T1435 plus other dhcp/dhcpv6-server enhancements

- T1435: dhcp-server: make ip-address optional in static-mapping
- remove [REQUIRED] from dhcpv6-server static-mapping identifier and ipv6-address
- verify if static-mapping ipv6-address is in subnet
- make help and error messages in conf-mode more descriptive
- remove regex ^$ anchors (implied in re.fullmatch)

2 files changed, 26 insertions, 11 deletions

diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py
index 78927a847..6d88ea95a 100755
--- a/src/conf_mode/dhcp_server.py
+++ b/src/conf_mode/dhcp_server.py
@@ -187,7 +187,9 @@ shared-network {{ network.name }} {
         {%- for host in subnet.static_mapping %}
         {% if not host.disabled -%}
         host {% if host_decl_name -%} {{ host.name }} {%- else -%} {{ network.name }}_{{ host.name }} {%- endif %} {
+            {%- if host.ip_address %}
             fixed-address {{ host.ip_address }};
+            {%- endif %}
             hardware ethernet {{ host.mac_address }};
             {%- if host.static_parameters %}
             # The following {{ host.static_parameters | length }} line(s) were added as static-mapping-parameters in the CLI and have not been validated
@@ -728,22 +730,19 @@ def verify(dhcp):
                 raise ConfigError('No DHCP address range or active static-mapping set\n' \
                                   'for subnet {0}!'.format(subnet['network']))
 
-            # Static IP address mappings require both an IP address and MAC address
+            # Static mappings require just a MAC address (will use an IP from the dynamic pool if IP is not set)
             for mapping in subnet['static_mapping']:
-                # Static IP address must be configured
-                if not mapping['ip_address']:
-                    raise ConfigError('DHCP static lease IP address not specified for static mapping\n' \
-                                      '{0} under shared network name {1}!'.format(mapping['name'], network['name']))
 
-                # Static IP address must be in bound
-                if not ipaddress.ip_address(mapping['ip_address']) in ipaddress.ip_network(subnet['network']):
-                    raise ConfigError('DHCP static lease IP address {0} for static mapping {1}\n' \
-                                      'in shared network {2} is outside DHCP lease subnet {3}!' \
-                                      .format(mapping['ip_address'], mapping['name'], network['name'], subnet['network']))
+                if mapping['ip_address']:
+                    # Static IP address must be in bound
+                    if not ipaddress.ip_address(mapping['ip_address']) in ipaddress.ip_network(subnet['network']):
+                        raise ConfigError('DHCP static lease IP address {0} for static mapping {1}\n' \
+                                          'in shared network {2} is outside DHCP lease subnet {3}!' \
+                                          .format(mapping['ip_address'], mapping['name'], network['name'], subnet['network']))
 
                 # Static mapping requires MAC address
                 if not mapping['mac_address']:
-                     raise ConfigError('DHCP static lease MAC address not specified for static mapping\n' \
+                    raise ConfigError('DHCP static lease MAC address not specified for static mapping\n' \
                                        '{0} under shared network name {1}!'.format(mapping['name'], network['name']))
 
             # There must be one subnet connected to a listen interface.
diff --git a/src/conf_mode/dhcpv6_server.py b/src/conf_mode/dhcpv6_server.py
index f5117de53..d2769466e 100755
--- a/src/conf_mode/dhcpv6_server.py
+++ b/src/conf_mode/dhcpv6_server.py
@@ -94,8 +94,12 @@ shared-network {{ network.name }} {
         {%- for host in subnet.static_mapping %}
         {% if not host.disabled -%}
         host {{ network.name }}_{{ host.name }} {
+            {%- if host.client_identifier %}
             host-identifier option dhcp6.client-id {{ host.client_identifier }};
+            {%- endif %}
+            {%- if host.ipv6_address %}
             fixed-address6 {{ host.ipv6_address }};
+            {%- endif %}
         }
         {%- endif %}
         {%- endfor %}
@@ -384,7 +388,19 @@ def verify(dhcpv6):
                         raise ConfigError('DHCPv6 prefix {0} is not in subnet {1}\n' \
                                           'specified for shared network {2}!'.format(prefix['prefix'], subnet['network'], network['name']))
 
+            # Static mappings don't require anything (but check if IP is in subnet if it's set)
+            for mapping in subnet['static_mapping']:
+                if mapping['ipv6_address']:
+                    # Static address must be in subnet
+                    if not ipaddress.ip_address(mapping['ipv6_address']) in ipaddress.ip_network(subnet['network']):
+                        raise ConfigError('DHCPv6 static mapping IPv6 address {0} for static mapping {1}\n' \
+                                          'in shared network {2} is outside subnet {3}!' \
+                                          .format(mapping['ipv6_address'], mapping['name'], network['name'], subnet['network']))
+
         # DHCPv6 requires at least one configured address range or one static mapping
+        # (FIXME: is not actually checked right now?)
+
+        # There must be one subnet connected to a listen interface if network is not disabled.
         if not network['disabled']:
             if vyos.validate.is_subnet_connected(subnet['network']):
                 listen_ok = True