HONEYCOMB-249 Add External IP pool management

Change-Id: I3e57b09733b8c7060445ed1af7a5edb3348dd4e1
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>

12 files changed, 281 insertions, 19 deletions

diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/init/NatInitializer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/init/NatInitializer.java
index 37c456133..1c5b20392 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/init/NatInitializer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/init/NatInitializer.java
@@ -48,6 +48,9 @@ public final class NatInitializer extends AbstractDataTreeConverter<NatState, Na
                         .setNatInstance(operationalData.getNatInstances().getNatInstance().stream()
                                 .map(operNatInstance -> new NatInstanceBuilder()
                                         .setId(operNatInstance.getId())
+                                        // Ext IP pools
+                                        .setExternalIpAddressPool(operNatInstance.getNatCurrentConfig().getExternalIpAddressPool())
+                                        // Mapping entries
                                         .setMappingTable(new MappingTableBuilder()
                                                 .setMappingEntry(
                                                         operNatInstance.getMappingTable().getMappingEntry().stream()
@@ -58,6 +61,7 @@ public final class NatInitializer extends AbstractDataTreeConverter<NatState, Na
                                 .collect(Collectors.toList()))
                         .build())
                 .build();
+
         // TODO implement initialization for nat inbound/outbound NAT feature after VPP-459
     }
 }
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ExternalIpPoolCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ExternalIpPoolCustomizer.java
new file mode 100644
index 000000000..206b15e63
--- /dev/null
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ExternalIpPoolCustomizer.java
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * 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 io.fd.honeycomb.nat.read;
+
+import io.fd.honeycomb.translate.read.ReadContext;
+import io.fd.honeycomb.translate.read.ReadFailedException;
+import io.fd.honeycomb.translate.spi.read.ListReaderCustomizer;
+import io.fd.honeycomb.translate.util.read.cache.DumpCacheManager;
+import io.fd.honeycomb.translate.util.read.cache.EntityDumpExecutor;
+import io.fd.honeycomb.translate.vpp.util.Ipv4Translator;
+import io.fd.honeycomb.translate.vpp.util.JvppReplyConsumer;
+import io.fd.vpp.jvpp.snat.dto.SnatAddressDetails;
+import io.fd.vpp.jvpp.snat.dto.SnatAddressDetailsReplyDump;
+import io.fd.vpp.jvpp.snat.dto.SnatAddressDump;
+import io.fd.vpp.jvpp.snat.future.FutureJVppSnatFacade;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.LongStream;
+import javax.annotation.Nonnull;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Prefix;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.parameters.ExternalIpAddressPool;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.parameters.ExternalIpAddressPoolBuilder;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.parameters.ExternalIpAddressPoolKey;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.NatInstance;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.NatInstanceKey;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.nat.instance.NatCurrentConfigBuilder;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+final class ExternalIpPoolCustomizer implements
+        ListReaderCustomizer<ExternalIpAddressPool, ExternalIpAddressPoolKey, ExternalIpAddressPoolBuilder>,
+        JvppReplyConsumer, Ipv4Translator {
+
+    private static final Logger LOG = LoggerFactory.getLogger(ExternalIpPoolCustomizer.class);
+
+    private final DumpCacheManager<SnatAddressDetailsReplyDump, Void> dumpMgr;
+
+    ExternalIpPoolCustomizer(final DumpCacheManager<SnatAddressDetailsReplyDump, Void> dumpMgr) {
+        this.dumpMgr = dumpMgr;
+    }
+
+    @Nonnull
+    @Override
+    public ExternalIpAddressPoolBuilder getBuilder(@Nonnull final InstanceIdentifier<ExternalIpAddressPool> id) {
+        return new ExternalIpAddressPoolBuilder();
+    }
+
+    @Override
+    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<ExternalIpAddressPool> id,
+                                      @Nonnull final ExternalIpAddressPoolBuilder builder,
+                                      @Nonnull final ReadContext ctx) throws ReadFailedException {
+        LOG.trace("Reading current attributes for external IP pool: {}", id);
+
+        final Long poolId = id.firstKeyOf(ExternalIpAddressPool.class).getPoolId();
+        final SnatAddressDetails details =
+                dumpMgr.getDump(id, getClass().getName(), ctx.getModificationCache(), null)
+                        .or(new SnatAddressDetailsReplyDump()).snatAddressDetails.get(Math.toIntExact(poolId));
+
+        builder.setExternalIpPool(new Ipv4Prefix(arrayToIpv4AddressNoZoneReversed(details.ipAddress).getValue() + "/32"));
+        builder.setPoolId(poolId);
+
+        LOG.trace("External IP pool: {}. Read as: {}", id, builder);
+    }
+
+    @Nonnull
+    @Override
+    public List<ExternalIpAddressPoolKey> getAllIds(@Nonnull final InstanceIdentifier<ExternalIpAddressPool> id,
+                                                    @Nonnull final ReadContext ctx) throws ReadFailedException {
+        final NatInstanceKey natKey = id.firstKeyOf(NatInstance.class);
+        if (!natKey.equals(NatInstanceCustomizer.DEFAULT_VRF_ID)) {
+            // IP Pools are not vrf aware ... so they are only visible under default vrf (nat-instance)
+            return Collections.emptyList();
+        }
+
+        LOG.trace("Listing IDs for all external IP pools within nat-instance(vrf):{}", natKey);
+
+        // Since VPP returns every single (unordered) address instead of address range,
+        // there is no way to determine what the original ranges were when writing the data into VPP.
+
+        // That's why the write and read is not symmetrical in terms of data structure, instead,
+        // this customizer also returns every single address as a 32 prefix and assigns an artificial key to them
+
+        final long addressCount = dumpMgr.getDump(id, getClass().getName(), ctx.getModificationCache(), null)
+                .or(new SnatAddressDetailsReplyDump()).snatAddressDetails.stream()
+                .count();
+
+        final List<ExternalIpAddressPoolKey> ids = LongStream.range(0, addressCount)
+                .mapToObj(ExternalIpAddressPoolKey::new)
+                .collect(Collectors.toList());
+
+        LOG.trace("List of external IP pool ids: {}", ids);
+        return ids;
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> builder,
+                      @Nonnull final List<ExternalIpAddressPool> readData) {
+        ((NatCurrentConfigBuilder) builder).setExternalIpAddressPool(readData);
+    }
+
+    static final class AddressRangeDumpExecutor implements EntityDumpExecutor<SnatAddressDetailsReplyDump, Void>,
+            JvppReplyConsumer {
+        private final FutureJVppSnatFacade jvppSnat;
+
+        AddressRangeDumpExecutor(final FutureJVppSnatFacade jvppSnat) {
+            this.jvppSnat = jvppSnat;
+        }
+
+        @Nonnull
+        @Override
+        public SnatAddressDetailsReplyDump executeDump(final InstanceIdentifier<?> identifier, final Void params)
+                throws ReadFailedException {
+            return getReplyForRead(jvppSnat.snatAddressDump(new SnatAddressDump()).toCompletableFuture(), identifier);
+        }
+    }
+}
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/MappingEntryCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/MappingEntryCustomizer.java
index 469d361ee..c0f70452b 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/MappingEntryCustomizer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/MappingEntryCustomizer.java
@@ -47,7 +47,7 @@ import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class MappingEntryCustomizer implements Ipv4Translator,
+final class MappingEntryCustomizer implements Ipv4Translator,
         ListReaderCustomizer<MappingEntry, MappingEntryKey, MappingEntryBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(MappingEntryCustomizer.class);
@@ -55,8 +55,8 @@ public class MappingEntryCustomizer implements Ipv4Translator,
     private final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> dumpCacheManager;
     private final MappingEntryContext mappingEntryContext;
 
-    public MappingEntryCustomizer(final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> dumpCacheManager,
-                                  final MappingEntryContext mappingEntryContext) {
+    MappingEntryCustomizer(final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> dumpCacheManager,
+                           final MappingEntryContext mappingEntryContext) {
         this.dumpCacheManager = dumpCacheManager;
         this.mappingEntryContext = mappingEntryContext;
     }
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatInstanceCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatInstanceCustomizer.java
index cb639b962..43f4f1e0c 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatInstanceCustomizer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatInstanceCustomizer.java
@@ -40,10 +40,11 @@ import org.slf4j.LoggerFactory;
 final class NatInstanceCustomizer implements ListReaderCustomizer<NatInstance, NatInstanceKey, NatInstanceBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(NatInstanceCustomizer.class);
+    static final NatInstanceKey DEFAULT_VRF_ID = new NatInstanceKey(0L);
 
     private final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> dumpCacheManager;
 
-    public NatInstanceCustomizer(final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> dumpCacheManager) {
+    NatInstanceCustomizer(final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> dumpCacheManager) {
         this.dumpCacheManager = dumpCacheManager;
     }
 
@@ -66,6 +67,8 @@ final class NatInstanceCustomizer implements ListReaderCustomizer<NatInstance, N
     public List<NatInstanceKey> getAllIds(@Nonnull final InstanceIdentifier<NatInstance> id,
                                           @Nonnull final ReadContext context) throws ReadFailedException {
         LOG.trace("Listing IDs for all nat-instances");
+
+        // Find the nat instance IDs (vrf-ids) by listing all static mappings and their VRF assignment
         final List<NatInstanceKey> vrfIds =
                 dumpCacheManager.getDump(id, getClass().getName(), context.getModificationCache(), null)
                         .or(new SnatStaticMappingDetailsReplyDump()).snatStaticMappingDetails.stream()
@@ -73,6 +76,11 @@ final class NatInstanceCustomizer implements ListReaderCustomizer<NatInstance, N
                         .map(vrfId -> new NatInstanceKey((long)vrfId))
                         .collect(Collectors.toList());
 
+        // Add default vrf id if not present
+        if (!vrfIds.contains(DEFAULT_VRF_ID)) {
+            vrfIds.add(0, DEFAULT_VRF_ID);
+        }
+
         LOG.debug("List of nat-instance keys (vrf-ids): {}", vrfIds);
         return vrfIds;
     }
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatReaderFactory.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatReaderFactory.java
index 949009c62..9ae0e12f9 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatReaderFactory.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/NatReaderFactory.java
@@ -23,6 +23,7 @@ import io.fd.honeycomb.translate.impl.read.GenericListReader;
 import io.fd.honeycomb.translate.read.ReaderFactory;
 import io.fd.honeycomb.translate.read.registry.ModifiableReaderRegistryBuilder;
 import io.fd.honeycomb.translate.util.read.cache.DumpCacheManager;
+import io.fd.vpp.jvpp.snat.dto.SnatAddressDetailsReplyDump;
 import io.fd.vpp.jvpp.snat.dto.SnatStaticMappingDetailsReplyDump;
 import io.fd.vpp.jvpp.snat.future.FutureJVppSnatFacade;
 import javax.annotation.Nonnull;
@@ -30,11 +31,14 @@ import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev1509
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.NatStateBuilder;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.mapping.entry.ExternalSrcPort;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.mapping.entry.InternalSrcPort;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.parameters.ExternalIpAddressPool;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.NatInstances;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.NatInstancesBuilder;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.NatInstance;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.nat.instance.MappingTable;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.nat.instance.MappingTableBuilder;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.nat.instance.NatCurrentConfig;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.nat.instance.NatCurrentConfigBuilder;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.state.nat.instances.nat.instance.mapping.table.MappingEntry;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 
@@ -43,33 +47,39 @@ public class NatReaderFactory implements ReaderFactory {
     private static final InstanceIdentifier<NatState> NAT_OPER_ID = InstanceIdentifier.create(NatState.class);
     private static final InstanceIdentifier<NatInstances> NAT_INSTANCES_ID = NAT_OPER_ID.child(NatInstances.class);
     private static final InstanceIdentifier<NatInstance> NAT_INSTANCE_ID = NAT_INSTANCES_ID.child(NatInstance.class);
+    private static final InstanceIdentifier<NatCurrentConfig> CURRENT_CONFIG = NAT_INSTANCE_ID.child(NatCurrentConfig.class);
     private static final InstanceIdentifier<MappingTable> MAP_TABLE_ID = NAT_INSTANCE_ID.child(MappingTable.class);
     private static final InstanceIdentifier<MappingEntry> MAP_ENTRY_ID = MAP_TABLE_ID.child(MappingEntry.class);
 
     private final MappingEntryContext mappingEntryContext;
-    private final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> dumpCacheManager;
+    private final DumpCacheManager<SnatStaticMappingDetailsReplyDump, Void> mapEntryDumpMgr;
+    private final DumpCacheManager<SnatAddressDetailsReplyDump, Void> addressRangeDumpMgr;
 
     @Inject
     public NatReaderFactory(final FutureJVppSnatFacade jvppSnat,
                             final MappingEntryContext mappingEntryContext) {
         this.mappingEntryContext = mappingEntryContext;
-        this.dumpCacheManager = new DumpCacheManager.DumpCacheManagerBuilder<SnatStaticMappingDetailsReplyDump, Void>()
+        this.mapEntryDumpMgr = new DumpCacheManager.DumpCacheManagerBuilder<SnatStaticMappingDetailsReplyDump, Void>()
                 .withExecutor(new MappingEntryCustomizer.MappingEntryDumpExecutor(jvppSnat))
                 .build();
+        this.addressRangeDumpMgr = new DumpCacheManager.DumpCacheManagerBuilder<SnatAddressDetailsReplyDump, Void>()
+                .withExecutor(new ExternalIpPoolCustomizer.AddressRangeDumpExecutor(jvppSnat))
+                .build();
     }
 
     @Override
     public void init(@Nonnull final ModifiableReaderRegistryBuilder registry) {
         registry.addStructuralReader(NAT_OPER_ID, NatStateBuilder.class);
         registry.addStructuralReader(NAT_INSTANCES_ID, NatInstancesBuilder.class);
-        registry.add(new GenericListReader<>(NAT_INSTANCE_ID, new NatInstanceCustomizer(dumpCacheManager)));
+        registry.add(new GenericListReader<>(NAT_INSTANCE_ID, new NatInstanceCustomizer(mapEntryDumpMgr)));
         registry.addStructuralReader(MAP_TABLE_ID, MappingTableBuilder.class);
         registry.subtreeAdd(Sets.newHashSet(InstanceIdentifier.create(MappingEntry.class).child(ExternalSrcPort.class),
                 InstanceIdentifier.create(MappingEntry.class).child(InternalSrcPort.class)),
                 new GenericListReader<>(MAP_ENTRY_ID,
-                        new MappingEntryCustomizer(dumpCacheManager, mappingEntryContext)));
-
-        // TODO VPP-453 Implement address range read
+                        new MappingEntryCustomizer(mapEntryDumpMgr, mappingEntryContext)));
 
+        registry.addStructuralReader(CURRENT_CONFIG, NatCurrentConfigBuilder.class);
+        registry.add(new GenericListReader<>(CURRENT_CONFIG.child(ExternalIpAddressPool.class),
+                new ExternalIpPoolCustomizer(addressRangeDumpMgr)));
     }
 }
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceInboundNatCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceInboundNatCustomizer.java
index e1ebdd6d8..5be35ce16 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceInboundNatCustomizer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceInboundNatCustomizer.java
@@ -29,7 +29,7 @@ import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public final class InterfaceInboundNatCustomizer implements ReaderCustomizer<Inbound, InboundBuilder> {
+final class InterfaceInboundNatCustomizer implements ReaderCustomizer<Inbound, InboundBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(InterfaceInboundNatCustomizer.class);
 
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceOutboundNatCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceOutboundNatCustomizer.java
index fe28584ff..cb0103111 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceOutboundNatCustomizer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/read/ifc/InterfaceOutboundNatCustomizer.java
@@ -29,7 +29,7 @@ import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public final class InterfaceOutboundNatCustomizer implements ReaderCustomizer<Outbound, OutboundBuilder> {
+final class InterfaceOutboundNatCustomizer implements ReaderCustomizer<Outbound, OutboundBuilder> {
 
     private static final Logger LOG = LoggerFactory.getLogger(InterfaceOutboundNatCustomizer.class);
 
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ExternalIpPoolCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ExternalIpPoolCustomizer.java
new file mode 100644
index 000000000..856bc1355
--- /dev/null
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ExternalIpPoolCustomizer.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * 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 io.fd.honeycomb.nat.write;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import io.fd.honeycomb.translate.spi.write.ListWriterCustomizer;
+import io.fd.honeycomb.translate.vpp.util.Ipv4AddressRange;
+import io.fd.honeycomb.translate.vpp.util.Ipv4Translator;
+import io.fd.honeycomb.translate.vpp.util.JvppReplyConsumer;
+import io.fd.honeycomb.translate.write.WriteContext;
+import io.fd.honeycomb.translate.write.WriteFailedException;
+import io.fd.vpp.jvpp.snat.dto.SnatAddAddressRange;
+import io.fd.vpp.jvpp.snat.future.FutureJVppSnatFacade;
+import javax.annotation.Nonnull;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Prefix;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.config.nat.instances.NatInstance;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.parameters.ExternalIpAddressPool;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.parameters.ExternalIpAddressPoolKey;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+final class ExternalIpPoolCustomizer implements ListWriterCustomizer<ExternalIpAddressPool, ExternalIpAddressPoolKey>,
+        JvppReplyConsumer, Ipv4Translator {
+
+    private static final Logger LOG = LoggerFactory.getLogger(ExternalIpPoolCustomizer.class);
+
+    private final FutureJVppSnatFacade jvppSnat;
+
+    ExternalIpPoolCustomizer(@Nonnull final FutureJVppSnatFacade jvppSnat) {
+        this.jvppSnat = jvppSnat;
+    }
+
+    @Override
+    public void writeCurrentAttributes(@Nonnull final InstanceIdentifier<ExternalIpAddressPool> id,
+                                       @Nonnull final ExternalIpAddressPool dataAfter,
+                                       @Nonnull final WriteContext writeContext) throws WriteFailedException {
+        checkArgument(id.firstKeyOf(NatInstance.class).getId() == 0,
+                "External IP pools are only assignable for nat instance(vrf-id) with ID 0");
+        LOG.trace("Adding address range:{}, as: {}", id, dataAfter);
+        // TODO check overlaps ? VPP-478 maybe no necessary, depending on how VPP handles them
+        getReplyForCreate(jvppSnat.snatAddAddressRange(
+                getRequest(dataAfter.getExternalIpPool(), true)).toCompletableFuture(), id, dataAfter);
+        LOG.debug("Address range: {} added successfully", id);
+    }
+
+    @Override
+    public void updateCurrentAttributes(@Nonnull final InstanceIdentifier<ExternalIpAddressPool> id,
+                                        @Nonnull final ExternalIpAddressPool dataBefore,
+                                        @Nonnull final ExternalIpAddressPool dataAfter,
+                                        @Nonnull final WriteContext writeContext) throws WriteFailedException {
+        throw new WriteFailedException.UpdateFailedException(id, dataBefore, dataAfter,
+                new UnsupportedOperationException("Address range update is not supported"));
+    }
+
+    @Override
+    public void deleteCurrentAttributes(@Nonnull final InstanceIdentifier<ExternalIpAddressPool> id,
+                                        @Nonnull final ExternalIpAddressPool dataBefore,
+                                        @Nonnull final WriteContext writeContext) throws WriteFailedException {
+        LOG.trace("Deleting address range:{}, as: {}", id, dataBefore);
+        getReplyForDelete(jvppSnat.snatAddAddressRange(
+                getRequest(dataBefore.getExternalIpPool(), false)).toCompletableFuture(), id);
+        LOG.debug("Deleting range: {} added successfully", id);
+    }
+
+    private SnatAddAddressRange getRequest(final Ipv4Prefix externalIpPool, boolean isAdd) {
+        SnatAddAddressRange request = new SnatAddAddressRange();
+        // SNAT supports only IPv4 now, so does the model
+        final Ipv4AddressRange range = Ipv4AddressRange.fromPrefix(externalIpPool);
+        LOG.trace("Handling address range: {}", range);
+        request.isIp4 = 1;
+        request.isAdd = (byte) (isAdd ? 1 : 0);
+        request.firstIpAddress = ipv4AddressNoZoneToArray(range.getStart());
+        request.lastIpAddress = ipv4AddressNoZoneToArray(range.getEnd());
+        return request;
+    }
+}
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/NatWriterFactory.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/NatWriterFactory.java
index ecc886bf0..7887d463a 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/NatWriterFactory.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/NatWriterFactory.java
@@ -31,6 +31,7 @@ import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev1509
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.config.nat.instances.NatInstance;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.config.nat.instances.nat.instance.MappingTable;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.config.nat.instances.nat.instance.mapping.table.MappingEntry;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.nat.rev150908.nat.parameters.ExternalIpAddressPool;
 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
 
 /**
@@ -62,5 +63,11 @@ public final class NatWriterFactory implements WriterFactory {
         registry.subtreeAdd(Sets.newHashSet(InstanceIdentifier.create(MappingEntry.class).child(ExternalSrcPort.class),
                 InstanceIdentifier.create(MappingEntry.class).child(InternalSrcPort.class)),
                 new GenericListWriter<>(MAP_ENTRY_ID, new MappingEntryCustomizer(jvppSnat, mappingEntryContext)));
+
+        // External address pool has to be executed before mapping entry. Because adding mapping entries requires to
+        //  already have an IP range predefined ... in some cases
+        registry.addBefore(new GenericListWriter<>(NAT_INSTANCE_ID.child(ExternalIpAddressPool.class),
+                new ExternalIpPoolCustomizer(jvppSnat)),
+                MAP_ENTRY_ID);
     }
 }
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceInboundNatCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceInboundNatCustomizer.java
index 8ab1c284c..e72e12ada 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceInboundNatCustomizer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceInboundNatCustomizer.java
@@ -28,7 +28,7 @@ final class InterfaceInboundNatCustomizer extends AbstractInterfaceNatCustomizer
     private static final Logger LOG = LoggerFactory.getLogger(InterfaceInboundNatCustomizer.class);
 
     InterfaceInboundNatCustomizer(@Nonnull final FutureJVppSnatFacade jvppSnat,
-                                         @Nonnull final NamingContext ifcContext) {
+                                  @Nonnull final NamingContext ifcContext) {
         super(jvppSnat, ifcContext);
     }
 
diff --git a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceOutboundNatCustomizer.java b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceOutboundNatCustomizer.java
index fdd174eba..488edc73c 100644
--- a/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceOutboundNatCustomizer.java
+++ b/nat/nat2vpp/src/main/java/io/fd/honeycomb/nat/write/ifc/InterfaceOutboundNatCustomizer.java
@@ -28,7 +28,7 @@ final class InterfaceOutboundNatCustomizer extends AbstractInterfaceNatCustomize
     private static final Logger LOG = LoggerFactory.getLogger(InterfaceOutboundNatCustomizer.class);
 
     InterfaceOutboundNatCustomizer(@Nonnull final FutureJVppSnatFacade jvppSnat,
-                                          @Nonnull final NamingContext ifcContext) {
+                                   @Nonnull final NamingContext ifcContext) {
         super(jvppSnat, ifcContext);
     }
 
diff --git a/vpp-common/vpp-translate-utils/src/main/java/io/fd/honeycomb/translate/vpp/util/Ipv4AddressRange.java b/vpp-common/vpp-translate-utils/src/main/java/io/fd/honeycomb/translate/vpp/util/Ipv4AddressRange.java
index 8408e79f4..7528c5464 100644
--- a/vpp-common/vpp-translate-utils/src/main/java/io/fd/honeycomb/translate/vpp/util/Ipv4AddressRange.java
+++ b/vpp-common/vpp-translate-utils/src/main/java/io/fd/honeycomb/translate/vpp/util/Ipv4AddressRange.java
@@ -20,16 +20,22 @@ import java.util.Objects;
 import javax.annotation.Nonnull;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4AddressNoZone;
 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Prefix;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * IPv4 address range representation.
  */
 public final class Ipv4AddressRange {
 
+    private static final Logger LOG = LoggerFactory.getLogger(Ipv4AddressRange.class);
+
     private final Ipv4AddressNoZone start;
     private final Ipv4AddressNoZone end;
 
-    private Ipv4AddressRange(@Nonnull final Ipv4AddressNoZone start, @Nonnull final Ipv4AddressNoZone end) {
+    private Ipv4AddressRange(
+                             @Nonnull final Ipv4AddressNoZone start,
+                             @Nonnull final Ipv4AddressNoZone end) {
         this.start = start;
         this.end = end;
     }
@@ -71,9 +77,9 @@ public final class Ipv4AddressRange {
     /**
      * Create address range from prefix.
      */
-    public static Ipv4AddressRange fromPrefix(final Ipv4Prefix externalIpPool) {
-        final String addressString = externalIpPool.getValue().split("/")[0];
-        byte prefixLength = Ipv4Translator.INSTANCE.extractPrefix(externalIpPool);
+    public static Ipv4AddressRange fromPrefix(@Nonnull final Ipv4Prefix prefix) {
+        final String addressString = prefix.getValue().split("/")[0];
+        byte prefixLength = Ipv4Translator.INSTANCE.extractPrefix(prefix);
 
         if (prefixLength == 32) {
             // 32 Prefix can be handled instantly
@@ -108,7 +114,8 @@ public final class Ipv4AddressRange {
             prefixAddrBytesF[i] = (byte) 255;
         }
 
-        return new Ipv4AddressRange(Ipv4Translator.INSTANCE.arrayToIpv4AddressNoZoneReversed(prefixAddrBytes0),
+        return new Ipv4AddressRange(
+                Ipv4Translator.INSTANCE.arrayToIpv4AddressNoZoneReversed(prefixAddrBytes0),
                 Ipv4Translator.INSTANCE.arrayToIpv4AddressNoZoneReversed(prefixAddrBytesF));
     }
 }