dhcp.py 文件源码

def generate_packet(src, data):
    min_size = ethhdr.min_size + ip4hdr.min_size + udphdr.min_size
    packet = bytearray(len(data) + min_size)

    eth = ethhdr({'src': src,
                  'dst': pnet.HWAddress(u'ff:ff:ff:ff:ff:ff'),
                  'type': pnet.ETH_P_IP},
                 buf=packet)

    ip4 = ip4hdr({'dst': ipaddress.IPv4Address(u'255.255.255.255'),
                  'proto': socket.IPPROTO_UDP,
                  'len': len(data) + ip4hdr.min_size + udphdr.min_size},
                 buf=eth.payload)

    udp = udphdr({'sport': 68,
                  'dport': 67,
                  'len': len(data) + udphdr.min_size},
                 buf=ip4.payload)

    ip4['csum'] = pnet.checksum(ip4.tobytes())
    udp['csum'] = pnet.ipv4_checksum(ip4, udp, data)
    udp.payload = data
    return packet