PacketOut based on L2 header (#40)

Makes the P4 program Tofino chip model independent by removing the dependency on the cpu port at compile time.
Instead this information is inserted at runtime by the controller into the switch_info table, and stored in the metadata for usage in the egress stages. To remove the dependency in the ingress parser (to detect PacketOuts from dataplane packets), we now use a special Ethertype in the serialized metadata header of PacketOuts.

p4src/build.sh

@@ -42,7 +42,6 @@ function do_p4c() {
   cpu_port=$2
   echo "*** Compiling profile '${PROFILE}' for ${pltf} platform..."
   echo "*** Output in ${P4C_OUT}/${pltf}"
-  pp_flags="-DCPU_PORT=${cpu_port}"
   p4c_flags="--auto-init-metadata"
   mkdir -p ${P4C_OUT}/${pltf}
   (

p4src/include/control/acl.p4

@@ -25,7 +25,8 @@ control Acl (inout parsed_headers_t hdr,
 
     // Send immendiatelly to CPU - skip the rest of ingress.
     action punt_to_cpu() {
-        ig_intr_md_for_tm.ucast_egress_port = CPU_PORT;
+        ig_intr_md_for_tm.copy_to_cpu = 1;
+        ig_intr_md_for_dprsr.drop_ctl = 1;
         fabric_md.skip_next = true;
         acl_counter.count();
     }

p4src/include/control/packetio.p4

@@ -9,8 +9,8 @@ control PacketIoIngress(inout parsed_headers_t hdr,
                         inout ingress_intrinsic_metadata_for_deparser_t ig_intr_md_for_dprsr) {
     @hidden
     action do_packet_out() {
-        hdr.packet_out.setInvalid();
         ig_intr_md_for_tm.ucast_egress_port = hdr.packet_out.egress_port;
+        hdr.packet_out.setInvalid();
         // Straight to output port.
         fabric_md.bridged.setInvalid();
         ig_intr_md_for_tm.bypass_egress = 1;
@@ -65,8 +65,21 @@ control PacketIoEgress(inout parsed_headers_t hdr,
                        inout fabric_egress_metadata_t fabric_md,
                        in egress_intrinsic_metadata_t eg_intr_md) {
 
+    action set_cpu_port(PortId_t cpu_port) {
+        fabric_md.cpu_port = cpu_port;
+    }
+
+    table switch_info {
+        actions = {
+            set_cpu_port;
+            @defaultonly nop;
+        }
+    }
+
     apply {
-        if (eg_intr_md.egress_port == CPU_PORT) {
+        switch_info.apply();
+        // Check if this is a clone of a copy_to_cpu packet.
+        if (eg_intr_md.egress_port == fabric_md.cpu_port) {
             hdr.packet_in.setValid();
             hdr.packet_in.ingress_port = fabric_md.bridged.ig_port;
             hdr.fake_ethernet.setInvalid();

p4src/include/define.p4

@@ -8,10 +8,6 @@
 
 #define MAX_PORTS 511
 
-#ifndef CPU_PORT
-#deinfe CPU_PORT 192
-#endif
-
 #if ! defined(WITH_SIMPLE_NEXT)
 #define WITH_HASHED_NEXT
 #endif
@@ -93,6 +89,7 @@ const bit<16> ETHERTYPE_IPV6 = 0x86dd;
 const bit<16> ETHERTYPE_ARP  = 0x0806;
 const bit<16> ETHERTYPE_PPPOED = 0x8863;
 const bit<16> ETHERTYPE_PPPOES = 0x8864;
+const bit<16> ETHERTYPE_PACKET_OUT = 0xBF01;
 
 // Fake ether types used to distinguish regular packets from those used for
 // CPU-based loopback testing.

p4src/include/header.p4

@@ -16,11 +16,14 @@ header packet_in_header_t {
     bit<7>   _pad0;
 }
 
+// This header must have a pseudo ethertype at offset 12, to be parseable as an
+// Ethernet frame in the ingress parser.
 @controller_header("packet_out")
 header packet_out_header_t {
     PortId_t          egress_port;
     CpuLoopbackMode_t cpu_loopback_mode;
-    bit<5>            pad0;
+    @padding bit<85>  pad0;
+    bit<16>           ether_type;
 }
 
 header ethernet_t {
@@ -195,6 +198,7 @@ struct fabric_ingress_metadata_t {
 @flexible
 struct fabric_egress_metadata_t {
     bridged_metadata_t    bridged;
+    PortId_t              cpu_port;
 #ifdef WITH_SPGW
     bool                  inner_ipv4_checksum_err;
 #endif // WITH_SPGW

p4src/include/int/int.p4

@@ -189,11 +189,8 @@ control IntEgress (
             // Reports don't need to go through the rest of the egress pipe.
             exit;
         } else {
-            if (fabric_md.bridged.ig_port != CPU_PORT &&
-                eg_intr_md.egress_port != CPU_PORT) {
-                if (watchlist.apply().hit) {
-                    mirror_session_id.apply();
-                }
+            if (watchlist.apply().hit) {
+                mirror_session_id.apply();
             }
         }
     }

p4src/include/parser.p4

@@ -25,14 +25,6 @@ parser FabricIngressParser (packet_in  packet,
         fabric_md.bridged.bridged_md_type = BridgedMdType_t.I2E;
         fabric_md.bridged.ig_port = ig_intr_md.ingress_port;
         fabric_md.bridged.ig_tstamp = ig_intr_md.ingress_mac_tstamp;
-        transition select(ig_intr_md.ingress_port) {
-            CPU_PORT: parse_packet_out;
-            default: check_ethernet;
-        }
-    }
-
-    state parse_packet_out {
-        packet.extract(hdr.packet_out);
         transition check_ethernet;
     }
 
@@ -43,6 +35,7 @@ parser FabricIngressParser (packet_in  packet,
         transition select(tmp.ether_type) {
             ETHERTYPE_CPU_LOOPBACK_INGRESS: parse_fake_ethernet;
             ETHERTYPE_CPU_LOOPBACK_EGRESS: parse_fake_ethernet_and_accept;
+            ETHERTYPE_PACKET_OUT: parse_packet_out;
             default: parse_ethernet;
         }
     }
@@ -58,6 +51,11 @@ parser FabricIngressParser (packet_in  packet,
         transition accept;
     }
 
+    state parse_packet_out {
+        packet.extract(hdr.packet_out);
+        transition parse_ethernet;
+    }
+
     state parse_ethernet {
         packet.extract(hdr.ethernet);
         transition select(packet.lookahead<bit<16>>()) {
@@ -273,6 +271,7 @@ parser FabricEgressParser (packet_in packet,
 
     state start {
         packet.extract(eg_intr_md);
+        fabric_md.cpu_port = 0;
         BridgedMdType_t bridged_md_type = packet.lookahead<BridgedMdType_t>();
         transition select(bridged_md_type) {
             BridgedMdType_t.I2E: parse_bridged_md;

ptf/tests/ptf/fabric.ptf/test.py

@@ -1128,8 +1128,6 @@ def doRunTest(self, pkt, tagged):
             self.verify_packet_in(pkt, port)
         self.verify_no_other_packets()
 
-    @tvsetup
-    @autocleanup
     def runTest(self):
         print ""
         for pkt_type in ["tcp", "udp", "icmp", "arp"]:
@@ -1158,8 +1156,6 @@ def doRunTest(self, pkt):
             self.verify_packet_in(pkt, port)
         self.verify_no_other_packets()
 
-    @tvsetup
-    @autocleanup
     def runTest(self):
         print ""
         for pkt_type in ["tcp", "udp", "icmp", "arp"]:

ptf/tests/ptf/fabric_test.py

@@ -44,6 +44,7 @@
 ETH_TYPE_PPPOE = 0x8864
 ETH_TYPE_MPLS_UNICAST = 0x8847
 
+ETH_TYPE_PACKET_OUT = 0xBF01
 ETH_TYPE_CPU_LOOPBACK_INGRESS = 0xBF02
 ETH_TYPE_CPU_LOOPBACK_EGRESS = 0xBF03
 
@@ -289,6 +290,10 @@ def build_packet_out(self, pkt, port, cpu_loopback_mode=CPU_LOOPBACK_MODE_DISABL
         pad0_md = packet_out.metadata.add()
         pad0_md.metadata_id = 3
         pad0_md.value = stringify(0, 1)
+        # ether type
+        ether_type_md = packet_out.metadata.add()
+        ether_type_md.metadata_id = 4
+        ether_type_md.value = stringify(ETH_TYPE_PACKET_OUT, 2)
         return packet_out
 
     def setup_int(self):
@@ -332,6 +337,22 @@ def setup_port(self, port_id, vlan_id, tagged=False, double_tagged=False, inner_
                                        vlan_valid=False, internal_vlan_id=vlan_id)
             self.set_egress_vlan_pop(egress_port=port_id, vlan_id=vlan_id)
 
+    def setup_cpu_port(self):
+        req = self.get_new_write_request()
+        self.push_update_add_entry_to_action(req,
+            "FabricEgress.pkt_io_egress.switch_info", None,
+            "FabricEgress.pkt_io_egress.set_cpu_port",
+            [("cpu_port", stringify(self.cpu_port, 2))])
+        return req, self.write_request(req, store=False)
+
+    def reset_cpu_port(self):
+        req = self.get_new_write_request()
+        self.push_update_add_entry_to_action(req,
+            "FabricEgress.pkt_io_egress.switch_info", None,
+            "nop",
+            [])
+        return req, self.write_request(req)
+
     def set_ingress_port_vlan(self, ingress_port,
                               vlan_valid=False,
                               vlan_id=0,
@@ -1220,6 +1241,7 @@ def runPacketOutTest(self, pkt):
 
 class PacketInTest(FabricTest):
     def runPacketInTest(self, pkt, eth_type, tagged=False, vlan_id=10):
+        self.setup_cpu_port()
         self.add_forwarding_acl_punt_to_cpu(eth_type=eth_type)
         for port in [self.port1, self.port2]:
             if tagged:

src/main/java/org/stratumproject/fabric/tna/behaviour/FabricInterpreter.java

@@ -53,6 +53,7 @@ public class FabricInterpreter extends AbstractFabricHandlerBehavior
     private static final int CPU_LOOPBACK_MODE_DISABLED = 0;
     private static final int CPU_LOOPBACK_MODE_DIRECT = 1;
     private static final int CPU_LOOPBACK_MODE_INGRESS = 2;
+    private static final int ETHER_TYPE_PACKET_OUT = 0xBF01;
 
     // Group tables by control block.
     private static final Set<PiTableId> FILTERING_CTRL_TBLS = ImmutableSet.of(
@@ -199,6 +200,10 @@ private Collection<PiPacketMetadata> createPacketMetadata(long portNumber)
                     .withId(P4InfoConstants.PAD0)
                     .withValue(copyFrom(0))
                     .build());
+            builder.add(PiPacketMetadata.builder()
+                    .withId(P4InfoConstants.ETHER_TYPE)
+                    .withValue(copyFrom(ETHER_TYPE_PACKET_OUT))
+                    .build());
             return builder.build();
         } catch (ImmutableByteSequence.ByteSequenceTrimException e) {
             throw new PiInterpreterException(format(

src/main/java/org/stratumproject/fabric/tna/behaviour/P4InfoConstants.java

@@ -92,6 +92,8 @@ private P4InfoConstants() {
             PiTableId.of("FabricEgress.int_egress.report");
     public static final PiTableId FABRIC_EGRESS_INT_EGRESS_WATCHLIST =
             PiTableId.of("FabricEgress.int_egress.watchlist");
+    public static final PiTableId FABRIC_EGRESS_PKT_IO_EGRESS_SWITCH_INFO =
+            PiTableId.of("FabricEgress.pkt_io_egress.switch_info");
     public static final PiTableId FABRIC_INGRESS_ACL_ACL =
             PiTableId.of("FabricIngress.acl.acl");
     public static final PiTableId FABRIC_INGRESS_FILTERING_FWD_CLASSIFIER =
@@ -153,6 +155,8 @@ private P4InfoConstants() {
             PiActionId.of("FabricEgress.int_egress.do_report_encap");
     public static final PiActionId FABRIC_EGRESS_INT_EGRESS_INIT_METADATA =
             PiActionId.of("FabricEgress.int_egress.init_metadata");
+    public static final PiActionId FABRIC_EGRESS_PKT_IO_EGRESS_SET_CPU_PORT =
+            PiActionId.of("FabricEgress.pkt_io_egress.set_cpu_port");
     public static final PiActionId FABRIC_INGRESS_ACL_COPY_TO_CPU =
             PiActionId.of("FabricIngress.acl.copy_to_cpu");
     public static final PiActionId FABRIC_INGRESS_ACL_DROP =
@@ -210,6 +214,8 @@ private P4InfoConstants() {
     public static final PiActionId NO_ACTION = PiActionId.of("NoAction");
     public static final PiActionId NOP = PiActionId.of("nop");
     // Action Param IDs
+    public static final PiActionParamId CPU_PORT =
+            PiActionParamId.of("cpu_port");
     public static final PiActionParamId CTR_ID = PiActionParamId.of("ctr_id");
     public static final PiActionParamId DIRECTION =
             PiActionParamId.of("direction");
@@ -257,6 +263,8 @@ private P4InfoConstants() {
             PiPacketMetadataId.of("cpu_loopback_mode");
     public static final PiPacketMetadataId EGRESS_PORT =
             PiPacketMetadataId.of("egress_port");
+    public static final PiPacketMetadataId ETHER_TYPE =
+            PiPacketMetadataId.of("ether_type");
     public static final PiPacketMetadataId INGRESS_PORT =
             PiPacketMetadataId.of("ingress_port");
     public static final PiPacketMetadataId PAD0 = PiPacketMetadataId.of("pad0");

src/main/java/org/stratumproject/fabric/tna/behaviour/pipeliner/FabricPipeliner.java

@@ -5,14 +5,19 @@
 
 import com.google.common.collect.ImmutableList;
 import org.onlab.util.SharedExecutors;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.PortNumber;
 import org.onosproject.net.behaviour.NextGroup;
 import org.onosproject.net.behaviour.Pipeliner;
 import org.onosproject.net.behaviour.PipelinerContext;
+import org.onosproject.net.flow.DefaultFlowRule;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
 import org.onosproject.net.flow.FlowRule;
 import org.onosproject.net.flow.FlowRuleOperations;
 import org.onosproject.net.flow.FlowRuleService;
+import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.flowobjective.FilteringObjective;
 import org.onosproject.net.flowobjective.FlowObjectiveStore;
 import org.onosproject.net.flowobjective.ForwardingObjective;
@@ -23,9 +28,13 @@
 import org.onosproject.net.flowobjective.ObjectiveError;
 import org.onosproject.net.group.GroupDescription;
 import org.onosproject.net.group.GroupService;
+import org.onosproject.net.pi.runtime.PiAction;
+import org.onosproject.net.pi.runtime.PiActionParam;
 import org.slf4j.Logger;
 import org.stratumproject.fabric.tna.behaviour.AbstractFabricHandlerBehavior;
 import org.stratumproject.fabric.tna.behaviour.FabricCapabilities;
+import org.stratumproject.fabric.tna.behaviour.P4InfoConstants;
+import org.stratumproject.fabric.tna.PipeconfLoader;
 
 import java.util.Collection;
 import java.util.List;
@@ -48,11 +57,14 @@ public class FabricPipeliner extends AbstractFabricHandlerBehavior
         implements Pipeliner {
 
     private static final Logger log = getLogger(FabricPipeliner.class);
+    private static final int DEFAULT_FLOW_PRIORITY = 100;
 
     protected DeviceId deviceId;
+    protected ApplicationId appId;
     protected FlowRuleService flowRuleService;
     protected GroupService groupService;
     protected FlowObjectiveStore flowObjectiveStore;
+    protected CoreService coreService;
 
     private FilteringObjectiveTranslator filteringTranslator;
     private ForwardingObjectiveTranslator forwardingTranslator;
@@ -86,6 +98,10 @@ public void init(DeviceId deviceId, PipelinerContext context) {
         this.filteringTranslator = new FilteringObjectiveTranslator(deviceId, capabilities);
         this.forwardingTranslator = new ForwardingObjectiveTranslator(deviceId, capabilities);
         this.nextTranslator = new NextObjectiveTranslator(deviceId, capabilities);
+        this.coreService = context.directory().get(CoreService.class);
+        this.appId = coreService.getAppId(PipeconfLoader.APP_NAME);
+
+        initializePipeline();
     }
 
     @Override
@@ -128,6 +144,26 @@ public List<String> getNextMappings(NextGroup nextGroup) {
                 .collect(Collectors.toList());
     }
 
+    protected void initializePipeline() {
+        final PiActionParam param = new PiActionParam(P4InfoConstants.CPU_PORT, capabilities.cpuPort().get());
+        final PiAction action = PiAction.builder()
+                .withId(P4InfoConstants.FABRIC_EGRESS_PKT_IO_EGRESS_SET_CPU_PORT)
+                .withParameter(param)
+                .build();
+        final TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+                .piTableAction(action)
+                .build();
+        FlowRule rule = DefaultFlowRule.builder()
+                .forDevice(deviceId)
+                .withTreatment(treatment)
+                .withPriority(DEFAULT_FLOW_PRIORITY)
+                .fromApp(appId)
+                .makePermanent()
+                .forTable(P4InfoConstants.FABRIC_EGRESS_PKT_IO_EGRESS_SWITCH_INFO)
+                .build();
+        flowRuleService.applyFlowRules(rule);
+    }
+
     private void handleResult(Objective obj, ObjectiveTranslation result) {
         if (result.error().isPresent()) {
             fail(obj, result.error().get());

src/test/java/org/stratumproject/fabric/tna/behaviour/FabricInterpreterTest.java

@@ -235,6 +235,10 @@ public void testMapOutboundPacket() throws PiPipelineInterpreter.PiInterpreterEx
                 .withId(P4InfoConstants.CPU_LOOPBACK_MODE)
                 .withValue(ImmutableByteSequence.copyFrom(0))
                 .build());
+        builder.add(PiPacketMetadata.builder()
+                .withId(P4InfoConstants.ETHER_TYPE)
+                .withValue(ImmutableByteSequence.copyFrom(0xBF01))
+                .build());
         builder.add(PiPacketMetadata.builder()
                 .withId(P4InfoConstants.PAD0)
                 .withValue(ImmutableByteSequence.copyFrom(0))