/**
******************************************************************************
* @addtogroup OpenPilotSystem OpenPilot System
* @{
* @addtogroup OpenPilotLibraries OpenPilot System Libraries
* @{
*
* @file uavtalk.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief UAVTalk library, implements to telemetry protocol. See the wiki for more details.
* This library should not be called directly by the application, it is only used by the
* Telemetry module.
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* 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 3 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
*/
#include "openpilot.h"
#include "uavtalk_priv.h"
// #define UAV_DEBUGLOG 1
#if defined UAV_DEBUGLOG && defined FLASH_FREERTOS
#define UAVT_DEBUGLOG_PRINTF(...) PIOS_DEBUGLOG_Printf(__VA_ARGS__)
// uncomment and adapt the following lines to filter verbose logging to include specific object(s) only
// #include "flighttelemetrystats.h"
// #define UAVT_DEBUGLOG_CPRINTF(objId, ...) if (objId == FLIGHTTELEMETRYSTATS_OBJID) { UAVT_DEBUGLOG_PRINTF(__VA_ARGS__); }
#endif
#ifndef UAVT_DEBUGLOG_PRINTF
#define UAVT_DEBUGLOG_PRINTF(...)
#endif
#ifndef UAVT_DEBUGLOG_CPRINTF
#define UAVT_DEBUGLOG_CPRINTF(objId, ...)
#endif
// Private functions
static int32_t objectTransaction(UAVTalkConnectionData *connection, uint8_t type, UAVObjHandle obj, uint16_t instId, int32_t timeout);
static int32_t sendObject(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId, UAVObjHandle obj);
static int32_t sendSingleObject(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId, UAVObjHandle obj);
static int32_t receiveObject(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId, uint8_t *data);
static void updateAck(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId);
/**
* Initialize the UAVTalk library
* \param[in] connection UAVTalkConnection to be used
* \param[in] outputStream Function pointer that is called to send a data buffer
* \return 0 Success
* \return -1 Failure
*/
UAVTalkConnection UAVTalkInitialize(UAVTalkOutputStream outputStream)
{
// allocate object
UAVTalkConnectionData *connection = pios_malloc(sizeof(UAVTalkConnectionData));
if (!connection) {
return 0;
}
connection->canari = UAVTALK_CANARI;
connection->iproc.rxPacketLength = 0;
connection->iproc.state = UAVTALK_STATE_SYNC;
connection->outStream = outputStream;
connection->lock = xSemaphoreCreateRecursiveMutex();
connection->transLock = xSemaphoreCreateRecursiveMutex();
// allocate buffers
connection->rxBuffer = pios_malloc(UAVTALK_MAX_PACKET_LENGTH);
if (!connection->rxBuffer) {
return 0;
}
connection->txBuffer = pios_malloc(UAVTALK_MAX_PACKET_LENGTH);
if (!connection->txBuffer) {
return 0;
}
vSemaphoreCreateBinary(connection->respSema);
xSemaphoreTake(connection->respSema, 0); // reset to zero
UAVTalkResetStats((UAVTalkConnection)connection);
return (UAVTalkConnection)connection;
}
/**
* Set the communication output stream
* \param[in] connection UAVTalkConnection to be used
* \param[in] outputStream Function pointer that is called to send a data buffer
* \return 0 Success
* \return -1 Failure
*/
int32_t UAVTalkSetOutputStream(UAVTalkConnection connectionHandle, UAVTalkOutputStream outputStream)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return -1);
// Lock
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
// set output stream
connection->outStream = outputStream;
// Release lock
xSemaphoreGiveRecursive(connection->lock);
return 0;
}
/**
* Get current output stream
* \param[in] connection UAVTalkConnection to be used
* @return UAVTarlkOutputStream the output stream used
*/
UAVTalkOutputStream UAVTalkGetOutputStream(UAVTalkConnection connectionHandle)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return NULL);
return connection->outStream;
}
/**
* Get communication statistics counters
* \param[in] connection UAVTalkConnection to be used
* @param[out] statsOut Statistics counters
*/
void UAVTalkGetStats(UAVTalkConnection connectionHandle, UAVTalkStats *statsOut, bool reset)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return );
// Lock
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
// Copy stats
memcpy(statsOut, &connection->stats, sizeof(UAVTalkStats));
if (reset) {
// Clear stats
memset(&connection->stats, 0, sizeof(UAVTalkStats));
}
// Release lock
xSemaphoreGiveRecursive(connection->lock);
}
/**
* Get communication statistics counters
* \param[in] connection UAVTalkConnection to be used
* @param[out] statsOut Statistics counters
*/
void UAVTalkAddStats(UAVTalkConnection connectionHandle, UAVTalkStats *statsOut, bool reset)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return );
// Lock
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
// Copy stats
statsOut->txBytes += connection->stats.txBytes;
statsOut->txObjectBytes += connection->stats.txObjectBytes;
statsOut->txObjects += connection->stats.txObjects;
statsOut->txErrors += connection->stats.txErrors;
statsOut->rxBytes += connection->stats.rxBytes;
statsOut->rxObjectBytes += connection->stats.rxObjectBytes;
statsOut->rxObjects += connection->stats.rxObjects;
statsOut->rxErrors += connection->stats.rxErrors;
statsOut->rxSyncErrors += connection->stats.rxSyncErrors;
statsOut->rxCrcErrors += connection->stats.rxCrcErrors;
if (reset) {
// Clear stats
memset(&connection->stats, 0, sizeof(UAVTalkStats));
}
// Release lock
xSemaphoreGiveRecursive(connection->lock);
}
/**
* Reset the statistics counters.
* \param[in] connection UAVTalkConnection to be used
*/
void UAVTalkResetStats(UAVTalkConnection connectionHandle)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return );
// Lock
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
// Clear stats
memset(&connection->stats, 0, sizeof(UAVTalkStats));
// Release lock
xSemaphoreGiveRecursive(connection->lock);
}
/**
* Accessor method to get the timestamp from the last UAVTalk message
*/
void UAVTalkGetLastTimestamp(UAVTalkConnection connectionHandle, uint16_t *timestamp)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return );
UAVTalkInputProcessor *iproc = &connection->iproc;
*timestamp = iproc->timestamp;
}
/**
* Request an update for the specified object, on success the object data would have been
* updated by the GCS.
* \param[in] connection UAVTalkConnection to be used
* \param[in] obj Object to update
* \param[in] instId The instance ID or UAVOBJ_ALL_INSTANCES for all instances.
* \param[in] timeout Time to wait for the response, when zero it will return immediately
* \return 0 Success
* \return -1 Failure
*/
int32_t UAVTalkSendObjectRequest(UAVTalkConnection connectionHandle, UAVObjHandle obj, uint16_t instId, int32_t timeout)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return -1);
return objectTransaction(connection, UAVTALK_TYPE_OBJ_REQ, obj, instId, timeout);
}
/**
* Send the specified object through the telemetry link.
* \param[in] connection UAVTalkConnection to be used
* \param[in] obj Object to send
* \param[in] instId The instance ID or UAVOBJ_ALL_INSTANCES for all instances.
* \param[in] acked Selects if an ack is required (1:ack required, 0: ack not required)
* \param[in] timeoutMs Time to wait for the ack, when zero it will return immediately
* \return 0 Success
* \return -1 Failure
*/
int32_t UAVTalkSendObject(UAVTalkConnection connectionHandle, UAVObjHandle obj, uint16_t instId, uint8_t acked, int32_t timeoutMs)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return -1);
// Send object
if (acked == 1) {
return objectTransaction(connection, UAVTALK_TYPE_OBJ_ACK, obj, instId, timeoutMs);
} else {
return objectTransaction(connection, UAVTALK_TYPE_OBJ, obj, instId, timeoutMs);
}
}
/**
* Send the specified object through the telemetry link with a timestamp.
* \param[in] connection UAVTalkConnection to be used
* \param[in] obj Object to send
* \param[in] instId The instance ID or UAVOBJ_ALL_INSTANCES for all instances.
* \param[in] acked Selects if an ack is required (1:ack required, 0: ack not required)
* \param[in] timeoutMs Time to wait for the ack, when zero it will return immediately
* \return 0 Success
* \return -1 Failure
*/
int32_t UAVTalkSendObjectTimestamped(UAVTalkConnection connectionHandle, UAVObjHandle obj, uint16_t instId, uint8_t acked, int32_t timeoutMs)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return -1);
// Send object
if (acked == 1) {
return objectTransaction(connection, UAVTALK_TYPE_OBJ_ACK_TS, obj, instId, timeoutMs);
} else {
return objectTransaction(connection, UAVTALK_TYPE_OBJ_TS, obj, instId, timeoutMs);
}
}
/**
* Execute the requested transaction on an object.
* \param[in] connection UAVTalkConnection to be used
* \param[in] type Transaction type
* UAVTALK_TYPE_OBJ: send object,
* UAVTALK_TYPE_OBJ_REQ: request object update
* UAVTALK_TYPE_OBJ_ACK: send object with an ack
* \param[in] obj Object
* \param[in] instId The instance ID of UAVOBJ_ALL_INSTANCES for all instances.
* \param[in] timeoutMs Time to wait for the ack, when zero it will return immediately
* \return 0 Success
* \return -1 Failure
*/
static int32_t objectTransaction(UAVTalkConnectionData *connection, uint8_t type, UAVObjHandle obj, uint16_t instId, int32_t timeoutMs)
{
int32_t respReceived;
int32_t ret = -1;
// Send object depending on if a response is needed
if (type == UAVTALK_TYPE_OBJ_ACK || type == UAVTALK_TYPE_OBJ_ACK_TS || type == UAVTALK_TYPE_OBJ_REQ) {
// Get transaction lock (will block if a transaction is pending)
xSemaphoreTakeRecursive(connection->transLock, portMAX_DELAY);
// Send object
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
// expected response type
connection->respType = (type == UAVTALK_TYPE_OBJ_REQ) ? UAVTALK_TYPE_OBJ : UAVTALK_TYPE_ACK;
connection->respObjId = UAVObjGetID(obj);
connection->respInstId = instId;
ret = sendObject(connection, type, UAVObjGetID(obj), instId, obj);
xSemaphoreGiveRecursive(connection->lock);
// Wait for response (or timeout) if sending the object succeeded
respReceived = pdFALSE;
if (ret == 0) {
respReceived = xSemaphoreTake(connection->respSema, timeoutMs / portTICK_RATE_MS);
}
// Check if a response was received
if (respReceived == pdTRUE) {
// We are done successfully
xSemaphoreGiveRecursive(connection->transLock);
ret = 0;
} else {
// Cancel transaction
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
// non blocking call to make sure the value is reset to zero (binary sema)
xSemaphoreTake(connection->respSema, 0);
connection->respObjId = 0;
xSemaphoreGiveRecursive(connection->lock);
xSemaphoreGiveRecursive(connection->transLock);
return -1;
}
} else if (type == UAVTALK_TYPE_OBJ || type == UAVTALK_TYPE_OBJ_TS) {
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
ret = sendObject(connection, type, UAVObjGetID(obj), instId, obj);
xSemaphoreGiveRecursive(connection->lock);
}
return ret;
}
/**
* Process an byte from the telemetry stream.
* \param[in] connectionHandle UAVTalkConnection to be used
* \param[in] rxbyte Received byte
* \return UAVTalkRxState
*/
UAVTalkRxState UAVTalkProcessInputStreamQuiet(UAVTalkConnection connectionHandle, uint8_t rxbyte)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return -1);
UAVTalkInputProcessor *iproc = &connection->iproc;
++connection->stats.rxBytes;
if (iproc->state == UAVTALK_STATE_ERROR || iproc->state == UAVTALK_STATE_COMPLETE) {
iproc->state = UAVTALK_STATE_SYNC;
}
if (iproc->rxPacketLength < 0xffff) {
// update packet byte count
iproc->rxPacketLength++;
}
// Receive state machine
switch (iproc->state) {
case UAVTALK_STATE_SYNC:
if (rxbyte != UAVTALK_SYNC_VAL) {
connection->stats.rxSyncErrors++;
break;
}
// Initialize and update the CRC
iproc->cs = PIOS_CRC_updateByte(0, rxbyte);
iproc->rxPacketLength = 1;
iproc->rxCount = 0;
iproc->type = 0;
iproc->state = UAVTALK_STATE_TYPE;
break;
case UAVTALK_STATE_TYPE:
if ((rxbyte & UAVTALK_TYPE_MASK) != UAVTALK_TYPE_VER) {
connection->stats.rxErrors++;
iproc->state = UAVTALK_STATE_SYNC;
break;
}
// update the CRC
iproc->cs = PIOS_CRC_updateByte(iproc->cs, rxbyte);
iproc->type = rxbyte;
iproc->packet_size = 0;
iproc->state = UAVTALK_STATE_SIZE;
break;
case UAVTALK_STATE_SIZE:
// update the CRC
iproc->cs = PIOS_CRC_updateByte(iproc->cs, rxbyte);
if (iproc->rxCount == 0) {
iproc->packet_size += rxbyte;
iproc->rxCount++;
break;
}
iproc->packet_size += rxbyte << 8;
iproc->rxCount = 0;
if (iproc->packet_size < UAVTALK_MIN_HEADER_LENGTH || iproc->packet_size > UAVTALK_MAX_HEADER_LENGTH + UAVTALK_MAX_PAYLOAD_LENGTH) {
// incorrect packet size
connection->stats.rxErrors++;
iproc->state = UAVTALK_STATE_ERROR;
break;
}
iproc->objId = 0;
iproc->state = UAVTALK_STATE_OBJID;
break;
case UAVTALK_STATE_OBJID:
// update the CRC
iproc->cs = PIOS_CRC_updateByte(iproc->cs, rxbyte);
iproc->objId += rxbyte << (8 * (iproc->rxCount++));
if (iproc->rxCount < 4) {
break;
}
iproc->rxCount = 0;
iproc->instId = 0;
iproc->state = UAVTALK_STATE_INSTID;
break;
case UAVTALK_STATE_INSTID:
// update the CRC
iproc->cs = PIOS_CRC_updateByte(iproc->cs, rxbyte);
iproc->instId += rxbyte << (8 * (iproc->rxCount++));
if (iproc->rxCount < 2) {
break;
}
iproc->rxCount = 0;
UAVObjHandle obj = UAVObjGetByID(iproc->objId);
// Determine data length
if (iproc->type == UAVTALK_TYPE_OBJ_REQ || iproc->type == UAVTALK_TYPE_ACK || iproc->type == UAVTALK_TYPE_NACK) {
iproc->length = 0;
iproc->timestampLength = 0;
} else {
iproc->timestampLength = (iproc->type & UAVTALK_TIMESTAMPED) ? 2 : 0;
if (obj) {
iproc->length = UAVObjGetNumBytes(obj);
} else {
iproc->length = iproc->packet_size - iproc->rxPacketLength - iproc->timestampLength;
}
}
// Check length
if (iproc->length >= UAVTALK_MAX_PAYLOAD_LENGTH) {
// packet error - exceeded payload max length
connection->stats.rxErrors++;
iproc->state = UAVTALK_STATE_ERROR;
break;
}
// Check the lengths match
if ((iproc->rxPacketLength + iproc->timestampLength + iproc->length) != iproc->packet_size) {
// packet error - mismatched packet size
connection->stats.rxErrors++;
iproc->state = UAVTALK_STATE_ERROR;
break;
}
// Determine next state
if (iproc->type & UAVTALK_TIMESTAMPED) {
// If there is a timestamp get it
iproc->timestamp = 0;
iproc->state = UAVTALK_STATE_TIMESTAMP;
} else {
// If there is a payload get it, otherwise receive checksum
if (iproc->length > 0) {
iproc->state = UAVTALK_STATE_DATA;
} else {
iproc->state = UAVTALK_STATE_CS;
}
}
break;
case UAVTALK_STATE_TIMESTAMP:
// update the CRC
iproc->cs = PIOS_CRC_updateByte(iproc->cs, rxbyte);
iproc->timestamp += rxbyte << (8 * (iproc->rxCount++));
if (iproc->rxCount < 2) {
break;
}
iproc->rxCount = 0;
// If there is a payload get it, otherwise receive checksum
if (iproc->length > 0) {
iproc->state = UAVTALK_STATE_DATA;
} else {
iproc->state = UAVTALK_STATE_CS;
}
break;
case UAVTALK_STATE_DATA:
// update the CRC
iproc->cs = PIOS_CRC_updateByte(iproc->cs, rxbyte);
connection->rxBuffer[iproc->rxCount++] = rxbyte;
if (iproc->rxCount < iproc->length) {
break;
}
iproc->rxCount = 0;
iproc->state = UAVTALK_STATE_CS;
break;
case UAVTALK_STATE_CS:
// Check the CRC byte
if (rxbyte != iproc->cs) {
// packet error - faulty CRC
UAVT_DEBUGLOG_PRINTF("BAD CRC");
connection->stats.rxCrcErrors++;
connection->stats.rxErrors++;
iproc->state = UAVTALK_STATE_ERROR;
break;
}
if (iproc->rxPacketLength != (iproc->packet_size + UAVTALK_CHECKSUM_LENGTH)) {
// packet error - mismatched packet size
connection->stats.rxErrors++;
iproc->state = UAVTALK_STATE_ERROR;
break;
}
connection->stats.rxObjects++;
connection->stats.rxObjectBytes += iproc->length;
iproc->state = UAVTALK_STATE_COMPLETE;
break;
default:
iproc->state = UAVTALK_STATE_ERROR;
break;
}
// Done
return iproc->state;
}
/**
* Process an byte from the telemetry stream.
* \param[in] connection UAVTalkConnection to be used
* \param[in] rxbyte Received byte
* \return UAVTalkRxState
*/
UAVTalkRxState UAVTalkProcessInputStream(UAVTalkConnection connectionHandle, uint8_t rxbyte)
{
UAVTalkRxState state = UAVTalkProcessInputStreamQuiet(connectionHandle, rxbyte);
if (state == UAVTALK_STATE_COMPLETE) {
UAVTalkReceiveObject(connectionHandle);
}
return state;
}
/**
* Send a parsed packet received on one connection handle out on a different connection handle.
* The packet must be in a complete state, meaning it is completed parsing.
* The packet is re-assembled from the component parts into a complete message and sent.
* This can be used to relay packets from one UAVTalk connection to another.
* \param[in] connection UAVTalkConnection to be used
* \param[in] rxbyte Received byte
* \return 0 Success
* \return -1 Failure
*/
int32_t UAVTalkRelayPacket(UAVTalkConnection inConnectionHandle, UAVTalkConnection outConnectionHandle)
{
UAVTalkConnectionData *inConnection;
CHECKCONHANDLE(inConnectionHandle, inConnection, return -1);
UAVTalkInputProcessor *inIproc = &inConnection->iproc;
// The input packet must be completely parsed.
if (inIproc->state != UAVTALK_STATE_COMPLETE) {
inConnection->stats.rxErrors++;
return -1;
}
UAVTalkConnectionData *outConnection;
CHECKCONHANDLE(outConnectionHandle, outConnection, return -1);
if (!outConnection->outStream) {
outConnection->stats.txErrors++;
return -1;
}
// Lock
xSemaphoreTakeRecursive(outConnection->lock, portMAX_DELAY);
outConnection->txBuffer[0] = UAVTALK_SYNC_VAL;
// Setup type
outConnection->txBuffer[1] = inIproc->type;
// next 2 bytes are reserved for data length (inserted here later)
// Setup object ID
outConnection->txBuffer[4] = (uint8_t)(inIproc->objId & 0xFF);
outConnection->txBuffer[5] = (uint8_t)((inIproc->objId >> 8) & 0xFF);
outConnection->txBuffer[6] = (uint8_t)((inIproc->objId >> 16) & 0xFF);
outConnection->txBuffer[7] = (uint8_t)((inIproc->objId >> 24) & 0xFF);
// Setup instance ID
outConnection->txBuffer[8] = (uint8_t)(inIproc->instId & 0xFF);
outConnection->txBuffer[9] = (uint8_t)((inIproc->instId >> 8) & 0xFF);
int32_t headerLength = 10;
// Add timestamp when the transaction type is appropriate
if (inIproc->type & UAVTALK_TIMESTAMPED) {
portTickType time = xTaskGetTickCount();
outConnection->txBuffer[10] = (uint8_t)(time & 0xFF);
outConnection->txBuffer[11] = (uint8_t)((time >> 8) & 0xFF);
headerLength += 2;
}
// Copy data (if any)
if (inIproc->length > 0) {
memcpy(&outConnection->txBuffer[headerLength], inConnection->rxBuffer, inIproc->length);
}
// Store the packet length
outConnection->txBuffer[2] = (uint8_t)((headerLength + inIproc->length) & 0xFF);
outConnection->txBuffer[3] = (uint8_t)(((headerLength + inIproc->length) >> 8) & 0xFF);
// Copy the checksum
outConnection->txBuffer[headerLength + inIproc->length] = inIproc->cs;
// Send the buffer.
int32_t rc = (*outConnection->outStream)(outConnection->txBuffer, headerLength + inIproc->length + UAVTALK_CHECKSUM_LENGTH);
// Update stats
outConnection->stats.txBytes += (rc > 0) ? rc : 0;
// evaluate return value before releasing the lock
int32_t ret = 0;
if (rc != (int32_t)(headerLength + inIproc->length + UAVTALK_CHECKSUM_LENGTH)) {
outConnection->stats.txErrors++;
ret = -1;
}
// Release lock
xSemaphoreGiveRecursive(outConnection->lock);
// Done
return ret;
}
/**
* Complete receiving a UAVTalk packet. This will cause the packet to be unpacked, acked, etc.
* \param[in] connectionHandle UAVTalkConnection to be used
* \return 0 Success
* \return -1 Failure
*/
int32_t UAVTalkReceiveObject(UAVTalkConnection connectionHandle)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return -1);
UAVTalkInputProcessor *iproc = &connection->iproc;
if (iproc->state != UAVTALK_STATE_COMPLETE) {
return -1;
}
return receiveObject(connection, iproc->type, iproc->objId, iproc->instId, connection->rxBuffer);
}
/**
* Get the object ID of the current packet.
* \param[in] connectionHandle UAVTalkConnection to be used
* \return The object ID, or 0 on error.
*/
uint32_t UAVTalkGetPacketObjId(UAVTalkConnection connectionHandle)
{
UAVTalkConnectionData *connection;
CHECKCONHANDLE(connectionHandle, connection, return 0);
return connection->iproc.objId;
}
/**
* Receive an object. This function process objects received through the telemetry stream.
*
* Parser errors are considered as transmission errors and are not NACKed.
* Some senders (GCS) can timeout and retry if the message is not answered by an ack or nack.
*
* Object handling errors are considered as application errors and are NACked.
* In that case we want to nack as there is no point in the sender retrying to send invalid objects.
*
* \param[in] connection UAVTalkConnection to be used
* \param[in] type Type of received message (UAVTALK_TYPE_OBJ, UAVTALK_TYPE_OBJ_REQ, UAVTALK_TYPE_OBJ_ACK, UAVTALK_TYPE_ACK, UAVTALK_TYPE_NACK)
* \param[in] objId ID of the object to work on
* \param[in] instId The instance ID of UAVOBJ_ALL_INSTANCES for all instances.
* \param[in] data Data buffer
* \param[in] length Buffer length
* \return 0 Success
* \return -1 Failure
*/
static int32_t receiveObject(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId, uint8_t *data)
{
UAVObjHandle obj;
int32_t ret = 0;
// Lock
xSemaphoreTakeRecursive(connection->lock, portMAX_DELAY);
// Get the handle to the object. Will be null if object does not exist.
// Warning :
// Here we ask for instance ID 0 without taking into account the provided instId
// The provided instId will be used later when packing, unpacking, etc...
// TODO the above should be fixed as it is cumbersome and error prone
obj = UAVObjGetByID(objId);
// Process message type
switch (type) {
case UAVTALK_TYPE_OBJ:
case UAVTALK_TYPE_OBJ_TS:
// All instances not allowed for OBJ messages
if (obj && (instId != UAVOBJ_ALL_INSTANCES)) {
// Unpack object, if the instance does not exist it will be created!
if (UAVObjUnpack(obj, instId, data) == 0) {
// Check if this object acks a pending OBJ_REQ message
// any OBJ message can ack a pending OBJ_REQ message
// even one that was not sent in response to the OBJ_REQ message
updateAck(connection, type, objId, instId);
} else {
ret = -1;
}
} else {
ret = -1;
}
break;
case UAVTALK_TYPE_OBJ_ACK:
case UAVTALK_TYPE_OBJ_ACK_TS:
UAVT_DEBUGLOG_CPRINTF(objId, "OBJ_ACK %X %d", objId, instId);
// All instances not allowed for OBJ_ACK messages
if (obj && (instId != UAVOBJ_ALL_INSTANCES)) {
// Unpack object, if the instance does not exist it will be created!
if (UAVObjUnpack(obj, instId, data) == 0) {
UAVT_DEBUGLOG_CPRINTF(objId, "OBJ ACK %X %d", objId, instId);
// Object updated or created, transmit ACK
sendObject(connection, UAVTALK_TYPE_ACK, objId, instId, NULL);
} else {
ret = -1;
}
} else {
ret = -1;
}
if (ret == -1) {
// failed to update object, transmit NACK
UAVT_DEBUGLOG_PRINTF("OBJ NACK %X %d", objId, instId);
sendObject(connection, UAVTALK_TYPE_NACK, objId, instId, NULL);
}
break;
case UAVTALK_TYPE_OBJ_REQ:
// Check if requested object exists
UAVT_DEBUGLOG_CPRINTF(objId, "REQ %X %d", objId, instId);
if (obj) {
// Object found, transmit it
// The sent object will ack the object request on the receiver side
ret = sendObject(connection, UAVTALK_TYPE_OBJ, objId, instId, obj);
} else {
ret = -1;
}
if (ret == -1) {
// failed to send object, transmit NACK
UAVT_DEBUGLOG_PRINTF("REQ NACK %X %d", objId, instId);
sendObject(connection, UAVTALK_TYPE_NACK, objId, instId, NULL);
}
break;
case UAVTALK_TYPE_NACK:
// Do nothing on flight side, let it time out.
// TODO:
// The transaction takes the result code of the "semaphore taking operation" into account to determine success.
// If we give that semaphore in time, its "success" (ack received)
// If we do not give that semaphore before the timeout it will return failure.
// What would have to be done here is give the semaphore, but set a flag (for example connection->respFail=true)
// that indicates failure and then above where it checks for the result code, have it behave as if it failed
// if the explicit failure is set.
break;
case UAVTALK_TYPE_ACK:
// All instances not allowed for ACK messages
if (obj && (instId != UAVOBJ_ALL_INSTANCES)) {
// Check if an ACK is pending
updateAck(connection, type, objId, instId);
} else {
ret = -1;
}
break;
default:
ret = -1;
}
// Unlock
xSemaphoreGiveRecursive(connection->lock);
// Done
return ret;
}
/**
* Check if an ack is pending on an object and give response semaphore
* \param[in] connection UAVTalkConnection to be used
* \param[in] obj Object
* \param[in] instId The instance ID of UAVOBJ_ALL_INSTANCES for all instances.
*/
static void updateAck(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId)
{
if ((connection->respObjId == objId) && (connection->respType == type)) {
if ((connection->respInstId == UAVOBJ_ALL_INSTANCES) && (instId == 0)) {
// last instance received, complete transaction
xSemaphoreGive(connection->respSema);
connection->respObjId = 0;
} else if (connection->respInstId == instId) {
xSemaphoreGive(connection->respSema);
connection->respObjId = 0;
}
}
}
/**
* Send an object through the telemetry link.
* \param[in] connection UAVTalkConnection to be used
* \param[in] type Transaction type
* \param[in] objId The object ID
* \param[in] instId The instance ID or UAVOBJ_ALL_INSTANCES for all instances
* \param[in] obj Object handle to send (null when type is NACK)
* \return 0 Success
* \return -1 Failure
*/
static int32_t sendObject(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId, UAVObjHandle obj)
{
uint32_t numInst;
uint32_t n;
int32_t ret = -1;
// Important note : obj can be null (when type is NACK for example) so protect all obj dereferences.
// If all instances are requested and this is a single instance object, force instance ID to zero
if ((obj != NULL) && (instId == UAVOBJ_ALL_INSTANCES) && UAVObjIsSingleInstance(obj)) {
instId = 0;
}
// Process message type
if (type == UAVTALK_TYPE_OBJ || type == UAVTALK_TYPE_OBJ_TS || type == UAVTALK_TYPE_OBJ_ACK || type == UAVTALK_TYPE_OBJ_ACK_TS) {
if (instId == UAVOBJ_ALL_INSTANCES) {
// Get number of instances
numInst = UAVObjGetNumInstances(obj);
// Send all instances in reverse order
// This allows the receiver to detect when the last object has been received (i.e. when instance 0 is received)
ret = 0;
for (n = 0; n < numInst; ++n) {
ret = sendSingleObject(connection, type, objId, numInst - n - 1, obj);
if (ret == -1) {
break;
}
}
} else {
ret = sendSingleObject(connection, type, objId, instId, obj);
}
} else if (type == UAVTALK_TYPE_OBJ_REQ) {
ret = sendSingleObject(connection, type, objId, instId, obj);
} else if (type == UAVTALK_TYPE_ACK || type == UAVTALK_TYPE_NACK) {
if (instId != UAVOBJ_ALL_INSTANCES) {
ret = sendSingleObject(connection, type, objId, instId, obj);
}
}
return ret;
}
/**
* Send an object through the telemetry link.
* \param[in] connection UAVTalkConnection to be used
* \param[in] type Transaction type
* \param[in] objId The object ID
* \param[in] instId The instance ID (can NOT be UAVOBJ_ALL_INSTANCES, use () instead)
* \param[in] obj Object handle to send (null when type is NACK)
* \return 0 Success
* \return -1 Failure
*/
static int32_t sendSingleObject(UAVTalkConnectionData *connection, uint8_t type, uint32_t objId, uint16_t instId, UAVObjHandle obj)
{
// IMPORTANT : obj can be null (when type is NACK for example)
if (!connection->outStream) {
connection->stats.txErrors++;
return -1;
}
// Setup sync byte
connection->txBuffer[0] = UAVTALK_SYNC_VAL;
// Setup type
connection->txBuffer[1] = type;
// next 2 bytes are reserved for data length (inserted here later)
// Setup object ID
connection->txBuffer[4] = (uint8_t)(objId & 0xFF);
connection->txBuffer[5] = (uint8_t)((objId >> 8) & 0xFF);
connection->txBuffer[6] = (uint8_t)((objId >> 16) & 0xFF);
connection->txBuffer[7] = (uint8_t)((objId >> 24) & 0xFF);
// Setup instance ID
connection->txBuffer[8] = (uint8_t)(instId & 0xFF);
connection->txBuffer[9] = (uint8_t)((instId >> 8) & 0xFF);
int32_t headerLength = 10;
// Add timestamp when the transaction type is appropriate
if (type & UAVTALK_TIMESTAMPED) {
portTickType time = xTaskGetTickCount();
connection->txBuffer[10] = (uint8_t)(time & 0xFF);
connection->txBuffer[11] = (uint8_t)((time >> 8) & 0xFF);
headerLength += 2;
}
// Determine data length
int32_t length;
if (type == UAVTALK_TYPE_OBJ_REQ || type == UAVTALK_TYPE_ACK || type == UAVTALK_TYPE_NACK) {
length = 0;
} else {
length = UAVObjGetNumBytes(obj);
}
// Check length
if (length > UAVOBJECTS_LARGEST) {
connection->stats.txErrors++;
return -1;
}
// Copy data (if any)
if (length > 0) {
if (UAVObjPack(obj, instId, &connection->txBuffer[headerLength]) == -1) {
connection->stats.txErrors++;
return -1;
}
}
// Store the packet length
connection->txBuffer[2] = (uint8_t)((headerLength + length) & 0xFF);
connection->txBuffer[3] = (uint8_t)(((headerLength + length) >> 8) & 0xFF);
// Calculate and store checksum
connection->txBuffer[headerLength + length] = PIOS_CRC_updateCRC(0, connection->txBuffer, headerLength + length);
// Send object
uint16_t tx_msg_len = headerLength + length + UAVTALK_CHECKSUM_LENGTH;
int32_t rc = (*connection->outStream)(connection->txBuffer, tx_msg_len);
// Update stats
if (rc == tx_msg_len) {
++connection->stats.txObjects;
connection->stats.txObjectBytes += length;
connection->stats.txBytes += tx_msg_len;
} else {
connection->stats.txErrors++;
// TODO rc == -1 connection not open, -2 buffer full should retry
connection->stats.txBytes += (rc > 0) ? rc : 0;
return -1;
}
// Done
return 0;
}
/**
* @}
* @}
*/