[yang]Add FG-ECMP yang model

src/sonic-yang-models/doc/Configuration.md

@@ -26,6 +26,9 @@ Table of Contents
          * [Device Metadata](#device-metadata)  
          * [Device neighbor metada](#device-neighbor-metada)  
          * [DSCP_TO_TC_MAP](#dscp_to_tc_map)  
+         * [FG_NHG](#fg_nhg)
+         * [FG_NHG_MEMBER](#fg_nhg_member)
+         * [FG_NHG_PREFIX](#fg_nhg_prefix)
          * [FLEX_COUNTER_TABLE](#flex_counter_table)  
          * [KDUMP](#kdump)  
          * [Kubernetes Master](#kubernetes-master)  
@@ -890,6 +893,54 @@ instance is supported in SONiC.
 ```
 
 
+### FG_NHG
+
+```
+"FG_NHG": {
+    "fgnhg_v4": {
+        "bucket_size": "120",
+        "match_mode": "nexthop-based"
+    },
+    "fgnhg_v6": {
+        "bucket_size": "120",
+        "match_mode": "nexthop-based"
+    }
+}
+
+```
+
+### FG_NHG_MEMBER
+
+```
+"FG_NHG_MEMBER": {
+    "200.200.200.4": {
+        "FG_NHG": "fgnhg_v4",
+        "bank": "0",
+        "link": "Ethernet8"
+    },
+    "200.200.200.5": {
+        "FG_NHG": "fgnhg_v4",
+        "bank": "1",
+        "link": "Ethernet12"
+    }
+}
+
+```
+
+### FG_NHG_PREFIX
+
+```
+"FG_NHG_PREFIX": {
+    "100.50.25.12/32": {
+	    "FG_NHG": "fgnhg_v4"
+	},
+    "fc:05::/128": {
+	    "FG_NHG": "fgnhg_v6"
+	}
+}
+
+```
+
 ### MPLS_TC_TO_TC_MAP
 ```
 {

src/sonic-yang-models/setup.py

@@ -116,6 +116,7 @@ def run(self):
                          './yang-models/sonic-extension.yang',
                          './yang-models/sonic-flex_counter.yang',
                          './yang-models/sonic-feature.yang',
+                         './yang-models/sonic-fine-grained-ecmp.yang',
                          './yang-models/sonic-system-defaults.yang',
                          './yang-models/sonic-interface.yang',
                          './yang-models/sonic-kdump.yang',
@@ -199,6 +200,7 @@ def run(self):
                          './cvlyang-models/sonic-extension.yang',
                          './cvlyang-models/sonic-flex_counter.yang',
                          './cvlyang-models/sonic-feature.yang',
+                         './cvlyang-models/sonic-fine-grained-ecmp.yang',
                          './cvlyang-models/sonic-system-defaults.yang',
                          './cvlyang-models/sonic-interface.yang',
                          './cvlyang-models/sonic-kdump.yang',

src/sonic-yang-models/tests/yang_model_tests/tests/fine-grained-ecmp.json

@@ -0,0 +1,5 @@
+{
+    "VALID_FINE_GRAINED_ECMP": {
+        "desc": "VALID_FINE_GRAINED_ECMP no failure."
+    }
+}

src/sonic-yang-models/tests/yang_model_tests/tests_config/fine_grained_ecmp.json

@@ -0,0 +1,44 @@
+{
+    "VALID_FINE_GRAINED_ECMP":{
+        "sonic-fine-grained-ecmp:sonic-fine-grained-ecmp":{
+            "sonic-fine-grained-ecmp:FG_NHG":{
+                "FG_NHG_LIST":[
+                    {
+                        "name":"fgnhg_v4",
+                        "bucket_size": "120",
+                        "match_mode": "nexthop-based"
+                    },
+                    {
+                        "name":"fgnhg_v6",
+                        "bucket_size": "120",
+                        "match_mode": "nexthop-based"
+                    }
+                ],
+                "FG_NHG_PREFIX_LIST":[
+                    {
+                        "ip_prefix":"100.50.25.12/32",
+                        "FG_NHG": "fgnhg_v4"
+                    },
+                    {
+                        "ip_prefix":"fc:05::/128",
+                        "FG_NHG": "fgnhg_v6"
+                    }
+                ],
+                "FG_NHG_MEMBER_LIST":[
+                    {
+                        "next_hop_ip":"200.200.200.4",
+                        "FG_NHG": "fgnhg_v4",
+                        "bank": "0",
+                        "link": "Ethernet8"
+                    },
+                    {
+                        "next_hop_ip":"200.200.200.5",
+                        "FG_NHG": "fgnhg_v4",
+                        "bank": "1",
+                        "link": "Ethernet12"
+                    }
+                ]
+            }
+        }
+    }
+}

src/sonic-yang-models/yang-models/sonic-fine-grained-ecmp.yang

@@ -0,0 +1,136 @@
+module sonic-fine-grained-ecmp {
+
+    yang-version 1.1;
+
+    namespace "http://github.com/Azure/sonic-fine-grained-ecmp";
+    prefix sfgecmp;
+
+    import ietf-inet-types {
+        prefix inet;
+    }   
+
+    import sonic-types {
+        prefix stypes;
+    }
+
+    organization
+        "SONiC";
+
+    contact
+        "SONiC";
+
+    description
+        "SONIC Fine Grained ECMP";
+
+    revision 2023-01-19 {
+        description "Initial revision.";
+    }
+
+
+    container sonic-fine-grained-ecmp {
+
+        container FG_NHG { 
+
+            description "FG_NHG part of config_db.json";
+
+            list FG_NHG_LIST{
+                key "name";
+
+                leaf name{
+                    type string;
+                    description "FG_NHG group name";
+                }
+
+                leaf bucket_size{
+                    type uint16;
+                    mandatory true;
+                    description "total hash bucket size desired, 
+                    recommended value of Lowest Common Multiple 
+                    of 1..{max # of next-hops}";
+                }
+
+                leaf match_mode{
+                    type string{
+                        pattern "(route-based|nexthop-based)"{
+                            error-message "Invalid FG_NHG match mode";
+                        }
+                    }
+                    mandatory true;
+                    description " The filtering method used to identify
+                    when to use Fine Grained vs regular route handling.
+                    nexthop-based looks to next-hop IP to filter routes
+                    and uses fine grained ecmp when nexthop IPs matches
+                    FG_NHG_MEMBER IPs. route-based looks to prefix to
+                    filter routes, and uses fine grained ecmp when the
+                    route prefix matches the FG_NHG_PREFIX prefix.";
+                }
+            }
+             /* end of list FG_NHG_LIST */
+        }
+        /* end of container FG_NHG */
+
+        container FG_NHG_PREFIX{
+
+            description "FG_NHG_PREFIX part of config_db.json";
+
+            list FG_NHG_PREFIX_LIST{
+
+                key "ip_prefix";
+
+                leaf ip_prefix{
+                    type stypes:sonic-ip-prefix;
+                    description "FG_NHG_PREFIX for which FG behavior is
+                    desired";
+                }
+
+                leaf FG_NHG{
+                    type string;
+                    mandatory true;
+                    description "Fine Grained next-hop group name";
+                }
+            }
+            /* end of list FG_NHG_PREFIX_LIST */
+        }
+        /* end of container FG_NHG_PREFIX */
+
+        container FG_NHG_MEMBER{
+
+            description "FG_NHG_MEMBER part of config_db.json";
+
+            list FG_NHG_MEMBER_LIST{
+
+                key "next_hop_ip";
+
+                leaf next_hop_ip{
+                    type inet:ip-address;
+                    description "FG_NHG next-hop-ip member associated
+                    with prefix";
+                }
+
+                leaf FG_NHG{
+                    type string;
+                    mandatory true;
+                    description "Fine Grained next-hop group name";
+                }
+
+                leaf bank{
+                    type uint16;
+                    mandatory true;
+                    description "An index which specifies a bank/group
+                    in which the redistribution is performed";
+                }
+
+                leaf link{
+                    type string;
+                    description "Link associated with next-hop-ip, if
+                    configured, enables next-hop withdrawal/addition
+                    per link's operational state changes";
+                }
+            }
+            /* end of list FG_NHG_MEMBER_LIST */
+        }
+        /* end of container FG_NHG_MEMBER */
+    }
+    /* end of container sonic-fine-grained-ecmp */
+}
+/* end of module sonic-fine-grained-ecmp */