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 --- src/conf_mode/dhcp_server.py | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py index 9be586cdf..1ab2d8d16 100755 --- a/src/conf_mode/dhcp_server.py +++ b/src/conf_mode/dhcp_server.py @@ -26,6 +26,7 @@ from vyos.template import render from vyos.util import call from vyos.util import dict_search from vyos.validate import is_subnet_connected +from vyos.validate import is_addr_assigned from vyos.xml import defaults from vyos import ConfigError from vyos import airbag @@ -246,10 +247,19 @@ def verify(dhcp): if net.overlaps(net2): raise ConfigError('Conflicting subnet ranges: "{net}" overlaps "{net2}"!') + for address in (dict_search('listen_address', dhcp) or []): + if is_addr_assigned(address): + listen_ok = True + # no need to probe further networks, we have one that is valid + continue + else: + raise ConfigError(f'listen-address "{address}" not configured on any interface') + + if not listen_ok: - raise ConfigError('DHCP server configuration error! None of the configured\n' \ - 'subnets have an appropriate primary IP address on any\n' - 'broadcast interface.') + raise ConfigError('None of the configured subnets have an appropriate primary IP address on any\n' + 'broadcast interface configured, nor was there an explicit listen-address\n' + 'configured for serving DHCP relay packets!') return None -- cgit v1.2.3