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gthiemongebeagles
gthiemonge
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beagles
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Fixed ip advertisement for ipv6
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‎templates/octaviaamphoracontroller/bin/ip_advertisement.py‎

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# Copyright 2020 Red Hat, Inc. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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#
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# Adapted from octavia/amphorae/backends/utils/ip_advertisement.py
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import fcntl
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import socket
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import struct
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from oslo_log import log as logging
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from octavia.amphorae.backends.utils import network_namespace
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from octavia.common import constants
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from octavia.common import utils as common_utils
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LOG = logging.getLogger(__name__)
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def garp(interface, ip_address, net_ns=None):
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"""Sends a gratuitous ARP for ip_address on the interface.
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:param interface: The interface name to send the GARP on.
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:param ip_address: The IP address to advertise in the GARP.
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:param net_ns: The network namespace to send the GARP from.
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:returns: None
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"""
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ARP_ETHERTYPE = 0x0806
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BROADCAST_MAC = b'\xff\xff\xff\xff\xff\xff'
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# Get a socket, optionally inside a network namespace
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garp_socket = None
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if net_ns:
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with network_namespace.NetworkNamespace(net_ns):
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garp_socket = socket.socket(socket.AF_PACKET, socket.SOCK_RAW)
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else:
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garp_socket = socket.socket(socket.AF_PACKET, socket.SOCK_RAW)
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# Bind the socket with the ARP ethertype protocol
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garp_socket.bind((interface, ARP_ETHERTYPE))
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# Get the MAC address of the interface
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source_mac = garp_socket.getsockname()[4]
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garp_msg = [
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struct.pack('!h', 1), # Hardware type ethernet
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struct.pack('!h', 0x0800), # Protocol type IPv4
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struct.pack('!B', 6), # Hardware size
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struct.pack('!B', 4), # Protocol size
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struct.pack('!h', 1), # Opcode request
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source_mac, # Sender MAC address
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socket.inet_aton(ip_address), # Sender IP address
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BROADCAST_MAC, # Target MAC address
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socket.inet_aton(ip_address)] # Target IP address
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garp_ethernet = [
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BROADCAST_MAC, # Ethernet destination
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source_mac, # Ethernet source
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struct.pack('!h', ARP_ETHERTYPE), # Ethernet type
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b''.join(garp_msg)] # The GARP message
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garp_socket.send(b''.join(garp_ethernet))
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garp_socket.close()
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def calculate_icmpv6_checksum(packet):
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"""Calculate the ICMPv6 checksum for a packet.
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:param packet: The packet bytes to checksum.
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:returns: The checksum integer.
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"""
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total = 0
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# Add up 16-bit words
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num_words = len(packet) // 2
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for chunk in struct.unpack(f"!{num_words}H", packet[0:num_words * 2]):
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total += chunk
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# Add any left over byte
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if len(packet) % 2:
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total += packet[-1] << 8
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# Fold 32-bits into 16-bits
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total = (total >> 16) + (total & 0xffff)
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total += total >> 16
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return ~total + 0x10000 & 0xffff
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def neighbor_advertisement(interface, ip_address, net_ns=None):
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"""Sends a unsolicited neighbor advertisement for an ip on the interface.
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:param interface: The interface name to send the GARP on.
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:param ip_address: The IP address to advertise in the GARP.
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:param net_ns: The network namespace to send the GARP from.
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:returns: None
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"""
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ALL_NODES_ADDR = 'ff02::1'
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SIOCGIFHWADDR = 0x8927
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# Get a socket, optionally inside a network namespace
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na_socket = None
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if net_ns:
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with network_namespace.NetworkNamespace(net_ns):
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na_socket = socket.socket(
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socket.AF_INET6, socket.SOCK_RAW,
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socket.getprotobyname(constants.IPV6_ICMP))
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else:
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na_socket = socket.socket(socket.AF_INET6, socket.SOCK_RAW,
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socket.getprotobyname(constants.IPV6_ICMP))
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# Per RFC 4861 section 4.4, the hop limit should be 255
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na_socket.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_MULTICAST_HOPS, 255)
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# TODO(gthiemonge) this line is specific for the octavia-operator
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# The original function didn't seem to send the packets on the right
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# interface
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na_socket.setsockopt(socket.SOL_SOCKET, 25, bytes(interface, 'ascii'))
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# Bind the socket with the source address
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na_socket.bind((ip_address, 0))
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# Get the byte representation of the MAC address of the interface
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# Note: You can't use getsockname() to get the MAC on this type of socket
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source_mac = fcntl.ioctl(
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na_socket.fileno(), SIOCGIFHWADDR, struct.pack(
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'256s', bytes(interface, 'utf-8')))[18:24]
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# Get the byte representation of the source IP address
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source_ip_bytes = socket.inet_pton(socket.AF_INET6, ip_address)
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icmpv6_na_msg_prefix = [
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struct.pack('!B', 136), # ICMP Type Neighbor Advertisement
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struct.pack('!B', 0)] # ICMP Code
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icmpv6_na_msg_postfix = [
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struct.pack('!I', 0xa0000000), # Flags (Router, Override)
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source_ip_bytes, # Target address
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struct.pack('!B', 2), # ICMPv6 option type target link-layer address
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struct.pack('!B', 1), # ICMPv6 option length
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source_mac] # ICMPv6 option link-layer address
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# Calculate the ICMPv6 checksum
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icmpv6_pseudo_header = [
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source_ip_bytes, # Source IP address
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socket.inet_pton(socket.AF_INET6, ALL_NODES_ADDR), # Destination IP
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struct.pack('!I', 58), # IPv6 next header (ICMPv6)
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struct.pack('!h', 32)] # IPv6 payload length
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icmpv6_tmp_chksum = struct.pack('!H', 0) # Checksum->zeros for calculation
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tmp_chksum_msg = b''.join(icmpv6_pseudo_header + icmpv6_na_msg_prefix +
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[icmpv6_tmp_chksum] + icmpv6_pseudo_header)
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checksum = struct.pack('!H', calculate_icmpv6_checksum(tmp_chksum_msg))
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# Build the ICMPv6 unsolicitated neighbor advertisement
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icmpv6_msg = b''.join(icmpv6_na_msg_prefix + [checksum] +
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icmpv6_na_msg_postfix)
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na_socket.sendto(icmpv6_msg, (ALL_NODES_ADDR, 0, 0, 0))
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na_socket.close()
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def send_ip_advertisement(interface, ip_address, net_ns=None):
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"""Send an address advertisement.
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This method will send either GARP (IPv4) or neighbor advertisements (IPv6)
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for the ip address specified.
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:param interface: The interface name to send the advertisement on.
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:param ip_address: The IP address to advertise.
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:param net_ns: The network namespace to send the advertisement from.
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:returns: None
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"""
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try:
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if common_utils.is_ipv4(ip_address):
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garp(interface, ip_address, net_ns)
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elif common_utils.is_ipv6(ip_address):
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neighbor_advertisement(interface, ip_address, net_ns)
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else:
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LOG.error('Unknown IP version for address: "%s". Skipping',
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ip_address)
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except Exception as e:
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LOG.warning('Unable to send address advertisement for address: "%s", '
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'error: %s. Skipping', ip_address, str(e))

‎templates/octaviaamphoracontroller/bin/octavia_hm_advertisement.py‎

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@@ -19,7 +19,7 @@
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from pyroute2 import IPRoute
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import octavia.amphorae.backends.utils.ip_advertisement as ip_adv
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import ip_advertisement as ip_adv
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try:
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interface_name = sys.argv[1]

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