From 1cadc320a512385bb7a32f77b6f5c11b24c5d755 Mon Sep 17 00:00:00 2001 From: Julius Lipp Date: Mon, 12 Apr 2021 21:36:17 +0200 Subject: [PATCH] improve crc calculation * removed TableObject::crc16Citt method and use the one in bits.h * do not save crc in flash, instead calculate on-the-fly in CallbackProperty when state==LS_LOADED * use DataProperty to store PID_PROG_VERSION * WARNING: segmentSize calculation for crc calculation is currently not correct. Need to somehow access size of data in class that inherits from TableObject (e.g. ApplicationObject or RouterObject) --- src/knx/application_program_object.cpp | 13 ++------- src/knx/table_object.cpp | 40 ++++++++------------------ src/knx/table_object.h | 2 -- 3 files changed, 15 insertions(+), 40 deletions(-) diff --git a/src/knx/application_program_object.cpp b/src/knx/application_program_object.cpp index 96f9406..f27d4d6 100644 --- a/src/knx/application_program_object.cpp +++ b/src/knx/application_program_object.cpp @@ -11,16 +11,7 @@ ApplicationProgramObject::ApplicationProgramObject(Memory& memory) Property* properties[] = { new DataProperty(PID_OBJECT_TYPE, false, PDT_UNSIGNED_INT, 1, ReadLv3 | WriteLv0, (uint16_t)OT_APPLICATION_PROG), - new CallbackProperty(this, PID_PROG_VERSION, true, PDT_GENERIC_05, 1, ReadLv3 | WriteLv3, - [](ApplicationProgramObject* io, uint16_t start, uint8_t count, uint8_t* data) -> uint8_t { - pushByteArray(io->_programVersion, 5, data); - return 1; - }, - [](ApplicationProgramObject* io, uint16_t start, uint8_t count, const uint8_t* data) -> uint8_t - { - memcpy(io->_programVersion, data, 5); - return 1; - }), + new DataProperty(PID_PROG_VERSION, true, PDT_GENERIC_05, 1, ReadLv3 | WriteLv3), new CallbackProperty(this, PID_PEI_TYPE, false, PDT_UNSIGNED_CHAR, 1, ReadLv3 | WriteLv0, [](ApplicationProgramObject* io, uint16_t start, uint8_t count, uint8_t* data) -> uint8_t { if(start == 0) @@ -40,6 +31,7 @@ ApplicationProgramObject::ApplicationProgramObject(Memory& memory) uint8_t* ApplicationProgramObject::save(uint8_t* buffer) { + property(PID_PROG_VERSION)->read(_programVersion); buffer = pushByteArray(_programVersion, 5, buffer); return TableObject::save(buffer); @@ -48,6 +40,7 @@ uint8_t* ApplicationProgramObject::save(uint8_t* buffer) const uint8_t* ApplicationProgramObject::restore(const uint8_t* buffer) { buffer = popByteArray(_programVersion, 5, buffer); + property(PID_PROG_VERSION)->write(_programVersion); return TableObject::restore(buffer); } diff --git a/src/knx/table_object.cpp b/src/knx/table_object.cpp index 8d213ec..bf5477b 100644 --- a/src/knx/table_object.cpp +++ b/src/knx/table_object.cpp @@ -31,8 +31,6 @@ uint8_t* TableObject::save(uint8_t* buffer) { buffer = pushByte(_state, buffer); - buffer = pushWord(_crc, buffer); - if (_data) buffer = pushInt(_memory.toRelative(_data), buffer); else @@ -48,8 +46,6 @@ const uint8_t* TableObject::restore(const uint8_t* buffer) buffer = popByte(state, buffer); _state = (LoadState)state; - buffer = popWord(_crc, buffer); - uint32_t relativeAddress = 0; buffer = popInt(relativeAddress, buffer); @@ -137,7 +133,6 @@ void TableObject::loadEventLoading(const uint8_t* data) case LE_START_LOADING: break; case LE_LOAD_COMPLETED: - _crc = Crc16Citt(_data, saveSize() - 4 - 1 - 2); // remove 4 (memory) + 1 (state) + 2 (crc) bytes loadState(LS_LOADED); break; case LE_UNLOAD: @@ -234,7 +229,7 @@ void TableObject::errorCode(ErrorCode errorCode) uint16_t TableObject::saveSize() { - return 5 + InterfaceObject::saveSize() + sizeof(_crc); + return 5 + InterfaceObject::saveSize(); } void TableObject::initializeProperties(size_t propertiesSize, Property** properties) @@ -272,14 +267,19 @@ void TableObject::initializeProperties(size_t propertiesSize, Property** propert pushInt(obj->tableReference(), data); return 1; }), - new CallbackProperty(this, PID_MCB_TABLE, false, PDT_GENERIC_08, 1, ReadLv3 | WriteLv0, + new CallbackProperty(this, PID_MCB_TABLE, false, PDT_GENERIC_08, 1, ReadLv3 | WriteLv0, [](TableObject* obj, uint16_t start, uint8_t count, uint8_t* data) -> uint8_t { - uint16_t size = obj->saveSize() - 5 - 2; // need to remove 5+2 extra bytes which were added in saveSize() + if (obj->_state != LS_LOADED) + return 0; // need to check return code for invalid - data = pushInt(size, data); // Segment Size (2 bytes) - data = pushByte(0, data); // CRC Control Byte: CRC always valid (1 byte) - data = pushByte(0xFF, data); // ReadAccess/WriteAccess (1 byte) - data = pushWord(obj->_crc, data); // CRC checksum according to CRC16-CCITT spec (2 bytes) + uint32_t segmentSize = obj->saveSize(); + uint16_t crc16 = crc16Ccitt(obj->data(), segmentSize); + + pushInt(segmentSize, data); // Segment size + pushByte(0x00, data + 4); // CRC control byte -> 0: always valid + pushByte(0xFF, data + 5); // Read access 4 bits + Write access 4 bits (unknown: value taken from real coupler device) + pushWord(crc16, data + 6); // CRC-16 CCITT of filter table + return 1; }), new DataProperty(PID_ERROR_CODE, false, PDT_ENUM8, 1, ReadLv3 | WriteLv0, (uint8_t)E_NO_FAULT) @@ -299,20 +299,4 @@ void TableObject::initializeProperties(size_t propertiesSize, Property** propert memcpy(allProperties + propertyCount, ownProperties, sizeof(ownProperties)); InterfaceObject::initializeProperties(sizeof(allProperties), allProperties); -} - -uint16_t TableObject::Crc16Citt(uint8_t* data, uint16_t length) -{ - uint16_t initialValue = 0x1D0F; - uint16_t Table[] = {0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7, 0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF, 0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6, 0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE, 0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485, 0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D, 0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4, 0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC, 0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823, 0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B, 0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12, 0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A, 0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41, 0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49, 0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70, 0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78, 0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F, 0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067, 0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E, 0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256, 0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D, 0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C, 0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634, 0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB, 0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3, 0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A, 0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92, 0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9, 0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1, 0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8, 0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0}; - if (data == nullptr) - return 0; - if (length == 0) - return 0; - uint16_t crc = initialValue; - for (int i = 0; i <= length; i++) - { - crc = (uint16_t)((crc << 8) ^ Table[((crc >> 8) ^ (0xff & data[i]))]); - } - return crc; } \ No newline at end of file diff --git a/src/knx/table_object.h b/src/knx/table_object.h index 9889579..7ae89fb 100644 --- a/src/knx/table_object.h +++ b/src/knx/table_object.h @@ -47,7 +47,6 @@ class TableObject: public InterfaceObject void errorCode(ErrorCode errorCode); void initializeProperties(size_t propertiesSize, Property** properties) override; - static uint16_t Crc16Citt(uint8_t* data, uint16_t length); private: uint32_t tableReference(); @@ -69,5 +68,4 @@ class TableObject: public InterfaceObject LoadState _state = LS_UNLOADED; Memory& _memory; uint8_t *_data = 0; - uint16_t _crc = 0; };