def __init__(self, packet=None, htype=None, ptype=None,
oper=None, sha=None, spa=None, tha=None, tpa=None):
"""Construct an ARP packet from binary packet data, or construct it
manually from the other arguments.
"""
if packet is not None:
self.parse(packet)
else:
if htype is None:
htype = 'ETHERNET'
self.htype = ARP_HTYPE[htype]
self.hlen = ARP_HLEN[htype]
if ptype is None:
ptype = 'IPv4'
self.ptype = ETHERTYPE[ptype]
self.plen = ARP_PLEN[ptype]
if oper is None:
oper = 'REQUEST'
self.oper = ARP_OPER[oper]
if isinstance(sha, macaddress.MACAddress):
self.sha = sha
else:
self.sha = macaddress.MACAddress(sha)
if isinstance(tha, macaddress.MACAddress):
self.tha = tha
else:
self.tha = macaddress.MACAddress(tha)
if isinstance(spa, ipaddress.IPv4Address):
self.spa = spa
else:
self.spa = ipaddress.IPv4Address(spa)
if isinstance(tpa, ipaddress.IPv4Address):
self.tpa = tpa
else:
self.tpa = ipaddress.IPv4Address(tpa)
def parse(self, frame):
"""Parse binary frame."""
header = unpack('!6s6sH', frame[0:14])
self.dst_mac = macaddress.MACAddress(header[0])
self.src_mac = macaddress.MACAddress(header[1])
self.ethertype = header[2]
self.payload = frame[14:]
def parse(self, packet):
"""Parse binary ARP packet data."""
header = unpack('!HHBB', packet[0:6])
self.htype = header[0]
if self.htype != ARP_HTYPE['ETHERNET']:
msg = 'Unsupported ARP hardware type %d'
raise ValueError(msg % self.htype)
self.ptype = header[1]
if self.ptype != ETHERTYPE['IPv4']:
msg = 'Unsupported ARP protocol type %d'
raise ValueError(msg % self.ptype)
self.hlen = header[2]
self.plen = header[3]
log.debug('hlen={}'.format(self.hlen))
log.debug('plen={}'.format(self.plen))
if self.hlen != ARP_HLEN['ETHERNET']:
msg = 'Unsupported ARP hardware length %d'
raise ValueError(msg % self.hlen)
if self.plen != ARP_PLEN['IPv4']:
msg = 'Unsupported ARP protocol length %d'
raise ValueError(msg % self.plen)
fmt = '!H{:d}s{:d}s{:d}s{:d}s'.format(self.hlen, self.plen,
self.hlen, self.plen)
log.debug('fmt={}'.format(fmt))
size = 8 + ((self.hlen + self.plen) * 2)
log.debug('size={}'.format(size))
data = unpack(fmt, packet[6:size])
self.oper = data[0]
self.sha = macaddress.MACAddress(data[1])
self.spa = ipaddress.IPv4Address(data[2])
self.tha = macaddress.MACAddress(data[3])
self.tpa = ipaddress.IPv4Address(data[4])
def __init__(self, frame=None, dst_mac=None, src_mac=None,
ethertype=None, payload=None):
"""Constructs an Ethernet frame either from a binary frame argument, or
from the individual parameters.
"""
if frame is not None:
self.parse(frame)
else:
if isinstance(dst_mac, macaddress.MACAddress):
self.dst_mac = dst_mac
else:
self.dst_mac = macaddress.MACAddress(dst_mac)
if isinstance(src_mac, macaddress.MACAddress):
self.src_mac = src_mac
else:
self.src_mac = macaddress.MACAddress(src_mac)
self.ethertype = ETHERTYPE[ethertype]
self.payload = payload
def _get_mac_info(self):
"""Return the MAC address of the interface. The result is cached for
subsequent access.
"""
if self.src_mac is not None:
return self.src_mac
else:
sock = self.transport._sock
interface = pack('256s', sock.getsockname()[0].encode('ascii'))
info = fcntl.ioctl(sock.fileno(), SIOCSIFHWADDR, interface)
self.src_mac = macaddress.MACAddress(info[18:24])
return self.src_mac