icmp.py 文件源码

def serialize(self, payload, prev):
        hdr = bytearray(struct.pack(icmp._PACK_STR, self.type,
                                    self.code, self.csum))

        if self.data is not None:
            if self.type in icmp._ICMP_TYPES:
                hdr += self.data.serialize()
            else:
                hdr += self.data
        else:
            self.data = echo()
            hdr += self.data.serialize()

        if self.csum == 0:
            self.csum = packet_utils.checksum(hdr)
            struct.pack_into('!H', hdr, 2, self.csum)

        return hdr