bgp: T5338: Added 'protocols bgp interface <int> mpls forwarding' feature

Added 'protocols bgp interface <int> mpls forwarding' feature.
It is possible to permit BGP install VPN prefixes without transport labels.
This configuration will install VPN prefixes originated from an e-bgp session,
and with the next-hop directly connected.

4 files changed, 117 insertions, 2 deletions

diff --git a/data/templates/frr/bgpd.frr.j2 b/data/templates/frr/bgpd.frr.j2
index 3e101820c..9cfc8b7cd 100644
--- a/data/templates/frr/bgpd.frr.j2
+++ b/data/templates/frr/bgpd.frr.j2
@@ -565,3 +565,13 @@ bgp route-reflector allow-outbound-policy
  timers bgp {{ timers.keepalive }} {{ timers.holdtime }}
 {% endif %}
 exit
+{% if interface is vyos_defined %}
+{%     for iface, iface_config in interface.items() %}
+ interface {{ iface }}
+{%         if iface_config.mpls.forwarding is vyos_defined %}
+ mpls bgp forwarding
+{%         endif %}
+ exit
+ !
+{%     endfor %}
+{% endif %}
diff --git a/interface-definitions/include/bgp/protocol-common-config.xml.i b/interface-definitions/include/bgp/protocol-common-config.xml.i
index d69fd7dab..f95031a75 100644
--- a/interface-definitions/include/bgp/protocol-common-config.xml.i
+++ b/interface-definitions/include/bgp/protocol-common-config.xml.i
@@ -873,6 +873,36 @@
     </node>
   </children>
 </node>
+<tagNode name="interface">
+  <properties>
+    <help>Enable MPLS on Interface</help>
+    <completionHelp>
+      <script>${vyos_completion_dir}/list_interfaces</script>
+    </completionHelp>
+    <valueHelp>
+      <format>txt</format>
+      <description>Interface name</description>
+    </valueHelp>
+    <constraint>
+      #include <include/constraint/interface-name.xml.i>
+    </constraint>
+  </properties>
+  <children>
+    <node name="mpls">
+      <properties>
+        <help> MPLS options</help>
+      </properties>
+      <children>
+        <leafNode name="forwarding">
+          <properties>
+            <help> Enable MPLS forwarding for eBGP directly connected peers</help>
+            <valueless/>
+          </properties>
+        </leafNode>
+      </children>
+    </node>
+  </children>
+</tagNode>
 <node name="listen">
   <properties>
     <help>Listen for and accept BGP dynamic neighbors from range</help>
diff --git a/smoketest/scripts/cli/test_protocols_bgp.py b/smoketest/scripts/cli/test_protocols_bgp.py
index 2fd5d0c9b..f4801486a 100755
--- a/smoketest/scripts/cli/test_protocols_bgp.py
+++ b/smoketest/scripts/cli/test_protocols_bgp.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2021-2022 VyOS maintainers and contributors
+# Copyright (C) 2021-2023 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -18,6 +18,7 @@ import unittest
 
 from base_vyostest_shim import VyOSUnitTestSHIM
 
+from vyos.ifconfig import Section
 from vyos.configsession import ConfigSessionError
 from vyos.template import is_ipv6
 from vyos.util import process_named_running
@@ -1072,5 +1073,38 @@ class TestProtocolsBGP(VyOSUnitTestSHIM.TestCase):
         with self.assertRaises(ConfigSessionError):
             self.cli_commit()
 
+    def test_bgp_22_interface_mpls_forwarding(self):
+        interfaces = Section.interfaces('ethernet')
+        self.cli_set(base_path + ['system-as', ASN])
+        for interface in interfaces:
+            self.cli_set(
+                base_path + ['interface', interface, 'mpls', 'forwarding'])
+        self.cli_commit()
+
+        for interface in interfaces:
+            frrconfig = self.getFRRconfig(f'interface {interface}')
+            self.assertIn(f'interface {interface}', frrconfig)
+            self.assertIn(f' mpls bgp forwarding', frrconfig)
+
+    def test_bgp_23_vrf_interface_mpls_forwarding(self):
+        self.create_bgp_instances_for_import_test()
+        interfaces = Section.interfaces('ethernet')
+        for interface in interfaces:
+            self.cli_set(
+                ['interfaces', 'ethernet', interface, 'vrf', import_vrf])
+            self.cli_set(
+                import_vrf_base + [import_vrf] + base_path + ['interface',
+                                                              interface,
+                                                              'mpls',
+                                                              'forwarding'])
+        self.cli_commit()
+
+        for interface in interfaces:
+            frrconfig = self.getFRRconfig(f'interface {interface}')
+            self.assertIn(f'interface {interface}', frrconfig)
+            self.assertIn(f' mpls bgp forwarding', frrconfig)
+            self.cli_delete(['interfaces', 'ethernet', interface, 'vrf'])
+
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/src/conf_mode/protocols_bgp.py b/src/conf_mode/protocols_bgp.py
index b23584bdb..532970735 100755
--- a/src/conf_mode/protocols_bgp.py
+++ b/src/conf_mode/protocols_bgp.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020-2022 VyOS maintainers and contributors
+# Copyright (C) 2020-2023 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -20,6 +20,7 @@ from sys import argv
 from vyos.base import Warning
 from vyos.config import Config
 from vyos.configdict import dict_merge
+from vyos.configdict import node_changed
 from vyos.configverify import verify_prefix_list
 from vyos.configverify import verify_route_map
 from vyos.configverify import verify_vrf
@@ -27,6 +28,7 @@ from vyos.template import is_ip
 from vyos.template import is_interface
 from vyos.template import render_to_string
 from vyos.util import dict_search
+from vyos.util import get_interface_config
 from vyos.validate import is_addr_assigned
 from vyos import ConfigError
 from vyos import frr
@@ -54,6 +56,20 @@ def get_config(config=None):
                                                  key_mangling=('-', '_'),
                                                  get_first_key=True,
                                                  no_tag_node_value_mangle=True)
+    # if config removed
+    interfaces_removed = node_changed(conf, base + ['interface'])
+    if interfaces_removed:
+        bgp['interface_removed'] = list(interfaces_removed)
+    # Add vrf mapping in <bgp interface ifname>
+    if 'interface' in bgp:
+        for interface in bgp['interface']:
+            tmp = get_interface_config(interface)
+            if dict_search('linkinfo.info_slave_kind', tmp) and \
+                    tmp['linkinfo']['info_slave_kind'] == 'vrf':
+                if 'master' in tmp:
+                    bgp['interface'][interface]['applied_vrf'] = tmp['master']
+            else:
+                bgp['interface'][interface]['applied_vrf'] = 'default'
 
     # Assign the name of our VRF context. This MUST be done before the return
     # statement below, else on deletion we will delete the default instance
@@ -231,6 +247,23 @@ def verify(bgp):
     if 'system_as' not in bgp:
         raise ConfigError('BGP system-as number must be defined!')
 
+    # Verify vrf on interface and bgp section
+    if 'interface' in bgp:
+        for interface in dict_search('interface', bgp):
+            if dict_search(f'interface.{interface}.mpls', bgp):
+                if 'forwarding' in bgp['interface'][interface]['mpls']:
+                    if 'vrf' in bgp:
+                        if bgp['interface'][interface]['applied_vrf'] != bgp['vrf']:
+                            raise ConfigError(
+                                f'Can not set mpls forwarding. Interface {interface} in different vrf')
+                    else:
+                        if bgp['interface'][interface]['applied_vrf'] != 'default':
+                            raise ConfigError(
+                                f'Can not set mpls forwarding. Interface {interface} in different vrf')
+            else:
+                raise ConfigError(
+                    f'<protocols bgp interface {interface}> command should have options')
+
     # Common verification for both peer-group and neighbor statements
     for neighbor in ['neighbor', 'peer_group']:
         # bail out early if there is no neighbor or peer-group statement
@@ -520,6 +553,14 @@ def apply(bgp):
         vrf = ' vrf ' + bgp['vrf']
 
     frr_cfg.load_configuration(bgp_daemon)
+
+    #If bgp interface config removed
+    for key in ['interface', 'interface_removed']:
+        if key not in bgp:
+            continue
+        for interface in bgp[key]:
+            frr_cfg.modify_section(f'^interface {interface}', stop_pattern='^exit', remove_stop_mark=True)
+
     frr_cfg.modify_section(f'^router bgp \d+{vrf}', stop_pattern='^exit', remove_stop_mark=True)
     if 'frr_bgpd_config' in bgp:
         frr_cfg.add_before(frr.default_add_before, bgp['frr_bgpd_config'])