
 * for UAC dialog, before any request is sent. After dialog has been 
 * established, the route set can not be changed.
 *
 * For UAS dialog,the route set will be initialized in pjsip_dlg_create_uas()
 * from the Record-Route headers in the incoming request.
 *
 * The route_set argument is standard list of Route headers (i.e. with 
 * sentinel).
 *
 * @param dlg		    The UAC dialog.
 * @param route_set	    List of Route header.