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

diff --git a/Projects/Benito/Lib/LightweightRingBuff.h b/Projects/Benito/Lib/LightweightRingBuff.h
index 9c25707..0ffe792 100644 (file)
--- a/Projects/Benito/Lib/LightweightRingBuff.h
+++ b/Projects/Benito/Lib/LightweightRingBuff.h
@@ -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

diff --git a/Projects/USBtoSerial/Lib/LightweightRingBuff.h b/Projects/USBtoSerial/Lib/LightweightRingBuff.h
index 9c25707..0ffe792 100644 (file)
--- a/Projects/USBtoSerial/Lib/LightweightRingBuff.h
+++ b/Projects/USBtoSerial/Lib/LightweightRingBuff.h
@@ -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

diff --git a/Projects/USBtoSerial/USBtoSerial.c b/Projects/USBtoSerial/USBtoSerial.c
index 145047c..1cd6f55 100644 (file)
--- a/Projects/USBtoSerial/USBtoSerial.c
+++ b/Projects/USBtoSerial/USBtoSerial.c
@@ -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));

diff --git a/Projects/XPLAINBridge/Lib/LightweightRingBuff.h b/Projects/XPLAINBridge/Lib/LightweightRingBuff.h
index 9c25707..0ffe792 100644 (file)
--- a/Projects/XPLAINBridge/Lib/LightweightRingBuff.h
+++ b/Projects/XPLAINBridge/Lib/LightweightRingBuff.h
@@ -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

diff --git a/Projects/XPLAINBridge/XPLAINBridge.c b/Projects/XPLAINBridge/XPLAINBridge.c
index f08dfc5..3bbc0bc 100644 (file)
--- a/Projects/XPLAINBridge/XPLAINBridge.c
+++ b/Projects/XPLAINBridge/XPLAINBridge.c
@@ -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 */