OPENVPN: T6555: add server-bridge options in mode server

(cherry picked from commit 4acad3eb8d9be173b76fecafc32b0c70eae9b192)

4 files changed, 130 insertions, 1 deletions

diff --git a/data/templates/openvpn/server.conf.j2 b/data/templates/openvpn/server.conf.j2
index 6ac525443..b6e90ed18 100644
--- a/data/templates/openvpn/server.conf.j2
+++ b/data/templates/openvpn/server.conf.j2
@@ -90,7 +90,9 @@ server-ipv6 {{ subnet }}
 {%                 endif %}
 {%             endfor %}
 {%         endif %}
-
+{%         if server.server_bridge is vyos_defined and server.server_bridge.disable is not vyos_defined %}
+server-bridge {{ server.server_bridge.gateway }} {{ server.server_bridge.subnet_mask }} {{ server.server_bridge.start }} {{ server.server_bridge.stop if server.server_bridge.stop is vyos_defined }}
+{%         endif %}
 {%         if server.client_ip_pool is vyos_defined and server.client_ip_pool.disable is not vyos_defined %}
 ifconfig-pool {{ server.client_ip_pool.start }} {{ server.client_ip_pool.stop }} {{ server.client_ip_pool.subnet_mask if server.client_ip_pool.subnet_mask is vyos_defined }}
 {%         endif %}
diff --git a/interface-definitions/interfaces_openvpn.xml.in b/interface-definitions/interfaces_openvpn.xml.in
index 1860523c2..46c22ac44 100644
--- a/interface-definitions/interfaces_openvpn.xml.in
+++ b/interface-definitions/interfaces_openvpn.xml.in
@@ -445,6 +445,62 @@
                   </leafNode>
                 </children>
               </tagNode>
+              <node name="server-bridge">
+                <properties>
+                  <help>Used with TAP device (layer 2)</help>
+                </properties>
+                <children>
+                  #include <include/generic-disable-node.xml.i>
+                  <leafNode name="start">
+                    <properties>
+                      <help>First IP address in the pool</help>
+                      <constraint>
+                        <validator name="ipv4-address"/>
+                      </constraint>
+                      <valueHelp>
+                        <format>ipv4</format>
+                        <description>IPv4 address</description>
+                      </valueHelp>
+                    </properties>
+                  </leafNode>
+                  <leafNode name="stop">
+                    <properties>
+                      <help>Last IP address in the pool</help>
+                      <constraint>
+                        <validator name="ipv4-address"/>
+                      </constraint>
+                      <valueHelp>
+                        <format>ipv4</format>
+                        <description>IPv4 address</description>
+                      </valueHelp>
+                    </properties>
+                  </leafNode>
+                  <leafNode name="subnet-mask">
+                    <properties>
+                      <help>Subnet mask pushed to dynamic clients.</help>
+                      <constraint>
+                        <validator name="ipv4-address"/>
+                      </constraint>
+                      <valueHelp>
+                        <format>ipv4</format>
+                        <description>IPv4 subnet mask</description>
+                      </valueHelp>
+                    </properties>
+                  </leafNode>
+                  <leafNode name="gateway">
+                    <properties>
+                      <help>Gateway IP address</help>
+                      <constraint>
+                        <validator name="ipv4-address"/>
+                      </constraint>
+                      <valueHelp>
+                        <format>ipv4</format>
+                        <description>IPv4 address</description>
+                      </valueHelp>
+                    </properties>
+                  </leafNode>
+                </children>
+              </node>
               <node name="client-ip-pool">
                 <properties>
                   <help>Pool of client IPv4 addresses</help>
diff --git a/smoketest/scripts/cli/test_interfaces_openvpn.py b/smoketest/scripts/cli/test_interfaces_openvpn.py
index 9ca661e87..53cfa6cf5 100755
--- a/smoketest/scripts/cli/test_interfaces_openvpn.py
+++ b/smoketest/scripts/cli/test_interfaces_openvpn.py
@@ -627,5 +627,60 @@ class TestInterfacesOpenVPN(VyOSUnitTestSHIM.TestCase):
             self.assertNotIn(interface, interfaces())
 
 
+    def test_openvpn_server_server_bridge(self):
+        # Create OpenVPN server interface using server-bridge.
+        # Validate configuration afterwards.
+        br_if = 'br0'
+        vtun_if = 'vtun5010'
+        auth_hash = 'sha256'
+        path = base_path + [vtun_if]
+        start_subnet = "192.168.0.100"
+        stop_subnet = "192.168.0.200"
+        mask_subnet = "255.255.255.0"
+        gw_subnet = "192.168.0.1"
+
+        self.cli_set(['interfaces', 'bridge', br_if, 'member', 'interface', vtun_if])
+        self.cli_set(path + ['device-type', 'tap'])
+        self.cli_set(path + ['encryption', 'data-ciphers', 'aes192'])
+        self.cli_set(path + ['hash', auth_hash])
+        self.cli_set(path + ['mode', 'server'])
+        self.cli_set(path + ['server', 'server-bridge', 'gateway', gw_subnet])
+        self.cli_set(path + ['server', 'server-bridge', 'start', start_subnet])
+        self.cli_set(path + ['server', 'server-bridge', 'stop', stop_subnet])
+        self.cli_set(path + ['server', 'server-bridge', 'subnet-mask', mask_subnet])
+        self.cli_set(path + ['keep-alive', 'failure-count', '5'])
+        self.cli_set(path + ['keep-alive', 'interval', '5'])
+        self.cli_set(path + ['tls', 'ca-certificate', 'ovpn_test'])
+        self.cli_set(path + ['tls', 'certificate', 'ovpn_test'])
+        self.cli_set(path + ['tls', 'dh-params', 'ovpn_test'])
+
+        self.cli_commit()
+
+
+
+        config_file = f'/run/openvpn/{vtun_if}.conf'
+        config = read_file(config_file)
+        self.assertIn(f'dev {vtun_if}', config)
+        self.assertIn(f'dev-type tap', config)
+        self.assertIn(f'proto udp', config) # default protocol
+        self.assertIn(f'auth {auth_hash}', config)
+        self.assertIn(f'data-ciphers AES-192-CBC', config)
+        self.assertIn(f'mode server', config)
+        self.assertIn(f'server-bridge {gw_subnet} {mask_subnet} {start_subnet} {stop_subnet}', config)
+        elf.assertIn(f'keepalive 5 25', config)
+
+
+
+        # TLS options
+        self.assertIn(f'ca /run/openvpn/{vtun_if}_ca.pem', config)
+        self.assertIn(f'cert /run/openvpn/{vtun_if}_cert.pem', config)
+        self.assertIn(f'key /run/openvpn/{vtun_if}_cert.key', config)
+        self.assertIn(f'dh /run/openvpn/{vtun_if}_dh.pem', config)
+
+        # check that no interface remained after deleting them
+        self.cli_delete((['interfaces', 'bridge', br_if, 'member', 'interface', vtun_if])
+        self.cli_delete(base_path)
+        self.cli_commit()
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/src/conf_mode/interfaces_openvpn.py b/src/conf_mode/interfaces_openvpn.py
index 320ab7b7b..fcbba30ce 100755
--- a/src/conf_mode/interfaces_openvpn.py
+++ b/src/conf_mode/interfaces_openvpn.py
@@ -378,6 +378,22 @@ def verify(openvpn):
                 if (client_v.get('ip') and len(client_v['ip']) > 1) or (client_v.get('ipv6_ip') and len(client_v['ipv6_ip']) > 1):
                     raise ConfigError(f'Server client "{client_k}": cannot specify more than 1 IPv4 and 1 IPv6 IP')
 
+        if dict_search('server.server_bridge', openvpn):
+            # check if server-bridge is a tap interfaces
+            if not openvpn['device_type'] == 'tap' and dict_search('server.server_bridge', openvpn):
+               raise ConfigError('Must specify "device-type tap" with server-bridge mode')
+            elif not (dict_search('server.server_bridge.start', openvpn) and dict_search('server.server_bridge.stop', openvpn)):
+                raise ConfigError('Server server-bridge requires both start and stop addresses')
+            else:
+                v4PoolStart = IPv4Address(dict_search('server.server_bridge.start', openvpn))
+                v4PoolStop = IPv4Address(dict_search('server.server_bridge.stop', openvpn))
+                if v4PoolStart > v4PoolStop:
+                    raise ConfigError(f'Server server-bridge start address {v4PoolStart} is larger than stop address {v4PoolStop}')
+
+                v4PoolSize = int(v4PoolStop) - int(v4PoolStart)
+                if v4PoolSize >= 65536:
+                    raise ConfigError(f'Server server_bridge is too large [{v4PoolStart} -> {v4PoolStop} = {v4PoolSize}], maximum is 65536 addresses.')
+
         if dict_search('server.client_ip_pool', openvpn):
             if not (dict_search('server.client_ip_pool.start', openvpn) and dict_search('server.client_ip_pool.stop', openvpn)):
                 raise ConfigError('Server client-ip-pool requires both start and stop addresses')