Improve fabric.p4 to reduce pipeline resources and refactor pipeconf impl
This patch affects both the P4 pipeline implementation and the
Java pipeconf.
P4 PIPELINE
- Less tables and smarter use of metadata to reduce inter-tables
dependencies and favor parallel execution of tables.
- Removed unused actions / renamed existing ones to make forwarding
behavior clearer (e.g. ingress_port_vlan table)
- Remove co-existence of simple and hansed table. Hashed should be the
default one, but implementations that do not support action profiles
might compile fabric.p4 to use the simple one.
- Use @name annotations for match fields to make control plane
independent of table implementation.
- Use @hidden to avoid showing actions and table on the p4info that
cannot be controlled at runtime.
- First attempt to support double VLAN cross-connect (xconnect table).
- New design has been tested with "fabric-refactoring" branch of
fabric-p4test:
github.com/opennetworkinglab/fabric-p4test/tree/fabric-refactoring
JAVA PIPECONF
This patch brings a major refactoring that reflects the experience
gathered in the past months of working on fabric.p4 and reasoning on its
pipeconf implementation. Indeed, the FlowObjective API is
under-specified and sometimes ambiguous which makes the process of
creating and maintaining a pipeliner implementation tedious. This
refactoring brings a simplified implementation by removing unused/
unnecessary functionalities and by recognizing commonality when possible
(e.g. by means of abstract and utility classes). It also makes design
patterns more explicit and consistent. Overall, the goal is to reduce
technical debt and to make it easier to support new features as we
evolve fabric.p4
Changes include:
- Changes in pipeliner/interpreter to reflect new pipeline design.
- By default translate objective treatment to PiAction. This favors
debuggability of flow rules in ONOS.
- Support new NextObjective’s NextTreatment class.
- Remove lots of unused/unnecessary code (e.g. async callback handling
for pending objective install status in pipeliner as current
implementation was always returning success)
- Gather commonality in abstract classes and simplify implementation
for objective translator (filtering, forwarding, next)
- New implementation of ForwardingFunctionTypes (FFT) that looks at
criterion instance values along with their types (to avoid relying on
case-specific if-else conditions to recognize variants of an FFT)
- Adaptive translation of NextObjective based on presence of simple or
hashed table.
- Support DENY FilteringObjective
Also:
- Fix onos-p4-gen-constants to avoid generating conflicting
PiMatchFieldId variable names.
- Install Graphviz tools in p4vm to generate p4c graphs
- Generate p4c graphs by default when compiling fabric.p4
- Use more compact Hex string when printing PI values
Change-Id: Ife79e44054dc5bc48833f95d0551a7370150eac5
diff --git a/pipelines/fabric/src/main/java/org/onosproject/pipelines/fabric/pipeliner/NextObjectiveTranslator.java b/pipelines/fabric/src/main/java/org/onosproject/pipelines/fabric/pipeliner/NextObjectiveTranslator.java
new file mode 100644
index 0000000..e45768a
--- /dev/null
+++ b/pipelines/fabric/src/main/java/org/onosproject/pipelines/fabric/pipeliner/NextObjectiveTranslator.java
@@ -0,0 +1,413 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.pipelines.fabric.pipeliner;
+
+import com.google.common.collect.Lists;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.DefaultTrafficSelector;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flow.criteria.PiCriterion;
+import org.onosproject.net.flow.criteria.VlanIdCriterion;
+import org.onosproject.net.flow.instructions.Instruction;
+import org.onosproject.net.flowobjective.DefaultNextTreatment;
+import org.onosproject.net.flowobjective.NextObjective;
+import org.onosproject.net.flowobjective.NextTreatment;
+import org.onosproject.net.flowobjective.Objective;
+import org.onosproject.net.flowobjective.ObjectiveError;
+import org.onosproject.net.group.DefaultGroupBucket;
+import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
+import org.onosproject.net.group.GroupBucket;
+import org.onosproject.net.group.GroupBuckets;
+import org.onosproject.net.group.GroupDescription;
+import org.onosproject.net.group.GroupKey;
+import org.onosproject.net.pi.model.PiTableId;
+import org.onosproject.net.pi.runtime.PiAction;
+import org.onosproject.net.pi.runtime.PiActionGroupId;
+import org.onosproject.net.pi.runtime.PiActionParam;
+import org.onosproject.net.pi.runtime.PiGroupKey;
+import org.onosproject.pipelines.fabric.FabricCapabilities;
+import org.onosproject.pipelines.fabric.FabricConstants;
+import org.onosproject.pipelines.fabric.FabricUtils;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import static java.lang.String.format;
+import static org.onosproject.net.flow.instructions.L2ModificationInstruction.L2SubType.VLAN_POP;
+import static org.onosproject.pipelines.fabric.FabricUtils.criterion;
+import static org.onosproject.pipelines.fabric.FabricUtils.l2Instruction;
+import static org.onosproject.pipelines.fabric.FabricUtils.outputPort;
+
+/**
+ * ObjectiveTranslator implementation for NextObjective.
+ */
+class NextObjectiveTranslator
+ extends AbstractObjectiveTranslator<NextObjective> {
+
+ NextObjectiveTranslator(DeviceId deviceId, FabricCapabilities capabilities) {
+ super(deviceId, capabilities);
+ }
+
+ @Override
+ public ObjectiveTranslation doTranslate(NextObjective obj)
+ throws FabricPipelinerException {
+
+ final ObjectiveTranslation.Builder resultBuilder =
+ ObjectiveTranslation.builder();
+
+ switch (obj.type()) {
+ case SIMPLE:
+ simpleNext(obj, resultBuilder, false);
+ break;
+ case HASHED:
+ hashedNext(obj, resultBuilder);
+ break;
+ case BROADCAST:
+ multicastNext(obj, resultBuilder);
+ break;
+ default:
+ log.warn("Unsupported NextObjective type '{}'", obj);
+ return ObjectiveTranslation.ofError(ObjectiveError.UNSUPPORTED);
+ }
+
+ if (!isGroupModifyOp(obj)) {
+ // Generate next VLAN rules.
+ nextVlan(obj, resultBuilder);
+ }
+
+ return resultBuilder.build();
+ }
+
+ private void nextVlan(NextObjective obj,
+ ObjectiveTranslation.Builder resultBuilder)
+ throws FabricPipelinerException {
+ if (obj.meta() == null) {
+ // Do nothing if there is no metadata in the NextObjective.
+ return;
+ }
+
+ final VlanIdCriterion vlanIdCriterion = (VlanIdCriterion) criterion(
+ obj.meta().criteria(), Criterion.Type.VLAN_VID);
+ if (vlanIdCriterion == null) {
+ // Do nothing if we can't find vlan from NextObjective metadata.
+ return;
+ }
+
+ // A VLAN ID as meta of a NextObjective indicates that packets matching
+ // the given next ID should be set with such VLAN ID.
+ final TrafficSelector selector = nextIdSelector(obj.id());
+ final TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+ .setVlanId(vlanIdCriterion.vlanId())
+ .build();
+
+ resultBuilder.addFlowRule(flowRule(
+ obj, FabricConstants.FABRIC_INGRESS_NEXT_NEXT_VLAN,
+ selector, treatment));
+ }
+
+ private void simpleNext(NextObjective obj,
+ ObjectiveTranslation.Builder resultBuilder,
+ boolean forceSimple)
+ throws FabricPipelinerException {
+
+ if (capabilities.hasHashedTable()) {
+ // Use hashed table when possible.
+ hashedNext(obj, resultBuilder);
+ return;
+ }
+
+ if (obj.nextTreatments().isEmpty()) {
+ // Do nothing.
+ return;
+ } else if (!forceSimple && obj.nextTreatments().size() != 1) {
+ throw new FabricPipelinerException(format(
+ "SIMPLE NextObjective should contain only 1 treatment, found %d",
+ obj.nextTreatments().size()), ObjectiveError.BADPARAMS);
+ }
+
+ final TrafficSelector selector = nextIdSelector(obj.id());
+
+ final List<DefaultNextTreatment> treatments = defaultNextTreatmentsOrFail(
+ obj.nextTreatments());
+
+ if (forceSimple && treatments.size() > 1) {
+ log.warn("Forcing SIMPLE behavior for NextObjective with {} treatments []",
+ treatments.size(), obj);
+ }
+
+ // If not forcing, we are essentially extracting the only available treatment.
+ final TrafficTreatment treatment = defaultNextTreatmentsOrFail(
+ obj.nextTreatments()).get(0).treatment();
+
+ resultBuilder.addFlowRule(flowRule(
+ obj, FabricConstants.FABRIC_INGRESS_NEXT_SIMPLE,
+ selector, treatment));
+
+ handleEgress(obj, treatment, resultBuilder, false);
+ }
+
+ private void hashedNext(NextObjective obj,
+ ObjectiveTranslation.Builder resultBuilder)
+ throws FabricPipelinerException {
+
+ if (!capabilities.hasHashedTable()) {
+ simpleNext(obj, resultBuilder, true);
+ return;
+ }
+
+ // Updated result builder with hashed group.
+ final int groupId = selectGroup(obj, resultBuilder);
+
+ if (isGroupModifyOp(obj)) {
+ // No changes to flow rules.
+ return;
+ }
+
+ final TrafficSelector selector = nextIdSelector(obj.id());
+ final TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+ .piTableAction(PiActionGroupId.of(groupId))
+ .build();
+
+ resultBuilder.addFlowRule(flowRule(
+ obj, FabricConstants.FABRIC_INGRESS_NEXT_HASHED,
+ selector, treatment));
+ }
+
+ private void handleEgress(NextObjective obj, TrafficTreatment treatment,
+ ObjectiveTranslation.Builder resultBuilder,
+ boolean strict)
+ throws FabricPipelinerException {
+ final PortNumber outPort = outputPort(treatment);
+ final Instruction popVlanInst = l2Instruction(treatment, VLAN_POP);
+ if (popVlanInst != null && outPort != null) {
+ if (strict && treatment.allInstructions().size() > 2) {
+ throw new FabricPipelinerException(
+ "Treatment contains instructions other " +
+ "than OUTPUT and VLAN_POP, cannot generate " +
+ "egress rules");
+ }
+ egressVlanPop(outPort, obj, resultBuilder);
+ }
+ }
+
+ private void egressVlanPop(PortNumber outPort, NextObjective obj,
+ ObjectiveTranslation.Builder resultBuilder)
+ throws FabricPipelinerException {
+
+ if (obj.meta() == null) {
+ throw new FabricPipelinerException(
+ "Cannot process egress pop VLAN rule, NextObjective has null meta",
+ ObjectiveError.BADPARAMS);
+ }
+
+ final VlanIdCriterion vlanIdCriterion = (VlanIdCriterion) criterion(
+ obj.meta(), Criterion.Type.VLAN_VID);
+ if (vlanIdCriterion == null) {
+ throw new FabricPipelinerException(
+ "Cannot process egress pop VLAN rule, missing VLAN_VID criterion " +
+ "in NextObjective meta",
+ ObjectiveError.BADPARAMS);
+ }
+
+ final PiCriterion egressVlanTableMatch = PiCriterion.builder()
+ .matchExact(FabricConstants.HDR_EG_PORT, outPort.toLong())
+ .build();
+ final TrafficSelector selector = DefaultTrafficSelector.builder()
+ .matchPi(egressVlanTableMatch)
+ .matchVlanId(vlanIdCriterion.vlanId())
+ .build();
+ final TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+ .popVlan()
+ .build();
+
+ resultBuilder.addFlowRule(flowRule(
+ obj, FabricConstants.FABRIC_EGRESS_EGRESS_NEXT_EGRESS_VLAN,
+ selector, treatment));
+ }
+
+ private TrafficSelector nextIdSelector(int nextId) {
+ final PiCriterion nextIdCriterion = PiCriterion.builder()
+ .matchExact(FabricConstants.HDR_NEXT_ID, nextId)
+ .build();
+ return DefaultTrafficSelector.builder()
+ .matchPi(nextIdCriterion)
+ .build();
+ }
+
+ private void multicastNext(NextObjective obj,
+ ObjectiveTranslation.Builder resultBuilder)
+ throws FabricPipelinerException {
+
+ // Create ALL group that will be translated to a PRE multicast entry.
+ final int groupId = allGroup(obj, resultBuilder);
+
+ if (isGroupModifyOp(obj)) {
+ // No changes to flow rules.
+ return;
+ }
+
+ final TrafficSelector selector = nextIdSelector(obj.id());
+ final PiActionParam groupIdParam = new PiActionParam(
+ FabricConstants.GROUP_ID, groupId);
+ final PiAction setMcGroupAction = PiAction.builder()
+ .withId(FabricConstants.FABRIC_INGRESS_NEXT_SET_MCAST_GROUP_ID)
+ .withParameter(groupIdParam)
+ .build();
+ final TrafficTreatment treatment = DefaultTrafficTreatment.builder()
+ .piTableAction(setMcGroupAction)
+ .build();
+
+ resultBuilder.addFlowRule(flowRule(
+ obj, FabricConstants.FABRIC_INGRESS_NEXT_MULTICAST,
+ selector, treatment));
+ }
+
+ private int selectGroup(NextObjective obj,
+ ObjectiveTranslation.Builder resultBuilder)
+ throws FabricPipelinerException {
+
+ final PiTableId hashedTableId = FabricConstants.FABRIC_INGRESS_NEXT_HASHED;
+ final List<DefaultNextTreatment> defaultNextTreatments =
+ defaultNextTreatmentsOrFail(obj.nextTreatments());
+ final List<TrafficTreatment> piTreatments = Lists.newArrayList();
+
+ for (DefaultNextTreatment t : defaultNextTreatments) {
+ // Map treatment to PI...
+ piTreatments.add(mapTreatmentToPiIfNeeded(t.treatment(), hashedTableId));
+ // ...and handle egress if necessary.
+ handleEgress(obj, t.treatment(), resultBuilder, false);
+ }
+
+ final List<GroupBucket> bucketList = piTreatments.stream()
+ .map(DefaultGroupBucket::createSelectGroupBucket)
+ .collect(Collectors.toList());
+
+ final int groupId = obj.id();
+ final PiGroupKey groupKey = new PiGroupKey(
+ hashedTableId,
+ FabricConstants.FABRIC_INGRESS_NEXT_HASHED_SELECTOR,
+ groupId);
+
+ resultBuilder.addGroup(new DefaultGroupDescription(
+ deviceId,
+ GroupDescription.Type.SELECT,
+ new GroupBuckets(bucketList),
+ groupKey,
+ groupId,
+ obj.appId()));
+
+ return groupId;
+ }
+
+ private int allGroup(NextObjective obj,
+ ObjectiveTranslation.Builder resultBuilder)
+ throws FabricPipelinerException {
+
+ final Collection<DefaultNextTreatment> defaultNextTreatments =
+ defaultNextTreatmentsOrFail(obj.nextTreatments());
+ // No need to map treatments to PI as translation of ALL groups to PRE
+ // multicast entries is based solely on the output port.
+ for (DefaultNextTreatment t : defaultNextTreatments) {
+ handleEgress(obj, t.treatment(), resultBuilder, true);
+ }
+
+ // FIXME: this implementation supports only the case in which each
+ // switch interface is associated with only one VLAN, otherwise we would
+ // need to support replicating multiple times the same packet for the
+ // same port while setting different VLAN IDs. Hence, collect in a set.
+ final Set<PortNumber> outPorts = defaultNextTreatments.stream()
+ .map(DefaultNextTreatment::treatment)
+ .map(FabricUtils::outputPort)
+ .filter(Objects::nonNull)
+ .collect(Collectors.toSet());
+
+ if (outPorts.size() != defaultNextTreatments.size()) {
+ throw new FabricPipelinerException(format(
+ "Found BROADCAST NextObjective with %d treatments but " +
+ "found only %d distinct OUTPUT port numbers, cannot " +
+ "translate to ALL groups",
+ defaultNextTreatments.size(), outPorts.size()),
+ ObjectiveError.UNSUPPORTED);
+ }
+
+ final List<GroupBucket> bucketList = outPorts.stream()
+ .map(p -> DefaultTrafficTreatment.builder().setOutput(p).build())
+ .map(DefaultGroupBucket::createAllGroupBucket)
+ .collect(Collectors.toList());
+ // FIXME: remove once support for clone sessions is available
+ // Right now we add a CPU port to all multicast groups. The egress
+ // pipeline is expected to drop replicated packets to the CPU if a clone
+ // was not requested in the ingress pipeline.
+ bucketList.add(
+ DefaultGroupBucket.createAllGroupBucket(
+ DefaultTrafficTreatment.builder()
+ .setOutput(PortNumber.CONTROLLER)
+ .build()));
+
+ final int groupId = obj.id();
+ // Use DefaultGroupKey instead of PiGroupKey as we don't have any
+ // action profile to apply to the groups of ALL type.
+ final GroupKey groupKey = new DefaultGroupKey(
+ FabricPipeliner.KRYO.serialize(groupId));
+
+ resultBuilder.addGroup(
+ new DefaultGroupDescription(
+ deviceId,
+ GroupDescription.Type.ALL,
+ new GroupBuckets(bucketList),
+ groupKey,
+ groupId,
+ obj.appId()));
+
+ return groupId;
+ }
+
+ private List<DefaultNextTreatment> defaultNextTreatmentsOrFail(
+ Collection<NextTreatment> nextTreatments)
+ throws FabricPipelinerException {
+ final List<DefaultNextTreatment> defaultNextTreatments = Lists.newArrayList();
+ final List<NextTreatment> unsupportedNextTreatments = Lists.newArrayList();
+ for (NextTreatment n : nextTreatments) {
+ if (n.type() == NextTreatment.Type.TREATMENT) {
+ defaultNextTreatments.add((DefaultNextTreatment) n);
+ } else {
+ unsupportedNextTreatments.add(n);
+ }
+ }
+ if (!unsupportedNextTreatments.isEmpty()) {
+ throw new FabricPipelinerException(format(
+ "Unsupported NextTreatments: %s",
+ unsupportedNextTreatments));
+ }
+ return defaultNextTreatments;
+ }
+
+ private boolean isGroupModifyOp(NextObjective obj) {
+ // If operation is ADD_TO_EXIST or REMOVE_FROM_EXIST, it means we modify
+ // group buckets only, no changes for flow rules.
+ return obj.op() == Objective.Operation.ADD_TO_EXISTING ||
+ obj.op() == Objective.Operation.REMOVE_FROM_EXISTING;
+ }
+}