# 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 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 if ipaddress.ip_address(addr.split(r'/')[0]).version == 4: return True else: 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 if ipaddress.ip_network(addr.split(r'/')[0]).version == 6: return True else: 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 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) # construct temporary variable holding IPv6 address and netmask # in CIDR notation tmp = ip['addr'] + prefixlen if addr == tmp: return True elif ip['addr'] == 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_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