bfd: T4043: add support for passive mode

Mark session as passive: a passive session will not attempt to start the
connection and will wait for control packets from peer before it begins
replying.

This feature is useful when you have a router that acts as the central node of
a star network and you want to avoid sending BFD control packets you don't
need to. The default is active-mode

3 files changed, 22 insertions, 0 deletions

diff --git a/data/templates/frr/bfdd.frr.tmpl b/data/templates/frr/bfdd.frr.tmpl
index dd26b930a..e0e94c24d 100644
--- a/data/templates/frr/bfdd.frr.tmpl
+++ b/data/templates/frr/bfdd.frr.tmpl
@@ -13,6 +13,9 @@ bfd
 {%     if profile_config.echo_mode is defined %}
   echo-mode
 {%     endif %}
+{%     if profile_config.passive is defined %}
+  passive-mode
+{%     endif %}
 {%     if profile_config.shutdown is defined %}
   shutdown
 {%     else %}
@@ -35,6 +38,9 @@ bfd
 {%     if peer_config.echo_mode is defined %}
   echo-mode
 {%     endif %}
+{%     if peer_config.passive is defined %}
+  passive-mode
+{%     endif %}
 {%     if peer_config.shutdown is defined %}
   shutdown
 {%     else %}
diff --git a/interface-definitions/include/bfd-common.xml.i b/interface-definitions/include/bfd-common.xml.i
index 6021576f6..8379784f7 100644
--- a/interface-definitions/include/bfd-common.xml.i
+++ b/interface-definitions/include/bfd-common.xml.i
@@ -63,6 +63,12 @@
     </leafNode>
   </children>
 </node>
+<leafNode name="passive">
+  <properties>
+    <help>Do not attempt to start sessions</help>
+    <valueless/>
+  </properties>
+</leafNode>
 <leafNode name="shutdown">
   <properties>
     <help>Disable this peer</help>
diff --git a/smoketest/scripts/cli/test_protocols_bfd.py b/smoketest/scripts/cli/test_protocols_bfd.py
index 532814ef3..d33a64301 100755
--- a/smoketest/scripts/cli/test_protocols_bfd.py
+++ b/smoketest/scripts/cli/test_protocols_bfd.py
@@ -38,6 +38,7 @@ peers = {
         'intv_mult'  : '100',
         'intv_rx'    : '222',
         'intv_tx'    : '333',
+        'passive'    : '',
         'shutdown'   : '',
         'source_intf': dum_if,
         },
@@ -63,6 +64,7 @@ profiles = {
     'bar' : {
         'intv_mult'  : '102',
         'intv_rx'    : '444',
+        'passive'    : '',
         },
 }
 
@@ -89,6 +91,8 @@ class TestProtocolsBFD(VyOSUnitTestSHIM.TestCase):
                 self.cli_set(base_path + ['peer', peer, 'interval', 'transmit', peer_config["intv_tx"]])
             if 'multihop' in peer_config:
                 self.cli_set(base_path + ['peer', peer, 'multihop'])
+            if 'passive' in peer_config:
+                self.cli_set(base_path + ['peer', peer, 'passive'])
             if 'shutdown' in peer_config:
                 self.cli_set(base_path + ['peer', peer, 'shutdown'])
             if 'source_addr' in peer_config:
@@ -128,6 +132,8 @@ class TestProtocolsBFD(VyOSUnitTestSHIM.TestCase):
                 self.assertIn(f'receive-interval {peer_config["intv_rx"]}', peerconfig)
             if 'intv_tx' in peer_config:
                 self.assertIn(f'transmit-interval {peer_config["intv_tx"]}', peerconfig)
+            if 'passive' in peer_config:
+                self.assertIn(f'passive-mode', peerconfig)
             if 'shutdown' in peer_config:
                 self.assertIn(f'shutdown', peerconfig)
             else:
@@ -149,6 +155,8 @@ class TestProtocolsBFD(VyOSUnitTestSHIM.TestCase):
                 self.cli_set(base_path + ['profile', profile, 'interval', 'receive', profile_config["intv_rx"]])
             if 'intv_tx' in profile_config:
                 self.cli_set(base_path + ['profile', profile, 'interval', 'transmit', profile_config["intv_tx"]])
+            if 'passive' in profile_config:
+                self.cli_set(base_path + ['profile', profile, 'passive'])
             if 'shutdown' in profile_config:
                 self.cli_set(base_path + ['profile', profile, 'shutdown'])
 
@@ -171,6 +179,8 @@ class TestProtocolsBFD(VyOSUnitTestSHIM.TestCase):
                 self.assertIn(f'receive-interval {profile_config["intv_rx"]}', config)
             if 'intv_tx' in profile_config:
                 self.assertIn(f'transmit-interval {profile_config["intv_tx"]}', config)
+            if 'passive' in profile_config:
+                self.assertIn(f'passive-mode', config)
             if 'shutdown' in profile_config:
                 self.assertIn(f'shutdown', config)
             else: