sip_xfer.c

一个开源SIP协议栈

	refer_to_uri = &xfer->refer_to_uri;
    } else {
	pj_strdup(xfer->dlg->pool, &xfer->refer_to_uri, refer_to_uri);
    }

    /* Create and add Refer-To header. */
    hdr = pjsip_generic_string_hdr_create(tdata->pool, &refer_to,
					  refer_to_uri);
    if (!hdr) {
	pjsip_tx_data_dec_ref(tdata);
	status = PJ_ENOMEM;
	goto on_return;
    }

    pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr*)hdr);


    /* Done. */
    *p_tdata = tdata;

    status = PJ_SUCCESS;

on_return:
    pjsip_dlg_dec_lock(xfer->dlg);
    return status;
}


/*
 * Accept the incoming REFER request by sending 2xx response.
 *
 */
PJ_DEF(pj_status_t) pjsip_xfer_accept( pjsip_evsub *sub,
				       pjsip_rx_data *rdata,
				       int st_code,
				       const pjsip_hdr *hdr_list )
{
    /*
     * Don't need to add custom headers, so just call basic
     * evsub response.
     */
    return pjsip_evsub_accept( sub, rdata, st_code, hdr_list );
}


/*
 * For notifier, create NOTIFY request to subscriber, and set the state 
 * of the subscription. 
 */
PJ_DEF(pj_status_t) pjsip_xfer_notify( pjsip_evsub *sub,
				       pjsip_evsub_state state,
				       int xfer_st_code,
				       const pj_str_t *xfer_st_text,
				       pjsip_tx_data **p_tdata)
{
    pjsip_tx_data *tdata;
    pjsip_xfer *xfer;
    const pj_str_t reason = { "noresource", 10 };
    char *body;
    int bodylen;
    pjsip_msg_body *msg_body;
    pj_status_t status;
    

    /* Check arguments. */
    PJ_ASSERT_RETURN(sub, PJ_EINVAL);

    /* Get the xfer object. */
    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_RETURN(xfer != NULL, PJSIP_ENOREFERSESSION);


    /* Lock object. */
    pjsip_dlg_inc_lock(xfer->dlg);

    /* Create the NOTIFY request. 
     * Note that reason is only used when state is TERMINATED, and
     * the defined termination reason for REFER is "noresource".
     */
    status = pjsip_evsub_notify( sub, state, NULL, &reason, &tdata);
    if (status != PJ_SUCCESS)
	goto on_return;


    /* Check status text */
    if (xfer_st_text==NULL || xfer_st_text->slen==0)
	xfer_st_text = pjsip_get_status_text(xfer_st_code);

    /* Save st_code and st_text, for current_notify() */
    xfer->last_st_code = xfer_st_code;
    pj_strdup(xfer->dlg->pool, &xfer->last_st_text, xfer_st_text);

    /* Create sipfrag content. */
    body = pj_pool_alloc(tdata->pool, 128);
    bodylen = pj_ansi_snprintf(body, 128, "SIP/2.0 %u %.*s",
			       xfer_st_code,
			       (int)xfer_st_text->slen,
			       xfer_st_text->ptr);
    PJ_ASSERT_ON_FAIL(bodylen > 0 && bodylen < 128, 
			{status=PJ_EBUG; pjsip_tx_data_dec_ref(tdata); 
			 goto on_return; });


    /* Create SIP message body. */
    msg_body = pj_pool_zalloc(tdata->pool, sizeof(pjsip_msg_body));
    msg_body->content_type.type = STR_MESSAGE;
    msg_body->content_type.subtype = STR_SIPFRAG;
    msg_body->content_type.param = STR_SIPFRAG_VERSION;
    msg_body->data = body;
    msg_body->len = bodylen;
    msg_body->print_body = &pjsip_print_text_body;
    msg_body->clone_data = &pjsip_clone_text_data;

    /* Attach sipfrag body. */
    tdata->msg->body = msg_body;


    /* Done. */
    *p_tdata = tdata;


on_return:
    pjsip_dlg_dec_lock(xfer->dlg);
    return status;

}


/*
 * Send current state and the last sipfrag body.
 */
PJ_DEF(pj_status_t) pjsip_xfer_current_notify( pjsip_evsub *sub,
					       pjsip_tx_data **p_tdata )
{
    pjsip_xfer *xfer;
    pj_status_t status;
    

    /* Check arguments. */
    PJ_ASSERT_RETURN(sub, PJ_EINVAL);

    /* Get the xfer object. */
    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_RETURN(xfer != NULL, PJSIP_ENOREFERSESSION);

    pjsip_dlg_inc_lock(xfer->dlg);

    status = pjsip_xfer_notify(sub, pjsip_evsub_get_state(sub),
			       xfer->last_st_code, &xfer->last_st_text,
			       p_tdata);

    pjsip_dlg_dec_lock(xfer->dlg);

    return status;
}


/*
 * Send request message. 
 */
PJ_DEF(pj_status_t) pjsip_xfer_send_request( pjsip_evsub *sub,
					     pjsip_tx_data *tdata)
{
    return pjsip_evsub_send_request(sub, tdata);
}


/*
 * This callback is called by event subscription when subscription
 * state has changed.
 */
static void xfer_on_evsub_state( pjsip_evsub *sub, pjsip_event *event)
{
    pjsip_xfer *xfer;

    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_ON_FAIL(xfer!=NULL, {return;});

    if (xfer->user_cb.on_evsub_state)
	(*xfer->user_cb.on_evsub_state)(sub, event);

}

/*
 * Called when transaction state has changed.
 */
static void xfer_on_evsub_tsx_state( pjsip_evsub *sub, pjsip_transaction *tsx,
				     pjsip_event *event)
{
    pjsip_xfer *xfer;

    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_ON_FAIL(xfer!=NULL, {return;});

    if (xfer->user_cb.on_tsx_state)
	(*xfer->user_cb.on_tsx_state)(sub, tsx, event);
}

/*
 * Called when REFER is received to refresh subscription.
 */
static void xfer_on_evsub_rx_refresh( pjsip_evsub *sub, 
				      pjsip_rx_data *rdata,
				      int *p_st_code,
				      pj_str_t **p_st_text,
				      pjsip_hdr *res_hdr,
				      pjsip_msg_body **p_body)
{
    pjsip_xfer *xfer;

    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_ON_FAIL(xfer!=NULL, {return;});

    if (xfer->user_cb.on_rx_refresh) {
	(*xfer->user_cb.on_rx_refresh)(sub, rdata, p_st_code, p_st_text,
				       res_hdr, p_body);

    } else {
	/* Implementors MUST send NOTIFY if it implements on_rx_refresh
	 * (implementor == "us" from evsub point of view.
	 */
	pjsip_tx_data *tdata;
	pj_status_t status;

	if (pjsip_evsub_get_state(sub)==PJSIP_EVSUB_STATE_TERMINATED) {
	    status = pjsip_xfer_notify( sub, PJSIP_EVSUB_STATE_TERMINATED,
					xfer->last_st_code,
					&xfer->last_st_text, 
					&tdata);
	} else {
	    status = pjsip_xfer_current_notify(sub, &tdata);
	}

	if (status == PJ_SUCCESS)
	    pjsip_xfer_send_request(sub, tdata);
    }
}


/*
 * Called when NOTIFY is received.
 */
static void xfer_on_evsub_rx_notify( pjsip_evsub *sub, 
				     pjsip_rx_data *rdata,
				     int *p_st_code,
				     pj_str_t **p_st_text,
				     pjsip_hdr *res_hdr,
				     pjsip_msg_body **p_body)
{
    pjsip_xfer *xfer;

    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_ON_FAIL(xfer!=NULL, {return;});

    if (xfer->user_cb.on_rx_notify)
	(*xfer->user_cb.on_rx_notify)(sub, rdata, p_st_code, p_st_text,
				      res_hdr, p_body);
}

/*
 * Called when it's time to send SUBSCRIBE.
 */
static void xfer_on_evsub_client_refresh(pjsip_evsub *sub)
{
    pjsip_xfer *xfer;

    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_ON_FAIL(xfer!=NULL, {return;});

    if (xfer->user_cb.on_client_refresh) {
	(*xfer->user_cb.on_client_refresh)(sub);
    } else {
	pj_status_t status;
	pjsip_tx_data *tdata;

	status = pjsip_xfer_initiate(sub, NULL, &tdata);
	if (status == PJ_SUCCESS)
	    pjsip_xfer_send_request(sub, tdata);
    }
}


/*
 * Called when no refresh is received after the interval.
 */
static void xfer_on_evsub_server_timeout(pjsip_evsub *sub)
{
    pjsip_xfer *xfer;

    xfer = pjsip_evsub_get_mod_data(sub, mod_xfer.id);
    PJ_ASSERT_ON_FAIL(xfer!=NULL, {return;});

    if (xfer->user_cb.on_server_timeout) {
	(*xfer->user_cb.on_server_timeout)(sub);
    } else {
	pj_status_t status;
	pjsip_tx_data *tdata;

	status = pjsip_xfer_notify(sub, PJSIP_EVSUB_STATE_TERMINATED,
				   xfer->last_st_code, 
				   &xfer->last_st_text, &tdata);
	if (status == PJ_SUCCESS)
	    pjsip_xfer_send_request(sub, tdata);
    }
}