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# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2013 Isaku Yamahata <yamahata at private email ne jp>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import contextlib
import socket
import struct
from os_ken.controller import handler
from os_ken.ofproto import ether
from os_ken.ofproto import inet
from os_ken.lib import addrconv
from os_ken.lib import hub
from os_ken.lib.packet import arp
from os_ken.lib.packet import vrrp
from os_ken.services.protocols.vrrp import monitor
from os_ken.services.protocols.vrrp import event as vrrp_event
from os_ken.services.protocols.vrrp import utils
# Those are not defined in socket module
SS_MAXSIZE = 128
MCAST_JOIN_GROUP = 42
MCAST_LEAVE_GROUP = 45
PACKET_ADD_MEMBERSHIP = 1
PACKET_DROP_MEMBERSHIP = 2
PACKET_MR_MULTICAST = 0
SOL_PACKET = 263
def if_nametoindex(ifname):
filename = '/sys/class/net/' + ifname + '/ifindex'
with contextlib.closing(open(filename)) as f:
for line in f:
return int(line)
@monitor.VRRPInterfaceMonitor.register(vrrp_event.VRRPInterfaceNetworkDevice)
class VRRPInterfaceMonitorNetworkDevice(monitor.VRRPInterfaceMonitor):
"""
This module uses raw socket so that privilege(CAP_NET_ADMIN capability)
is required.
"""
def __init__(self, *args, **kwargs):
super(VRRPInterfaceMonitorNetworkDevice, self).__init__(*args,
**kwargs)
self.__is_active = True
config = self.config
if config.is_ipv6:
family = socket.AF_INET6
ether_type = ether.ETH_TYPE_IPV6
mac_address = vrrp.vrrp_ipv6_src_mac_address(config.vrid)
else:
family = socket.AF_INET
ether_type = ether.ETH_TYPE_IP
mac_address = vrrp.vrrp_ipv4_src_mac_address(config.vrid)
# socket module doesn't define IPPROTO_VRRP
self.ip_socket = socket.socket(family, socket.SOCK_RAW,
inet.IPPROTO_VRRP)
self.packet_socket = socket.socket(socket.AF_PACKET, socket.SOCK_RAW,
socket.htons(ether_type))
self.packet_socket.bind((self.interface.device_name, ether_type,
socket.PACKET_MULTICAST,
arp.ARP_HW_TYPE_ETHERNET,
addrconv.mac.text_to_bin(mac_address)))
self.ifindex = if_nametoindex(self.interface.device_name)
def start(self):
# discard received packets before joining multicast membership
packet_socket = self.packet_socket
packet_socket.setblocking(0)
with hub.Timeout(0.1, False):
while True:
try:
packet_socket.recv(1500)
except socket.error:
break
packet_socket.setblocking(1)
self._join_multicast_membership(True)
self._join_vrrp_group(True)
super(VRRPInterfaceMonitorNetworkDevice, self).start()
self.threads.append(hub.spawn(self._recv_loop))
def stop(self):
self.__is_active = False
super(VRRPInterfaceMonitorNetworkDevice, self).stop()
# we assume that the structures in the following two functions for
# multicast are aligned in the same way on all the archtectures.
def _join_multicast_membership(self, join_leave):
config = self.config
if config.is_ipv6:
mac_address = vrrp.vrrp_ipv6_src_mac_address(config.vrid)
else:
mac_address = vrrp.vrrp_ipv4_src_mac_address(config.vrid)
if join_leave:
add_drop = PACKET_ADD_MEMBERSHIP
else:
add_drop = PACKET_DROP_MEMBERSHIP
# struct packet_mreq {
# int mr_ifindex;
# unsigned short mr_type;
# unsigned short mr_alen;
# unsigned char mr_mr_address[8];
# };
packet_mreq = struct.pack('IHH8s', self.ifindex,
PACKET_MR_MULTICAST, 6,
addrconv.mac.text_to_bin(mac_address))
self.packet_socket.setsockopt(SOL_PACKET, add_drop, packet_mreq)
def _join_vrrp_group(self, join_leave):
if join_leave:
join_leave = MCAST_JOIN_GROUP
else:
join_leave = MCAST_LEAVE_GROUP
# struct group_req {
# __u32 gr_interface; /* interface index */
# struct __kernel_sockaddr_storage gr_group; /* group address */
# };
group_req = struct.pack('I', self.ifindex)
# padding to gr_group. This is environment dependent
group_req += b'\x00' * (struct.calcsize('P') - struct.calcsize('I'))
if self.config.is_ipv6:
# struct sockaddr_in6 {
# sa_family_t sin6_family; /* AF_INET6 */
# in_port_t sin6_port; /* port number */
# uint32_t sin6_flowinfo; /* IPv6 flow information */
# struct in6_addr sin6_addr; /* IPv6 address */
# uint32_t sin6_scope_id; /* Scope ID (new in 2.4) */
# };
# struct in6_addr {
# unsigned char s6_addr[16]; /* IPv6 address */
# };
family = socket.IPPROTO_IPV6
sockaddr = struct.pack('H', socket.AF_INET6)
sockaddr += struct.pack('!H', 0)
sockaddr += struct.pack('!I', 0)
sockaddr += addrconv.ipv6.text_to_bin(vrrp.VRRP_IPV6_DST_ADDRESS)
sockaddr += struct.pack('I', 0)
else:
# #define __SOCK_SIZE__ 16 /* sizeof(struct sockaddr) */
# struct sockaddr_in {
# __kernel_sa_family_t sin_family; /* Address family */
# __be16 sin_port; /* Port number */
# struct in_addr sin_addr; /* Internet address */
# /* Pad to size of `struct sockaddr'. */
# unsigned char __pad[__SOCK_SIZE__ - sizeof(short int) -
# sizeof(unsigned short int) - sizeof(struct in_addr)];
# };
# struct in_addr {
# __be32 s_addr;
# };
family = socket.IPPROTO_IP
sockaddr = struct.pack('H', socket.AF_INET)
sockaddr += struct.pack('!H', 0)
sockaddr += addrconv.ipv4.text_to_bin(vrrp.VRRP_IPV4_DST_ADDRESS)
sockaddr += b'\x00' * (SS_MAXSIZE - len(sockaddr))
group_req += sockaddr
self.ip_socket.setsockopt(family, join_leave, group_req)
return
def _recv_loop(self):
packet_socket = self.packet_socket
packet_socket.settimeout(1.3) # to check activeness periodically
try:
while self.__is_active:
try:
buf = packet_socket.recv(128)
except socket.timeout:
self.logger.debug('timeout')
continue
except:
self.logger.error('recv failed')
continue
if len(buf) == 0:
self.__is_active = False
break
self.logger.debug('recv buf')
self._send_vrrp_packet_received(buf)
finally:
self._join_vrrp_group(False)
self._join_multicast_membership(False)
@handler.set_ev_handler(vrrp_event.EventVRRPTransmitRequest)
def vrrp_transmit_request_handler(self, ev):
self.logger.debug('send')
try:
self.packet_socket.sendto(ev.data,
(self.interface.device_name, 0))
except:
self.logger.error('send failed')
def _initialize(self):
# nothing
pass
def _shutdown(self):
self.__is_active = False
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