org.opendaylight.sfc.provider.api.SfcServicePathId Maven / Gradle / Ivy
/*
* Copyright (c) 2015, 2017 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.sfc.provider.api;
import java.util.Random;
import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
import org.opendaylight.yang.gen.v1.urn.cisco.params.xml.ns.yang.service.path.id.rev150804.GenerationAlgorithmEnum;
import org.opendaylight.yang.gen.v1.urn.cisco.params.xml.ns.yang.service.path.id.rev150804.ServicePathIds;
import org.opendaylight.yang.gen.v1.urn.cisco.params.xml.ns.yang.service.path.id.rev150804.ServicePathIdsBuilder;
import org.opendaylight.yang.gen.v1.urn.cisco.params.xml.ns.yang.service.path.id.rev150804.service.path.ids.ServicePathId;
import org.opendaylight.yang.gen.v1.urn.cisco.params.xml.ns.yang.service.path.id.rev150804.service.path.ids.ServicePathIdBuilder;
import org.opendaylight.yang.gen.v1.urn.cisco.params.xml.ns.yang.service.path.id.rev150804.service.path.ids.ServicePathIdKey;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
/**
* This class has the APIs to operate on the Service PathIds.
*
*
*
* @author Reinaldo Penno ([email protected])
* @version 0.1
* @since 2015-08-09
*/
public final class SfcServicePathId {
/*
* We only use half of the path-id space in order to use algorithmic
* symmetric path-id generation
*/
private static final int MAX_PATH_ID = (int) Math.pow(2, 12) - 1;
private static final int MIN_PATH_ID = 0;
private static final int DEFAULT_GENERATION_ALGORITHM = GenerationAlgorithmEnum.Random.getIntValue();
private static final Random RANDOM_GENERATOR = new Random();
private static int nextPathId = 0;
private static final int NUM_PATH_ID = MAX_PATH_ID - MIN_PATH_ID + 1;
/* Determines the trade-off */
private static final int N = 64;
private SfcServicePathId() {
}
/**
* Algorithm to randomize the generation of pathIds. Provides security by
* making path-id less predictable. Adapted from NAT port allocation
* algorithm
*
*
*
* @return Pathid or error if none available
*/
public static int generatePathIdRandomIncrements() {
int pathid;
int count = NUM_PATH_ID;
do {
nextPathId = nextPathId + RANDOM_GENERATOR.nextInt(NUM_PATH_ID) % N + 1;
pathid = MIN_PATH_ID + nextPathId % NUM_PATH_ID;
if (checkSuitablePathId(pathid)) {
return pathid;
}
count--;
}
while (count > 0);
return -1;
}
/**
* Algorithm to sequentially generate pathIds.
*
*
*
* @return Pathid or error if none available
*/
private static int generatePathIdSequentialIncrements() {
int pathid;
int count = NUM_PATH_ID;
do {
nextPathId = nextPathId + 1;
pathid = MIN_PATH_ID + nextPathId;
if (checkSuitablePathId(pathid) && allocatePathId(pathid)) {
return pathid;
}
count--;
}
while (count > 0);
return -1;
}
/**
* Check and allocate Pathid if available.
*
*
*
* @param pathid
* Candidate Path Id
* @return True if allocated, otherwise false.
*/
public static long chechAndAllocatePathId(long pathid) {
if (SfcConcurrencyAPI.getPathIdLock()) {
try {
if (checkSuitablePathId(pathid) && allocatePathId(pathid)) {
return pathid;
} else {
return -1;
}
} finally {
SfcConcurrencyAPI.releasePathIdLock();
}
} else {
return -1;
}
}
/**
* Check and allocate symmetric Pathid if available.
*
*
*
* @param pathid
* Candidate Path Id
* @return True if allocated, otherwise false.
*/
public static long checkAndAllocateSymmetricPathId(long pathid) {
if (SfcConcurrencyAPI.getPathIdLock()) {
try {
long symmetricId = -1;
GenerationAlgorithmEnum genAlg = getGenerationAlgorithm();
if (genAlg == GenerationAlgorithmEnum.Random) {
symmetricId = pathid ^ 1 << 23;
if (!checkSuitablePathId(symmetricId)) {
symmetricId = -1;
}
} else if (genAlg == GenerationAlgorithmEnum.Sequential) {
symmetricId = generatePathIdSequentialIncrements();
}
if (symmetricId >= MIN_PATH_ID && allocatePathId(symmetricId)) {
return symmetricId;
} else {
return -1;
}
} finally {
SfcConcurrencyAPI.releasePathIdLock();
}
} else {
return -1;
}
}
/**
* Generate pathid, check and allocate if available.
*
*
*
* @return True if allocated, otherwise false.
*/
public static long checkAndAllocatePathId() {
if (SfcConcurrencyAPI.getPathIdLock()) {
try {
long pathId = -1;
GenerationAlgorithmEnum genAlg = getGenerationAlgorithm();
if (genAlg == GenerationAlgorithmEnum.Random) {
pathId = generatePathIdRandomIncrements();
} else if (genAlg == GenerationAlgorithmEnum.Sequential) {
pathId = generatePathIdSequentialIncrements();
}
if (pathId >= MIN_PATH_ID && allocatePathId(pathId)) {
return pathId;
} else {
return -1;
}
} finally {
SfcConcurrencyAPI.releasePathIdLock();
}
} else {
return -1;
}
}
/**
* Check if Pathid is available.
*
*
*
* @param pathid
* Candidate Path Id
* @return True if available, otherwise false.
*/
public static boolean checkSuitablePathId(long pathid) {
ServicePathIdKey servicePathIdKey = new ServicePathIdKey(pathid / Long.SIZE);
/* Entry into the bitarray */
long bitEntry = pathid % Long.SIZE;
InstanceIdentifier spIID;
spIID = InstanceIdentifier.builder(ServicePathIds.class).child(ServicePathId.class, servicePathIdKey).build();
ServicePathId servicePathId = SfcDataStoreAPI.readTransactionAPI(spIID, LogicalDatastoreType.OPERATIONAL);
return servicePathId == null || (1L << 64 - bitEntry & servicePathId.getPathIdBitarray()) == 0;
}
/**
* Allocate Pathid.
*
*
*
* @param pathid
* Path Id to be allocated
* @return True if allocated, otherwise false.
*/
public static boolean allocatePathId(long pathid) {
ServicePathIdKey servicePathIdKey = new ServicePathIdKey(pathid / Long.SIZE);
/* Entry into the bitarray */
long bitEntry = pathid % Long.SIZE;
long pathIdBitArray = 0;
InstanceIdentifier spIID;
spIID = InstanceIdentifier.builder(ServicePathIds.class).child(ServicePathId.class, servicePathIdKey).build();
ServicePathId servicePathId = SfcDataStoreAPI.readTransactionAPI(spIID, LogicalDatastoreType.OPERATIONAL);
if (servicePathId != null) {
pathIdBitArray = servicePathId.getPathIdBitarray() != null ? servicePathId.getPathIdBitarray() : 0;
}
ServicePathIdBuilder servicePathIdBuilder = new ServicePathIdBuilder();
servicePathIdBuilder.setPathIdBitarray(pathIdBitArray | 1L << Long.SIZE - bitEntry);
servicePathIdBuilder.withKey(servicePathIdKey);
return SfcDataStoreAPI.writeMergeTransactionAPI(spIID, servicePathIdBuilder.build(),
LogicalDatastoreType.OPERATIONAL);
}
/**
* Free Pathid.
*
*
*
* @param pathid
* Path Id to be freed
* @return True if freed, otherwise false.
*/
public static boolean freePathId(long pathid) {
if (SfcConcurrencyAPI.getPathIdLock()) {
try {
ServicePathIdKey servicePathIdKey = new ServicePathIdKey(pathid / Long.SIZE);
/* Entry into the bitarray */
long bitEntry = pathid % Long.SIZE;
InstanceIdentifier spIID;
spIID = InstanceIdentifier.builder(ServicePathIds.class).child(ServicePathId.class, servicePathIdKey)
.build();
ServicePathId servicePathId = SfcDataStoreAPI.readTransactionAPI(spIID,
LogicalDatastoreType.OPERATIONAL);
ServicePathIdBuilder servicePathIdBuilder = new ServicePathIdBuilder(servicePathId);
servicePathIdBuilder.withKey(servicePathIdKey);
servicePathIdBuilder
.setPathIdBitarray(servicePathId.getPathIdBitarray() & ~(1L << Long.SIZE - bitEntry));
return SfcDataStoreAPI.writeMergeTransactionAPI(spIID, servicePathIdBuilder.build(),
LogicalDatastoreType.OPERATIONAL);
} finally {
SfcConcurrencyAPI.releasePathIdLock();
}
}
return false;
}
/**
* Get the Path-Id Generation-algorithm from the data-store.
*
*
* If its not present, create it with the default value.
*
*
*
* @return generation-algorithm enum value
*/
private static GenerationAlgorithmEnum getGenerationAlgorithm() {
InstanceIdentifier spIID = InstanceIdentifier.builder(ServicePathIds.class).build();
ServicePathIds servicePathIds = SfcDataStoreAPI.readTransactionAPI(spIID, LogicalDatastoreType.OPERATIONAL);
if (servicePathIds == null) {
setGenerationAlgorithm(DEFAULT_GENERATION_ALGORITHM);
return GenerationAlgorithmEnum.forValue(DEFAULT_GENERATION_ALGORITHM);
}
GenerationAlgorithmEnum genAlgorithm = servicePathIds.getGenerationAlgorithm();
if (genAlgorithm == null) {
setGenerationAlgorithm(DEFAULT_GENERATION_ALGORITHM);
return GenerationAlgorithmEnum.forValue(DEFAULT_GENERATION_ALGORITHM);
} else {
return genAlgorithm;
}
}
/**
* Set the PathId Generate-algorithm in the data-store.
*
*
*
* @param genAlgorithm
* integer value as taken from service-path-id.yang
* @return True if successful, otherwise false
*/
private static boolean setGenerationAlgorithm(int genAlgorithm) {
return setGenerationAlgorithm(GenerationAlgorithmEnum.forValue(genAlgorithm));
}
/**
* Set the PathId Generate-algorithm in the data-store.
*
*
*
* @param genAlgorithm
* enum string value as taken from service-path-id.yang
* @return True if successful, otherwise false
*/
public static boolean setGenerationAlgorithm(GenerationAlgorithmEnum genAlgorithm) {
InstanceIdentifier spIID = InstanceIdentifier.builder(ServicePathIds.class).build();
ServicePathIdsBuilder servicePathIdsBuilder = new ServicePathIdsBuilder();
servicePathIdsBuilder.setGenerationAlgorithm(genAlgorithm);
return SfcDataStoreAPI.writeMergeTransactionAPI(spIID, servicePathIdsBuilder.build(),
LogicalDatastoreType.OPERATIONAL);
}
}