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Bugfix: allocate enough bytes for digital pins. Add more sanity check…
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…s when allocating memory
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@habazut
habazut committed Jan 20, 2024
1 parent 818e05b commit fb414a7
Showing 1 changed file with 54 additions and 34 deletions.
88 changes: 54 additions & 34 deletions IO_EXIOExpander.h
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Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
/*
* © 2022, Peter Cole. All rights reserved.
* © 2024, Harald Barth. All rights reserved.
*
* This file is part of EX-CommandStation
*
Expand Down Expand Up @@ -98,34 +99,53 @@ class EXIOExpander : public IODevice {
_numAnaloguePins = receiveBuffer[2];

// See if we already have suitable buffers assigned
size_t digitalBytesNeeded = (_numDigitalPins + 7) / 8;
if (_digitalPinBytes < digitalBytesNeeded) {
// Not enough space, free any existing buffer and allocate a new one
if (_digitalPinBytes > 0) free(_digitalInputStates);
_digitalInputStates = (byte*) calloc(_digitalPinBytes, 1);
_digitalPinBytes = digitalBytesNeeded;
}
size_t analogueBytesNeeded = _numAnaloguePins * 2;
if (_analoguePinBytes < analogueBytesNeeded) {
// Free any existing buffers and allocate new ones.
if (_analoguePinBytes > 0) {
free(_analogueInputBuffer);
free(_analogueInputStates);
free(_analoguePinMap);
if (_numDigitalPins>0) {
size_t digitalBytesNeeded = (_numDigitalPins + 7) / 8;
if (_digitalPinBytes < digitalBytesNeeded) {
// Not enough space, free any existing buffer and allocate a new one
if (_digitalPinBytes > 0) free(_digitalInputStates);
if ((_digitalInputStates = (byte*) calloc(digitalBytesNeeded, 1)) != NULL) {
_digitalPinBytes = digitalBytesNeeded;
} else {
DIAG(F("EX-IOExpander I2C:%s ERROR alloc %d bytes"), _I2CAddress.toString(), digitalBytesNeeded);
_deviceState = DEVSTATE_FAILED;
_digitalPinBytes = 0;
return;
}
}
_analogueInputStates = (uint8_t*) calloc(analogueBytesNeeded, 1);
_analogueInputBuffer = (uint8_t*) calloc(analogueBytesNeeded, 1);
_analoguePinMap = (uint8_t*) calloc(_numAnaloguePins, 1);
_analoguePinBytes = analogueBytesNeeded;
}
} else {
DIAG(F("EX-IOExpander I2C:%s ERROR configuring device"), _I2CAddress.toString());
_deviceState = DEVSTATE_FAILED;
return;
}
}
// We now need to retrieve the analogue pin map
if (status == I2C_STATUS_OK) {
if (_numAnaloguePins>0) {
size_t analogueBytesNeeded = _numAnaloguePins * 2;
if (_analoguePinBytes < analogueBytesNeeded) {
// Free any existing buffers and allocate new ones.
if (_analoguePinBytes > 0) {
free(_analogueInputBuffer);
free(_analogueInputStates);
free(_analoguePinMap);
}
_analogueInputStates = (uint8_t*) calloc(analogueBytesNeeded, 1);
_analogueInputBuffer = (uint8_t*) calloc(analogueBytesNeeded, 1);
_analoguePinMap = (uint8_t*) calloc(_numAnaloguePins, 1);
if (_analogueInputStates != NULL &&
_analogueInputBuffer != NULL &&
_analoguePinMap != NULL) {
_analoguePinBytes = analogueBytesNeeded;
} else {
DIAG(F("EX-IOExpander I2C:%s ERROR alloc analog pin bytes"), _I2CAddress.toString());
_deviceState = DEVSTATE_FAILED;
_analoguePinBytes = 0;
return;
}
}
}
} else {
DIAG(F("EX-IOExpander I2C:%s ERROR configuring device"), _I2CAddress.toString());
_deviceState = DEVSTATE_FAILED;
return;
}
}
// We now need to retrieve the analogue pin map if there are analogue pins
if (status == I2C_STATUS_OK && _numAnaloguePins>0) {
commandBuffer[0] = EXIOINITA;
status = I2CManager.read(_I2CAddress, _analoguePinMap, _numAnaloguePins, commandBuffer, 1);
}
Expand Down Expand Up @@ -239,15 +259,15 @@ class EXIOExpander : public IODevice {

// If we're not doing anything now, check to see if a new input transfer is due.
if (_readState == RDS_IDLE) {
if (currentMicros - _lastDigitalRead > _digitalRefresh) { // Delay for digital read refresh
if (_numDigitalPins>0 && currentMicros - _lastDigitalRead > _digitalRefresh) { // Delay for digital read refresh
// Issue new read request for digital states. As the request is non-blocking, the buffer has to
// be allocated from heap (object state).
_readCommandBuffer[0] = EXIORDD;
I2CManager.read(_I2CAddress, _digitalInputStates, (_numDigitalPins+7)/8, _readCommandBuffer, 1, &_i2crb);
// non-blocking read
_lastDigitalRead = currentMicros;
_readState = RDS_DIGITAL;
} else if (currentMicros - _lastAnalogueRead > _analogueRefresh) { // Delay for analogue read refresh
} else if (_numAnaloguePins>0 && currentMicros - _lastAnalogueRead > _analogueRefresh) { // Delay for analogue read refresh
// Issue new read for analogue input states
_readCommandBuffer[0] = EXIORDAN;
I2CManager.read(_I2CAddress, _analogueInputBuffer,
Expand Down Expand Up @@ -362,14 +382,14 @@ class EXIOExpander : public IODevice {
uint8_t _minorVer = 0;
uint8_t _patchVer = 0;

uint8_t* _digitalInputStates;
uint8_t* _analogueInputStates;
uint8_t* _analogueInputBuffer; // buffer for I2C input transfers
uint8_t* _digitalInputStates = NULL;
uint8_t* _analogueInputStates = NULL;
uint8_t* _analogueInputBuffer = NULL; // buffer for I2C input transfers
uint8_t _readCommandBuffer[1];

uint8_t _digitalPinBytes = 0; // Size of allocated memory buffer (may be longer than needed)
uint8_t _analoguePinBytes = 0; // Size of allocated memory buffers (may be longer than needed)
uint8_t* _analoguePinMap;
uint8_t _digitalPinBytes = 0; // Size of allocated memory buffer (may be longer than needed)
uint8_t _analoguePinBytes = 0; // Size of allocated memory buffer (may be longer than needed)
uint8_t* _analoguePinMap = NULL;
I2CRB _i2crb;

enum {RDS_IDLE, RDS_DIGITAL, RDS_ANALOGUE}; // Read operation states
Expand Down

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