dhcp: T3316: Support hostname, DUID and MAC address in reservation

Reinstate support for hostname in DHCP reservation. Having `hostname` in
allows for server-side assignment of hostname. This is useful for static
lookup of hostname.

Ensure that hostname is a valid FQDN (doesn't have underscore, etc.)

Additionally, support using either of DUID or MAC address for
reservation. While MAC address is typically used for IPv4, and DUID is
typically used for IPv6, either of them can be used in IPv4 and IPv6
reservations in Kea.

5 files changed, 40 insertions, 45 deletions

diff --git a/interface-definitions/dhcp-server.xml.in b/interface-definitions/dhcp-server.xml.in
index 081f7ed42..8aaeeb29d 100644
--- a/interface-definitions/dhcp-server.xml.in
+++ b/interface-definitions/dhcp-server.xml.in
@@ -284,11 +284,11 @@
                   </tagNode>
                   <tagNode name="static-mapping">
                     <properties>
-                      <help>Name of static mapping</help>
+                      <help>Hostname for static mapping reservation</help>
                       <constraint>
-                        <regex>[-_a-zA-Z0-9.]+</regex>
+                        <validator name="fqdn"/>
                       </constraint>
-                      <constraintErrorMessage>Invalid static mapping name, may only be alphanumeric, dot and hyphen</constraintErrorMessage>
+                      <constraintErrorMessage>Invalid static mapping hostname</constraintErrorMessage>
                     </properties>
                     <children>
                       #include <include/generic-disable-node.xml.i>
@@ -304,18 +304,8 @@
                           </constraint>
                         </properties>
                       </leafNode>
-                      <leafNode name="mac-address">
-                        <properties>
-                          <help>Media Access Control (MAC) address</help>
-                          <valueHelp>
-                            <format>macaddr</format>
-                            <description>Hardware (MAC) address</description>
-                          </valueHelp>
-                          <constraint>
-                            <validator name="mac-address"/>
-                          </constraint>
-                        </properties>
-                      </leafNode>
+                      #include <include/interface/mac.xml.i>
+                      #include <include/interface/duid.xml.i>
                     </children>
                   </tagNode>
                   <tagNode name="static-route">
diff --git a/interface-definitions/dhcpv6-server.xml.in b/interface-definitions/dhcpv6-server.xml.in
index b37f79434..10fdbf3f7 100644
--- a/interface-definitions/dhcpv6-server.xml.in
+++ b/interface-definitions/dhcpv6-server.xml.in
@@ -301,27 +301,16 @@
                   </leafNode>
                   <tagNode name="static-mapping">
                     <properties>
-                      <help>Name of static mapping</help>
+                      <help>Hostname for static mapping reservation</help>
                       <constraint>
-                        <regex>[-_a-zA-Z0-9.]+</regex>
+                        <validator name="fqdn"/>
                       </constraint>
-                      <constraintErrorMessage>Invalid static mapping name. May only contain letters, numbers and .-_</constraintErrorMessage>
+                      <constraintErrorMessage>Invalid static mapping hostname</constraintErrorMessage>
                     </properties>
                     <children>
                       #include <include/generic-disable-node.xml.i>
-                      <leafNode name="identifier">
-                        <properties>
-                          <help>Client identifier (DUID) for this static mapping</help>
-                          <valueHelp>
-                            <format>h[[:h]...]</format>
-                            <description>DUID: colon-separated hex list (as used by isc-dhcp option dhcpv6.client-id)</description>
-                          </valueHelp>
-                          <constraint>
-                            <regex>([0-9A-Fa-f]{1,2}[:])*([0-9A-Fa-f]{1,2})</regex>
-                          </constraint>
-                          <constraintErrorMessage>Invalid DUID, must be in the format h[[:h]...]</constraintErrorMessage>
-                        </properties>
-                      </leafNode>
+                      #include <include/interface/mac.xml.i>
+                      #include <include/interface/duid.xml.i>
                       <leafNode name="ipv6-address">
                         <properties>
                           <help>Client IPv6 address for this static mapping</help>
diff --git a/python/vyos/kea.py b/python/vyos/kea.py
index 4a517da5f..819fe16a9 100644
--- a/python/vyos/kea.py
+++ b/python/vyos/kea.py
@@ -121,14 +121,20 @@ def kea_parse_subnet(subnet, config):
             if 'disable' in host_config:
                 continue
 
-            obj = {
-                'hw-address': host_config['mac_address']
+            reservation = {
+                'hostname': host,
             }
 
+            if 'mac' in host_config:
+                reservation['hw-address'] = host_config['mac']
+
+            if 'duid' in host_config:
+                reservation['duid'] = host_config['duid']
+
             if 'ip_address' in host_config:
-                obj['ip-address'] = host_config['ip_address']
+                reservation['ip-address'] = host_config['ip_address']
 
-            reservations.append(obj)
+            reservations.append(reservation)
         out['reservations'] = reservations
 
     unifi_controller = dict_search_args(config, 'vendor_option', 'ubiquiti', 'unifi_controller')
@@ -178,7 +184,7 @@ def kea6_parse_options(config):
 
         if addrs:
             options.append({'name': 'sip-server-addr', 'data': ", ".join(addrs)})
-        
+
         if hosts:
             options.append({'name': 'sip-server-dns', 'data': ", ".join(hosts)})
 
@@ -234,10 +240,15 @@ def kea6_parse_subnet(subnet, config):
             if 'disable' in host_config:
                 continue
 
-            reservation = {}
+            reservation = {
+                'hostname': host
+            }
+
+            if 'mac' in host_config:
+                reservation['hw-address'] = host_config['mac']
 
-            if 'identifier' in host_config:
-                reservation['duid'] = host_config['identifier']
+            if 'duid' in host_config:
+                reservation['duid'] = host_config['duid']
 
             if 'ipv6_address' in host_config:
                 reservation['ip-addresses'] = [ host_config['ipv6_address'] ]
@@ -305,7 +316,7 @@ def kea_get_active_config(inet):
     ctrl_socket = f'/run/kea/dhcp{inet}-ctrl-socket'
 
     config = _ctrl_socket_command(ctrl_socket, 'config-get')
-    
+
     if not config or 'result' not in config or config['result'] != 0:
         return None
 
diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py
index 958e90014..abccdb6a9 100755
--- a/src/conf_mode/dhcp_server.py
+++ b/src/conf_mode/dhcp_server.py
@@ -18,7 +18,6 @@ import os
 
 from ipaddress import ip_address
 from ipaddress import ip_network
-from netaddr import IPAddress
 from netaddr import IPRange
 from sys import exit
 
@@ -141,7 +140,7 @@ def get_config(config=None):
                                 {'range' : new_range_dict})
 
     if dict_search('failover.certificate', dhcp):
-        dhcp['pki'] = conf.get_config_dict(['pki'], key_mangling=('-', '_'), get_first_key=True, no_tag_node_value_mangle=True) 
+        dhcp['pki'] = conf.get_config_dict(['pki'], key_mangling=('-', '_'), get_first_key=True, no_tag_node_value_mangle=True)
 
     return dhcp
 
@@ -226,9 +225,10 @@ def verify(dhcp):
                             raise ConfigError(f'Configured static lease address for mapping "{mapping}" is\n' \
                                               f'not within shared-network "{network}, {subnet}"!')
 
-                        if 'mac_address' not in mapping_config:
-                            raise ConfigError(f'MAC address required for static mapping "{mapping}"\n' \
-                                              f'within shared-network "{network}, {subnet}"!')
+                        if ('mac' not in mapping_config and 'duid' not in mapping_config) or \
+                            ('mac' in mapping_config and 'duid' in mapping_config):
+                            raise ConfigError(f'Either MAC address or Client identifier (DUID) is required for '
+                                              f'static mapping "{mapping}" within shared-network "{network}, {subnet}"!')
 
             # There must be one subnet connected to a listen interface.
             # This only counts if the network itself is not disabled!
diff --git a/src/conf_mode/dhcpv6_server.py b/src/conf_mode/dhcpv6_server.py
index b01f510e5..f9da3d84a 100755
--- a/src/conf_mode/dhcpv6_server.py
+++ b/src/conf_mode/dhcpv6_server.py
@@ -135,6 +135,11 @@ def verify(dhcpv6):
                         if ip_address(mapping_config['ipv6_address']) not in ip_network(subnet):
                             raise ConfigError(f'static-mapping address for mapping "{mapping}" is not in subnet "{subnet}"!')
 
+                        if ('mac' not in mapping_config and 'duid' not in mapping_config) or \
+                            ('mac' in mapping_config and 'duid' in mapping_config):
+                            raise ConfigError(f'Either MAC address or Client identifier (DUID) is required for '
+                                              f'static mapping "{mapping}" within shared-network "{network}, {subnet}"!')
+
             if 'vendor_option' in subnet_config:
                 if len(dict_search('vendor_option.cisco.tftp_server', subnet_config)) > 2:
                     raise ConfigError(f'No more then two Cisco tftp-servers should be defined for subnet "{subnet}"!')