dhcpv6-relay: T3095: improve verify()

- Upstream interfaces require a DHCPv6 server to be configured
- Listen interface must have a a global unicast address assigned, else
  ISC dhcrelay won't start.

3 files changed, 24 insertions, 3 deletions

diff --git a/data/templates/dhcp-relay/dhcrelay6.conf.tmpl b/data/templates/dhcp-relay/dhcrelay6.conf.tmpl
index 165216592..58c216b7c 100644
--- a/data/templates/dhcp-relay/dhcrelay6.conf.tmpl
+++ b/data/templates/dhcp-relay/dhcrelay6.conf.tmpl
@@ -10,7 +10,11 @@
 {# listen_interface is mandatory so it's always present #}
 {% set listen = namespace(value='')  %}
 {% for interface, config in listen_interface.items() %}
-{%   set listen.value = listen.value + '-l ' + config.address + '%' + interface + ' ' %}
+{%   if config.address is defined and config.address is not none %}
+{%     set listen.value = listen.value + '-l ' + config.address + '%' + interface + ' ' %}
+{%   else %}
+{%     set listen.value = listen.value + '-l ' + interface + ' ' %}
+{%   endif %}
 {% endfor %}
 
 OPTIONS="{{ listen.value }} {{ upstream.value }} -c {{ max_hop_count }} {{ '-I' if use_interface_id_option is defined }}"
diff --git a/src/conf_mode/dhcpv6_relay.py b/src/conf_mode/dhcpv6_relay.py
index 9a91ace1c..cf8a26674 100755
--- a/src/conf_mode/dhcpv6_relay.py
+++ b/src/conf_mode/dhcpv6_relay.py
@@ -20,9 +20,11 @@ from sys import exit
 
 from vyos.config import Config
 from vyos.configdict import dict_merge
+from vyos.ifconfig import Interface
 from vyos.template import render
 from vyos.util import call
 from vyos.util import dict_search
+from vyos.validate import is_ipv6_link_local
 from vyos.xml import defaults
 from vyos import ConfigError
 from vyos import airbag
@@ -54,10 +56,25 @@ def verify(relay):
 
     if 'upstream_interface' not in relay:
         raise ConfigError('At least one upstream interface required!')
+    for interface, config in relay['upstream_interface'].items():
+        if 'address' not in config:
+            raise ConfigError('DHCPv6 server required for upstream ' \
+                              f'interface {interface}!')
 
     if 'listen_interface' not in relay:
         raise ConfigError('At least one listen interface required!')
 
+    # DHCPv6 relay requires at least one global unicat address assigned to the
+    # interface
+    for interface in relay['listen_interface']:
+        has_global = False
+        for addr in Interface(interface).get_addr():
+            if not is_ipv6_link_local(addr.split('/')[0]):
+                has_global = True
+        if not has_global:
+            raise ConfigError(f'Interface {interface} does not have global '\
+                              'IPv6 address assigned!')
+
     return None
 
 def generate(relay):
diff --git a/src/systemd/isc-dhcp-relay6.service b/src/systemd/isc-dhcp-relay6.service
index 8788d1ed6..30037e013 100644
--- a/src/systemd/isc-dhcp-relay6.service
+++ b/src/systemd/isc-dhcp-relay6.service
@@ -12,8 +12,8 @@ WorkingDirectory=/run/dhcp-relay
 RuntimeDirectory=dhcp-relay
 RuntimeDirectoryPreserve=yes
 EnvironmentFile=/run/dhcp-relay/dhcrelay6.conf
-PIDFile=/run/dhcp-relay/dhcrelayv6.pid
-ExecStart=/usr/sbin/dhcrelay -6 -pf /run/dhcp-relay/dhcrelayv6.pid $OPTIONS
+PIDFile=/run/dhcp-relay/dhcrelay6.pid
+ExecStart=/usr/sbin/dhcrelay -6 -pf /run/dhcp-relay/dhcrelay6.pid $OPTIONS
 Restart=always
 
 [Install]