/* Return: amount of PDU data */
uint16_t MSTP_Get_Send(
volatile struct mstp_port_struct_t * mstp_port,
unsigned timeout)
{ /* milliseconds to wait for a packet */
uint16_t pdu_len = 0;
uint8_t destination = 0; /* destination address */
(void) timeout;
if (!Transmit_Packet.ready) {
return 0;
}
/* load destination MAC address */
if (Transmit_Packet.address.mac_len == 1) {
destination = Transmit_Packet.address.mac[0];
} else {
return 0;
}
if ((MAX_HEADER + Transmit_Packet.pdu_len) > MAX_MPDU) {
return 0;
}
/* convert the PDU into the MSTP Frame */
pdu_len = MSTP_Create_Frame(&mstp_port->OutputBuffer[0], /* <-- loading this */
mstp_port->OutputBufferSize, Transmit_Packet.frame_type, destination,
mstp_port->This_Station, &Transmit_Packet.pdu[0],
Transmit_Packet.pdu_len);
Transmit_Packet.ready = false;
return pdu_len;
}
/* returns number of bytes sent on success, zero on failure */
int dlmstp_send_pdu(
BACNET_ADDRESS * dest, /* destination address */
BACNET_NPDU_DATA * npdu_data, /* network information */
uint8_t * pdu, /* any data to be sent - may be null */
unsigned pdu_len)
{ /* number of bytes of data */
int bytes_sent = 0;
unsigned npdu_len = 0;
uint8_t frame_type = 0;
uint8_t destination = 0; /* destination address */
BACNET_ADDRESS src;
unsigned i = 0; /* loop counter */
if (MSTP_Port.TxReady == false) {
if (npdu_data->data_expecting_reply)
MSTP_Port.TxFrameType = FRAME_TYPE_BACNET_DATA_EXPECTING_REPLY;
else
MSTP_Port.TxFrameType = FRAME_TYPE_BACNET_DATA_NOT_EXPECTING_REPLY;
/* load destination MAC address */
if (dest && dest->mac_len == 1) {
destination = dest->mac[0];
} else {
return -2;
}
dlmstp_get_my_address(&src);
if ((MAX_HEADER + pdu_len) > MAX_MPDU) {
return -4;
}
bytes_sent =
MSTP_Create_Frame((uint8_t *) & MSTP_Port.TxBuffer[0],
sizeof(MSTP_Port.TxBuffer), MSTP_Port.TxFrameType, destination,
MSTP_Port.This_Station, pdu, pdu_len);
MSTP_Port.TxLength = bytes_sent;
MSTP_Port.TxReady = true;
MSTP_Packets++;
}
return bytes_sent;
}
/* Get the reply to a DATA_EXPECTING_REPLY frame, or nothing */
uint16_t MSTP_Get_Reply(
volatile struct mstp_port_struct_t * mstp_port,
unsigned timeout)
{ /* milliseconds to wait for a packet */
uint16_t pdu_len = 0; /* return value */
uint8_t destination = 0; /* destination address */
bool matched = false;
(void) timeout;
if (!Transmit_Packet.ready) {
return 0;
}
/* load destination MAC address */
if (Transmit_Packet.address.mac_len == 1) {
destination = Transmit_Packet.address.mac[0];
} else {
return 0;
}
if ((MAX_HEADER + Transmit_Packet.pdu_len) > MAX_MPDU) {
return 0;
}
/* is this the reply to the DER? */
matched =
dlmstp_compare_data_expecting_reply(&mstp_port->InputBuffer[0],
mstp_port->DataLength, mstp_port->SourceAddress,
&Transmit_Packet.pdu[0], Transmit_Packet.pdu_len,
&Transmit_Packet.address);
if (!matched)
return 0;
/* convert the PDU into the MSTP Frame */
pdu_len = MSTP_Create_Frame(&mstp_port->OutputBuffer[0], /* <-- loading this */
mstp_port->OutputBufferSize, Transmit_Packet.frame_type, destination,
mstp_port->This_Station, &Transmit_Packet.pdu[0],
Transmit_Packet.pdu_len);
Transmit_Packet.ready = false;
return pdu_len;
}