/* $Id$ */ /* * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) * Copyright (C) 2003-2008 Benny Prijono * * 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 __SIP_100REL_H__ #define __SIP_100REL_H__ /** * @file sip_100rel.h * @brief PRACK (Reliability of Provisional Responses) */ #include /** * @defgroup PJSIP_100REL 100rel/PRACK - Reliability of Provisional Responses * @ingroup PJSIP_HIGH_UA * @brief PRACK - Reliability of Provisional Responses * @{ * * This module provides management of Reliability of Provisional Responses * (\a 100rel and \a PRACK), as described in RFC 3262. * * Other than the #pjsip_100rel_init_module() function, the 100rel API * exported by this module are not intended to be used by application, but * rather they will be invoked by the \ref PJSIP_INV. * * \section pjsip_100rel_using Using Reliable Provisional Response * * \subsection pjsip_100rel_init Initializing 100rel Module * * Application must explicitly initialize 100rel module by calling * #pjsip_100rel_init_module() in application initialization function. * * Once the 100rel module is initialized, it will register \a PRACK method * in \a Allow header, and \a 100rel tag in \a Supported header. * * \subsection pjsip_100rel_sess Using 100rel in a Session * * For UAC, \a 100rel support will be enabled in the session if \a 100rel * support is enabled in the library (default is yes). * Outgoing INVITE request will include \a 100rel tag in \a Supported * header and \a PRACK method in \a Allow header. When callee endpoint * sends reliable provisional responses, the UAC will automatically send * \a PRACK request to acknowledge the response. If callee endpoint doesn't * send reliable provisional response, the response will be handled using * normal, non-100rel procedure (that is, \a PRACK will not be sent). * * If the UAC wants to mandate \a 100rel support, it can specify * #PJSIP_INV_REQUIRE_100REL in the \a options argument when calling * #pjsip_inv_create_uac(). In this case, PJSIP will add \a 100rel tag * in the \a Require header of the outgoing INVITE request. * * For UAS, if it wants to support \a 100rel but not to mandate it, * it must specify #PJSIP_INV_SUPPORT_100REL flag in the \a options * argument when calling #pjsip_inv_verify_request(), and pass the same * \a options variable when calling #pjsip_inv_verify_request. If UAC had * specified \a 100rel in it's list of extensions in \a Require header, * the UAS will send provisional responses reliably. If UAC only listed * \a 100rel in its \a Supported header but not in \a Require header, * or if UAC does not list \a 100rel support at all, the UAS WILL NOT * send provisional responses reliably. * The snippet below can be used to accomplish this task: * * \verbatim unsigned options = 0; options |= PJSIP_INV_SUPPORT_100REL; status = pjsip_inv_verify_request(rdata, &options, answer, NULL, endpt, &resp); if (status != PJ_SUCCESS) { // INVITE request cannot be handled. // Reject the request with the response in resp. ... return; } // Create UAS dialog, populate Contact header, etc. ... // Create UAS invite session status = pjsip_inv_create_uas( dlg, rdata, answer, options, &inv); .. \endverbatim * * For another requirement, if UAS wants to mandate \a 100rel support, * it can specify #PJSIP_INV_REQUIRE_100REL flag when calling * #pjsip_inv_verify_request(), and pass the \a options when calling * #pjsip_inv_verify_request. In this case, * \a 100rel extension will be used if UAC specifies \a 100rel in its * \a Supported header. If UAC does not list \a 100rel in \a Supported header, * the incoming INVITE request will be rejected with 421 (Extension Required) * response. For the sample code, it should be identical to the snippet * above, except that application must specify #PJSIP_INV_REQUIRE_100REL * flag in the \a options instead of #PJSIP_INV_SUPPORT_100REL. * * For yet another requirement, if UAS does not want to support * \a 100rel extension, it can reject incoming INVITE request with * 420 (Bad Extension) response whenever incoming INVITE request has * \a 100rel tag in its \a Require header. This can be done by specifying * zero as the \a options when calling #pjsip_inv_verify_request(). */ PJ_BEGIN_DECL /** * PRACK method constant. * @see pjsip_get_prack_method() */ PJ_DECL_DATA(const pjsip_method) pjsip_prack_method; /** * Get #pjsip_invite_method constant. */ PJ_DECL(const pjsip_method*) pjsip_get_prack_method(void); /** * Initialize 100rel module. This function must be called once during * application initialization, to register 100rel module to SIP endpoint. * * @param endpt The SIP endpoint instance. * * @return PJ_SUCCESS if module is successfully initialized. */ PJ_DECL(pj_status_t) pjsip_100rel_init_module(pjsip_endpoint *endpt); /** * Add 100rel support to the specified invite session. This function will * be called internally by the invite session if it detects that the * session needs 100rel support. * * @param inv The invite session. * * @return PJ_SUCCESS on successful. */ PJ_DECL(pj_status_t) pjsip_100rel_attach(pjsip_inv_session *inv); /** * Check if incoming response has reliable provisional response feature. * * @param rdata Receive data buffer containing the response. * * @return PJ_TRUE if the provisional response is reliable. */ PJ_DECL(pj_bool_t) pjsip_100rel_is_reliable(pjsip_rx_data *rdata); /** * Create PRACK request for the incoming reliable provisional response. * Note that PRACK request MUST be sent using #pjsip_100rel_send_prack(). * * @param inv The invite session. * @param rdata The incoming reliable provisional response. * @param p_tdata Upon return, it will be initialized with the * PRACK request. * * @return PJ_SUCCESS on successful. */ PJ_DECL(pj_status_t) pjsip_100rel_create_prack(pjsip_inv_session *inv, pjsip_rx_data *rdata, pjsip_tx_data **p_tdata); /** * Send PRACK request. * * @param inv The invite session. * @param tdata The PRACK request. * * @return PJ_SUCCESS on successful. */ PJ_DECL(pj_status_t) pjsip_100rel_send_prack(pjsip_inv_session *inv, pjsip_tx_data *tdata); /** * Handle incoming PRACK request. * * @param inv The invite session. * @param rdata Incoming PRACK request. * * @return PJ_SUCCESS on successful. */ PJ_DECL(pj_status_t) pjsip_100rel_on_rx_prack(pjsip_inv_session *inv, pjsip_rx_data *rdata); /** * Transmit INVITE response (provisional or final) reliably according to * 100rel specification. The 100rel module will take care of retransmitting * or enqueueing the response according to the current state of the * reliable response processing. This function will be called internally * by invite session. * * @param inv The invite session. * @param tdata The INVITE response. * * @return PJ_SUCCESS on successful. */ PJ_DECL(pj_status_t) pjsip_100rel_tx_response(pjsip_inv_session *inv, pjsip_tx_data *tdata); /** * Notify 100rel module that the invite session has been disconnected. * * @param inv The invite session. * * @return PJ_SUCCESS on successful. */ PJ_DECL(pj_status_t) pjsip_100rel_end_session(pjsip_inv_session *inv); PJ_END_DECL /** * @} */ #endif /* __SIP_100REL_H__ */