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# Copyright 2018 VyOS maintainers and contributors <maintainers@vyos.io>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library. If not, see <http://www.gnu.org/licenses/>.
import socket
import netifaces
import ipaddress
def is_ip(addr):
"""
Check addr if it is an IPv4 or IPv6 address
"""
return is_ipv4(addr) or is_ipv6(addr)
def is_ipv4(addr):
"""
Check addr if it is an IPv4 address/network. Returns True/False
"""
# With the below statement we can check for IPv4 networks and host
# addresses at the same time
try:
if ipaddress.ip_address(addr.split(r'/')[0]).version == 4:
return True
except:
pass
return False
def is_ipv6(addr):
"""
Check addr if it is an IPv6 address/network. Returns True/False
"""
# With the below statement we can check for IPv4 networks and host
# addresses at the same time
try:
if ipaddress.ip_network(addr.split(r'/')[0]).version == 6:
return True
except:
pass
return False
def is_ipv6_link_local(addr):
"""
Check addr if it is an IPv6 link-local address/network. Returns True/False
"""
addr = addr.split('%')[0]
if is_ipv6(addr):
if ipaddress.IPv6Address(addr).is_link_local:
return True
return False
def is_intf_addr_assigned(intf, addr):
"""
Verify if the given IPv4/IPv6 address is assigned to specific interface.
It can check both a single IP address (e.g. 192.0.2.1 or a assigned CIDR
address 192.0.2.1/24.
"""
# determine IP version (AF_INET or AF_INET6) depending on passed address
addr_type = netifaces.AF_INET
if is_ipv6(addr):
addr_type = netifaces.AF_INET6
# check if the requested address type is configured at all
try:
netifaces.ifaddresses(intf)
except ValueError as e:
print(e)
return False
addr_host, addr_mask = addr.split('/')
if addr_type in netifaces.ifaddresses(intf).keys():
# Check every IP address on this interface for a match
for ip in netifaces.ifaddresses(intf)[addr_type]:
# Check if it matches to the address requested
# If passed address contains a '/' indicating a normalized IP
# address we have to take this into account, too
if r'/' in addr:
prefixlen = ''
if is_ipv6(addr):
# Note that currently expanded netmasks are not supported. That means
# 2001:db00::0/24 is a valid argument while 2001:db00::0/ffff:ff00:: not.
# see https://docs.python.org/3/library/ipaddress.html
bits = bin( int(ip['netmask'].replace(':',''), 16) ).count('1')
prefixlen = str(bits)
else:
prefixlen = str(ipaddress.IPv4Network('0.0.0.0/' + ip['netmask']).prefixlen)
# the netmask are different
if prefixlen != addr_mask:
continue
addr_af = socket.AF_INET if is_ipv4(addr_host) else socket.AF_INET6
ip_af = socket.AF_INET if is_ipv4(ip['addr']) else socket.AF_INET6
# compare the binary representation of the IP
if socket.inet_pton(addr_af, addr_host) == socket.inet_pton(ip_af, ip['addr']):
return True
return False
def is_addr_assigned(addr):
"""
Verify if the given IPv4/IPv6 address is assigned to any interface
"""
for intf in netifaces.interfaces():
tmp = is_intf_addr_assigned(intf, addr)
if tmp == True:
return True
return False
def is_loopback_addr(addr):
"""
Check if supplied IPv4/IPv6 address is a loopback address
"""
return ipaddress.ip_address(addr).is_loopback
def is_subnet_connected(subnet, primary=False):
"""
Verify is the given IPv4/IPv6 subnet is connected to any interface on this
system.
primary check if the subnet is reachable via the primary IP address of this
interface, or in other words has a broadcast address configured. ISC DHCP
for instance will complain if it should listen on non broadcast interfaces.
Return True/False
"""
# determine IP version (AF_INET or AF_INET6) depending on passed address
addr_type = netifaces.AF_INET
if is_ipv6(subnet):
addr_type = netifaces.AF_INET6
for interface in netifaces.interfaces():
# check if the requested address type is configured at all
if addr_type not in netifaces.ifaddresses(interface).keys():
continue
# An interface can have multiple addresses, but some software components
# only support the primary address :(
if primary:
ip = netifaces.ifaddresses(interface)[addr_type][0]['addr']
if ipaddress.ip_address(ip) in ipaddress.ip_network(subnet):
return True
else:
# Check every assigned IP address if it is connected to the subnet
# in question
for ip in netifaces.ifaddresses(interface)[addr_type]:
# remove interface extension (e.g. %eth0) that gets thrown on the end of _some_ addrs
addr = ip['addr'].split('%')[0]
if ipaddress.ip_address(addr) in ipaddress.ip_network(subnet):
return True
return False
def assert_boolean(b):
if int(b) not in (0, 1):
raise ValueError(f'Value {b} out of range')
def assert_range(value, lower=0, count=3):
if int(value) not in range(lower,lower+count):
raise ValueError("Value out of range")
def assert_list(s, l):
if s not in l:
o = ' or '.join([f'"{n}"' for n in l])
raise ValueError(f'state must be {o}, got {s}')
def assert_number(n):
if not str(n).isnumeric():
raise ValueError(f'{n} must be a number')
def assert_positive(n, smaller=0):
assert_number(n)
if int(n) < smaller:
raise ValueError(f'{n} is smaller than {limit}')
def assert_mtu(mtu, min=68, max=9000):
assert_number(mtu)
if int(mtu) < min or int(mtu) > max:
raise ValueError(f'Invalid MTU size: "{mtu}"')
def assert_mac(m):
split = m.split(':')
size = len(split)
# a mac address consits out of 6 octets
if size != 6:
raise ValueError(f'wrong number of MAC octets ({size}): {m}')
octets = []
try:
for octet in split:
octets.append(int(octet, 16))
except ValueError:
raise ValueError(f'invalid hex number "{octet}" in : {m}')
# validate against the first mac address byte if it's a multicast
# address
if octets[0] & 1:
raise ValueError(f'{m} is a multicast MAC address')
# overall mac address is not allowed to be 00:00:00:00:00:00
if sum(octets) == 0:
raise ValueError('00:00:00:00:00:00 is not a valid MAC address')
if octets[:5] == (0, 0, 94, 0, 1):
raise ValueError(f'{m} is a VRRP MAC address')
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