Decode sniffing data with parityBit in Python Software

If parity bit check failed, ! is appended to the data and raw data is diaplayed

Currently Software layer parity bit check and removal is only enabled in sniffing mode

(cherry picked from commit 2cfd54a)

Software/Chameleon/Log.py

@@ -2,6 +2,40 @@
 
 import struct
 import binascii
+import math
+
+def checkParityBit(data):
+    byteCount = len(data)
+    # Short frame, no parityBit
+    if (byteCount == 1):
+        return (True, data)
+
+    # 9 bit is a group, validate bit count is calculated below
+    bitCount = int((byteCount*8)/9) * 9
+    parsedData = bytearray(int(bitCount/9))
+
+    oneCounter = 0            # Counter for count ones in a byte
+    for i in range(0, bitCount):
+        # Get bit i in data
+        byteIndex = math.floor(i/8)
+        bitIndex = i % 8
+        bit = (data[byteIndex] >> bitIndex) & 0x01
+
+        # Check parityBit
+        # Current bit is parityBit
+        if(i % 9 == 8):
+            # Even number of ones in current byte
+            if(oneCounter % 2 and bit == 1):
+                return (False, data)
+            # Odd number of ones in current byte
+            elif((not oneCounter % 2) and bit == 0):
+                return (False, data)
+            oneCounter = 0
+        # Current bit is normal bit
+        else:
+            oneCounter += bit
+            parsedData[int(i/9)] |= bit << (i%9)
+    return (True, parsedData)
 
 def noDecoder(data):
     return ""
@@ -12,6 +46,13 @@ def textDecoder(data):
 def binaryDecoder(data):
     return binascii.hexlify(data).decode()
 
+def binaryParityDecoder(data):
+    isValid, checkedData = checkParityBit(data)
+    if(isValid):
+        return binascii.hexlify(checkedData).decode()
+    else:
+        return binascii.hexlify(checkedData).decode()+"!"
+
 eventTypes = {
     0x00: { 'name': 'EMPTY',          'decoder': noDecoder },
     0x10: { 'name': 'GENERIC',        'decoder': textDecoder },
@@ -25,6 +66,12 @@ eventTypes = {
     0x42: { 'name': 'CODEC RX W/PARITY', 'decoder': binaryDecoder },
     0x43: { 'name': 'CODEC TX W/PARITY', 'decoder': binaryDecoder },
 
+    0x44: { 'name': 'CODEC RX SNI READER',          'decoder': binaryDecoder },
+    0x45: { 'name': 'CODEC RX SNI READER W/PARITY', 'decoder': binaryParityDecoder },
+    0x46: { 'name': 'CODEC RX SNI CARD',            'decoder': binaryDecoder },
+    0x47: { 'name': 'CODEC RX SNI CARD W/PARITY',   'decoder': binaryParityDecoder },
+   
+
     0x80: { 'name': 'APP READ',       'decoder': binaryDecoder },
     0x81: { 'name': 'APP WRITE',      'decoder': binaryDecoder },
     0x84: { 'name': 'APP INC',        'decoder': binaryDecoder },

Software/chamlog.py

@@ -58,6 +58,7 @@ def main():
     else:
         verboseFunc = None
 
+    print("\nNote: If parityBit check failed, '!' is appended to the decoded data and raw data with parity bit is displayed.\n")
     if (args.live):
         # Live logging mode
         if (args.port is not None):