Merge branch 't4203-dhcp' into current

* t4203-dhcp:
  smoketest: dhcp: T4203: move testcase to base class
  static: T4203: obey interface dhcp default route distance
  interface: T4203: prevent DHCP client restart if not necessary

2 files changed, 95 insertions, 23 deletions

diff --git a/python/vyos/configdict.py b/python/vyos/configdict.py
index e7f515ea9..f2ec93520 100644
--- a/python/vyos/configdict.py
+++ b/python/vyos/configdict.py
@@ -319,34 +319,42 @@ def is_source_interface(conf, interface, intftype=None):
 def get_dhcp_interfaces(conf, vrf=None):
     """ Common helper functions to retrieve all interfaces from current CLI
     sessions that have DHCP configured. """
-    dhcp_interfaces = []
+    dhcp_interfaces = {}
     dict = conf.get_config_dict(['interfaces'], get_first_key=True)
     if not dict:
         return dhcp_interfaces
 
     def check_dhcp(config, ifname):
-        out = []
+        tmp = {}
         if 'address' in config and 'dhcp' in config['address']:
+            options = {}
+            if 'dhcp_options' in config and 'default_route_distance' in config['dhcp_options']:
+                options.update({'distance' : config['dhcp_options']['default_route_distance']})
             if 'vrf' in config:
-                if vrf is config['vrf']: out.append(ifname)
-            else: out.append(ifname)
-        return out
+                if vrf is config['vrf']: tmp.update({ifname : options})
+            else: tmp.update({ifname : options})
+        return tmp
 
     for section, interface in dict.items():
-        for ifname, ifconfig in interface.items():
+        for ifname in interface:
+            # we already have a dict representation of the config from get_config_dict(),
+            # but with the extended information from get_interface_dict() we also
+            # get the DHCP client default-route-distance default option if not specified.
+            ifconfig = get_interface_dict(conf, ['interfaces', section], ifname)
+
             tmp = check_dhcp(ifconfig, ifname)
-            dhcp_interfaces.extend(tmp)
+            dhcp_interfaces.update(tmp)
             # check per VLAN interfaces
             for vif, vif_config in ifconfig.get('vif', {}).items():
                 tmp = check_dhcp(vif_config, f'{ifname}.{vif}')
-                dhcp_interfaces.extend(tmp)
+                dhcp_interfaces.update(tmp)
             # check QinQ VLAN interfaces
             for vif_s, vif_s_config in ifconfig.get('vif-s', {}).items():
                 tmp = check_dhcp(vif_s_config, f'{ifname}.{vif_s}')
-                dhcp_interfaces.extend(tmp)
+                dhcp_interfaces.update(tmp)
                 for vif_c, vif_c_config in vif_s_config.get('vif-c', {}).items():
                     tmp = check_dhcp(vif_c_config, f'{ifname}.{vif_s}.{vif_c}')
-                    dhcp_interfaces.extend(tmp)
+                    dhcp_interfaces.update(tmp)
 
     return dhcp_interfaces
 
@@ -405,6 +413,12 @@ def get_interface_dict(config, base, ifname=''):
     if 'deleted' not in dict:
         dict = dict_merge(default_values, dict)
 
+        # If interface does not request an IPv4 DHCP address there is no need
+        # to keep the dhcp-options key
+        if 'address' not in dict or 'dhcp' not in dict['address']:
+            if 'dhcp_options' in dict:
+                del dict['dhcp_options']
+
     # XXX: T2665: blend in proper DHCPv6-PD default values
     dict = T2665_set_dhcpv6pd_defaults(dict)
 
@@ -423,6 +437,15 @@ def get_interface_dict(config, base, ifname=''):
     bond = is_member(config, ifname, 'bonding')
     if bond: dict.update({'is_bond_member' : bond})
 
+    # Check if any DHCP options changed which require a client restat
+    for leaf_node in ['client-id', 'default-route-distance', 'host-name',
+                 'no-default-route', 'vendor-class-id']:
+        dhcp = leaf_node_changed(config, ['dhcp-options', leaf_node])
+        if dhcp:
+            dict.update({'dhcp_options_old' : dhcp})
+            # one option is suffiecient to set 'dhcp_options_old' key
+            break
+
     # Some interfaces come with a source_interface which must also not be part
     # of any other bond or bridge interface as it is exclusivly assigned as the
     # Kernels "lower" interface to this new "virtual/upper" interface.
@@ -466,10 +489,25 @@ def get_interface_dict(config, base, ifname=''):
             # XXX: T2665: blend in proper DHCPv6-PD default values
             dict['vif'][vif] = T2665_set_dhcpv6pd_defaults(dict['vif'][vif])
 
+            # If interface does not request an IPv4 DHCP address there is no need
+            # to keep the dhcp-options key
+            if 'address' not in dict['vif'][vif] or 'dhcp' not in dict['vif'][vif]['address']:
+                if 'dhcp_options' in dict['vif'][vif]:
+                    del dict['vif'][vif]['dhcp_options']
+
         # Check if we are a member of a bridge device
         bridge = is_member(config, f'{ifname}.{vif}', 'bridge')
         if bridge: dict['vif'][vif].update({'is_bridge_member' : bridge})
 
+        # Check if any DHCP options changed which require a client restat
+        for leaf_node in ['client-id', 'default-route-distance', 'host-name',
+                     'no-default-route', 'vendor-class-id']:
+            dhcp = leaf_node_changed(config, ['vif', vif, 'dhcp-options', leaf_node])
+            if dhcp:
+                dict['vif'][vif].update({'dhcp_options_old' : dhcp})
+                # one option is suffiecient to set 'dhcp_options_old' key
+                break
+
     for vif_s, vif_s_config in dict.get('vif_s', {}).items():
         default_vif_s_values = defaults(base + ['vif-s'])
         # XXX: T2665: we only wan't the vif-s defaults - do not care about vif-c
@@ -491,10 +529,26 @@ def get_interface_dict(config, base, ifname=''):
             # XXX: T2665: blend in proper DHCPv6-PD default values
             dict['vif_s'][vif_s] = T2665_set_dhcpv6pd_defaults(dict['vif_s'][vif_s])
 
+            # If interface does not request an IPv4 DHCP address there is no need
+            # to keep the dhcp-options key
+            if 'address' not in dict['vif_s'][vif_s] or 'dhcp' not in \
+                dict['vif_s'][vif_s]['address']:
+                if 'dhcp_options' in dict['vif_s'][vif_s]:
+                    del dict['vif_s'][vif_s]['dhcp_options']
+
         # Check if we are a member of a bridge device
         bridge = is_member(config, f'{ifname}.{vif_s}', 'bridge')
         if bridge: dict['vif_s'][vif_s].update({'is_bridge_member' : bridge})
 
+        # Check if any DHCP options changed which require a client restat
+        for leaf_node in ['client-id', 'default-route-distance', 'host-name',
+                     'no-default-route', 'vendor-class-id']:
+            dhcp = leaf_node_changed(config, ['vif-s', vif_s, 'dhcp-options', leaf_node])
+            if dhcp:
+                dict['vif_s'][vif_s].update({'dhcp_options_old' : dhcp})
+                # one option is suffiecient to set 'dhcp_options_old' key
+                break
+
         for vif_c, vif_c_config in vif_s_config.get('vif_c', {}).items():
             default_vif_c_values = defaults(base + ['vif-s', 'vif-c'])
 
@@ -516,11 +570,28 @@ def get_interface_dict(config, base, ifname=''):
                 dict['vif_s'][vif_s]['vif_c'][vif_c] = T2665_set_dhcpv6pd_defaults(
                     dict['vif_s'][vif_s]['vif_c'][vif_c])
 
+                # If interface does not request an IPv4 DHCP address there is no need
+                # to keep the dhcp-options key
+                if 'address' not in dict['vif_s'][vif_s]['vif_c'][vif_c] or 'dhcp' \
+                    not in dict['vif_s'][vif_s]['vif_c'][vif_c]['address']:
+                    if 'dhcp_options' in dict['vif_s'][vif_s]['vif_c'][vif_c]:
+                        del dict['vif_s'][vif_s]['vif_c'][vif_c]['dhcp_options']
+
             # Check if we are a member of a bridge device
             bridge = is_member(config, f'{ifname}.{vif_s}.{vif_c}', 'bridge')
             if bridge: dict['vif_s'][vif_s]['vif_c'][vif_c].update(
                 {'is_bridge_member' : bridge})
 
+            # Check if any DHCP options changed which require a client restat
+            for leaf_node in ['client-id', 'default-route-distance', 'host-name',
+                         'no-default-route', 'vendor-class-id']:
+                dhcp = leaf_node_changed(config, ['vif-s', vif_s, 'vif-c', vif_c,
+                                                  'dhcp-options', leaf_node])
+                if dhcp:
+                    dict['vif_s'][vif_s]['vif_c'][vif_c].update({'dhcp_options_old' : dhcp})
+                    # one option is suffiecient to set 'dhcp_options_old' key
+                    break
+
     # Check vif, vif-s/vif-c VLAN interfaces for removal
     dict = get_removed_vlans(config, dict)
     return dict
@@ -545,7 +616,6 @@ def get_vlan_ids(interface):
 
     return vlan_ids
 
-
 def get_accel_dict(config, base, chap_secrets):
     """
     Common utility function to retrieve and mangle the Accel-PPP configuration
diff --git a/python/vyos/ifconfig/interface.py b/python/vyos/ifconfig/interface.py
index 91c7f0c33..cf1887bf6 100755
--- a/python/vyos/ifconfig/interface.py
+++ b/python/vyos/ifconfig/interface.py
@@ -1228,12 +1228,11 @@ class Interface(Control):
         options_file = f'{config_base}_{ifname}.options'
         pid_file = f'{config_base}_{ifname}.pid'
         lease_file = f'{config_base}_{ifname}.leases'
-
-        # Stop client with old config files to get the right IF_METRIC.
         systemd_service = f'dhclient@{ifname}.service'
-        if is_systemd_service_active(systemd_service):
-            self._cmd(f'systemctl stop {systemd_service}')
 
+        # 'up' check is mandatory b/c even if the interface is A/D, as soon as
+        # the DHCP client is started the interface will be placed in u/u state.
+        # This is not what we intended to do when disabling an interface.
         if enable and 'disable' not in self._config:
             if dict_search('dhcp_options.host_name', self._config) == None:
                 # read configured system hostname.
@@ -1244,16 +1243,19 @@ class Interface(Control):
                     tmp = {'dhcp_options' : { 'host_name' : hostname}}
                     self._config = dict_merge(tmp, self._config)
 
-            render(options_file, 'dhcp-client/daemon-options.tmpl',
-                   self._config)
-            render(config_file, 'dhcp-client/ipv4.tmpl',
-                   self._config)
+            render(options_file, 'dhcp-client/daemon-options.tmpl', self._config)
+            render(config_file, 'dhcp-client/ipv4.tmpl', self._config)
 
-            # 'up' check is mandatory b/c even if the interface is A/D, as soon as
-            # the DHCP client is started the interface will be placed in u/u state.
-            # This is not what we intended to do when disabling an interface.
-            return self._cmd(f'systemctl restart {systemd_service}')
+            # When the DHCP client is restarted a brief outage will occur, as
+            # the old lease is released a new one is acquired (T4203). We will
+            # only restart DHCP client if it's option changed, or if it's not
+            # running, but it should be running (e.g. on system startup)
+            if 'dhcp_options_old' in self._config or not is_systemd_service_active(systemd_service):
+                return self._cmd(f'systemctl restart {systemd_service}')
+            return None
         else:
+            if is_systemd_service_active(systemd_service):
+                self._cmd(f'systemctl stop {systemd_service}')
             # cleanup old config files
             for file in [config_file, options_file, pid_file, lease_file]:
                 if os.path.isfile(file):