# Copyright (C) 2013-2014 Canonical Ltd.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Blake Rouse <blake.rouse@canonical.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
import errno
import ipaddress
import logging
import os
import re
from cloudinit import subp
from cloudinit import util
from cloudinit.net.network_state import mask_to_net_prefix
from cloudinit.url_helper import UrlError, readurl
LOG = logging.getLogger(__name__)
SYS_CLASS_NET = "/sys/class/net/"
DEFAULT_PRIMARY_INTERFACE = 'eth0'
def natural_sort_key(s, _nsre=re.compile('([0-9]+)')):
"""Sorting for Humans: natural sort order. Can be use as the key to sort
functions.
This will sort ['eth0', 'ens3', 'ens10', 'ens12', 'ens8', 'ens0'] as
['ens0', 'ens3', 'ens8', 'ens10', 'ens12', 'eth0'] instead of the simple
python way which will produce ['ens0', 'ens10', 'ens12', 'ens3', 'ens8',
'eth0']."""
return [int(text) if text.isdigit() else text.lower()
for text in re.split(_nsre, s)]
def get_sys_class_path():
"""Simple function to return the global SYS_CLASS_NET."""
return SYS_CLASS_NET
def sys_dev_path(devname, path=""):
return get_sys_class_path() + devname + "/" + path
def read_sys_net(devname, path, translate=None,
on_enoent=None, on_keyerror=None,
on_einval=None):
dev_path = sys_dev_path(devname, path)
try:
contents = util.load_file(dev_path)
except (OSError, IOError) as e:
e_errno = getattr(e, 'errno', None)
if e_errno in (errno.ENOENT, errno.ENOTDIR):
if on_enoent is not None:
return on_enoent(e)
if e_errno in (errno.EINVAL,):
if on_einval is not None:
return on_einval(e)
raise
contents = contents.strip()
if translate is None:
return contents
try:
return translate[contents]
except KeyError as e:
if on_keyerror is not None:
return on_keyerror(e)
else:
LOG.debug("Found unexpected (not translatable) value"
" '%s' in '%s", contents, dev_path)
raise
def read_sys_net_safe(iface, field, translate=None):
def on_excp_false(e):
return False
return read_sys_net(iface, field,
on_keyerror=on_excp_false,
on_enoent=on_excp_false,
on_einval=on_excp_false,
translate=translate)
def read_sys_net_int(iface, field):
val = read_sys_net_safe(iface, field)
if val is False:
return None
try:
return int(val)
except ValueError:
return None
def is_up(devname):
# The linux kernel says to consider devices in 'unknown'
# operstate as up for the purposes of network configuration. See
# Documentation/networking/operstates.txt in the kernel source.
translate = {'up': True, 'unknown': True, 'down': False}
return read_sys_net_safe(devname, "operstate", translate=translate)
def is_bridge(devname):
return os.path.exists(sys_dev_path(devname, "bridge"))
def is_bond(devname):
return os.path.exists(sys_dev_path(devname, "bonding"))
def get_master(devname):
"""Return the master path for devname, or None if no master"""
path = sys_dev_path(devname, path="master")
if os.path.exists(path):
return path
return None
def master_is_bridge_or_bond(devname):
"""Return a bool indicating if devname's master is a bridge or bond"""
master_path = get_master(devname)
if master_path is None:
return False
bonding_path = os.path.join(master_path, "bonding")
bridge_path = os.path.join(master_path, "bridge")
return (os.path.exists(bonding_path) or os.path.exists(bridge_path))
def is_netfailover(devname, driver=None):
""" netfailover driver uses 3 nics, master, primary and standby.
this returns True if the device is either the primary or standby
as these devices are to be ignored.
"""
if driver is None:
driver = device_driver(devname)
if is_netfail_primary(devname, driver) or is_netfail_standby(devname,
driver):
return True
return False
def get_dev_features(devname):
""" Returns a str from reading /sys/class/net/<devname>/device/features."""
features = ''
try:
features = read_sys_net(devname, 'device/features')
except Exception:
pass
return features
def has_netfail_standby_feature(devname):
""" Return True if VIRTIO_NET_F_STANDBY bit (62) is set.
https://github.com/torvalds/linux/blob/ \
089cf7f6ecb266b6a4164919a2e69bd2f938374a/ \
include/uapi/linux/virtio_net.h#L60
"""
features = get_dev_features(devname)
if not features or len(features) < 64:
return False
return features[62] == "1"
def is_netfail_master(devname, driver=None):
""" A device is a "netfail master" device if:
- The device does NOT have the 'master' sysfs attribute
- The device driver is 'virtio_net'
- The device has the standby feature bit set
Return True if all of the above is True.
"""
if get_master(devname) is not None:
return False
if driver is None:
driver = device_driver(devname)
if driver != "virtio_net":
return False
if not has_netfail_standby_feature(devname):
return False
return True
def is_netfail_primary(devname, driver=None):
""" A device is a "netfail primary" device if:
- the device has a 'master' sysfs file
- the device driver is not 'virtio_net'
- the 'master' sysfs file points to device with virtio_net driver
- the 'master' device has the 'standby' feature bit set
Return True if all of the above is True.
"""
# /sys/class/net/<devname>/master -> ../../<master devname>
master_sysfs_path = sys_dev_path(devname, path='master')
if not os.path.exists(master_sysfs_path):
return False
if driver is None:
driver = device_driver(devname)
if driver == "virtio_net":
return False
master_devname = os.path.basename(os.path.realpath(master_sysfs_path))
master_driver = device_driver(master_devname)
if master_driver != "virtio_net":
return False
master_has_standby = has_netfail_standby_feature(master_devname)
if not master_has_standby:
return False
return True
def is_netfail_standby(devname, driver=None):
""" A device is a "netfail standby" device if:
- The device has a 'master' sysfs attribute
- The device driver is 'virtio_net'
- The device has the standby feature bit set
Return True if all of the above is True.
"""
if get_master(devname) is None:
return False
if driver is None:
driver = device_driver(devname)
if driver != "virtio_net":
return False
if not has_netfail_standby_feature(devname):
return False
return True
def is_renamed(devname):
"""
/* interface name assignment types (sysfs name_assign_type attribute) */
#define NET_NAME_UNKNOWN 0 /* unknown origin (not exposed to user) */
#define NET_NAME_ENUM 1 /* enumerated by kernel */
#define NET_NAME_PREDICTABLE 2 /* predictably named by the kernel */
#define NET_NAME_USER 3 /* provided by user-space */
#define NET_NAME_RENAMED 4 /* renamed by user-space */
"""
name_assign_type = read_sys_net_safe(devname, 'name_assign_type')
if name_assign_type and name_assign_type in ['3', '4']:
return True
return False
def is_vlan(devname):
uevent = str(read_sys_net_safe(devname, "uevent"))
return 'DEVTYPE=vlan' in uevent.splitlines()
def device_driver(devname):
"""Return the device driver for net device named 'devname'."""
driver = None
driver_path = sys_dev_path(devname, "device/driver")
# driver is a symlink to the driver *dir*
if os.path.islink(driver_path):
driver = os.path.basename(os.readlink(driver_path))
return driver
def device_devid(devname):
"""Return the device id string for net device named 'devname'."""
dev_id = read_sys_net_safe(devname, "device/device")
if dev_id is False:
return None
return dev_id
def get_devicelist():
if util.is_FreeBSD():
return list(get_interfaces_by_mac().values())
try:
devs = os.listdir(get_sys_class_path())
except OSError as e:
if e.errno == errno.ENOENT:
devs = []
else:
raise
return devs
class ParserError(Exception):
"""Raised when a parser has issue parsing a file/content."""
def is_disabled_cfg(cfg):
if not cfg or not isinstance(cfg, dict):
return False
return cfg.get('config') == "disabled"
def find_fallback_nic(blacklist_drivers=None):
"""Return the name of the 'fallback' network device."""
if util.is_FreeBSD():
return find_fallback_nic_on_freebsd(blacklist_drivers)
elif util.is_NetBSD() or util.is_OpenBSD():
return find_fallback_nic_on_netbsd_or_openbsd(blacklist_drivers)
else:
return find_fallback_nic_on_linux(blacklist_drivers)
def find_fallback_nic_on_netbsd_or_openbsd(blacklist_drivers=None):
values = list(sorted(
get_interfaces_by_mac().values(),
key=natural_sort_key))
if values:
return values[0]
def find_fallback_nic_on_freebsd(blacklist_drivers=None):
"""Return the name of the 'fallback' network device on FreeBSD.
@param blacklist_drivers: currently ignored
@return default interface, or None
we'll use the first interface from ``ifconfig -l -u ether``
"""
stdout, _stderr = subp.subp(['ifconfig', '-l', '-u', 'ether'])
values = stdout.split()
if values:
return values[0]
# On FreeBSD <= 10, 'ifconfig -l' ignores the interfaces with DOWN
# status
values = list(get_interfaces_by_mac().values())
values.sort()
if values:
return values[0]
def find_fallback_nic_on_linux(blacklist_drivers=None):
"""Return the name of the 'fallback' network device on Linux."""
if not blacklist_drivers:
blacklist_drivers = []
if 'net.ifnames=0' in util.get_cmdline():
LOG.debug('Stable ifnames disabled by net.ifnames=0 in /proc/cmdline')
else:
unstable = [device for device in get_devicelist()
if device != 'lo' and not is_renamed(device)]
if len(unstable):
LOG.debug('Found unstable nic names: %s; calling udevadm settle',
unstable)
msg = 'Waiting for udev events to settle'
util.log_time(LOG.debug, msg, func=util.udevadm_settle)
# get list of interfaces that could have connections
invalid_interfaces = set(['lo'])
potential_interfaces = set([device for device in get_devicelist()
if device_driver(device) not in
blacklist_drivers])
potential_interfaces = potential_interfaces.difference(invalid_interfaces)
# sort into interfaces with carrier, interfaces which could have carrier,
# and ignore interfaces that are definitely disconnected
connected = []
possibly_connected = []
for interface in potential_interfaces:
if interface.startswith("veth"):
continue
if is_bridge(interface):
# skip any bridges
continue
if is_bond(interface):
# skip any bonds
continue
if is_netfailover(interface):
# ignore netfailover primary/standby interfaces
continue
carrier = read_sys_net_int(interface, 'carrier')
if carrier:
connected.append(interface)
continue
# check if nic is dormant or down, as this may make a nick appear to
# not have a carrier even though it could acquire one when brought
# online by dhclient
dormant = read_sys_net_int(interface, 'dormant')
if dormant:
possibly_connected.append(interface)
continue
operstate = read_sys_net_safe(interface, 'operstate')
if operstate in ['dormant', 'down', 'lowerlayerdown', 'unknown']:
possibly_connected.append(interface)
continue
# don't bother with interfaces that might not be connected if there are
# some that definitely are
if connected:
potential_interfaces = connected
else:
potential_interfaces = possibly_connected
# if eth0 exists use it above anything else, otherwise get the interface
# that we can read 'first' (using the sorted definition of first).
names = list(sorted(potential_interfaces, key=natural_sort_key))
if DEFAULT_PRIMARY_INTERFACE in names:
names.remove(DEFAULT_PRIMARY_INTERFACE)
names.insert(0, DEFAULT_PRIMARY_INTERFACE)
# pick the first that has a mac-address
for name in names:
if read_sys_net_safe(name, 'address'):
return name
return None
def generate_fallback_config(blacklist_drivers=None, config_driver=None):
"""Generate network cfg v2 for dhcp on the NIC most likely connected."""
if not config_driver:
config_driver = False
target_name = find_fallback_nic(blacklist_drivers=blacklist_drivers)
if not target_name:
# can't read any interfaces addresses (or there are none); give up
return None
# netfail cannot use mac for matching, they have duplicate macs
if is_netfail_master(target_name):
match = {'name': target_name}
else:
match = {
'macaddress': read_sys_net_safe(target_name, 'address').lower()}
cfg = {'dhcp4': True, 'set-name': target_name, 'match': match}
if config_driver:
driver = device_driver(target_name)
if driver:
cfg['match']['driver'] = driver
nconf = {'ethernets': {target_name: cfg}, 'version': 2}
return nconf
def extract_physdevs(netcfg):
def _version_1(netcfg):
physdevs = []
for ent in netcfg.get('config', {}):
if ent.get('type') != 'physical':
continue
mac = ent.get('mac_address')
if not mac:
continue
name = ent.get('name')
driver = ent.get('params', {}).get('driver')
device_id = ent.get('params', {}).get('device_id')
if not driver:
driver = device_driver(name)
if not device_id:
device_id = device_devid(name)
physdevs.append([mac, name, driver, device_id])
return physdevs
def _version_2(netcfg):
physdevs = []
for ent in netcfg.get('ethernets', {}).values():
# only rename if configured to do so
name = ent.get('set-name')
if not name:
continue
# cloud-init requires macaddress for renaming
mac = ent.get('match', {}).get('macaddress')
if not mac:
continue
driver = ent.get('match', {}).get('driver')
device_id = ent.get('match', {}).get('device_id')
if not driver:
driver = device_driver(name)
if not device_id:
device_id = device_devid(name)
physdevs.append([mac, name, driver, device_id])
return physdevs
version = netcfg.get('version')
if version == 1:
return _version_1(netcfg)
elif version == 2:
return _version_2(netcfg)
raise RuntimeError('Unknown network config version: %s' % version)
def apply_network_config_names(netcfg, strict_present=True, strict_busy=True):
"""read the network config and rename devices accordingly.
if strict_present is false, then do not raise exception if no devices
match. if strict_busy is false, then do not raise exception if the
device cannot be renamed because it is currently configured.
renames are only attempted for interfaces of type 'physical'. It is
expected that the network system will create other devices with the
correct name in place."""
try:
_rename_interfaces(extract_physdevs(netcfg))
except RuntimeError as e:
raise RuntimeError(
'Failed to apply network config names: %s' % e
) from e
def interface_has_own_mac(ifname, strict=False):
"""return True if the provided interface has its own address.
Based on addr_assign_type in /sys. Return true for any interface
that does not have a 'stolen' address. Examples of such devices
are bonds or vlans that inherit their mac from another device.
Possible values are:
0: permanent address 2: stolen from another device
1: randomly generated 3: set using dev_set_mac_address"""
assign_type = read_sys_net_int(ifname, "addr_assign_type")
if assign_type is None:
# None is returned if this nic had no 'addr_assign_type' entry.
# if strict, raise an error, if not return True.
if strict:
raise ValueError("%s had no addr_assign_type.")
return True
return assign_type in (0, 1, 3)
def _get_current_rename_info(check_downable=True):
"""Collect information necessary for rename_interfaces.
returns a dictionary by mac address like:
{name:
{
'downable': None or boolean indicating that the
device has only automatically assigned ip addrs.
'device_id': Device id value (if it has one)
'driver': Device driver (if it has one)
'mac': mac address (in lower case)
'name': name
'up': boolean: is_up(name)
}}
"""
cur_info = {}
for (name, mac, driver, device_id) in get_interfaces():
cur_info[name] = {
'downable': None,
'device_id': device_id,
'driver': driver,
'mac': mac.lower(),
'name': name,
'up': is_up(name),
}
if check_downable:
nmatch = re.compile(r"[0-9]+:\s+(\w+)[@:]")
ipv6, _err = subp.subp(['ip', '-6', 'addr', 'show', 'permanent',
'scope', 'global'], capture=True)
ipv4, _err = subp.subp(['ip', '-4', 'addr', 'show'], capture=True)
nics_with_addresses = set()
for bytes_out in (ipv6, ipv4):
nics_with_addresses.update(nmatch.findall(bytes_out))
for d in cur_info.values():
d['downable'] = (d['up'] is False or
d['name'] not in nics_with_addresses)
return cur_info
def _rename_interfaces(renames, strict_present=True, strict_busy=True,
current_info=None):
if not len(renames):
LOG.debug("no interfaces to rename")
return
if current_info is None:
current_info = _get_current_rename_info()
cur_info = {}
for name, data in current_info.items():
cur = data.copy()
if cur.get('mac'):
cur['mac'] = cur['mac'].lower()
cur['name'] = name
cur_info[name] = cur
def update_byname(bymac):
return dict((data['name'], data)
for data in cur_info.values())
def rename(cur, new):
subp.subp(["ip", "link", "set", cur, "name", new], capture=True)
def down(name):
subp.subp(["ip", "link", "set", name, "down"], capture=True)
def up(name):
subp.subp(["ip", "link", "set", name, "up"], capture=True)
ops = []
errors = []
ups = []
cur_byname = update_byname(cur_info)
tmpname_fmt = "cirename%d"
tmpi = -1
def entry_match(data, mac, driver, device_id):
"""match if set and in data"""
if mac and driver and device_id:
return (data['mac'] == mac and
data['driver'] == driver and
data['device_id'] == device_id)
elif mac and driver:
return (data['mac'] == mac and
data['driver'] == driver)
elif mac:
return (data['mac'] == mac)
return False
def find_entry(mac, driver, device_id):
match = [data for data in cur_info.values()
if entry_match(data, mac, driver, device_id)]
if len(match):
if len(match) > 1:
msg = ('Failed to match a single device. Matched devices "%s"'
' with search values "(mac:%s driver:%s device_id:%s)"'
% (match, mac, driver, device_id))
raise ValueError(msg)
return match[0]
return None
for mac, new_name, driver, device_id in renames:
if mac:
mac = mac.lower()
cur_ops = []
cur = find_entry(mac, driver, device_id)
if not cur:
if strict_present:
errors.append(
"[nic not present] Cannot rename mac=%s to %s"
", not available." % (mac, new_name))
continue
cur_name = cur.get('name')
if cur_name == new_name:
# nothing to do
continue
if not cur_name:
if strict_present:
errors.append(
"[nic not present] Cannot rename mac=%s to %s"
", not available." % (mac, new_name))
continue
if cur['up']:
msg = "[busy] Error renaming mac=%s from %s to %s"
if not cur['downable']:
if strict_busy:
errors.append(msg % (mac, cur_name, new_name))
continue
cur['up'] = False
cur_ops.append(("down", mac, new_name, (cur_name,)))
ups.append(("up", mac, new_name, (new_name,)))
if new_name in cur_byname:
target = cur_byname[new_name]
if target['up']:
msg = "[busy-target] Error renaming mac=%s from %s to %s."
if not target['downable']:
if strict_busy:
errors.append(msg % (mac, cur_name, new_name))
continue
else:
cur_ops.append(("down", mac, new_name, (new_name,)))
tmp_name = None
while tmp_name is None or tmp_name in cur_byname:
tmpi += 1
tmp_name = tmpname_fmt % tmpi
cur_ops.append(("rename", mac, new_name, (new_name, tmp_name)))
target['name'] = tmp_name
cur_byname = update_byname(cur_info)
if target['up']:
ups.append(("up", mac, new_name, (tmp_name,)))
cur_ops.append(("rename", mac, new_name, (cur['name'], new_name)))
cur['name'] = new_name
cur_byname = update_byname(cur_info)
ops += cur_ops
opmap = {'rename': rename, 'down': down, 'up': up}
if len(ops) + len(ups) == 0:
if len(errors):
LOG.debug("unable to do any work for renaming of %s", renames)
else:
LOG.debug("no work necessary for renaming of %s", renames)
else:
LOG.debug("achieving renaming of %s with ops %s", renames, ops + ups)
for op, mac, new_name, params in ops + ups:
try:
opmap.get(op)(*params)
except Exception as e:
errors.append(
"[unknown] Error performing %s%s for %s, %s: %s" %
(op, params, mac, new_name, e))
if len(errors):
raise Exception('\n'.join(errors))
def get_interface_mac(ifname):
"""Returns the string value of an interface's MAC Address"""
path = "address"
if os.path.isdir(sys_dev_path(ifname, "bonding_slave")):
# for a bond slave, get the nic's hwaddress, not the address it
# is using because its part of a bond.
path = "bonding_slave/perm_hwaddr"
return read_sys_net_safe(ifname, path)
def get_ib_interface_hwaddr(ifname, ethernet_format):
"""Returns the string value of an Infiniband interface's hardware
address. If ethernet_format is True, an Ethernet MAC-style 6 byte
representation of the address will be returned.
"""
# Type 32 is Infiniband.
if read_sys_net_safe(ifname, 'type') == '32':
mac = get_interface_mac(ifname)
if mac and ethernet_format:
# Use bytes 13-15 and 18-20 of the hardware address.
mac = mac[36:-14] + mac[51:]
return mac
def get_interfaces_by_mac():
if util.is_FreeBSD():
return get_interfaces_by_mac_on_freebsd()
elif util.is_NetBSD():
return get_interfaces_by_mac_on_netbsd()
elif util.is_OpenBSD():
return get_interfaces_by_mac_on_openbsd()
else:
return get_interfaces_by_mac_on_linux()
def get_interfaces_by_mac_on_freebsd():
(out, _) = subp.subp(['ifconfig', '-a', 'ether'])
# flatten each interface block in a single line
def flatten(out):
curr_block = ''
for line in out.split('\n'):
if line.startswith('\t'):
curr_block += line
else:
if curr_block:
yield curr_block
curr_block = line
yield curr_block
# looks for interface and mac in a list of flatten block
def find_mac(flat_list):
for block in flat_list:
m = re.search(
r"^(?P<ifname>\S*): .*ether\s(?P<mac>[\da-f:]{17}).*",
block)
if m:
yield (m.group('mac'), m.group('ifname'))
results = {mac: ifname for mac, ifname in find_mac(flatten(out))}
return results
def get_interfaces_by_mac_on_netbsd():
ret = {}
re_field_match = (
r"(?P<ifname>\w+).*address:\s"
r"(?P<mac>([\da-f]{2}[:-]){5}([\da-f]{2})).*"
)
(out, _) = subp.subp(['ifconfig', '-a'])
if_lines = re.sub(r'\n\s+', ' ', out).splitlines()
for line in if_lines:
m = re.match(re_field_match, line)
if m:
fields = m.groupdict()
ret[fields['mac']] = fields['ifname']
return ret
def get_interfaces_by_mac_on_openbsd():
ret = {}
re_field_match = (
r"(?P<ifname>\w+).*lladdr\s"
r"(?P<mac>([\da-f]{2}[:-]){5}([\da-f]{2})).*")
(out, _) = subp.subp(['ifconfig', '-a'])
if_lines = re.sub(r'\n\s+', ' ', out).splitlines()
for line in if_lines:
m = re.match(re_field_match, line)
if m:
fields = m.groupdict()
ret[fields['mac']] = fields['ifname']
return ret
def get_interfaces_by_mac_on_linux():
"""Build a dictionary of tuples {mac: name}.
Bridges and any devices that have a 'stolen' mac are excluded."""
ret = {}
for name, mac, _driver, _devid in get_interfaces():
if mac in ret:
raise RuntimeError(
"duplicate mac found! both '%s' and '%s' have mac '%s'" %
(name, ret[mac], mac))
ret[mac] = name
# Try to get an Infiniband hardware address (in 6 byte Ethernet format)
# for the interface.
ib_mac = get_ib_interface_hwaddr(name, True)
if ib_mac:
if ib_mac in ret:
raise RuntimeError(
"duplicate mac found! both '%s' and '%s' have mac '%s'" %
(name, ret[ib_mac], ib_mac))
ret[ib_mac] = name
return ret
def get_interfaces():
"""Return list of interface tuples (name, mac, driver, device_id)
Bridges and any devices that have a 'stolen' mac are excluded."""
ret = []
devs = get_devicelist()
# 16 somewhat arbitrarily chosen. Normally a mac is 6 '00:' tokens.
zero_mac = ':'.join(('00',) * 16)
for name in devs:
if not interface_has_own_mac(name):
continue
if is_bridge(name):
continue
if is_vlan(name):
continue
if is_bond(name):
continue
if get_master(name) is not None and not master_is_bridge_or_bond(name):
continue
if is_netfailover(name):
continue
mac = get_interface_mac(name)
# some devices may not have a mac (tun0)
if not mac:
continue
# skip nics that have no mac (00:00....)
if name != 'lo' and mac == zero_mac[:len(mac)]:
continue
ret.append((name, mac, device_driver(name), device_devid(name)))
return ret
def get_ib_hwaddrs_by_interface():
"""Build a dictionary mapping Infiniband interface names to their hardware
address."""
ret = {}
for name, _, _, _ in get_interfaces():
ib_mac = get_ib_interface_hwaddr(name, False)
if ib_mac:
if ib_mac in ret:
raise RuntimeError(
"duplicate mac found! both '%s' and '%s' have mac '%s'" %
(name, ret[ib_mac], ib_mac))
ret[name] = ib_mac
return ret
def has_url_connectivity(url):
"""Return true when the instance has access to the provided URL
Logs a warning if url is not the expected format.
"""
if not any([url.startswith('http://'), url.startswith('https://')]):
LOG.warning(
"Ignoring connectivity check. Expected URL beginning with http*://"
" received '%s'", url)
return False
try:
readurl(url, timeout=5)
except UrlError:
return False
return True
def is_ip_address(s: str) -> bool:
"""Returns a bool indicating if ``s`` is an IP address.
:param s:
The string to test.
:return:
A bool indicating if the string contains an IP address or not.
"""
try:
ipaddress.ip_address(s)
except ValueError:
return False
return True
def is_ipv4_address(s: str) -> bool:
"""Returns a bool indicating if ``s`` is an IPv4 address.
:param s:
The string to test.
:return:
A bool indicating if the string contains an IPv4 address or not.
"""
try:
ipaddress.IPv4Address(s)
except ValueError:
return False
return True
class EphemeralIPv4Network(object):
"""Context manager which sets up temporary static network configuration.
No operations are performed if the provided interface already has the
specified configuration.
This can be verified with the connectivity_url.
If unconnected, bring up the interface with valid ip, prefix and broadcast.
If router is provided setup a default route for that interface. Upon
context exit, clean up the interface leaving no configuration behind.
"""
def __init__(self, interface, ip, prefix_or_mask, broadcast, router=None,
connectivity_url=None, static_routes=None):
"""Setup context manager and validate call signature.
@param interface: Name of the network interface to bring up.
@param ip: IP address to assign to the interface.
@param prefix_or_mask: Either netmask of the format X.X.X.X or an int
prefix.
@param broadcast: Broadcast address for the IPv4 network.
@param router: Optionally the default gateway IP.
@param connectivity_url: Optionally, a URL to verify if a usable
connection already exists.
@param static_routes: Optionally a list of static routes from DHCP
"""
if not all([interface, ip, prefix_or_mask, broadcast]):
raise ValueError(
'Cannot init network on {0} with {1}/{2} and bcast {3}'.format(
interface, ip, prefix_or_mask, broadcast))
try:
self.prefix = mask_to_net_prefix(prefix_or_mask)
except ValueError as e:
raise ValueError(
'Cannot setup network: {0}'.format(e)
) from e
self.connectivity_url = connectivity_url
self.interface = interface
self.ip = ip
self.broadcast = broadcast
self.router = router
self.static_routes = static_routes
self.cleanup_cmds = [] # List of commands to run to cleanup state.
def __enter__(self):
"""Perform ephemeral network setup if interface is not connected."""
if self.connectivity_url:
if has_url_connectivity(self.connectivity_url):
LOG.debug(
'Skip ephemeral network setup, instance has connectivity'
' to %s', self.connectivity_url)
return
self._bringup_device()
# rfc3442 requires us to ignore the router config *if* classless static
# routes are provided.
#
# https://tools.ietf.org/html/rfc3442
#
# If the DHCP server returns both a Classless Static Routes option and
# a Router option, the DHCP client MUST ignore the Router option.
#
# Similarly, if the DHCP server returns both a Classless Static Routes
# option and a Static Routes option, the DHCP client MUST ignore the
# Static Routes option.
if self.static_routes:
self._bringup_static_routes()
elif self.router:
self._bringup_router()
def __exit__(self, excp_type, excp_value, excp_traceback):
"""Teardown anything we set up."""
for cmd in self.cleanup_cmds:
subp.subp(cmd, capture=True)
def _delete_address(self, address, prefix):
"""Perform the ip command to remove the specified address."""
subp.subp(
['ip', '-family', 'inet', 'addr', 'del',
'%s/%s' % (address, prefix), 'dev', self.interface],
capture=True)
def _bringup_device(self):
"""Perform the ip comands to fully setup the device."""
cidr = '{0}/{1}'.format(self.ip, self.prefix)
LOG.debug(
'Attempting setup of ephemeral network on %s with %s brd %s',
self.interface, cidr, self.broadcast)
try:
subp.subp(
['ip', '-family', 'inet', 'addr', 'add', cidr, 'broadcast',
self.broadcast, 'dev', self.interface],
capture=True, update_env={'LANG': 'C'})
except subp.ProcessExecutionError as e:
if "File exists" not in e.stderr:
raise
LOG.debug(
'Skip ephemeral network setup, %s already has address %s',
self.interface, self.ip)
else:
# Address creation success, bring up device and queue cleanup
subp.subp(
['ip', '-family', 'inet', 'link', 'set', 'dev', self.interface,
'up'], capture=True)
self.cleanup_cmds.append(
['ip', '-family', 'inet', 'link', 'set', 'dev', self.interface,
'down'])
self.cleanup_cmds.append(
['ip', '-family', 'inet', 'addr', 'del', cidr, 'dev',
self.interface])
def _bringup_static_routes(self):
# static_routes = [("169.254.169.254/32", "130.56.248.255"),
# ("0.0.0.0/0", "130.56.240.1")]
for net_address, gateway in self.static_routes:
via_arg = []
if gateway != "0.0.0.0/0":
via_arg = ['via', gateway]
subp.subp(
['ip', '-4', 'route', 'add', net_address] + via_arg +
['dev', self.interface], capture=True)
self.cleanup_cmds.insert(
0, ['ip', '-4', 'route', 'del', net_address] + via_arg +
['dev', self.interface])
def _bringup_router(self):
"""Perform the ip commands to fully setup the router if needed."""
# Check if a default route exists and exit if it does
out, _ = subp.subp(['ip', 'route', 'show', '0.0.0.0/0'], capture=True)
if 'default' in out:
LOG.debug(
'Skip ephemeral route setup. %s already has default route: %s',
self.interface, out.strip())
return
subp.subp(
['ip', '-4', 'route', 'add', self.router, 'dev', self.interface,
'src', self.ip], capture=True)
self.cleanup_cmds.insert(
0,
['ip', '-4', 'route', 'del', self.router, 'dev', self.interface,
'src', self.ip])
subp.subp(
['ip', '-4', 'route', 'add', 'default', 'via', self.router,
'dev', self.interface], capture=True)
self.cleanup_cmds.insert(
0, ['ip', '-4', 'route', 'del', 'default', 'dev', self.interface])
class RendererNotFoundError(RuntimeError):
pass
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