From eecec6b5caeaef14a03ddbb1d09f9c599273b998 Mon Sep 17 00:00:00 2001 From: Christian Poessinger Date: Sun, 6 Dec 2020 13:44:56 +0100 Subject: dhcp: T2562: add "listen-address" CLI node for better DHCP relay support Running ISC DHCP server as backend server for multiple pools served to relay agents requires DHCPd to explicitly listen on give interfaces or a "transit" subnet declaration facing the network where we receive the DHCPREQ messages on. This implements a new "listen-address" CLI node, the given address is validated if it is assigned to the system and upon success, a proper "subnet { }" statement is added into dhcpd.conf --- python/vyos/template.py | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-) (limited to 'python') diff --git a/python/vyos/template.py b/python/vyos/template.py index 5993ffd95..63d400642 100644 --- a/python/vyos/template.py +++ b/python/vyos/template.py @@ -123,23 +123,56 @@ def render( ################################## @register_filter('address_from_cidr') -def address_from_cidr(text): +def address_from_cidr(prefix): """ Take an IPv4/IPv6 CIDR prefix and convert the network to an "address". Example: 192.0.2.0/24 -> 192.0.2.0, 2001:db8::/48 -> 2001:db8:: """ from ipaddress import ip_network - return str(ip_network(text).network_address) + return str(ip_network(prefix).network_address) @register_filter('netmask_from_cidr') -def netmask_from_cidr(text): +def netmask_from_cidr(prefix): """ Take CIDR prefix and convert the prefix length to a "subnet mask". Example: - 192.0.2.0/24 -> 255.255.255.0 - 2001:db8::/48 -> ffff:ffff:ffff:: """ from ipaddress import ip_network - return str(ip_network(text).netmask) + return str(ip_network(prefix).netmask) + +@register_filter('netmask_from_ipv4') +def netmask_from_ipv4(address): + """ Take IP address and search all attached interface IP addresses for the + given one. After address has been found, return the associated netmask. + + Example: + - 172.18.201.10 -> 255.255.255.128 + """ + from netifaces import interfaces, ifaddresses, AF_INET + for interface in interfaces(): + tmp = ifaddresses(interface) + if AF_INET in tmp: + for af_addr in tmp[AF_INET]: + if 'addr' in af_addr: + if af_addr['addr'] == address: + return af_addr['netmask'] + + raise ValueError + +@register_filter('network_from_ipv4') +def network_from_ipv4(address): + """ Take IP address and search all attached interface IP addresses for the + given one. After address has been found, return the associated network + address. + + Example: + - 172.18.201.10 has mask 255.255.255.128 -> network is 172.18.201.0 + """ + netmask = netmask_from_ipv4(address) + from ipaddress import ip_interface + cidr_prefix = ip_interface(f'{address}/{netmask}').network + return address_from_cidr(cidr_prefix) @register_filter('is_ip') def is_ip(addr): -- cgit v1.2.3