def _icmp_packetin_handler(self):
conn = self._connection
ofdef = self._connection.openflowdef
l3input = self.parent._gettableindex("l3input",self._connection.protocol.vhost)
transactid = uint16.create(os.urandom(2))
def send_packet_out(portid,packet):
for m in self.execute_commands(conn,
[
ofdef.ofp_packet_out(
buffer_id = ofdef.OFP_NO_BUFFER,
in_port = ofdef.OFPP_CONTROLLER,
actions = [
ofdef.ofp_action_output(port = portid,
max_len = ofdef.OFPCML_NO_BUFFER
)
],
data = packet._tobytes()
)
]):
yield m
icmp_packetin_matcher = OpenflowAsyncMessageEvent.createMatcher(ofdef.OFPT_PACKET_IN,None,None,l3input,2,
self._connection,self._connection.connmark)
while True:
yield (icmp_packetin_matcher,)
msg = self.event.message
inport = ofdef.ofp_port_no.create(ofdef.get_oxm(msg.match.oxm_fields,ofdef.OXM_OF_IN_PORT))
# it must be icmp packet ...
icmp_packet = ethernet_l7.create(msg.data)
transactid = (transactid + 1) & 0xffff
reply_packet = ip4_packet_l7((ip4_payload,ip4_icmp_payload),
(icmp_bestparse, icmp_echo),
dl_src = icmp_packet.dl_dst,
dl_dst = icmp_packet.dl_src,
ip_src = icmp_packet.ip_dst,
ip_dst = icmp_packet.ip_src,
frag_off = icmp_packet.frag_off,
ttl = 128,
identifier = transactid,
icmp_type = ICMP_ECHOREPLY,
icmp_code = icmp_packet.icmp_code,
icmp_id = icmp_packet.icmp_id,
icmp_seq = icmp_packet.icmp_seq,
data = icmp_packet.data
)
self.subroutine(send_packet_out(inport,reply_packet))
def _icmp_packetin_handler(self):
conn = self._connection
ofdef = self._connection.openflowdef
l3input = self.parent._gettableindex("l3input",self._connection.protocol.vhost)
transactid = uint16.create(os.urandom(2))
def send_packet_out(portid,packet):
for m in self.execute_commands(conn,
[
ofdef.ofp_packet_out(
buffer_id = ofdef.OFP_NO_BUFFER,
in_port = ofdef.OFPP_CONTROLLER,
actions = [
ofdef.ofp_action_output(port = portid,
max_len = ofdef.OFPCML_NO_BUFFER
)
],
data = packet._tobytes()
)
]):
yield m
icmp_packetin_matcher = OpenflowAsyncMessageEvent.createMatcher(ofdef.OFPT_PACKET_IN,None,None,l3input,2,
self._connection,self._connection.connmark)
while True:
yield (icmp_packetin_matcher,)
msg = self.event.message
inport = ofdef.ofp_port_no.create(ofdef.get_oxm(msg.match.oxm_fields,ofdef.OXM_OF_IN_PORT))
# it must be icmp packet ...
icmp_packet = ethernet_l7.create(msg.data)
transactid = (transactid + 1) & 0xffff
reply_packet = ip4_packet_l7((ip4_payload,ip4_icmp_payload),
(icmp_bestparse, icmp_echo),
dl_src = icmp_packet.dl_dst,
dl_dst = icmp_packet.dl_src,
ip_src = icmp_packet.ip_dst,
ip_dst = icmp_packet.ip_src,
frag_off = icmp_packet.frag_off,
ttl = 128,
identifier = transactid,
icmp_type = ICMP_ECHOREPLY,
icmp_code = icmp_packet.icmp_code,
icmp_id = icmp_packet.icmp_id,
icmp_seq = icmp_packet.icmp_seq,
data = icmp_packet.data
)
self.subroutine(send_packet_out(inport,reply_packet))
def _dhcp_handler(self):
conn = self._connection
ofdef = self._connection.openflowdef
l3 = self._parent._gettableindex('l3input',
self._connection.protocol.vhost)
dhcp_packet_matcher = OpenflowAsyncMessageEvent.createMatcher(
ofdef.OFPT_PACKET_IN, None, None, l3, 1, self._connection,
self._connection.connmark)
required_tags = [
d.OPTION_MESSAGE_TYPE, d.OPTION_SERVER_IDENTIFIER,
d.OPTION_NETMASK, d.OPTION_ROUTER, d.OPTION_DNSSERVER,
d.OPTION_BROADCAST, d.OPTION_MTU, d.OPTION_LEASE_TIME, d.OPTION_T1,
d.OPTION_T2
]
server_mac = mac_addr(self._parent.servermac)
trans_id = uint16.create(os.urandom(2))
def set_options(payload,
option_dict,
provide_options,
message_type,
remove_lease=False):
message_type_opt = d.dhcp_option_message_type(value=message_type)
if d.OPTION_REQUESTED_OPTIONS in option_dict:
reqs = set(option_dict[d.OPTION_REQUESTED_OPTIONS].value)
send_tags = [t for t in option_dict[d.OPTION_REQUESTED_OPTIONS].value
if t == d.OPTION_MESSAGE_TYPE or t in provide_options] \
+ [t for t in required_tags
if (t in provide_options or t == d.OPTION_MESSAGE_TYPE) and t not in reqs] \
+ [t for t in provide_options
if t not in reqs and t not in required_tags]
else:
send_tags = [t for t in required_tags
if t in provide_options or t == d.OPTION_MESSAGE_TYPE] \
+ [t for t in set(provide_options.keys()).difference(required_tags)]
d.build_options(
payload, [
message_type_opt
if t == d.OPTION_MESSAGE_TYPE else provide_options[t]
for t in send_tags
if not remove_lease or (t != d.OPTION_LEASE_TIME and t !=
d.OPTION_T1 and t != OPTION_T2)
],
max(min(option_dict[d.OPTION_MAX_MESSAGE_SIZE].value, 1400),
576) if d.OPTION_MAX_MESSAGE_SIZE in option_dict else 576)
def send_packet(pid, packet):
for m in self.execute_commands(conn, [
ofdef.ofp_packet_out(
buffer_id=ofdef.OFP_NO_BUFFER,
in_port=ofdef.OFPP_CONTROLLER,
actions=[
ofdef.ofp_action_output(
port=pid, max_len=ofdef.OFPCML_NO_BUFFER)
],
data=packet._tobytes())
]):
yield m
while True:
yield (dhcp_packet_matcher, )
msg = self.event.message
try:
in_port = ofdef.ofp_port_no.create(
ofdef.get_oxm(msg.match.oxm_fields, ofdef.OXM_OF_IN_PORT))
if in_port not in self._dhcpentries:
continue
port_mac, port_ip, server_ip, provide_options = self._dhcpentries[
in_port]
l7_packet = ethernet_l7.create(msg.data)
dhcp_packet = d.dhcp_payload.create(l7_packet.data)
if dhcp_packet.op != d.BOOTREQUEST or \
dhcp_packet.hlen != 6 or dhcp_packet.htype != 1 or \
dhcp_packet.magic_cookie != d.BOOTP_MAGIC_COOKIE or \
dhcp_packet.giaddr != 0:
raise ValueError('Unsupported DHCP packet')
options = d.reassemble_options(dhcp_packet)
option_dict = dict((o.tag, o) for o in options)
if d.OPTION_MESSAGE_TYPE not in option_dict:
raise ValueError('Message type not found')
message_type = option_dict[d.OPTION_MESSAGE_TYPE].value
is_nak = False
if message_type == d.DHCPDISCOVER:
if dhcp_packet.chaddr[:6].ljust(
6, b'\x00') != mac_addr.tobytes(port_mac):
# Ignore this packet
continue
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=0,
yiaddr=port_ip,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
set_options(dhcp_reply, option_dict, provide_options,
d.DHCPOFFER)
elif message_type == d.DHCPREQUEST:
if d.OPTION_SERVER_IDENTIFIER in option_dict and option_dict[
d.OPTION_SERVER_IDENTIFIER].value != server_ip:
# Ignore packets to wrong address
continue
if dhcp_packet.chaddr[:6].ljust(6, b'\x00') != mac_addr.tobytes(port_mac) \
or (d.OPTION_REQUESTED_IP in option_dict and option_dict[d.OPTION_REQUESTED_IP].value != port_ip) \
or (dhcp_packet.ciaddr != 0 and dhcp_packet.ciaddr != port_ip):
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=0,
yiaddr=0,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
d.build_options(dhcp_reply, [
d.dhcp_option_message_type(value=d.DHCPNAK),
d.dhcp_option_address(
tag=d.OPTION_SERVER_IDENTIFIER,
value=server_ip)
], 576, 0)
is_nak = True
else:
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=dhcp_packet.ciaddr,
yiaddr=port_ip,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
set_options(dhcp_reply, option_dict, provide_options,
d.DHCPACK)
elif message_type == d.DHCPDECLINE:
self._logger.warning('DHCP client reports DHCPDECLINE, there should be some problems.'\
' Connection = %r(%016x), port = %d.',
self._connection, self._connection.openflow_datapathid)
elif message_type == d.DHCPRELEASE:
# Safe to ignore
continue
elif message_type == d.DHCPINFORM:
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=dhcp_packet.ciaddr,
yiaddr=0,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
set_options(dhcp_reply, option_dict, provide_options,
d.DHCPACK, True)
trans_id = (trans_id + 1) & 0xffff
if (dhcp_packet.flags & d.DHCPFLAG_BROADCAST) or is_nak:
dl_dst = [0xff, 0xff, 0xff, 0xff, 0xff, 0xff]
ip_dst = 0xffffffff
else:
dl_dst = l7_packet.dl_src
ip_dst = port_ip
reply_packet = ip4_packet_l7((ip4_payload, ip4_udp_payload),
dl_src=server_mac,
dl_dst=dl_dst,
identifier=trans_id,
ttl=128,
ip_src=server_ip,
ip_dst=ip_dst,
sport=67,
dport=68,
data=dhcp_reply._tobytes())
self.subroutine(send_packet(in_port, reply_packet), True)
except Exception:
self._logger.info('Invalid DHCP packet received: %r',
msg.data,
exc_info=True)
async def _dhcp_handler(self):
"""
Mini DHCP server, respond DHCP packets from OpenFlow
"""
conn = self._connection
ofdef = self._connection.openflowdef
l3 = self._parent._gettableindex('l3input',
self._connection.protocol.vhost)
dhcp_packet_matcher = OpenflowAsyncMessageEvent.createMatcher(
ofdef.OFPT_PACKET_IN, None, None, l3, 1, self._connection,
self._connection.connmark)
# These tags are important options. They are sent first to make sure the client
# correctly receive these options.
required_tags = [
d.OPTION_MESSAGE_TYPE, d.OPTION_SERVER_IDENTIFIER,
d.OPTION_NETMASK, d.OPTION_ROUTER, d.OPTION_DNSSERVER,
d.OPTION_BROADCAST, d.OPTION_MTU, d.OPTION_LEASE_TIME, d.OPTION_T1,
d.OPTION_T2
]
server_mac = mac_addr(self._parent.servermac)
# IP fragment identifier
trans_id = uint16.create(os.urandom(2))
def set_options(payload,
option_dict,
provide_options,
message_type,
remove_lease=False):
"""
Set DHCP options to output payload regarding the incoming request
:param payload: output DHCP payload
:param option_dict: incoming DHCP options in request
:param provide_options: all DHCP options that are ready to sent to the client
:param message_type: output DHCP message type
:param remove_lease: remove all leases options. DHCPINFORM cannot contain
leases options. See https://tools.ietf.org/html/rfc2131#section-3.4
"""
message_type_opt = d.dhcp_option_message_type(value=message_type)
if d.OPTION_REQUESTED_OPTIONS in option_dict:
# First requested options, then required options, then others
reqs = set(option_dict[d.OPTION_REQUESTED_OPTIONS].value)
send_tags = [t for t in option_dict[d.OPTION_REQUESTED_OPTIONS].value
if t == d.OPTION_MESSAGE_TYPE or t in provide_options] \
+ [t for t in required_tags
if (t in provide_options or t == d.OPTION_MESSAGE_TYPE) and t not in reqs] \
+ [t for t in provide_options
if t not in reqs and t not in required_tags]
else:
# Required options, then others
send_tags = [t for t in required_tags
if t in provide_options or t == d.OPTION_MESSAGE_TYPE] \
+ [t for t in set(provide_options.keys()).difference(required_tags)]
# If the client has sent an option for max message size, use it; or use the RFC required 576 bytes
not_finished = d.build_options(
payload, [
message_type_opt
if t == d.OPTION_MESSAGE_TYPE else provide_options[t]
for t in send_tags
if not remove_lease or (t != d.OPTION_LEASE_TIME and t !=
d.OPTION_T1 and t != OPTION_T2)
],
max(min(option_dict[d.OPTION_MAX_MESSAGE_SIZE].value, 1400),
576) if d.OPTION_MAX_MESSAGE_SIZE in option_dict else 576)
async def send_packet(pid, packet):
"""
Send DHCP packet to specified port
"""
await self.execute_commands(conn, [
ofdef.ofp_packet_out(buffer_id=ofdef.OFP_NO_BUFFER,
in_port=ofdef.OFPP_CONTROLLER,
actions=[
ofdef.ofp_action_output(
port=pid,
max_len=ofdef.OFPCML_NO_BUFFER)
],
data=packet._tobytes())
])
while True:
ev = await dhcp_packet_matcher
msg = ev.message
try:
in_port = ofdef.ofp_port_no.create(
ofdef.get_oxm(msg.match.oxm_fields, ofdef.OXM_OF_IN_PORT))
if in_port not in self._dhcpentries:
# Not a DHCP-enabled port
continue
port_mac, port_ip, server_ip, provide_options = self._dhcpentries[
in_port]
# Fragmented DHCP packets are not supported - this is allowed according
# to RFC: server and clients are only needed to support at least 576 bytes
# DHCP messages.
l7_packet = ethernet_l7.create(msg.data)
dhcp_packet = d.dhcp_payload.create(l7_packet.data)
# We only process a DHCP request directly sent from the logical port
if (dhcp_packet.op != d.BOOTREQUEST # A DHCP server packet
or dhcp_packet.hlen != 6 or dhcp_packet.htype !=
1 # Hardware address not ethernet (48-bit)
or dhcp_packet.magic_cookie !=
d.BOOTP_MAGIC_COOKIE # Magic cookie not match
or dhcp_packet.giaddr != 0): # A relayed DHCP message
raise ValueError('Unsupported DHCP packet')
# Reassemble DHCP options
options = d.reassemble_options(dhcp_packet)
option_dict = dict((o.tag, o) for o in options)
if d.OPTION_MESSAGE_TYPE not in option_dict:
raise ValueError('Message type not found')
message_type = option_dict[d.OPTION_MESSAGE_TYPE].value
is_nak = False
if message_type == d.DHCPDISCOVER:
# A DHCPDISCOVER should get a DHCPOFFER response
if dhcp_packet.chaddr[:6].ljust(
6, b'\x00') != mac_addr.tobytes(port_mac):
# MAC address not match, ignore this packet
continue
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=0,
yiaddr=port_ip,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
set_options(dhcp_reply, option_dict, provide_options,
d.DHCPOFFER)
elif message_type == d.DHCPREQUEST:
# A DHCPREQUEST should get a DHCPACK reply
if d.OPTION_SERVER_IDENTIFIER in option_dict and option_dict[
d.OPTION_SERVER_IDENTIFIER].value != server_ip:
# Ignore packets to wrong address
continue
if dhcp_packet.chaddr[:6].ljust(6, b'\x00') != mac_addr.tobytes(port_mac) \
or (d.OPTION_REQUESTED_IP in option_dict and option_dict[d.OPTION_REQUESTED_IP].value != port_ip) \
or (dhcp_packet.ciaddr != 0 and dhcp_packet.ciaddr != port_ip):
# Requested MAC or IP not matched, send a NACK
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=0,
yiaddr=0,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
# Do not send more options in NACK
d.build_options(dhcp_reply, [
d.dhcp_option_message_type(value=d.DHCPNAK),
d.dhcp_option_address(
tag=d.OPTION_SERVER_IDENTIFIER,
value=server_ip)
], 576, 0)
is_nak = True
else:
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=dhcp_packet.ciaddr,
yiaddr=port_ip,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
set_options(dhcp_reply, option_dict, provide_options,
d.DHCPACK)
elif message_type == d.DHCPDECLINE:
# Address already in use?
self._logger.warning('DHCP client reports DHCPDECLINE, there should be some problems.'\
' Connection = %r(%016x), port = %d.',
self._connection, self._connection.openflow_datapathid)
elif message_type == d.DHCPRELEASE:
# Safe to ignore, we do not use a dynamic IP address pool
continue
elif message_type == d.DHCPINFORM:
# Client setup IP addresses itself, but requesting more information
# DHCPINFORM reply cannot have lease options, and yiaddr = 0
dhcp_reply = d.dhcp_payload(
op=d.BOOTREPLY,
htype=1,
hlen=6,
hops=0,
xid=dhcp_packet.xid,
secs=0,
flags=dhcp_packet.flags,
ciaddr=dhcp_packet.ciaddr,
yiaddr=0,
siaddr=0,
giaddr=dhcp_packet.giaddr,
chaddr=dhcp_packet.chaddr,
magic_cookie=d.BOOTP_MAGIC_COOKIE)
set_options(dhcp_reply, option_dict, provide_options,
d.DHCPACK, True)
trans_id = (trans_id + 1) & 0xffff
if (dhcp_packet.flags & d.DHCPFLAG_BROADCAST) or is_nak:
# client request broadcast, or DHCPNAK
# RFC requires that DHCPNAK uses broadcast
dl_dst = [0xff, 0xff, 0xff, 0xff, 0xff, 0xff]
ip_dst = 0xffffffff
else:
dl_dst = l7_packet.dl_src
ip_dst = port_ip
reply_packet = ip4_packet_l7((ip4_payload, ip4_udp_payload),
dl_src=server_mac,
dl_dst=dl_dst,
identifier=trans_id,
ttl=128,
ip_src=server_ip,
ip_dst=ip_dst,
sport=67,
dport=68,
data=dhcp_reply._tobytes())
# Send packet to the incoming port
self.subroutine(send_packet(in_port, reply_packet), True)
except Exception:
self._logger.info('Invalid DHCP packet received: %r',
msg.data,
exc_info=True)
def _dhcp_handler(self):
conn = self._connection
ofdef = self._connection.openflowdef
l3 = self._parent._gettableindex('l3input', self._connection.protocol.vhost)
dhcp_packet_matcher = OpenflowAsyncMessageEvent.createMatcher(ofdef.OFPT_PACKET_IN, None, None, l3, 1,
self._connection, self._connection.connmark)
required_tags = [d.OPTION_MESSAGE_TYPE, d.OPTION_SERVER_IDENTIFIER,
d.OPTION_NETMASK, d.OPTION_ROUTER,
d.OPTION_DNSSERVER, d.OPTION_BROADCAST, d.OPTION_MTU,
d.OPTION_LEASE_TIME, d.OPTION_T1, d.OPTION_T2]
server_mac = mac_addr(self._parent.servermac)
trans_id = uint16.create(os.urandom(2))
def set_options(payload, option_dict, provide_options, message_type, remove_lease = False):
message_type_opt = d.dhcp_option_message_type(value = message_type)
if d.OPTION_REQUESTED_OPTIONS in option_dict:
reqs = set(option_dict[d.OPTION_REQUESTED_OPTIONS].value)
send_tags = [t for t in option_dict[d.OPTION_REQUESTED_OPTIONS].value
if t == d.OPTION_MESSAGE_TYPE or t in provide_options] \
+ [t for t in required_tags
if (t in provide_options or t == d.OPTION_MESSAGE_TYPE) and t not in reqs] \
+ [t for t in provide_options
if t not in reqs and t not in required_tags]
else:
send_tags = [t for t in required_tags
if t in provide_options or t == d.OPTION_MESSAGE_TYPE] \
+ [t for t in set(provide_options.keys()).difference(required_tags)]
d.build_options(payload, [message_type_opt if t == d.OPTION_MESSAGE_TYPE
else provide_options[t] for t in send_tags
if not remove_lease or (t != d.OPTION_LEASE_TIME and t != d.OPTION_T1 and t != OPTION_T2)],
max(min(option_dict[d.OPTION_MAX_MESSAGE_SIZE].value, 1400), 576)
if d.OPTION_MAX_MESSAGE_SIZE in option_dict
else 576)
def send_packet(pid, packet):
for m in self.execute_commands(conn,
[ofdef.ofp_packet_out(
buffer_id = ofdef.OFP_NO_BUFFER,
in_port = ofdef.OFPP_CONTROLLER,
actions = [ofdef.ofp_action_output(port = pid,
max_len = ofdef.OFPCML_NO_BUFFER)],
data = packet._tobytes()
)]):
yield m
while True:
yield (dhcp_packet_matcher,)
msg = self.event.message
try:
in_port = ofdef.ofp_port_no.create(ofdef.get_oxm(msg.match.oxm_fields, ofdef.OXM_OF_IN_PORT))
if in_port not in self._dhcpentries:
continue
port_mac, port_ip, server_ip, provide_options = self._dhcpentries[in_port]
l7_packet = ethernet_l7.create(msg.data)
dhcp_packet = d.dhcp_payload.create(l7_packet.data)
if dhcp_packet.op != d.BOOTREQUEST or \
dhcp_packet.hlen != 6 or dhcp_packet.htype != 1 or \
dhcp_packet.magic_cookie != d.BOOTP_MAGIC_COOKIE or \
dhcp_packet.giaddr != 0:
raise ValueError('Unsupported DHCP packet')
options = d.reassemble_options(dhcp_packet)
option_dict = dict((o.tag, o) for o in options)
if d.OPTION_MESSAGE_TYPE not in option_dict:
raise ValueError('Message type not found')
message_type = option_dict[d.OPTION_MESSAGE_TYPE].value
is_nak = False
if message_type == d.DHCPDISCOVER:
if dhcp_packet.chaddr[:6].ljust(6, b'\x00') != mac_addr.tobytes(port_mac):
# Ignore this packet
continue
dhcp_reply = d.dhcp_payload(op = d.BOOTREPLY,
htype = 1,
hlen = 6,
hops = 0,
xid = dhcp_packet.xid,
secs = 0,
flags = dhcp_packet.flags,
ciaddr = 0,
yiaddr = port_ip,
siaddr = 0,
giaddr = dhcp_packet.giaddr,
chaddr = dhcp_packet.chaddr,
magic_cookie = d.BOOTP_MAGIC_COOKIE
)
set_options(dhcp_reply, option_dict, provide_options, d.DHCPOFFER)
elif message_type == d.DHCPREQUEST:
if d.OPTION_SERVER_IDENTIFIER in option_dict and option_dict[d.OPTION_SERVER_IDENTIFIER].value != server_ip:
# Ignore packets to wrong address
continue
if dhcp_packet.chaddr[:6].ljust(6, b'\x00') != mac_addr.tobytes(port_mac) \
or (d.OPTION_REQUESTED_IP in option_dict and option_dict[d.OPTION_REQUESTED_IP].value != port_ip) \
or (dhcp_packet.ciaddr != 0 and dhcp_packet.ciaddr != port_ip):
dhcp_reply = d.dhcp_payload(op = d.BOOTREPLY,
htype = 1,
hlen = 6,
hops = 0,
xid = dhcp_packet.xid,
secs = 0,
flags = dhcp_packet.flags,
ciaddr = 0,
yiaddr = 0,
siaddr = 0,
giaddr = dhcp_packet.giaddr,
chaddr = dhcp_packet.chaddr,
magic_cookie = d.BOOTP_MAGIC_COOKIE
)
d.build_options(dhcp_reply, [d.dhcp_option_message_type(value = d.DHCPNAK),
d.dhcp_option_address(tag = d.OPTION_SERVER_IDENTIFIER,
value = server_ip)], 576, 0)
is_nak = True
else:
dhcp_reply = d.dhcp_payload(op = d.BOOTREPLY,
htype = 1,
hlen = 6,
hops = 0,
xid = dhcp_packet.xid,
secs = 0,
flags = dhcp_packet.flags,
ciaddr = dhcp_packet.ciaddr,
yiaddr = port_ip,
siaddr = 0,
giaddr = dhcp_packet.giaddr,
chaddr = dhcp_packet.chaddr,
magic_cookie = d.BOOTP_MAGIC_COOKIE
)
set_options(dhcp_reply, option_dict, provide_options, d.DHCPACK)
elif message_type == d.DHCPDECLINE:
self._logger.warning('DHCP client reports DHCPDECLINE, there should be some problems.'\
' Connection = %r(%016x), port = %d.',
self._connection, self._connection.openflow_datapathid)
elif message_type == d.DHCPRELEASE:
# Safe to ignore
continue
elif message_type == d.DHCPINFORM:
dhcp_reply = d.dhcp_payload(op = d.BOOTREPLY,
htype = 1,
hlen = 6,
hops = 0,
xid = dhcp_packet.xid,
secs = 0,
flags = dhcp_packet.flags,
ciaddr = dhcp_packet.ciaddr,
yiaddr = 0,
siaddr = 0,
giaddr = dhcp_packet.giaddr,
chaddr = dhcp_packet.chaddr,
magic_cookie = d.BOOTP_MAGIC_COOKIE
)
set_options(dhcp_reply, option_dict, provide_options, d.DHCPACK, True)
trans_id = (trans_id + 1) & 0xffff
if (dhcp_packet.flags & d.DHCPFLAG_BROADCAST) or is_nak:
dl_dst = [0xff, 0xff, 0xff, 0xff, 0xff, 0xff]
ip_dst = 0xffffffff
else:
dl_dst = l7_packet.dl_src
ip_dst = port_ip
reply_packet = ip4_packet_l7((ip4_payload, ip4_udp_payload),
dl_src = server_mac,
dl_dst = dl_dst,
identifier = trans_id,
ttl = 128,
ip_src = server_ip,
ip_dst = ip_dst,
sport = 67,
dport = 68,
data = dhcp_reply._tobytes()
)
self.subroutine(send_packet(in_port, reply_packet), True)
except Exception:
self._logger.info('Invalid DHCP packet received: %r', msg.data, exc_info = True)