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Ensure we don't get or set labels that are too long
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@peternewman
peternewman committed Jul 13, 2021
1 parent 6cdfbfc commit 71cfd3c
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Showing 2 changed files with 20 additions and 12 deletions.
28 changes: 18 additions & 10 deletions src/DMXSerial2.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -222,7 +222,7 @@ struct EEPROMVALUES {
byte sig1; // 0x6D signature 1, EPROM values are valid of both signatures match.
byte sig2; // 0x68 signature 2
uint16_t startAddress; // the DMX start address can be changed by a RDM command.
char deviceLabel[DMXSERIAL_MAX_RDM_STRING_LENGTH]; // the device Label can be changed by a RDM command.
char deviceLabel[DMXSERIAL_MAX_RDM_STRING_LENGTH]; // the device Label can be changed by a RDM command. Don't store the null in the EPROM for backwards compatibility.
DEVICEID deviceID; // store the device ID to allow easy software updates.
}; // struct EEPROMVALUES

Expand Down Expand Up @@ -354,7 +354,8 @@ void DMXSerialClass2::init(struct RDMINIT *initData, RDMCallbackFunction func, R
// check if the EEEPROM values are from the RDM library
if ((eeprom.sig1 == 0x6D) && (eeprom.sig2 == 0x68)) {
_startAddress = eeprom.startAddress;
strcpy (deviceLabel, eeprom.deviceLabel);
// Restricting this to 32 characters or the length, whichever is shorter
strncpy(deviceLabel, eeprom.deviceLabel, DMXSERIAL_MAX_RDM_STRING_LENGTH);
DeviceIDCpy(_devID, eeprom.deviceID);

// setup the manufacturer addressing device-ID
Expand All @@ -364,7 +365,7 @@ void DMXSerialClass2::init(struct RDMINIT *initData, RDMCallbackFunction func, R
} else {
// set default values
_startAddress = 1;
strcpy (deviceLabel, "new");
strncpy(deviceLabel, "new", DMXSERIAL_MAX_RDM_STRING_LENGTH);
_devID[4] = random255(); // random(255);
_devID[5] = random255(); // random(255);
} // if
Expand Down Expand Up @@ -500,7 +501,7 @@ void DMXSerialClass2::tick(void)
// check if my _devID is in the discovery range
if ((DeviceIDCmp(rdm->Data, _devID) <= 0) && (DeviceIDCmp(_devID, rdm->Data+6) <= 0)) {

// respond a special discovery message !
// respond with a special discovery message !
struct DISCOVERYMSG *disc = &_rdm.discovery;
_rdmCheckSum = 6 * 0xFF;

Expand Down Expand Up @@ -595,7 +596,7 @@ void DMXSerialClass2::term(void)

// Process the RDM Command Message by changing the _rdm buffer and returning (true).
// if returning (false) a NAK will be sent.
// This method processes the commands/parameters regarding mute, DEviceInfo, devicelabel,
// This method processes the commands/parameters regarding mute, DeviceInfo, devicelabel,
// manufacturer label, DMX Start address.
// When parameters are changed by a SET command they are persisted into EEPROM.
// When doRespond is true, send an answer back to the controller node.
Expand Down Expand Up @@ -675,6 +676,7 @@ void DMXSerialClass2::_processRDMMessage(byte CmdClass, uint16_t Parameter, bool
} else {
// return the manufacturer label
_rdm.packet.DataLength = strlen(_initData->manufacturerLabel);
_rdm.packet.DataLength = min(_rdm.packet.DataLength, DMXSERIAL_MAX_RDM_STRING_LENGTH);
memcpy(_rdm.packet.Data, _initData->manufacturerLabel, _rdm.packet.DataLength);
handled = true;
}
Expand All @@ -689,6 +691,7 @@ void DMXSerialClass2::_processRDMMessage(byte CmdClass, uint16_t Parameter, bool
} else {
// return the DEVICE MODEL DESCRIPTION
_rdm.packet.DataLength = strlen(_initData->deviceModel);
_rdm.packet.DataLength = min(_rdm.packet.DataLength, DMXSERIAL_MAX_RDM_STRING_LENGTH);
memcpy(_rdm.packet.Data, _initData->deviceModel, _rdm.packet.DataLength);
handled = true;
}
Expand All @@ -700,7 +703,7 @@ void DMXSerialClass2::_processRDMMessage(byte CmdClass, uint16_t Parameter, bool
nackReason = E120_NR_FORMAT_ERROR;
} else {
memcpy(deviceLabel, _rdm.packet.Data, _rdm.packet.DataLength);
deviceLabel[_rdm.packet.DataLength] = '\0';
deviceLabel[min(_rdm.packet.DataLength, DMXSERIAL_MAX_RDM_STRING_LENGTH)] = '\0';
_rdm.packet.DataLength = 0;
// persist in EEPROM
_saveEEPRom();
Expand All @@ -715,6 +718,7 @@ void DMXSerialClass2::_processRDMMessage(byte CmdClass, uint16_t Parameter, bool
nackReason = E120_NR_SUB_DEVICE_OUT_OF_RANGE;
} else {
_rdm.packet.DataLength = strlen(deviceLabel);
_rdm.packet.DataLength = min(_rdm.packet.DataLength, DMXSERIAL_MAX_RDM_STRING_LENGTH);
memcpy(_rdm.packet.Data, deviceLabel, _rdm.packet.DataLength);
handled = true;
}
Expand All @@ -730,6 +734,7 @@ void DMXSerialClass2::_processRDMMessage(byte CmdClass, uint16_t Parameter, bool
} else {
// return the SOFTWARE_VERSION_LABEL
_rdm.packet.DataLength = strlen(_softwareLabel);
_rdm.packet.DataLength = min(_rdm.packet.DataLength, DMXSERIAL_MAX_RDM_STRING_LENGTH);
memcpy(_rdm.packet.Data, _softwareLabel, _rdm.packet.DataLength);
handled = true;
}
Expand Down Expand Up @@ -822,7 +827,9 @@ void DMXSerialClass2::_processRDMMessage(byte CmdClass, uint16_t Parameter, bool
// Out of range sensor
nackReason = E120_NR_DATA_OUT_OF_RANGE;
} else {
_rdm.packet.DataLength = 13 + strlen(_initData->sensors[sensorNr].description);
_rdm.packet.DataLength = strlen(_initData->sensors[sensorNr].description);
_rdm.packet.DataLength = min(_rdm.packet.DataLength, DMXSERIAL_MAX_RDM_STRING_LENGTH);
_rdm.packet.DataLength = 13 + _rdm.packet.DataLength;
_rdm.packet.Data[0] = sensorNr;
_rdm.packet.Data[1] = _initData->sensors[sensorNr].type;
_rdm.packet.Data[2] = _initData->sensors[sensorNr].unit;
Expand Down Expand Up @@ -922,12 +929,13 @@ void DMXSerialClass2::_saveEEPRom()
eeprom.sig1 = 0x6D;
eeprom.sig2 = 0x68;
eeprom.startAddress = _startAddress;
strcpy (eeprom.deviceLabel, deviceLabel);
// This needs restricting to 32 chars (potentially no null), for backwards compatibility
strncpy(eeprom.deviceLabel, deviceLabel, DMXSERIAL_MAX_RDM_STRING_LENGTH);
DeviceIDCpy(eeprom.deviceID, _devID);

for (unsigned int i = 0; i < sizeof(eeprom); i++) {
if (((byte *)(&eeprom))[i] != EEPROM.read(i))
EEPROM.write(i, ((byte *)(&eeprom))[i]);
// EEPROM.update does a read/write check and only writes on a change
EEPROM.update(i, ((byte *)(&eeprom))[i]);
} // for
} // _saveEEPRom

Expand Down
4 changes: 2 additions & 2 deletions src/DMXSerial2.h
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Original file line number Diff line number Diff line change
Expand Up @@ -252,8 +252,8 @@ class DMXSerialClass2
/// Terminate operation.
void term(void);

/// A short custom label given to the device.
char deviceLabel[DMXSERIAL_MAX_RDM_STRING_LENGTH];
/// A short custom label given to the device. Add an extra char for a null.
char deviceLabel[DMXSERIAL_MAX_RDM_STRING_LENGTH + 1];

/// don't use that method from extern.
void _processRDMMessage(byte CmdClass, uint16_t Parameter, bool8 isHandled);
Expand Down

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