Implement configurable RIPv2/RIPng protocol timers (#1315)

docs/module/ripv2.md

@@ -18,13 +18,13 @@ This configuration module configures the RIPv2 and RIPng. The module supports th
 
 The following table describes per-platform support of individual RIPv2/RIPng features:
 
-| Operating system      | IPv4<br>(RIPv2) | IPv6<br>(RIPng) | Passive<br>interfaces | Route<br>import | VRF<br>instances |
-| ------------------ | :-: | :-: | :-: | :-: | :-: |
-| Arista EOS         | ✅  |  ❌  |  ❌  |  ❌  |
-| Cisco IOSv/IOSvL2  | ✅  | ✅  | ✅ [❗](caveats-iosv) | ✅  [❗](caveats-iosv) | ✅ |
-| Cisco IOS XE[^18v] | ✅  | ✅  | ✅ [❗](caveats-iosv) | ✅  [❗](caveats-iosv) | ✅ |
-| Cumulus Linux      | ✅  | ✅  | ✅  | ✅  | ✅  |
-| FRR                | ✅  | ✅  | ✅  | ✅  | ✅  |
+| Operating system      | IPv4<br>(RIPv2) | IPv6<br>(RIPng) | Passive<br>interfaces | Route<br>import | VRF<br>instances | RIP<br>timers |
+| ------------------ | :-: | :-: | :-: | :-: | :-: | :-: |
+| Arista EOS         | ✅  |  ❌  |  ❌  |  ❌  |  ❌  | ✅ |
+| Cisco IOSv/IOSvL2  | ✅  | ✅  | ✅ [❗](caveats-iosv) | ✅  [❗](caveats-iosv) | ✅ | ✅ |
+| Cisco IOS XE[^18v] | ✅  | ✅  | ✅ [❗](caveats-iosv) | ✅  [❗](caveats-iosv) | ✅ | ✅ |
+| Cumulus Linux      | ✅  | ✅  | ✅  | ✅  | ✅  | ✅ |
+| FRR                | ✅  | ✅  | ✅  | ✅  | ✅  | ✅ |
 | VyOS               | ✅  | ✅  | ✅  |  ❌  |
 
 ```{tip}
@@ -35,16 +35,31 @@ See [RIP Integration Tests Results](https://release.netlab.tools/_html/coverage.
 
 ## Lab Topology Parameters
 
-RIPv2/RIPng module does not have global parameters. The only relevant node parameter is the **ripv2.import** parameter specifying the [import (redistribution) of routes](routing_import) into the global RIP instance (default: no route import).
+You can change the RIPv2/RIPng timers with the global **rip.timers** dictionary ([more details](rip-timers)).
+
+The RIPv2/RIPng configuration module supports these node parameters:
+
+* **rip.timers**: Change RIP timers for a single node
+* **ripv2.import**: Specify the [import (redistribution) of routes](routing_import) into the global RIP instance (default: no route import).
 
 RIPv2 also supports [](routing_passive) and [](routing_external).
 
 ## VRF Parameters
 
 * By default, _netlab_ redistributes BGP- and connected routes into VRF RIPv2/RIPng instances on all network devices. You can change that on devices supporting configurable route import with the **[ripv2.import](routing_import)** VRF parameter.
+* Use **rip.timers** VRF parameter to change RIP timers for a single VRF instance
 * Set **ripv2.active** to *True* to force a VRF to use RIPv2/RIPng even when no routers are attached to the VRF interfaces.
 * To disable RIPv2/RIPng in a VRF set **ripv2** to *False* (see also [](routing_disable_vrf)).
 
+(rip-timers)=
+## Changing RIP Timers
+
+You can change the RIP protocol timers with the **rip.timers** global/node/VRF dictionary. The dictionary has these elements:
+
+* **update**: periodic RIP update timer. Default: 30 seconds, minimum: 5 seconds
+* **timeout**: route expiration timer. Default: six times the **update** timer, minimum: 5 seconds)
+* **garbage**: garbage collection timer (the time after which an invalid route is removed from the routing table). Default: four times the **update** timer, minimum: 5 seconds
+
 ## Example
 
 We want to create a simple two-router RIPv2 network using Cumulus Linux:

netsim/ansible/templates/ripv2/eos.j2

@@ -2,6 +2,9 @@
 {% if ripv2.af.ipv4|default(False) %}
 router rip
   no shutdown
+{%     if 'timers' in ripv2 %}
+  timers {{ ripv2.timers['update'] }} {{ ripv2.timers.timeout }} {{ ripv2.timers.garbage }}
+{%     endif %}
 {%   for intf in netlab_interfaces if 'ripv2' in intf and intf.ipv4|default('')|ipaddr() %}
   network {{ intf.ipv4|ipaddr(0) }}
 {%   endfor %}

netsim/ansible/templates/ripv2/frr.macro.j2

@@ -4,6 +4,9 @@
 {%   if ripv2.af.ipv4|default(False) %}
 router rip{% if vrf %} vrf {{ vrf }}{% endif +%}
  version 2
+{%     if 'timers' in ripv2 %}
+ timers basic {{ ripv2.timers['update'] }} {{ ripv2.timers.timeout }} {{ ripv2.timers.garbage }}
+{%     endif %}
 {{     redistribute.config(ripv2,af='ipv4') }}
 {%     for intf in ripv2.interfaces|default(netlab_interfaces) if 'ripv2' in intf and 'ipv4' in intf %}
  network {{ intf.ifname }}
@@ -15,6 +18,9 @@ router rip{% if vrf %} vrf {{ vrf }}{% endif +%}
 !
 {%   if ripv2.af.ipv6|default(False) %}
 router ripng{% if vrf %} vrf {{ vrf }}{% endif +%}
+{%     if 'timers' in ripv2 %}
+ timers basic {{ ripv2.timers['update'] }} {{ ripv2.timers.timeout }} {{ ripv2.timers.garbage }}
+{%     endif %}
 {{     redistribute.config(ripv2,af='ipv6') }}
 {%     for intf in ripv2.interfaces|default(netlab_interfaces) if 'ripv2' in intf and 'ipv6' in intf %}
  network {{ intf.ifname }}

netsim/ansible/templates/ripv2/ios.macro.j2

@@ -12,6 +12,9 @@ router rip
 {%     if 'import' in ripv2 %}
   default-metric {{ netlab_ripv2_default_metric|default(5) }}
 {%     endif %}
+{%     if 'timers' in ripv2 %}
+  timers basic {{ ripv2.timers['update'] }} {{ ripv2.timers.timeout }} {{ ripv2.timers.garbage }} 1
+{%     endif %}
 {{     redistribute.config(ripv2,af='ipv4',ospf_pid=ospf_pid)|indent(1,first=True) }}
 {%     for intf in ripv2.interfaces|default(netlab_interfaces) %}
 {%       if 'ripv2' in intf and intf.ipv4|default(False) is string %}
@@ -30,6 +33,9 @@ ipv6 router rip default
 {%     if vrf %}
  address-family ipv6 vrf {{ vrf }}
 {%     endif %}
+{%     if 'timers' in ripv2 %}
+  timers {{ ripv2.timers['update'] }} {{ ripv2.timers.timeout }} {{ ripv2.timers.garbage }} 1
+{%     endif %}
 {{     redistribute.config(ripv2,af='ipv6',ospf_pid=ospf_pid)|indent(1,first=True) }}
 !
 {%     for intf in ripv2.interfaces|default(netlab_interfaces) if 'ripv2' in intf and 'ipv6' in intf %}

netsim/modules/_routing.py

@@ -700,3 +700,18 @@ def igp_post_transform(
 
   process_imports(node,proto,topology,['bgp','connected'])
   process_default_route(node,proto,topology)
+
+"""
+routing_protocol_data: Given a node and a protocol name, returns the global protocol data
+and any VRF instances
+
+You can use this generator to iterate over all routing protocol instances without going through
+the "global first, then VRFs" logic on your own
+"""
+def routing_protocol_data(node: Box, proto: str) -> typing.Generator:
+  if isinstance(node.get(proto,None),Box):
+    yield node[proto]
+
+  for vname,vdata in node.get('vrfs',{}).items():
+    if isinstance(vdata.get(proto,None),Box):
+      yield vdata[proto]

netsim/modules/ripv2.py

@@ -10,6 +10,29 @@
 from ..utils import log
 from ..augment import devices
 
+"""
+adjust_rip_timers: Make sure all three timers are set if at least one of the 'ripv2.timers'
+attributes are set (data validation makes sure we're not dealing with bogus attributes)
+
+Having consistent set of three timers makes the configuration templates cleaner and avoids
+dealing with device-specific defaults (some devices accept less than three timers)
+
+Finally: it seems like 'update' might be a valid method for the dictionary object,
+so we're using traditional dict expression to access the update timer.
+"""
+def adjust_rip_timers(rip_data: Box) -> None:
+  if 'timers' not in rip_data:
+    return
+
+  if 'update' not in rip_data.timers:             # If we want to set timers, we need the update timer
+    rip_data.timers['update'] = 30                # ... if it's missing, we'll use the default value
+
+  if 'timeout' not in rip_data.timers:            # RFC says the default timeout value is 6 times the update timer
+    rip_data.timers.timeout = rip_data.timers['update'] * 6
+
+  if 'garbage' not in rip_data.timers:            # ... and the default GC value is 4 times the update timer
+    rip_data.timers.garbage = rip_data.timers['update'] * 4
+
 class RIPv2(_Module):
 
   def node_post_transform(self, node: Box, topology: Box) -> None:
@@ -28,5 +51,8 @@ def node_post_transform(self, node: Box, topology: Box) -> None:
     _routing.igp_post_transform(node,topology,proto='ripv2',vrf_aware=True)
     _routing.check_vrf_protocol_support(node,proto='ripv2',af='ipv4',feature='ripv2',topology=topology)
     _routing.check_vrf_protocol_support(node,proto='ripv2',af='ipv6',feature='ripng',topology=topology)
+    for rip_data in _routing.routing_protocol_data(node,'ripv2'):
+      adjust_rip_timers(rip_data)
+
     if 'ripv2' in node and 'loopback' in node:
       node.loopback.ripv2.passive = False

netsim/modules/ripv2.yml

@@ -7,6 +7,10 @@ config_after: [ vlan, dhcp, routing ]
 attributes:
   global:
     version: { type: int, min_value: 2, max_value: 2 }
+    timers:
+      update: { type: int, min_value: 5, max_value: 60 }
+      timeout: { type: int, min_value: 5, max_value: 3600 }
+      garbage: { type: int, min_value: 5, max_value: 600 }
     af:
       _list_to_dict: True
       _alt_types: [ NoneType ]
@@ -20,8 +24,13 @@ attributes:
     af:
     version:
     import: _r_import
+    timers:
+      copy: global
   vrf:
     active: bool
+    timers:
+      copy: global
+  vrf_copy: [ timers ]
   link:
     passive: bool
 warnings:

tests/integration/ripv2/topology-defaults.yml

@@ -0,0 +1,5 @@
+---
+ripv2.timers:
+  update: 5                 # Change the RIP update timer to speed up the tests
+  timeout: 180              # ... but leave the other timers intact to avoid route expiration failures
+  garbage: 120              # ... with devices that do not support fast timers