+ #
+ # Use an odd-byte payload size to check for correct padding.
+ #
+ # 49 + 2 == 51 which should pad +1 to 52 for 4 byte alignment, +5
+ # to 56 for 8 byte alignment, and +13 to 64 for 64 byte alignment.
+ # This should catch bugs where the code is incorrectly over-padding
+ # for algorithms that don't require it
+ psz = 49 - len(IP()/ICMP()) if payload_size is None else payload_size