[sairedis]vs SAI support for voq neighbor (sonic-net#725)

Changes include SAI support for voq neighbor. VOQ neighbor requires an
additional attribute to set the encap index. For local neighbors the
encap index iis assigned by SAI, if not imposed. For remote neighbors,
the encap index is required to be supplised by the upper layer. The
changes validate these conditions for remote neighbors.

vslib/inc/SwitchStateBase.h

@@ -351,6 +351,12 @@ namespace saivs
             bool check_object_list_default_state(
                     _Out_ const std::vector<sai_object_id_t>& objlist);
 
+            sai_status_t createVoqSystemNeighborEntry(
+                    _In_ const std::string &serializedObjectId,
+                    _In_ sai_object_id_t switch_id,
+                    _In_ uint32_t attr_count,
+                    _In_ const sai_attribute_t *attr_list);
+
         protected: // custom debug counter
 
             uint32_t getNewDebugCounterIndex();

vslib/src/SwitchStateBase.cpp

@@ -168,6 +168,12 @@ sai_status_t SwitchStateBase::create(
         return createMACsecSA(object_id, switch_id, attr_count, attr_list);
     }
 
+    if (object_type == SAI_OBJECT_TYPE_NEIGHBOR_ENTRY && m_system_port_list.size())
+    {
+        // Neighbor entry programming for VOQ systems
+        return createVoqSystemNeighborEntry(serializedObjectId, switch_id, attr_count, attr_list);
+    }
+
     return create_internal(object_type, serializedObjectId, switch_id, attr_count, attr_list);
 }
 
@@ -2764,6 +2770,110 @@ sai_status_t SwitchStateBase::refresh_system_port_list(
     return SAI_STATUS_SUCCESS;
 }
 
+sai_status_t SwitchStateBase::createVoqSystemNeighborEntry(
+        _In_ const std::string &serializedObjectId,
+        _In_ sai_object_id_t switch_id,
+        _In_ uint32_t attr_count,
+        _In_ const sai_attribute_t *attr_list)
+{
+    SWSS_LOG_ENTER();
+
+    // For VOQ switch, encap index attribute should be set for local neighbors. For
+    // remote neighbors check for presence of encap index supplied from upper layer.
+    // And also validate isLocal and impose encap index flags in the attribute list
+
+    // Determine whether this neighbor is local neighbor or remote neighbor by checking the
+    // RIF id provided. If the port of the RIF is system port, the neighbor is remote neighbor
+
+    bool is_system_neigh = false;
+    sai_attribute_t attr;
+    sai_neighbor_entry_t nbr_entry;
+
+    sai_deserialize_neighbor_entry(serializedObjectId, nbr_entry);
+
+    attr.id = SAI_ROUTER_INTERFACE_ATTR_PORT_ID;
+
+    CHECK_STATUS(get(SAI_OBJECT_TYPE_ROUTER_INTERFACE, nbr_entry.rif_id, 1, &attr));
+
+    if (objectTypeQuery(attr.value.oid) == SAI_OBJECT_TYPE_SYSTEM_PORT)
+    {
+        is_system_neigh = true;
+    }
+
+    uint32_t encap_index = 0;
+    bool impose_encap_index = false;
+    bool is_local = true;
+
+    for (uint32_t i = 0; i < attr_count; i++)
+    {
+        switch (attr_list[i].id)
+        {
+            case SAI_NEIGHBOR_ENTRY_ATTR_ENCAP_INDEX:
+
+                encap_index = attr_list[i].value.u32;
+
+                break;
+
+            case SAI_NEIGHBOR_ENTRY_ATTR_ENCAP_IMPOSE_INDEX:
+
+                impose_encap_index = attr_list[i].value.booldata;
+
+                break;
+
+            case SAI_NEIGHBOR_ENTRY_ATTR_IS_LOCAL:
+
+                is_local = attr_list[i].value.booldata;
+
+                break;
+
+            default:
+                break;
+        }
+    }
+
+    if (impose_encap_index && encap_index == 0)
+    {
+        SWSS_LOG_ERROR("Impose invalid encap index %d for %s neigh %s",
+                encap_index,
+                (is_system_neigh ? "VOQ" : "local"),
+                serializedObjectId.c_str());
+
+        return SAI_STATUS_FAILURE;
+    }
+
+    if (is_system_neigh && is_local)
+    {
+        SWSS_LOG_ERROR("VOQ neigh info mismatch for %s. RIF is remote. attr is_local is true", serializedObjectId.c_str());
+
+        return SAI_STATUS_FAILURE;
+    }
+
+    if (!is_local && encap_index == 0)
+    {
+        SWSS_LOG_ERROR("VOQ neigh info mismatch for %s. attr is_local is false. encap_index is 0", serializedObjectId.c_str());
+
+        return SAI_STATUS_FAILURE;
+    }
+
+    CHECK_STATUS(create_internal(SAI_OBJECT_TYPE_NEIGHBOR_ENTRY, serializedObjectId, switch_id, attr_count, attr_list));
+
+    if (impose_encap_index == false)
+    {
+        // Encap index is not imposed. Assign encap index.
+        // The only requirement for the encap index is it must be locally
+        // unique in asic. Lower 32 bits of the ip address is used as encap index
+
+        encap_index = nbr_entry.ip_address.addr.ip4;
+
+        attr.id = SAI_NEIGHBOR_ENTRY_ATTR_ENCAP_INDEX;
+        attr.value.u32 = encap_index;
+
+        CHECK_STATUS(set_internal(SAI_OBJECT_TYPE_NEIGHBOR_ENTRY, serializedObjectId, &attr));
+    }
+
+    return SAI_STATUS_SUCCESS;
+}
+
 void SwitchStateBase::findObjects(
         _In_ sai_object_type_t object_type,
         _In_ const sai_attribute_t &expect,