Commit e2e1fe5a authored by Dean Camera's avatar Dean Camera
Browse files

Fixed possible buffer overrun in the XPLAINBridge project when in serial bridge mode.

parent 7cef08e1
......@@ -75,6 +75,26 @@
Buffer->Count = 0;
}
/** Atomically determines if the specified ring buffer contains any free space. This should
* be tested before storing data to the buffer, to ensure that no data is lost due to a
* buffer overrun.
*
* \param[in,out] Buffer Pointer to a ring buffer structure to insert into
*
* \return Boolean true if the buffer contains no free space, false otherwise
*/
static inline bool RingBuffer_IsFull(RingBuff_t* const Buffer)
{
bool IsFull;
ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
{
IsFull = (Buffer->Count == BUFFER_SIZE);
}
return IsFull;
}
/** Atomically inserts an element into the ring buffer.
*
* \param[in,out] Buffer Pointer to a ring buffer structure to insert into
......
......@@ -75,6 +75,26 @@
Buffer->Count = 0;
}
/** Atomically determines if the specified ring buffer contains any free space. This should
* be tested before storing data to the buffer, to ensure that no data is lost due to a
* buffer overrun.
*
* \param[in,out] Buffer Pointer to a ring buffer structure to insert into
*
* \return Boolean true if the buffer contains no free space, false otherwise
*/
static inline bool RingBuffer_IsFull(RingBuff_t* const Buffer)
{
bool IsFull;
ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
{
IsFull = (Buffer->Count == BUFFER_SIZE);
}
return IsFull;
}
/** Atomically inserts an element into the ring buffer.
*
* \param[in,out] Buffer Pointer to a ring buffer structure to insert into
......
......@@ -84,7 +84,7 @@ int main(void)
/* Read bytes from the USB OUT endpoint into the USART transmit buffer */
for (uint8_t DataBytesRem = CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface); DataBytesRem != 0; DataBytesRem--)
{
if (!(BUFFER_SIZE - USBtoUSART_Buffer.Count))
if (RingBuffer_IsFull(&USBtoUSART_Buffer))
break;
RingBuffer_AtomicInsert(&USBtoUSART_Buffer, CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface));
......
......@@ -75,6 +75,26 @@
Buffer->Count = 0;
}
/** Atomically determines if the specified ring buffer contains any free space. This should
* be tested before storing data to the buffer, to ensure that no data is lost due to a
* buffer overrun.
*
* \param[in,out] Buffer Pointer to a ring buffer structure to insert into
*
* \return Boolean true if the buffer contains no free space, false otherwise
*/
static inline bool RingBuffer_IsFull(RingBuff_t* const Buffer)
{
bool IsFull;
ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
{
IsFull = (Buffer->Count == BUFFER_SIZE);
}
return IsFull;
}
/** Atomically inserts an element into the ring buffer.
*
* \param[in,out] Buffer Pointer to a ring buffer structure to insert into
......
......@@ -120,7 +120,7 @@ void UARTBridge_Task(void)
return;
/* Read bytes from the USB OUT endpoint into the UART transmit buffer */
if (CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface))
if (CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface) && !(RingBuffer_IsFull(&USBtoUART_Buffer)))
RingBuffer_AtomicInsert(&USBtoUART_Buffer, CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface));
/* Check if the software UART flush timer has expired */
......
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