[orchagent] Add separate next hop table and orch

    **What I did**
    Added a new next hop group table to APP_DB, and orchagent support
    to use this as an alternative to including next hop information in
    the route table

    **Why I did it**
    Improves performance and occupancy usage when using the new table

    **How I verified it**
    Extended SWSS unit tests to cover new code, and ran existing tests

    Signed-off-by: Thomas Cappleman <thomas.cappleman@metaswitch.com>

.gitignore

@@ -77,3 +77,7 @@ tests/mock_tests/tests.trs
 tests/test-suite.log
 tests/tests.log
 tests/tests.trs
+
+# IDE files #
+#############
+.vscode

doc/swss-schema.md

@@ -159,8 +159,29 @@ and reflects the LAG ports into the redis under: `LAG_TABLE:<team0>:port`
     ;Status: Mandatory
     key           = ROUTE_TABLE:prefix
     nexthop       = *prefix, ;IP addresses separated “,” (empty indicates no gateway)
-    intf          = ifindex? PORT_TABLE.key  ; zero or more separated by “,” (zero indicates no interface)
-    blackhole     = BIT ; Set to 1 if this route is a blackhole (or null0)
+    ifname        = ifindex? PORT_TABLE.key  ; zero or more separated by “,” (zero indicates no interface)
+    weight        = weight_list              ; List of weights.
+    nexthop_group = string ; index within the NEXT_HOP_GROUP_TABLE, used instead of nexthop and intf fields
+
+---------------------------------------------
+
+###### LABEL_ROUTE_TABLE
+; Defines schema for MPLS label route table attributes
+key           = LABEL_ROUTE_TABLE:mpls_label ; MPLS label
+; field       = value
+nexthop       = STRING                   ; Comma-separated list of nexthops.
+ifname        = STRING                   ; Comma-separated list of interfaces.
+weight        = STRING                   ; Comma-separated list of weights.
+nexthop_group = string ; index within the NEXT_HOP_GROUP_TABLE, used instead of nexthop and intf fields
+
+---------------------------------------------
+### NEXT_HOP_GROUP_TABLE
+    ;Stores a list of groups of one or more next hops
+    ;Status: Mandatory
+    key           = NEXT_HOP_GROUP_TABLE:string ; arbitrary index for the next hop group
+    nexthop       = *prefix, ;IP addresses separated “,” (empty indicates no gateway)
+    ifname        = ifindex? PORT_TABLE.key  ; zero or more separated by “,” (zero indicates no interface)
+    weight        = weight_list              ; List of weights.
 
 ---------------------------------------------
 ### NEIGH_TABLE

orchagent/Makefile.am

@@ -32,6 +32,7 @@ orchagent_SOURCES = \
             orchdaemon.cpp \
             orch.cpp \
             notifications.cpp \
+            nhgorch.cpp \ 
             routeorch.cpp \
             neighorch.cpp \
             intfsorch.cpp \

orchagent/neighorch.cpp

@@ -7,6 +7,7 @@
 #include "directory.h"
 #include "muxorch.h"
 #include "subscriberstatetable.h"
+#include "nhgorch.h"
 
 extern sai_neighbor_api_t*         sai_neighbor_api;
 extern sai_next_hop_api_t*         sai_next_hop_api;
@@ -15,6 +16,7 @@ extern PortsOrch *gPortsOrch;
 extern sai_object_id_t gSwitchId;
 extern CrmOrch *gCrmOrch;
 extern RouteOrch *gRouteOrch;
+extern NhgOrch *gNhgOrch;
 extern FgNhgOrch *gFgNhgOrch;
 extern Directory<Orch*> gDirectory;
 extern string gMySwitchType;
@@ -322,6 +324,7 @@ bool NeighOrch::setNextHopFlag(const NextHopKey &nexthop, const uint32_t nh_flag
     {
         case NHFLAGS_IFDOWN:
             rc = gRouteOrch->invalidnexthopinNextHopGroup(nexthop, count);
+            rc &= gNhgOrch->invalidateNextHop(nexthop);
             break;
         default:
             assert(0);
@@ -351,6 +354,7 @@ bool NeighOrch::clearNextHopFlag(const NextHopKey &nexthop, const uint32_t nh_fl
     {
         case NHFLAGS_IFDOWN:
             rc = gRouteOrch->validnexthopinNextHopGroup(nexthop, count);
+            rc &= gNhgOrch->validateNextHop(nexthop);
             break;
         default:
             assert(0);

orchagent/nexthopkey.h

@@ -4,6 +4,7 @@
 #include "ipaddress.h"
 #include "tokenize.h"
 #include "label.h"
+#include "intfsorch.h"
 
 #define LABELSTACK_DELIMITER '+'
 #define NH_DELIMITER '@'
@@ -32,6 +33,8 @@ struct NextHopKey
     NextHopKey(const std::string &str) :
         vni(0), mac_address(), outseg_type(SAI_OUTSEG_TYPE_SWAP)
     {
+        SWSS_LOG_ENTER();
+
         if (str.find(NHG_DELIMITER) != string::npos)
         {
             std::string err = "Error converting " + str + " to NextHop";
@@ -174,6 +177,11 @@ struct NextHopKey
         }
         return str;
     }
+
+    NextHopKey ipKey() const
+    {
+        return NextHopKey(ip_address, alias);
+    }
 };
 
 #endif /* SWSS_NEXTHOPKEY_H */