sip_inv.c

一个开源SIP协议栈

    /* Set cause code. */
    inv_set_cause(inv, st_code, st_text);

    /* Create appropriate message. */
    switch (inv->state) {
    case PJSIP_INV_STATE_CALLING:
    case PJSIP_INV_STATE_EARLY:
    case PJSIP_INV_STATE_INCOMING:

	if (inv->role == PJSIP_ROLE_UAC) {

	    /* For UAC when session has not been confirmed, create CANCEL. */

	    /* MUST have the original UAC INVITE transaction. */
	    PJ_ASSERT_RETURN(inv->invite_tsx != NULL, PJ_EBUG);

	    /* But CANCEL should only be called when we have received a
	     * provisional response. If we haven't received any responses,
	     * just destroy the transaction.
	     */
	    if (inv->invite_tsx->status_code < 100) {

		pjsip_tsx_terminate(inv->invite_tsx, 487);
		*p_tdata = NULL;
		return PJ_SUCCESS;
	    }

	    /* The CSeq here assumes that the dialog is started with an
	     * INVITE session. This may not be correct; dialog can be 
	     * started as SUBSCRIBE session.
	     * So fix this!
	     */
	    status = pjsip_endpt_create_cancel(inv->dlg->endpt, 
					       inv->invite_tsx->last_tx,
					       &tdata);

	} else {

	    /* For UAS, send a final response. */
	    tdata = inv->invite_tsx->last_tx;
	    PJ_ASSERT_RETURN(tdata != NULL, PJ_EINVALIDOP);

	    //status = pjsip_dlg_modify_response(inv->dlg, tdata, st_code,
	    //				       st_text);
	    status = pjsip_inv_answer(inv, st_code, st_text, NULL, &tdata);
	}
	break;

    case PJSIP_INV_STATE_CONNECTING:
    case PJSIP_INV_STATE_CONFIRMED:
	/* For established dialog, send BYE */
	status = pjsip_dlg_create_request(inv->dlg, &pjsip_bye_method, -1, 
					  &tdata);
	break;

    case PJSIP_INV_STATE_DISCONNECTED:
	/* No need to do anything. */
	return PJSIP_ESESSIONTERMINATED;

    default:
	pj_assert("!Invalid operation!");
	return PJ_EINVALIDOP;
    }

    if (status != PJ_SUCCESS)
	return status;


    /* Done */

    *p_tdata = tdata;

    return PJ_SUCCESS;
}


/*
 * Create re-INVITE.
 */
PJ_DEF(pj_status_t) pjsip_inv_reinvite( pjsip_inv_session *inv,
					const pj_str_t *new_contact,
					const pjmedia_sdp_session *new_offer,
					pjsip_tx_data **p_tdata )
{
    pj_status_t status;
    pjsip_contact_hdr *contact_hdr = NULL;

    /* Check arguments. */
    PJ_ASSERT_RETURN(inv && p_tdata, PJ_EINVAL);

    /* Must NOT have a pending INVITE transaction */
    PJ_ASSERT_RETURN(inv->invite_tsx==NULL, PJ_EINVALIDOP);


    pjsip_dlg_inc_lock(inv->dlg);

    if (new_contact) {
	pj_str_t tmp;
	const pj_str_t STR_CONTACT = { "Contact", 7 };

	pj_strdup_with_null(inv->dlg->pool, &tmp, new_contact);
	contact_hdr = pjsip_parse_hdr(inv->dlg->pool, &STR_CONTACT, 
				      tmp.ptr, tmp.slen, NULL);
	if (!contact_hdr) {
	    status = PJSIP_EINVALIDURI;
	    goto on_return;
	}
    }


    if (new_offer) {
	if (!inv->neg) {
	    status = pjmedia_sdp_neg_create_w_local_offer(inv->pool, new_offer,
							  &inv->neg);
	    if (status != PJ_SUCCESS)
		goto on_return;

	} else switch (pjmedia_sdp_neg_get_state(inv->neg)) {

	    case PJMEDIA_SDP_NEG_STATE_NULL:
		pj_assert(!"Unexpected SDP neg state NULL");
		status = PJ_EBUG;
		goto on_return;

	    case PJMEDIA_SDP_NEG_STATE_LOCAL_OFFER:
		PJ_LOG(4,(inv->obj_name, 
			  "pjsip_inv_reinvite: already have an offer, new "
			  "offer is ignored"));
		break;

	    case PJMEDIA_SDP_NEG_STATE_REMOTE_OFFER:
		status = pjmedia_sdp_neg_set_local_answer(inv->pool, inv->neg,
							  new_offer);
		if (status != PJ_SUCCESS)
		    goto on_return;
		break;

	    case PJMEDIA_SDP_NEG_STATE_WAIT_NEGO:
		PJ_LOG(4,(inv->obj_name, 
			  "pjsip_inv_reinvite: SDP in WAIT_NEGO state, new "
			  "offer is ignored"));
		break;

	    case PJMEDIA_SDP_NEG_STATE_DONE:
		status = pjmedia_sdp_neg_modify_local_offer(inv->pool,inv->neg,
							    new_offer);
		if (status != PJ_SUCCESS)
		    goto on_return;
		break;
	}
    }

    if (contact_hdr)
	inv->dlg->local.contact = contact_hdr;

    status = pjsip_inv_invite(inv, p_tdata);

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

/*
 * Create UPDATE.
 */
PJ_DEF(pj_status_t) pjsip_inv_update (	pjsip_inv_session *inv,
					const pj_str_t *new_contact,
					const pjmedia_sdp_session *new_offer,
					pjsip_tx_data **p_tdata )
{
    PJ_UNUSED_ARG(inv);
    PJ_UNUSED_ARG(new_contact);
    PJ_UNUSED_ARG(new_offer);
    PJ_UNUSED_ARG(p_tdata);

    PJ_TODO(CREATE_UPDATE_REQUEST);
    return PJ_ENOTSUP;
}

/*
 * Send a request or response message.
 */
PJ_DEF(pj_status_t) pjsip_inv_send_msg( pjsip_inv_session *inv,
					pjsip_tx_data *tdata)
{
    pj_status_t status;

    /* Verify arguments. */
    PJ_ASSERT_RETURN(inv && tdata, PJ_EINVAL);

    PJ_LOG(5,(inv->obj_name, "Sending %s", 
	      pjsip_tx_data_get_info(tdata)));

    if (tdata->msg->type == PJSIP_REQUEST_MSG) {
	struct tsx_inv_data *tsx_inv_data;

	pjsip_dlg_inc_lock(inv->dlg);

	tsx_inv_data = pj_pool_zalloc(inv->pool, sizeof(struct tsx_inv_data));
	tsx_inv_data->inv = inv;

	pjsip_dlg_dec_lock(inv->dlg);

	status = pjsip_dlg_send_request(inv->dlg, tdata, mod_inv.mod.id, 
					tsx_inv_data);
	if (status != PJ_SUCCESS)
	    return status;

    } else {
	pjsip_cseq_hdr *cseq;

	/* Can only do this to send response to original INVITE
	 * request.
	 */
	PJ_ASSERT_RETURN((cseq=pjsip_msg_find_hdr(tdata->msg, PJSIP_H_CSEQ, NULL))!=NULL
			  && (cseq->cseq == inv->invite_tsx->cseq),
			 PJ_EINVALIDOP);

	status = pjsip_dlg_send_response(inv->dlg, inv->invite_tsx, tdata);
	if (status != PJ_SUCCESS)
	    return status;
    }

    /* Done (?) */
    return PJ_SUCCESS;
}


/*
 * Respond to incoming CANCEL request.
 */
static void inv_respond_incoming_cancel(pjsip_inv_session *inv,
					pjsip_transaction *cancel_tsx,
					pjsip_rx_data *rdata)
{
    pjsip_tx_data *tdata;
    pjsip_transaction *invite_tsx;
    pj_str_t key;
    pj_status_t status;

    /* See if we have matching INVITE server transaction: */

    pjsip_tsx_create_key(rdata->tp_info.pool, &key, PJSIP_ROLE_UAS,
			 &pjsip_invite_method, rdata);
    invite_tsx = pjsip_tsx_layer_find_tsx(&key, PJ_TRUE);

    if (invite_tsx == NULL) {

	/* Invite transaction not found! 
	 * Respond CANCEL with 491 (RFC 3261 Section 9.2 page 42)
	 */
	status = pjsip_dlg_create_response( inv->dlg, rdata, 200, NULL, 
					    &tdata);

    } else {
	/* Always answer CANCEL will 200 (OK) regardless of
	 * the state of the INVITE transaction.
	 */
	status = pjsip_dlg_create_response( inv->dlg, rdata, 200, NULL, 
					    &tdata);
    }

    /* See if we have created the response successfully. */
    if (status != PJ_SUCCESS) return;

    /* Send the CANCEL response */
    status = pjsip_dlg_send_response(inv->dlg, cancel_tsx, tdata);
    if (status != PJ_SUCCESS) return;


    /* See if we need to terminate the UAS INVITE transaction
     * with 487 (Request Terminated) response. 
     */
    if (invite_tsx && invite_tsx->status_code < 200) {

	pj_assert(invite_tsx->last_tx != NULL);

	tdata = invite_tsx->last_tx;

	status = pjsip_dlg_modify_response(inv->dlg, tdata, 487, NULL);
	if (status == PJ_SUCCESS)
	    pjsip_dlg_send_response(inv->dlg, invite_tsx, tdata);
    }

    if (invite_tsx)
	pj_mutex_unlock(invite_tsx->mutex);
}


/*
 * Respond to incoming BYE request.
 */
static void inv_respond_incoming_bye( pjsip_inv_session *inv,
				      pjsip_transaction *bye_tsx,
				      pjsip_rx_data *rdata,
				      pjsip_event *e )
{
    pj_status_t status;
    pjsip_tx_data *tdata;

    /* Respond BYE with 200: */

    status = pjsip_dlg_create_response(inv->dlg, rdata, 200, NULL, &tdata);
    if (status != PJ_SUCCESS) return;

    status = pjsip_dlg_send_response(inv->dlg, bye_tsx, tdata);
    if (status != PJ_SUCCESS) return;

    /* Terminate session: */

    if (inv->state != PJSIP_INV_STATE_DISCONNECTED) {
	inv_set_cause(inv, PJSIP_SC_OK, NULL);
	inv_set_state(inv, PJSIP_INV_STATE_DISCONNECTED, e);
    }
}

/*
 * Respond to BYE request.
 */
static void inv_handle_bye_response( pjsip_inv_session *inv,
				     pjsip_transaction *tsx,
				     pjsip_rx_data *rdata,
				     pjsip_event *e )
{
    pj_status_t status;
    
    if (e->body.tsx_state.type != PJSIP_EVENT_RX_MSG) {
	inv_set_cause(inv, PJSIP_SC_OK, NULL);
	inv_set_state(inv, PJSIP_INV_STATE_DISCONNECTED, e);
	return;
    }

    /* Handle 401/407 challenge. */
    if (tsx->status_code == 401 || tsx->status_code == 407) {

	pjsip_tx_data *tdata;
	
	status = pjsip_auth_clt_reinit_req( &inv->dlg->auth_sess, 
					    rdata,
					    tsx->last_tx,
					    &tdata);
	
	if (status != PJ_SUCCESS) {
	    
	    /* Does not have proper credentials. 
	     * End the session anyway.
	     */
	    inv_set_cause(inv, PJSIP_SC_OK, NULL);
	    inv_set_state(inv, PJSIP_INV_STATE_DISCONNECTED, e);
	    
	} else {
	    /* Re-send BYE. */
	    status = pjsip_inv_send_msg(inv, tdata);
	}

    } else {

	/* End the session. */
	inv_set_cause(inv, PJSIP_SC_OK, NULL);
	inv_set_state(inv, PJSIP_INV_STATE_DISCONNECTED, e);
    }

}

/*
 * State NULL is before anything is sent/received.
 */
static void inv_on_state_null( pjsip_inv_session *inv, pjsip_event *e)
{
    pjsip_transaction *tsx = e->body.tsx_state.tsx;
    pjsip_dialog *dlg = pjsip_tsx_get_dlg(tsx);

    PJ_ASSERT_ON_FAIL(tsx && dlg, return);

    if (tsx->method.id == PJSIP_INVITE_METHOD) {

	/* Keep the initial INVITE transaction. */
	if (inv->invite_tsx == NULL)
	    inv->invite_tsx = tsx;

	if (dlg->role == PJSIP_ROLE_UAC) {

	    switch (tsx->state) {
	    case PJSIP_TSX_STATE_CALLING:
		inv_set_state(inv, PJSIP_INV_STATE_CALLING, e);
		break;
	    default:
		inv_on_state_calling(inv, e);
		break;
	    }

	} else {
	    switch (tsx->state) {
	    case PJSIP_TSX_STATE_TRYING:
		inv_set_state(inv, PJSIP_INV_STATE_INCOMING, e);
		break;
	    case PJSIP_TSX_STATE_PROCEEDING:
		inv_set_state(inv, PJSIP_INV_STATE_INCOMING, e);
		if (tsx->status_code > 100)
		    inv_set_state(inv, PJSIP_INV_STATE_EARLY, e);
		break;
	    default:
		inv_on_state_incoming(inv, e);
		break;
	    }
	}

    } else {
	pj_assert(!"Unexpected transaction type");
    }
}

/*
 * State CALLING is after sending initial INVITE request but before
 * any response (with tag) is received.
 */
static void inv_on_state_calling( pjsip_inv_session *inv, pjsip_event *e)
{
    pjsip_transaction *tsx = e->body.tsx_state.tsx;
    pjsip_dialog *dlg = pjsip_tsx_get_dlg(tsx);
    pj_status_t status;

    PJ_ASSERT_ON_FAIL(tsx && dlg, return);
    
    if (tsx == inv->invite_tsx) {

	switch (tsx->state) {

	case PJSIP_TSX_STATE_CALLING:
	    inv_set_state(inv, PJSIP_INV_STATE_CALLING, e);
	    break;

	case PJSIP_TSX_STATE_PROCEEDING:
	    if (dlg->remote.info->tag.slen) {

		inv_set_state(inv, PJSIP_INV_STATE_EARLY, e);

		inv_check_sdp_in_incoming_msg(inv, tsx, 
					      e->body.tsx_state.src.rdata);

	    } else {
		/* Ignore 100 (Trying) response, as it doesn't change
		 * session state. It only ceases retransmissions.
		 */
	    }
	    break;

	case PJSIP_TSX_STATE_COMPLETED:
	    if (tsx->status_code/100 == 2) {
		
		/* This should not happen.
		 * When transaction receives 2xx, it should be terminated
		 */
		pj_assert(0);
		inv_set_state(inv, PJSIP_INV_STATE_CONNECTING, e);
    
		inv_check_sdp_in_incoming_msg(inv, tsx, 
					      e->body.tsx_state.src.rdata);

	    } else if (tsx->status_code==401 || tsx->status_code==407) {

		/* Handle authentication failure:
		 * Resend the request with Authorization header.
		 */
		pjsip_tx_data *tdata;

		status = pjsip_auth_clt_reinit_req(&inv->dlg->auth_sess, 
						   e->body.tsx_state.src.rdata,
						   tsx->last_tx,
						   &tdata);

		if (status != PJ_SUCCESS) {

		    /* Does not have proper credentials. 
		     * End the session.
		     */
		    inv_set_cause(inv, tsx->status_code, &tsx->status_text);
		    inv_set_state(inv, PJSIP_INV_STATE_DISCONNECTED, e);

		} else {

		    /* Restart session. */
		    inv->state = PJSIP_INV_STATE_NULL;
		    inv->invite_tsx = NULL;

		    /* Send the request. */
		    status = pjsip_inv_send_msg(inv, tdata);
		}

	    } else {

		inv_set_cause(inv, tsx->status_code, &tsx->status_text);
		inv_set_state(inv, PJSIP_INV_STATE_DISCONNECTED, e);

	    }
	    break;