T6258: Add sysctl base-reachable-time for IPv6

Add abiilty to change `base_reachable_time_ms` option
/proc/sys/net/ipv6/neigh/{ifname}/base_reachable_time_ms

3 files changed, 44 insertions, 1 deletions

diff --git a/interface-definitions/include/interface/base-reachable-time.xml.i b/interface-definitions/include/interface/base-reachable-time.xml.i
new file mode 100644
index 000000000..fb0d70101
--- /dev/null
+++ b/interface-definitions/include/interface/base-reachable-time.xml.i
@@ -0,0 +1,16 @@
+<!-- include start from interface/base-reachable-time.xml.i -->
+<leafNode name="base-reachable-time">
+  <properties>
+    <help>Base reachable time in seconds</help>
+    <valueHelp>
+      <format>u32:1-86400</format>
+      <description>Base reachable time in seconds</description>
+    </valueHelp>
+    <constraint>
+      <validator name="numeric" argument="--range 1-86400"/>
+    </constraint>
+    <constraintErrorMessage>Base reachable time must be between 1 and 86400 seconds</constraintErrorMessage>
+  </properties>
+  <defaultValue>30</defaultValue>
+</leafNode>
+<!-- include end -->
diff --git a/interface-definitions/include/interface/ipv6-options.xml.i b/interface-definitions/include/interface/ipv6-options.xml.i
index edb4a74f9..ec6ec64ee 100644
--- a/interface-definitions/include/interface/ipv6-options.xml.i
+++ b/interface-definitions/include/interface/ipv6-options.xml.i
@@ -5,6 +5,7 @@
   </properties>
   <children>
     #include <include/interface/adjust-mss.xml.i>
+    #include <include/interface/base-reachable-time.xml.i>
     #include <include/interface/disable-forwarding.xml.i>
     #include <include/interface/ipv6-accept-dad.xml.i>
     #include <include/interface/ipv6-address.xml.i>
diff --git a/python/vyos/ifconfig/interface.py b/python/vyos/ifconfig/interface.py
index 1b86982c4..f0897bc21 100644
--- a/python/vyos/ifconfig/interface.py
+++ b/python/vyos/ifconfig/interface.py
@@ -1,4 +1,4 @@
-# Copyright 2019-2023 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2019-2024 VyOS maintainers and contributors <maintainers@vyos.io>
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -193,6 +193,9 @@ class Interface(Control):
             'validate': assert_positive,
             'location': '/proc/sys/net/ipv6/conf/{ifname}/dad_transmits',
         },
+        'ipv6_cache_tmo': {
+            'location': '/proc/sys/net/ipv6/neigh/{ifname}/base_reachable_time_ms',
+        },
         'path_cost': {
             # XXX: we should set a maximum
             'validate': assert_positive,
@@ -261,6 +264,9 @@ class Interface(Control):
         'ipv6_dad_transmits': {
             'location': '/proc/sys/net/ipv6/conf/{ifname}/dad_transmits',
         },
+        'ipv6_cache_tmo': {
+            'location': '/proc/sys/net/ipv6/neigh/{ifname}/base_reachable_time_ms',
+        },
         'proxy_arp': {
             'location': '/proc/sys/net/ipv4/conf/{ifname}/proxy_arp',
         },
@@ -613,6 +619,21 @@ class Interface(Control):
             return None
         return self.set_interface('arp_cache_tmo', tmo)
 
+    def set_ipv6_cache_tmo(self, tmo):
+        """
+        Set IPv6 cache timeout value in seconds. Internal Kernel representation
+        is in milliseconds.
+
+        Example:
+        >>> from vyos.ifconfig import Interface
+        >>> Interface('eth0').set_ipv6_cache_tmo(40)
+        """
+        tmo = str(int(tmo) * 1000)
+        tmp = self.get_interface('ipv6_cache_tmo')
+        if tmp == tmo:
+            return None
+        return self.set_interface('ipv6_cache_tmo', tmo)
+
     def _cleanup_mss_rules(self, table, ifname):
         commands = []
         results = self._cmd(f'nft -a list chain {table} VYOS_TCP_MSS').split("\n")
@@ -1698,6 +1719,11 @@ class Interface(Control):
             for addr in tmp:
                 self.add_ipv6_eui64_address(addr)
 
+        # Configure IPv6 base time in milliseconds - has default value
+        tmp = dict_search('ipv6.base_reachable_time', config)
+        value = tmp if (tmp != None) else '30'
+        self.set_ipv6_cache_tmo(value)
+
         # re-add ourselves to any bridge we might have fallen out of
         if 'is_bridge_member' in config:
             tmp = config.get('is_bridge_member')