switch config

Summary:
Modeling static MPLS routes in switch config

MplsNextHop defines "Next Hop Label Forwarding Entry" as found in RFC's. This defines  label forwarding operation to perform and next hop to which MPLS packet must be forwarded. If more than one next hops are provided then MPLS packet will be ECMPed across the next hops

StaticIp2MplsRoute defines "ingress LER" route. FEC in this case is "prefix".  L3 packets destined towards network "prefix" (as determined by longest prefix match), will be  forwarded towards "nexthops". Push label forwarding operation is implied. So each nexthop must provide label stack.

StaticMplsRouteWithNextHops define "LSR" route. An incoming MPLS packet, with label on top of the label stack matching with "ingressLabel" will be forwarded to "nexthop".

Note:

Each nexthop must have same label forwarding action, this is a requirement of current ASIC, though MPLS architecture does not impose this restriction.

StaticMplsRouteWithNoNextHops defines "LSR route" either to redirect MPLS packets, with label on the top of label stack matching with "ingressLabel"  to CPU or to drop

Reviewed By: saifhhasan

Differential Revision: D14068676

fbshipit-source-id: 6906f99153d47beea3b06707ee1d6e1c2f4b78ba

CMakeLists.txt

@@ -55,11 +55,19 @@ add_thrift_cpp2_library(
   network_address_cpp2
   common/network/if/Address.thrift
 )
+add_thrift_cpp2_library(
+  mpls_cpp2
+  fboss/agent/if/mpls.thrift
+  OPTIONS
+    json
+)
 add_thrift_cpp2_library(
   switch_config_cpp2
   fboss/agent/switch_config.thrift
   OPTIONS
     json
+  DEPENDS
+    mpls_cpp2
 )
 add_thrift_cpp2_library(
   agent_config_cpp2
@@ -99,8 +107,6 @@ add_thrift_cpp2_library(
 add_thrift_cpp2_library(
   transceiver_cpp2
   fboss/qsfp_service/if/transceiver.thrift
-  DEPENDS
-    switch_config_cpp2
 )
 add_thrift_cpp2_library(
   optic_cpp2
@@ -116,10 +122,6 @@ add_thrift_cpp2_library(
   sflow_cpp2
   fboss/agent/if/sflow.thrift
 )
-add_thrift_cpp2_library(
-  mpls_cpp2
-  fboss/agent/if/mpls.thrift
-)
 add_thrift_cpp2_library(
   ctrl_cpp2
   fboss/agent/if/ctrl.thrift
@@ -179,6 +181,7 @@ add_thrift_cpp2_library(
     fboss_cpp2
     transceiver_cpp2
     switch_config_cpp2
+    mpls_cpp2
 )
 add_thrift_cpp2_library(
   netlink_manager_service_cpp2
@@ -526,6 +529,7 @@ target_link_libraries(
     packettrace_cpp2
     bcmswitch_cpp2
     hardware_stats_cpp2
+    mpls_cpp2
     pcap_pubsub_cpp2
     qsfp_cpp2
     netlink_manager_service_cpp2

fboss/agent/if/mpls.thrift

@@ -26,3 +26,10 @@ struct MplsAction {
   2: optional MplsLabel swapLabel,         // Required if action == SWAP
   3: optional MplsLabelStack pushLabels,   // Required if action == PUSH
 }
+
+struct MplsNextHop {
+  /* nexthop */
+  1: string nexthop
+  /* label forwarding action towards nexthop */
+  2: MplsAction labelForwardingAction
+}

fboss/agent/switch_config.thrift

@@ -6,6 +6,7 @@ namespace py3 neteng.fboss
 namespace py.asyncio neteng.fboss.asyncio.switch_config
 namespace cpp2 facebook.fboss.cfg
 
+include "fboss/agent/if/mpls.thrift"
 
 /**
  * Administrative port state. ie "should the port be enabled?"
@@ -799,6 +800,26 @@ struct StaticRouteNoNextHops {
 }
 
 
+struct StaticIp2MplsRoute {
+  /** The VRF where the static route belongs to */
+  1: i32 routerID = 0
+  /* Prefix in the format like 10.0.0.0/8 */
+  2: string prefix
+  /* mpls next hops with push labels */
+  3: list<mpls.MplsNextHop > nexthops
+}
+
+struct StaticMplsRouteWithNextHops {
+  /* Look up MPLS packet based on label */
+  1: mpls.MplsLabel  ingressLabel
+  /* forward MPLS packet to nexthops */
+  2: list<mpls.MplsNextHop > nexthop
+}
+
+struct StaticMplsRouteNoNextHops {
+  1: mpls.MplsLabel  ingressLabel
+}
+
 struct SflowCollector {
   1: string ip
   2: i16 port
@@ -950,4 +971,12 @@ struct SwitchConfig {
   33: list<TrafficCounter> trafficCounters = []
   34: list<QosPolicy> qosPolicies = []
   35: list<PortQueue> defaultPortQueues = []
+  // Static MPLS routes with next hops
+  36: list<StaticMplsRouteWithNextHops> staticMplsRoutesWithNhops = []
+  // MPLS labels for which to drop traffic
+  37: list<StaticMplsRouteNoNextHops> staticMplsoutesToNull = []
+  // MPLS labels for which to send traffic to CPU
+  38: list<StaticMplsRouteNoNextHops> staticMplsRoutesToCPU = []
+  // ingress LER routes
+  39: list<StaticIp2MplsRoute> staticIp2MplsRoutes = []
 }