From fd4ed02260c5be44360edcc1eaf4c7b018d7fa14 Mon Sep 17 00:00:00 2001
From: Santosh P K <sapk@vmware.com>
Date: Fri, 20 Dec 2019 00:30:57 -0800
Subject: [PATCH] lib: FRR next-hop yang data model.

A common nexthop and group nexthop yang data model
for all protocols in FRR.

Co-authored-by: Santosh P K <sapk@vmware.com>
Co-authored-by: Vishaldhingra <vdhingra@vmware.com>
Signed-off-by: Santosh P K <sapk@vmware.com>
---
 yang/frr-nexthop.yang | 144 ++++++++++++++++++++++++------------------
 1 file changed, 81 insertions(+), 63 deletions(-)

diff --git a/yang/frr-nexthop.yang b/yang/frr-nexthop.yang
index 7d8ce1b8ed14..2b326207c692 100644
--- a/yang/frr-nexthop.yang
+++ b/yang/frr-nexthop.yang
@@ -10,10 +10,15 @@ module frr-nexthop {
   import ietf-routing-types {
     prefix rt-types;
   }
+
   import frr-interface {
     prefix frr-interface;
   }
 
+  import frr-vrf {
+    prefix "frr-vrf";
+  }
+
   organization
     "Free Range Routing";
   contact
@@ -31,6 +36,9 @@ module frr-nexthop {
     type inet:ip-address;
   }
 
+  /*
+   * Nexthop types.
+   */
   typedef nexthop-type {
     type enumeration {
       enum "ifindex" {
@@ -68,6 +76,9 @@ module frr-nexthop {
       "Nexthop types.";
   }
 
+  /*
+   * Blockhole nexthop type.
+   */
   typedef blackhole-type {
     type enumeration {
       enum "unspec" {
@@ -97,113 +108,120 @@ module frr-nexthop {
   }
 
   /*
-   * Nexthop object
+   * Common nexthop attributes grouping.
    */
-
-  grouping frr-nexthop {
+  grouping frr-nexthop-attributes {
     leaf nh-type {
       type nexthop-type;
       mandatory true;
       description
         "The nexthop type.";
     }
-
+    leaf vrf {
+      type frr-vrf:vrf-ref;
+      description
+        "The nexthop vrf name, if different from the route.";
+    }
     leaf gateway {
-      type gateway-address;
+      when "../nh-type = 'ip4' or ../nh-type = 'ip6'";
+      type frr-nexthop:gateway-address;
       description
         "The nexthop gateway address.";
     }
-
-    leaf vrf {
-      type string {
-        length "1..36";
+    container gateway-interface {
+      when "../nh-type = 'ip4-ifindex' or
+        ../nh-type = 'ip6-ifindex'";
+      leaf gateway {
+        type frr-nexthop:gateway-address;
+        description
+          "The nexthop gateway address.";
+      }
+      leaf interface {
+        type frr-interface:interface-ref;
+        description
+          "The nexthop egress interface.";
+      }
+      leaf onlink {
+        type boolean;
+        default false;
+        description
+          "Nexthop is directly connected.";
       }
-      description
-        "The nexthop vrf name, if different from the route.";
     }
-
     leaf interface {
+      when "../nh-type = 'ifindex'";
       type frr-interface:interface-ref;
       description
         "The nexthop egress interface.";
     }
-
     leaf bh-type {
+      when "../nh-type = 'blackhole'";
       type blackhole-type;
       description
         "A blackhole sub-type, if the nexthop is a blackhole type.";
     }
 
-    leaf flags {
-      type uint32;
-      description
-        "The nexthop's raw flags value.";
-    }
-
-    leaf is-duplicate {
-      type empty;
-      description
-        "Duplicate nexthop; will be ignored.";
-    }
-
-    leaf is-recursive {
-      type empty;
-      description
-        "Nexthop must be resolved through another gateway.";
-    }
-
-    leaf is-onlink {
-      type empty;
-      description
-        "Nexthop is directly connected.";
-    }
-
-    leaf is-active {
-      type empty;
-      description
-        "Nexthop is active.";
-    }
-
     uses rt-types:mpls-label-stack {
       description
         "Nexthop's MPLS label stack.";
     }
+  }
 
-    leaf mtu {
-      type uint32;
+  /*
+   * Single nexthop grouping.
+   */
+  grouping frr-nexthop {
+    container frr-nexthops {
       description
-        "The nexthop's specific MTU.";
+        "FRR nexthop object.";
+      list nexthops {
+        key "nexthop-id";
+        description
+          "A list of nexthop objects.";
+
+        leaf nexthop-id {
+          type uint32;
+          description
+            "Identifies a nexthop within a list of nexthops; the entries
+            are ordered by id value, and the value has no other meaning.";
+        }
+
+        uses frr-nexthop-attributes;
+      }
     }
   }
 
-  // End of nexthop
+
   /*
-   * Nexthop-group container
+   * Container for FRR nexthop group.
    */
-
-  grouping frr-nexthop-group {
+  container frr-nexthop-group {
     description
       "A nexthop-group, represented as a list of nexthop objects.";
-    leaf name {
-      type string;
-      description
-        "The nexthop-group name.";
-    }
 
-    list entry {
-      key "id";
+    list nexthop-group {
+      key "name";
       description
-        "A list of nexthop objects.";
-      leaf id {
-        type uint32;
+        "A group of nexthops.";
+
+      leaf name {
+        type string;
         description
-          "Identifies a nexthop within a nexthop group; the entries
-           are ordered by id value, and the value has no other meaning.";
+          "The nexthop-group name.";
       }
 
       uses frr-nexthop;
     }
   }
 
-  // End of frr-nexthop-group
+  /*
+   * Agument weight attributes to nexthop group.
+   */
+  augment "/frr-nexthop-group/nexthop-group/frr-nexthops/nexthops" {
+    leaf weight {
+      type uint8;
+      description
+        "Weight to be used by the nexthop for purposes of ECMP";
+    }
+  }
 }