From d139a1a7f435869fb7906083693a198b5a934ba3 Mon Sep 17 00:00:00 2001
From: kongr45gpen <electrovesta@gmail.com>
Date: Thu, 20 Dec 2018 19:35:34 +0000
Subject: [PATCH] TC parser
---
inc/ErrorHandler.hpp | 9 +++++++
inc/MessageParser.hpp | 49 +++++++++++++++++++++++++-----------
src/MessageParser.cpp | 57 ++++++++++++++++++++++++++++++++++++++++++
test/MessageParser.cpp | 20 +++++++++++++--
4 files changed, 118 insertions(+), 17 deletions(-)
diff --git a/inc/ErrorHandler.hpp b/inc/ErrorHandler.hpp
index b18ae744..21710efa 100644
--- a/inc/ErrorHandler.hpp
+++ b/inc/ErrorHandler.hpp
@@ -50,6 +50,11 @@ public:
* A string is larger than the largest allowed string
*/
StringTooLarge = 4,
+
+ /**
+ * An error in the header of a packet makes it unable to be parsed
+ */
+ UnacceptablePacket = 5,
};
/**
@@ -72,6 +77,10 @@ public:
* Cannot read a string, because it is larger than the largest allowed string
*/
StringTooShort = 4,
+ /**
+ * Cannot parse a Message, because there is an error in its secondary header
+ */
+ UnacceptableMessage = 5,
};
/**
diff --git a/inc/MessageParser.hpp b/inc/MessageParser.hpp
index ca2fd599..0af0afbf 100644
--- a/inc/MessageParser.hpp
+++ b/inc/MessageParser.hpp
@@ -1,34 +1,53 @@
#ifndef ECSS_SERVICES_MESSAGEPARSER_HPP
#define ECSS_SERVICES_MESSAGEPARSER_HPP
-// include all the header files for the services that have been implemented for the time being
-#include "Services/TestService.hpp"
-#include "Services/RequestVerificationService.hpp"
-#include <iostream> // This file should be removed
+#include "Message.hpp"
/**
* A generic class responsible for the execution of the incoming telemetry and telecommand
* packets.
*
- * @todo Make the connection between the ST[01]-request verification service and the services
- * that initiate it
* @todo Implement the execute function in the upcoming services or generally in the upcoming
* activities
*
*/
-
class MessageParser {
public:
-/**
- * It is responsible to call the suitable function that execute the proper service. The way that
- * the services are selected is based on the serviceType(class member of Message) of the param
- * message
- *
- * @todo The implementation of the execute function should correspond to the numbers of the
- * services/activities that have been created
- */
+ /**
+ * It is responsible to call the suitable function that executes the proper service. The way that
+ * the services are selected is based on the serviceType of the \p message
+ *
+ * @todo The implementation of the execute function should correspond to the numbers of the
+ * services/activities that have been created
+ */
void execute(Message &message);
+
+ /**
+ * Parse a message that contains the CCSDS and ECSS packet headers, as well as the data
+ *
+ * As defined in CCSDS 133.0-B-1
+ *
+ * @param data The data of the message (not null-terminated)
+ * @param length The size of the message
+ * @return A new object that represents the parsed message
+ */
+ Message parse(uint8_t * data, uint32_t length);
+
+private:
+ /**
+ * Parse the ECSS Telecommand packet secondary header
+ *
+ * As specified in section 7.4.4.1 of the standard
+ *
+ * @todo Implement the acknowledgement flags
+ * @todo Store and parse the source ID, if needed
+ *
+ * @param data The data of the header (not null-terminated)
+ * @param length The size of the header
+ * @param message The Message to modify based on the header
+ */
+ void parseTC(uint8_t *data, uint16_t length, Message &message);
};
diff --git a/src/MessageParser.cpp b/src/MessageParser.cpp
index 83326eba..fe2426e5 100644
--- a/src/MessageParser.cpp
+++ b/src/MessageParser.cpp
@@ -1,4 +1,9 @@
+#include <cstring>
+#include "ErrorHandler.hpp"
#include "MessageParser.hpp"
+#include "macros.hpp"
+#include "Services/TestService.hpp"
+#include "Services/RequestVerificationService.hpp"
TestService TestService::instance;
RequestVerificationService RequestVerificationService::instance;
@@ -17,3 +22,55 @@ void MessageParser::execute(Message &message) {
break;
}
}
+
+Message MessageParser::parse(uint8_t *data, uint32_t length) {
+ assertI(length >= 6, ErrorHandler::UnacceptablePacket);
+
+ uint16_t packetHeaderIdentification = (data[0] << 8) | data[1];
+ uint16_t packetSequenceControl = (data[2] << 8) | data[3];
+ uint16_t packetDataLength = (data[4] << 8) | data[5];
+
+ // Individual fields of the CCSDS Space Packet primary header
+ uint8_t versionNumber = data[0] >> 5;
+ Message::PacketType packetType = ((data[0] & 0x10) == 0) ? Message::TM : Message::TC;
+ uint8_t secondaryHeaderFlag = data[0] & static_cast<uint8_t>(0x08);
+ uint16_t APID = packetHeaderIdentification & static_cast<uint16_t>(0x07ff);
+ auto sequenceFlags = static_cast<uint8_t>(packetSequenceControl >> 14);
+
+ // Returning an internal error, since the Message is not available yet
+ assertI(versionNumber == 0, ErrorHandler::UnacceptablePacket);
+ assertI(secondaryHeaderFlag == 1, ErrorHandler::UnacceptablePacket);
+ assertI(sequenceFlags == 0x3, ErrorHandler::UnacceptablePacket);
+ assertI(packetDataLength == length - 6, ErrorHandler::UnacceptablePacket);
+
+ Message message(0, 0, packetType, APID);
+
+ if (packetType == Message::TC) {
+ parseTC(data + 6, packetDataLength, message);
+ } else {
+ assert(false); // Not implemented yet
+ }
+
+ return message;
+}
+
+void MessageParser::parseTC(uint8_t *data, uint16_t length, Message &message) {
+ ErrorHandler::assertRequest(length >= 5, message, ErrorHandler::UnacceptableMessage);
+
+ // Individual fields of the TC header
+ uint8_t pusVersion = data[0] >> 4;
+ uint8_t serviceType = data[1];
+ uint8_t messageType = data[2];
+
+ ErrorHandler::assertRequest(pusVersion == 2, message, ErrorHandler::UnacceptableMessage);
+
+ // Remove the length of the header
+ length -= 5;
+
+ // Copy the data to the message
+ // TODO: See if memcpy is needed for this
+ message.serviceType = serviceType;
+ message.messageType = messageType;
+ memcpy(message.data, data + 5, length);
+ message.dataSize = length;
+}
diff --git a/test/MessageParser.cpp b/test/MessageParser.cpp
index 1d7436ec..25265d55 100644
--- a/test/MessageParser.cpp
+++ b/test/MessageParser.cpp
@@ -2,10 +2,11 @@
#include <Services/TestService.hpp>
#include <Services/RequestVerificationService.hpp>
#include <Message.hpp>
+#include <cstring>
#include "MessageParser.hpp"
#include "Services/ServiceTests.hpp"
-TEST_CASE("ST[01] message parsing", "[MessageParser][st01]") {
+TEST_CASE("ST[01] message execution", "[MessageParser][st01]") {
MessageParser messageParser;
Message message = Message(1, 1, Message::TC, 2);
@@ -44,7 +45,7 @@ TEST_CASE("ST[01] message parsing", "[MessageParser][st01]") {
CHECK(response.packetType == Message::TM);
}
-TEST_CASE("ST[17] message parsing", "[MessageParser][st17]") {
+TEST_CASE("ST[17] message execution", "[MessageParser][st17]") {
MessageParser messageParser;
Message message = Message(17, 1, Message::TC, 1);
@@ -62,3 +63,18 @@ TEST_CASE("ST[17] message parsing", "[MessageParser][st17]") {
CHECK(response.messageType == 4);
CHECK(response.packetType == Message::TM);
}
+
+TEST_CASE("TC message parsing", "[MessageParser]") {
+ MessageParser messageParser;
+
+ uint8_t packet[] = {0x18, 0x07, 0xc0, 0x4d, 0x00, 0x0a, 0x20, 0x81, 0x1f, 0x00, 0x00, 0x68,
+ 0x65, 0x6c, 0x6c, 0x6f};
+
+ Message message = messageParser.parse(packet, 16);
+ CHECK(message.packetType == Message::TC);
+ CHECK(message.applicationId == 7);
+ CHECK(message.dataSize == 5);
+ CHECK(message.serviceType == 129);
+ CHECK(message.messageType == 31);
+ CHECK(memcmp(message.data, "hello", 5) == 0);
+}
--
GitLab