Refactored and corrected size computation
Refactored and corrected size computation

levigross/gopacket,levigross/gopacket,xuzhaokui/gopacket,skyportsystems/gopacket,google/gopacket,xuzhaokui/gopacket,google/gopacket,levigross/gopacket,rouzier/gopacket,rouzier/gopacket,xuzhaokui/gopacket,skyportsystems/gopacket,skyportsystems/gopacket,rouzier/gopacket,google/gopacket