# Copyright 2014 Rackspace, Inc.
#
# 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 ctypes
import fcntl
import os
import select
import socket
import struct
import sys
import netifaces
from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import netutils
from ironic_python_agent import utils
LOG = logging.getLogger(__name__)
CONF = cfg.CONF
LLDP_ETHERTYPE = 0x88cc
IFF_PROMISC = 0x100
SIOCGIFFLAGS = 0x8913
SIOCSIFFLAGS = 0x8914
INFINIBAND_ADDR_LEN = 59
# LLDP definitions needed to extract vlan information
LLDP_TLV_ORG_SPECIFIC = 127
# 802.1Q defines from http://www.ieee802.org/1/pages/802.1Q-2014.html, Annex D
LLDP_802dot1_OUI = "0080c2"
# subtypes
dot1_VLAN_NAME = "03"
VLAN_ID_LEN = len(LLDP_802dot1_OUI + dot1_VLAN_NAME)
[docs]
class ifreq(ctypes.Structure):
"""Class for setting flags on a socket."""
_fields_ = [("ifr_ifrn", ctypes.c_char * 16),
("ifr_flags", ctypes.c_short)]
[docs]
class RawPromiscuousSockets(object):
def __init__(self, interface_names, protocol):
"""Initialize context manager.
:param interface_names: a list of interface names to bind to
:param protocol: the protocol to listen for
:returns: A list of tuple of (interface_name, bound_socket), or [] if
there is an exception binding or putting the sockets in
promiscuous mode
"""
if not interface_names:
raise ValueError('interface_names must be a non-empty list of '
'network interface names to bind to.')
self.protocol = protocol
# A 3-tuple of (interface_name, socket, ifreq object)
self.interfaces = [(name, self._get_socket(), ifreq())
for name in interface_names]
def __enter__(self):
for interface_name, sock, ifr in self.interfaces:
LOG.info('Interface %s entering promiscuous mode to capture ',
interface_name)
try:
ifr.ifr_ifrn = interface_name.encode()
# Get current flags
fcntl.ioctl(sock.fileno(), SIOCGIFFLAGS, ifr) # G for Get
# bitwise or the flags with promiscuous mode, set the new flags
ifr.ifr_flags |= IFF_PROMISC
fcntl.ioctl(sock.fileno(), SIOCSIFFLAGS, ifr) # S for Set
# Bind the socket so it can be used
LOG.debug('Binding interface %(interface)s for protocol '
'%(proto)s', {'interface': interface_name,
'proto': self.protocol})
sock.bind((interface_name, self.protocol))
except Exception:
LOG.error('Failed to open all RawPromiscuousSockets, '
'attempting to close any opened sockets.')
self.__exit__(*sys.exc_info())
raise
# No need to return each interfaces ifreq.
return [(sock[0], sock[1]) for sock in self.interfaces]
def __exit__(self, exception_type, exception_val, trace):
for name, sock, ifr in self.interfaces:
# bitwise or with the opposite of promiscuous mode to remove
ifr.ifr_flags &= ~IFF_PROMISC
try:
fcntl.ioctl(sock.fileno(), SIOCSIFFLAGS, ifr)
sock.close()
except Exception:
LOG.exception('Failed to close raw socket for interface %s',
name)
def _get_socket(self):
return socket.socket(socket.AF_PACKET, socket.SOCK_RAW, self.protocol)
[docs]
def get_lldp_info(interface_names):
"""Get LLDP info from the switch(es) the agent is connected to.
Listens on either a single or all interfaces for LLDP packets, then
parses them. If no LLDP packets are received before lldp_timeout,
returns a dictionary in the form {'interface': [],...}.
:param interface_names: The interface to listen for packets on. If
None, will listen on each interface.
:return: A dictionary in the form
{'interface': [(lldp_type, lldp_data)],...}
"""
with RawPromiscuousSockets(interface_names, LLDP_ETHERTYPE) as interfaces:
try:
return _get_lldp_info(interfaces)
except Exception as e:
LOG.exception('Error while getting LLDP info: %s', str(e))
raise
def _parse_tlv(buff):
"""Iterate over a buffer and generate structured TLV data.
:param buff: An ethernet packet with the header trimmed off (first
14 bytes)
"""
lldp_info = []
while len(buff) >= 2:
# TLV structure: type (7 bits), length (9 bits), val (0-511 bytes)
tlvhdr = struct.unpack('!H', buff[:2])[0]
tlvtype = (tlvhdr & 0xfe00) >> 9
tlvlen = (tlvhdr & 0x01ff)
tlvdata = buff[2:tlvlen + 2]
buff = buff[tlvlen + 2:]
lldp_info.append((tlvtype, tlvdata))
if buff:
LOG.warning("Trailing byte received in an LLDP package: %r", buff)
return lldp_info
def _receive_lldp_packets(sock):
"""Receive LLDP packets and process them.
:param sock: A bound socket
:return: A list of tuples in the form (lldp_type, lldp_data)
"""
pkt = sock.recv(1600)
# Filter invalid packets
if not pkt or len(pkt) < 14:
return []
# Skip header (dst MAC, src MAC, ethertype)
pkt = pkt[14:]
return _parse_tlv(pkt)
def _get_lldp_info(interfaces):
"""Wait for packets on each socket, parse the received LLDP packets."""
LOG.debug('Getting LLDP info for interfaces %s', interfaces)
lldp_info = {}
if not interfaces:
return {}
while interfaces:
LOG.info('Waiting on LLDP info for interfaces: %(interfaces)s, '
'timeout: %(timeout)s', {'interfaces': interfaces,
'timeout': CONF.lldp_timeout})
socks = [interface[1] for interface in interfaces]
# rlist is a list of sockets ready for reading
rlist, _, _ = select.select(socks, [], [], CONF.lldp_timeout)
if not rlist:
# Empty read list means timeout on all interfaces
LOG.warning('LLDP timed out, remaining interfaces: %s',
interfaces)
break
for s in rlist:
# Find interface name matching socket ready for read
# Create a copy of interfaces to avoid deleting while iterating.
for index, interface in enumerate(list(interfaces)):
if s == interface[1]:
try:
lldp_info[interface[0]] = _receive_lldp_packets(s)
except socket.error:
LOG.exception('Socket for network interface %s said '
'that it was ready to read we were '
'unable to read from the socket while '
'trying to get LLDP packet. Skipping '
'this network interface.', interface[0])
else:
LOG.info('Found LLDP info for interface: %s',
interface[0])
# Remove interface from the list, only need one packet
del interfaces[index]
# Add any interfaces that didn't get a packet as empty lists
for name, _sock in interfaces:
lldp_info[name] = []
return lldp_info
[docs]
def get_default_ip_addr(type, interface_id):
"""Retrieve default IPv4 or IPv6 address."""
try:
addrs = netifaces.ifaddresses(interface_id)
return addrs[type][0]['addr']
except (ValueError, IndexError, KeyError):
# No default IP address found
return None
[docs]
def get_ipv4_addr(interface_id):
return get_default_ip_addr(netifaces.AF_INET, interface_id)
[docs]
def get_ipv6_addr(interface_id):
return get_default_ip_addr(netifaces.AF_INET6, interface_id)
[docs]
def get_mac_addr(interface_id):
try:
addrs = netifaces.ifaddresses(interface_id)
return addrs[netifaces.AF_LINK][0]['addr']
except (ValueError, IndexError, KeyError):
# No mac address found
return None
# Other options...
# 1. import os; os.uname()[1]
# 2. import platform; platform.node()
[docs]
def get_hostname():
return socket.gethostname()
[docs]
def is_network_device(interface_name):
device_path = f'/sys/class/net/{interface_name}/device'
return os.path.exists(device_path)
[docs]
def is_vlan(interface_name):
# A VLAN interface does not have /device, check naming convention
# used when adding VLAN interface
interface, sep, vlan = interface_name.partition('.')
return vlan.isdigit()
[docs]
def is_bond(interface_name):
device_path = f'/sys/class/net/{interface_name}/bonding'
return os.path.exists(device_path)
[docs]
def list_interfaces():
iface_names = os.listdir('/sys/class/net')
return [name for name in iface_names
if is_vlan(name) or is_network_device(name) or is_bond(name)]
[docs]
def interface_has_carrier(interface_name):
path = '/sys/class/net/{}/carrier'.format(interface_name)
try:
with open(path, 'rt') as fp:
return fp.read().strip() == '1'
except EnvironmentError:
LOG.debug('No carrier information for interface %s',
interface_name)
return False
[docs]
def wrap_ipv6(ip):
if netutils.is_valid_ipv6(ip):
return "[%s]" % ip
return ip
[docs]
def get_wildcard_address():
if netutils.is_ipv6_enabled():
return "::"
return "0.0.0.0"
def _get_configured_vlans():
return [x.strip() for x in CONF.enable_vlan_interfaces.split(',')
if x.strip()]
def _add_vlan_interface(interface, vlan, interfaces_list):
vlan_name = interface + '.' + vlan
# if any(x for x in interfaces_list if x.name == vlan_name):
if any(x.name == vlan_name for x in interfaces_list):
LOG.info("VLAN interface %s has already been added", vlan_name)
return ''
try:
LOG.info('Adding VLAN interface %s', vlan_name)
# Add the interface
utils.execute('ip', 'link', 'add', 'link', interface, 'name',
vlan_name, 'type', 'vlan', 'id', vlan,
check_exit_code=[0, 2])
# Bring up interface
utils.execute('ip', 'link', 'set', 'dev', vlan_name, 'up')
except Exception as exc:
LOG.warning('Exception when running ip commands to add VLAN '
'interface: %s', exc)
return ''
return vlan_name
def _add_vlans_from_lldp(lldp, interface, interfaces_list):
interfaces = []
# Get the lldp packets received on this interface
if lldp:
for type, value in lldp:
if (type == LLDP_TLV_ORG_SPECIFIC
and value.startswith(LLDP_802dot1_OUI
+ dot1_VLAN_NAME)):
vlan = str(int(value[VLAN_ID_LEN: VLAN_ID_LEN + 4], 16))
name = _add_vlan_interface(interface, vlan,
interfaces_list)
if name:
interfaces.append(name)
else:
LOG.debug('VLAN interface %s does not have lldp info', interface)
return interfaces
[docs]
def bring_up_vlan_interfaces(interfaces_list):
"""Bring up vlan interfaces based on kernel params
Use the configured value of ``enable_vlan_interfaces`` to determine
if VLAN interfaces should be brought up using ``ip`` commands. If
``enable_vlan_interfaces`` defines a particular vlan then bring up
that vlan. If it defines an interface or ``all`` then use LLDP info
to figure out which VLANs should be brought up.
:param interfaces_list: List of current interfaces
:return: List of vlan interface names that have been added
"""
interfaces = []
vlan_interfaces = _get_configured_vlans()
for vlan_int in vlan_interfaces:
# TODO(bfournie) skip if pxe boot interface
if '.' in vlan_int:
# interface and vlan are provided
interface, vlan = vlan_int.split('.', 1)
if any(x.name == interface for x in interfaces_list):
name = _add_vlan_interface(interface, vlan,
interfaces_list)
if name:
interfaces.append(name)
else:
LOG.warning('Provided VLAN interface %s does not exist',
interface)
elif CONF.collect_lldp:
# Get the vlans from lldp info
if vlan_int == 'all':
# Use all interfaces
for iface in interfaces_list:
names = _add_vlans_from_lldp(
iface.lldp, iface.name, interfaces_list)
if names:
interfaces.extend(names)
else:
# Use provided interface
lldp = next((x.lldp for x in interfaces_list
if x.name == vlan_int), None)
if lldp:
names = _add_vlans_from_lldp(lldp, vlan_int,
interfaces_list)
if names:
interfaces.extend(names)
else:
LOG.warning('Provided interface name %s was not found',
vlan_int)
else:
LOG.warning('Attempting to add VLAN interfaces but specific '
'interface not provided and LLDP not enabled')
return interfaces
