def start(self):
eth_length = 14
arp_length = 28
while self.run:
# receive arp requests
try:
packet = self.raw_socket.recvfrom(65565)
packet = packet[0]
eth_frame = self.parse_eth_frame(packet[0:eth_length])
arp_packet = self.parse_arp_packet(packet[eth_length:(eth_length+arp_length)])
arp_type = struct.unpack("!h", arp_packet["oper"])[0]
if LOG:
print "ARP-PROXY: received ARP-" + ("REQUEST" if (arp_type == 1) else "REPLY") +" SRC: "+eth_frame["src_mac"]+" / "+arp_packet["src_ip"]+" "+"DST: "+eth_frame["dst_mac"]+" / "+arp_packet["dst_ip"]
if arp_type == 1:
# check if the arp request stems from one of the participants
if eth_frame["src_mac"] in self.xrs.portmac_2_participant:
# then craft reply using VNH to VMAC mapping
if LOG:
print "Crafting REPLY for received Request"
vmac_addr = vmac(arp_packet["dst_ip"], self.xrs.portmac_2_participant[eth_frame["src_mac"]], self.xrs)
# only send arp request if a vmac exists
if vmac_addr <> "":
if LOG:
print "ARP-PROXY: reply with VMAC "+vmac_addr
data = self.craft_arp_packet(arp_packet, vmac_addr)
eth_packet = self.craft_eth_frame(eth_frame, vmac_addr, data)
self.raw_socket.send(''.join(eth_packet))
except socket.timeout:
if LOG:
print 'Socket Timeout Occured'
def start(self):
eth_length = 14
arp_length = 28
while self.run:
# receive arp requests
try:
packet = self.raw_socket.recvfrom(65565)
packet = packet[0]
eth_frame = self.parse_eth_frame(packet[0:eth_length])
arp_packet = self.parse_arp_packet(packet[eth_length:(eth_length+arp_length)])
arp_type = struct.unpack("!h", arp_packet["oper"])[0]
if LOG:
print "ARP-PROXY: received ARP-" + ("REQUEST" if (arp_type == 1) else "REPLY") +" SRC: "+eth_frame["src_mac"]+" / "+arp_packet["src_ip"]+" "+"DST: "+eth_frame["dst_mac"]+" / "+arp_packet["dst_ip"]
if arp_type == 1:
# check if the arp request stems from one of the participants
if eth_frame["src_mac"] in self.xrs.portmac_2_participant:
# then craft reply using VNH to VMAC mapping
print "Crafting REPLY for received Request"
vmac_addr = vmac(arp_packet["dst_ip"], self.xrs.portmac_2_participant[eth_frame["src_mac"]], self.xrs)
# only send arp request if a vmac exists
if vmac_addr <> "":
if LOG:
print "ARP-PROXY: reply with VMAC "+vmac_addr
data = self.craft_arp_packet(arp_packet, vmac_addr)
eth_packet = self.craft_eth_frame(eth_frame, vmac_addr, data)
self.raw_socket.send(''.join(eth_packet))
except socket.timeout:
if LOG:
print 'Socket Timeout Occured'
def send_gratuitous_arp(self, changes):
# then craft reply using VNH to VMAC mapping
vmac_addr = vmac(changes["VNH"], changes["participant"], self.xrs)
dst_mac = vmac_best_path(changes["participant"], self.xrs)
arp_packet = [
# HTYPE
struct.pack("!h", 1),
# PTYPE (IPv4)
struct.pack("!h", 0x0800),
# HLEN
struct.pack("!B", 6),
# PLEN
struct.pack("!B", 4),
# OPER (reply)
struct.pack("!h", 2),
# SHA
binascii.unhexlify(vmac_addr.replace(':', '')),
# SPA
socket.inet_aton(str(changes["VNH"])),
# THA
binascii.unhexlify(vmac_addr.replace(':', '')),
# TPA
socket.inet_aton(str(changes["VNH"]))
]
eth_frame = [
# Destination address:
binascii.unhexlify(dst_mac.replace(':', '')),
# Source address:
binascii.unhexlify(vmac_addr.replace(':', '')),
# Protocol
struct.pack("!h", ETH_TYPE_ARP),
# Data
''.join(arp_packet)
]
self.raw_socket.send(''.join(eth_frame))
def send_gratuitous_arp(self, changes):
# then craft reply using VNH to VMAC mapping
vmac_addr = vmac(changes["VNH"], changes["participant"], self.xrs)
dst_mac = vmac_best_path(changes["participant"], self.xrs)
arp_packet = [
# HTYPE
struct.pack("!h", 1),
# PTYPE (IPv4)
struct.pack("!h", 0x0800),
# HLEN
struct.pack("!B", 6),
# PLEN
struct.pack("!B", 4),
# OPER (reply)
struct.pack("!h", 2),
# SHA
binascii.unhexlify(vmac_addr.replace(':', '')),
# SPA
socket.inet_aton(str(changes["VNH"])),
# THA
binascii.unhexlify(vmac_addr.replace(':', '')),
# TPA
socket.inet_aton(str(changes["VNH"]))
]
eth_frame = [
# Destination address:
binascii.unhexlify(dst_mac.replace(':', '')),
# Source address:
binascii.unhexlify(vmac_addr.replace(':', '')),
# Protocol
struct.pack("!h", ETH_TYPE_ARP),
# Data
''.join(arp_packet)
]
self.raw_socket.send(''.join(eth_frame))
