traceroute.py 文件源码

def parse_ip4(pack):
    arr = struct_ip4.unpack(pack[:20])
    hdr = {
        "version"  : arr[0] >> 4,       # should be 4 ...
        "ihl"      : arr[0] & 0xF,
        "tos"      : arr[1],
        "tot_len"  : arr[2],
        "id"       : arr[3],
        "frag_off" : arr[4],
        "ttl"      : arr[5],
        "protcol"  : arr[6],
        "check"    : arr[7],
        "saddr"    : ipaddress.IPv4Address(arr[8]),
        "daddr"    : ipaddress.IPv4Address(arr[9])
    }
    hdr_len = hdr["ihl"] * 4
    return hdr, pack[hdr_len:]