Make some DHCP options and host discovery configurable

- Added broadcast option
- Made host discovery from DHCP configurable
- Some code cleanups

Change-Id: I42191c2fd17ef309c73a5382730d708686b835cd

@@ -15,7 +15,6 @@
  */
 package org.onosproject.cordvtn.impl;
 
-import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
@@ -34,6 +33,7 @@ import org.onosproject.cordvtn.api.Instance;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
 import org.onosproject.dhcp.DhcpService;
+import org.onosproject.dhcp.IpAssignment;
 import org.onosproject.mastership.MastershipService;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.DefaultAnnotations;
@@ -70,7 +70,7 @@ import org.onosproject.xosclient.api.XosAccess;
 import org.onosproject.xosclient.api.XosClientService;
 import org.slf4j.Logger;
 
-import java.util.List;
+import java.util.Date;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
@@ -82,6 +82,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
 import static org.onlab.util.Tools.groupedThreads;
 import static org.onosproject.cordvtn.api.Instance.*;
+import static org.onosproject.dhcp.IpAssignment.AssignmentStatus.Option_RangeNotEnforced;
+import static org.onosproject.xosclient.api.VtnService.NetworkType.MANAGEMENT;
 import static org.onosproject.xosclient.api.VtnService.NetworkType.PRIVATE;
 import static org.slf4j.LoggerFactory.getLogger;
 
@@ -97,6 +99,7 @@ public class CordVtnInstanceManager extends AbstractProvider implements HostProv
     private static final String XOS_ACCESS_ERROR = "XOS access is not configured";
     private static final String OPENSTACK_ACCESS_ERROR = "OpenStack access is not configured";
     private static final Ip4Address DEFAULT_DNS = Ip4Address.valueOf("8.8.8.8");
+    private static final int DHCP_INFINITE_LEASE = -1;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected CoreService coreService;
@@ -273,7 +276,6 @@ public class CordVtnInstanceManager extends AbstractProvider implements HostProv
             arpProxy.addGateway(service.serviceIp(), privateGatewayMac);
             arpProxy.sendGratuitousArpForGateway(service.serviceIp(), Sets.newHashSet(instance));
         }
-
         if (!instance.isNestedInstance()) {
             registerDhcpLease(instance, service);
         }
@@ -295,17 +297,25 @@ public class CordVtnInstanceManager extends AbstractProvider implements HostProv
     }
 
     private void registerDhcpLease(Instance instance, VtnService service) {
-        List<Ip4Address> options = Lists.newArrayList();
-        options.add(Ip4Address.makeMaskPrefix(service.subnet().prefixLength()));
-        options.add(service.serviceIp().getIp4Address());
-        options.add(service.serviceIp().getIp4Address());
-        options.add(DEFAULT_DNS);
+        Ip4Address broadcast = Ip4Address.makeMaskedAddress(
+                instance.ipAddress(),
+                service.subnet().prefixLength());
+
+        IpAssignment.Builder ipBuilder = IpAssignment.builder()
+                .ipAddress(instance.ipAddress())
+                .leasePeriod(DHCP_INFINITE_LEASE)
+                .timestamp(new Date())
+                .subnetMask(Ip4Address.makeMaskPrefix(service.subnet().prefixLength()))
+                .broadcast(broadcast)
+                .domainServer(DEFAULT_DNS)
+                .assignmentStatus(Option_RangeNotEnforced);
+
+        if (service.networkType() != MANAGEMENT) {
+            ipBuilder = ipBuilder.routerAddress(service.serviceIp().getIp4Address());
+        }
 
         log.debug("Set static DHCP mapping for {} {}", instance.mac(), instance.ipAddress());
-        dhcpService.setStaticMapping(instance.mac(),
-                                     instance.ipAddress(),
-                                     true,
-                                     options);
+        dhcpService.setStaticMapping(instance.mac(), ipBuilder.build());
     }
 
     private VtnService getVtnService(VtnServiceId serviceId) {

@@ -19,7 +19,6 @@ import org.onlab.packet.Ip4Address;
 import org.onlab.packet.MacAddress;
 import org.onosproject.net.HostId;
 
-import java.util.List;
 import java.util.Map;
 
 
@@ -58,16 +57,12 @@ public interface DhcpService {
 
     /**
      * Registers a static IP mapping with the DHCP Server.
-     * Supports rangeNotEnforced option
      *
-     * @param macID macID of the client
-     * @param ipAddress IP Address requested for the client
-     * @param rangeNotEnforced true if rangeNotEnforced was set and the mapping will be eternal
-     * @param addressList subnetMask, DHCP/Router/DNS IP Addresses if rangeNotEnforced was set
+     * @param macAddress mac address to have a given ip assignment
+     * @param ipRequest ip address and dhcp options
      * @return true if the mapping was successfully added, false otherwise
      */
-    boolean setStaticMapping(MacAddress macID, Ip4Address ipAddress, boolean rangeNotEnforced,
-                             List<Ip4Address> addressList);
+    boolean setStaticMapping(MacAddress macAddress, IpAssignment ipRequest);
 
     /**
      * Removes a static IP mapping with the DHCP Server.

@@ -19,7 +19,6 @@ import org.onlab.packet.Ip4Address;
 import org.onlab.packet.MacAddress;
 import org.onosproject.net.HostId;
 
-import java.util.List;
 import java.util.Map;
 
 
@@ -41,7 +40,7 @@ public interface DhcpStore {
      *
      * @param hostId Host ID of the client requesting an IP
      * @param requestedIP requested IP address
-     * @return IP address assigned to the Mac ID
+     * @return IP address assigned to the Mac address; null if no available IP
      */
     Ip4Address suggestIP(HostId hostId, Ip4Address requestedIP);
 
@@ -50,14 +49,10 @@ public interface DhcpStore {
      * Assigns the requested IP to the Mac ID, in response to a DHCP REQUEST message.
      *
      * @param hostId Host Id of the client requesting an IP
-     * @param ipAddr IP Address being requested
-     * @param leaseTime Lease time offered by the server for this mapping
-     * @param rangeNotEnforced true if rangeNotEnforced was set
-     * @param addressList subnetMask, DHCP/Router/DNS IP Addresses if rangeNotEnforced was set
+     * @param ipAssignment ip assignment
      * @return returns true if the assignment was successful, false otherwise
      */
-    boolean assignIP(HostId hostId, Ip4Address ipAddr, int leaseTime, boolean rangeNotEnforced,
-                     List<Ip4Address> addressList);
+    boolean assignIP(HostId hostId, IpAssignment ipAssignment);
 
 
     /**
@@ -92,21 +87,19 @@ public interface DhcpStore {
     /**
      * Assigns the requested IP to the MAC ID (if available) for an indefinite period of time.
      *
-     * @param macID macID of the client
-     * @param ipAddr IP Address requested for the client
-     * @param rangeNotEnforced true if rangeNotEnforced was set
-     * @param addressList subnetMask, DHCP/Router/DNS IP Addresses rangeNotEnforced was set
+     * @param macAddress mac address of the client
+     * @param ipAssignment ip address and dhcp options requested for the client
      * @return true if the mapping was successfully registered, false otherwise
      */
-    boolean assignStaticIP(MacAddress macID, Ip4Address ipAddr, boolean rangeNotEnforced, List<Ip4Address> addressList);
+    boolean assignStaticIP(MacAddress macAddress, IpAssignment ipAssignment);
 
     /**
      * Removes a static IP mapping associated with the given MAC ID from the DHCP Server.
      *
-     * @param macID macID of the client
+     * @param macAddress mac address of the client
      * @return true if the mapping was successfully registered, false otherwise
      */
-    boolean removeStaticIP(MacAddress macID);
+    boolean removeStaticIP(MacAddress macAddress);
 
     /**
      * Returns the list of all the available IPs with the server.

@@ -27,22 +27,15 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
 public final class IpAssignment {
 
+    // TODO make some dhcp options optional
     private final Ip4Address ipAddress;
-
     private final Date timestamp;
-
     private final long leasePeriod;
-
     private final Ip4Address subnetMask;
-
+    private final Ip4Address broadcast;
     private final Ip4Address dhcpServer;
-
     private final Ip4Address routerAddress;
-
     private final Ip4Address domainServer;
-
-    private final boolean rangeNotEnforced;
-
     private final AssignmentStatus assignmentStatus;
 
     public enum AssignmentStatus {
@@ -52,8 +45,10 @@ public final class IpAssignment {
         Option_Requested,
 
         /**
-         * IP Assignment has been requested by a OpenStack.
+         * Static IP Assignment with unregistered IP range.
+         * This assignment can only be added or removed by set or remove static mapping.
          */
+        // TODO allow multiple IP ranges and remove this option
         Option_RangeNotEnforced,
         /**
          * IP has been assigned to a host.
@@ -70,30 +65,34 @@ public final class IpAssignment {
      * Constructor for IPAssignment, where the ipAddress, the lease period, the timestamp
      * and assignment status is supplied.
      *
-     * @param ipAddress
-     * @param leasePeriod
-     * @param timestamp
-     * @param assignmentStatus
-     * @param subnetMask
-     * @param dhcpServer
-     * @param routerAddress
-     * @param domainServer
-     * @param rangeNotEnforced
+     * @param ipAddress ip address to assign
+     * @param leasePeriod lease period
+     * @param timestamp time stamp of the assignment
+     * @param assignmentStatus statue of the assignment
+     * @param subnetMask subnet mask of assigned ip range
+     * @param broadcast broadcast address
+     * @param dhcpServer dhcp server address
+     * @param routerAddress router address
+     * @param domainServer domain server address
      */
     private IpAssignment(Ip4Address ipAddress,
                          long leasePeriod,
                          Date timestamp,
-                         AssignmentStatus assignmentStatus, Ip4Address subnetMask, Ip4Address dhcpServer,
-                         Ip4Address routerAddress, Ip4Address domainServer, boolean rangeNotEnforced) {
+                         AssignmentStatus assignmentStatus,
+                         Ip4Address subnetMask,
+                         Ip4Address broadcast,
+                         Ip4Address dhcpServer,
+                         Ip4Address routerAddress,
+                         Ip4Address domainServer) {
         this.ipAddress = ipAddress;
         this.leasePeriod = leasePeriod;
         this.timestamp = timestamp;
         this.assignmentStatus = assignmentStatus;
         this.subnetMask = subnetMask;
+        this.broadcast = broadcast;
         this.dhcpServer = dhcpServer;
         this.routerAddress = routerAddress;
         this.domainServer = domainServer;
-        this.rangeNotEnforced = rangeNotEnforced;
     }
 
     /**
@@ -141,26 +140,51 @@ public final class IpAssignment {
         return (int) this.leasePeriod * 1000;
     }
 
+    /**
+     * Returns subnet mask of the IP assignment.
+     *
+     * @return subnet mask
+     */
     public Ip4Address subnetMask() {
         return subnetMask;
     }
 
+    /**
+     * Returns broadcast address of the IP assignment.
+     *
+     * @return broadcast address
+     */
+    public Ip4Address broadcast() {
+        return broadcast;
+    }
+
+    /**
+     * Returns dhcp server of the IP assignment.
+     *
+     * @return dhcp server ip address
+     */
     public Ip4Address dhcpServer() {
         return dhcpServer;
     }
 
+    /**
+     * Returns router address of the IP assignment.
+     *
+     * @return router ip address
+     */
     public Ip4Address routerAddress() {
         return routerAddress;
     }
 
+    /**
+     * Returns domain server address.
+     *
+     * @return domain server ip address
+     */
     public Ip4Address domainServer() {
         return domainServer;
     }
 
-    public boolean rangeNotEnforced() {
-        return rangeNotEnforced;
-    }
-
     @Override
     public String toString() {
         return MoreObjects.toStringHelper(getClass())
@@ -169,10 +193,10 @@ public final class IpAssignment {
                 .add("lease", leasePeriod)
                 .add("assignmentStatus", assignmentStatus)
                 .add("subnetMask", subnetMask)
+                .add("broadcast", broadcast)
                 .add("dhcpServer", dhcpServer)
                 .add("routerAddress", routerAddress)
                 .add("domainServer", domainServer)
-                .add("rangeNotEnforced", rangeNotEnforced)
                 .toString();
     }
 
@@ -201,25 +225,16 @@ public final class IpAssignment {
     public static final class Builder {
 
         private Ip4Address ipAddress;
-
         private Date timeStamp;
-
         private long leasePeriod;
-
         private AssignmentStatus assignmentStatus;
-
         private Ip4Address subnetMask;
-
+        private Ip4Address broadcast;
         private Ip4Address dhcpServer;
-
-        private Ip4Address domainServer;
-
         private Ip4Address routerAddress;
-
-        private boolean rangeNotEnforced = false;
+        private Ip4Address domainServer;
 
         private Builder() {
-
         }
 
         private Builder(IpAssignment ipAssignment) {
@@ -227,12 +242,24 @@ public final class IpAssignment {
             timeStamp = ipAssignment.timestamp();
             leasePeriod = ipAssignment.leasePeriod();
             assignmentStatus = ipAssignment.assignmentStatus();
+            subnetMask = ipAssignment.subnetMask();
+            broadcast = ipAssignment.broadcast();
+            dhcpServer = ipAssignment.dhcpServer();
+            routerAddress = ipAssignment.routerAddress();
+            domainServer = ipAssignment.domainServer();
         }
 
         public IpAssignment build() {
             validateInputs();
-            return new IpAssignment(ipAddress, leasePeriod, timeStamp, assignmentStatus, subnetMask,
-                    dhcpServer, routerAddress, domainServer, rangeNotEnforced);
+            return new IpAssignment(ipAddress,
+                                    leasePeriod,
+                                    timeStamp,
+                                    assignmentStatus,
+                                    subnetMask,
+                                    broadcast,
+                                    dhcpServer,
+                                    routerAddress,
+                                    domainServer);
         }
 
         public Builder ipAddress(Ip4Address addr) {
@@ -260,6 +287,11 @@ public final class IpAssignment {
             return this;
         }
 
+        public Builder broadcast(Ip4Address broadcast) {
+            this.broadcast = broadcast;
+            return this;
+        }
+
         public Builder dhcpServer(Ip4Address dhcpServer) {
             this.dhcpServer = dhcpServer;
             return this;
@@ -275,25 +307,12 @@ public final class IpAssignment {
             return this;
         }
 
-        public Builder rangeNotEnforced(boolean rangeNotEnforced) {
-            this.rangeNotEnforced = rangeNotEnforced;
-            return this;
-        }
-
-
         private void validateInputs() {
             checkNotNull(ipAddress, "IP Address must be specified");
             checkNotNull(assignmentStatus, "Assignment Status must be specified");
             checkNotNull(leasePeriod, "Lease Period must be specified");
             checkNotNull(timeStamp, "Timestamp must be specified");
 
-            if (rangeNotEnforced) {
-                checkNotNull(subnetMask, "subnetMask must be specified in case of rangeNotEnforced");
-                checkNotNull(dhcpServer, "dhcpServer must be specified in case of rangeNotEnforced");
-                checkNotNull(domainServer, "domainServer must be specified in case of rangeNotEnforced");
-                checkNotNull(routerAddress, "routerAddress must be specified in case of rangeNotEnforced");
-            }
-
             switch (assignmentStatus) {
                 case Option_Requested:
                 case Option_RangeNotEnforced:

@@ -15,13 +15,17 @@
  */
 package org.onosproject.dhcp.cli;
 
-import com.google.common.collect.Lists;
 import org.apache.karaf.shell.commands.Argument;
 import org.apache.karaf.shell.commands.Command;
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.MacAddress;
 import org.onosproject.cli.AbstractShellCommand;
 import org.onosproject.dhcp.DhcpService;
+import org.onosproject.dhcp.IpAssignment;
+
+import java.util.Date;
+
+import static org.onosproject.dhcp.IpAssignment.AssignmentStatus.Option_Requested;
 
 /**
  * Registers a static MAC Address to IP Mapping with the DHCP Server.
@@ -49,7 +53,15 @@ public class DhcpSetStaticMapping extends AbstractShellCommand {
         try {
             MacAddress macID = MacAddress.valueOf(macAddr);
             Ip4Address ipAddress = Ip4Address.valueOf(ipAddr);
-            if (dhcpService.setStaticMapping(macID, ipAddress, false, Lists.newArrayList())) {
+
+            IpAssignment ipAssignment = IpAssignment.builder()
+                    .ipAddress(ipAddress)
+                    .leasePeriod(dhcpService.getLeaseTime())
+                    .timestamp(new Date())
+                    .assignmentStatus(Option_Requested)
+                    .build();
+
+            if (dhcpService.setStaticMapping(macID, ipAssignment)) {
                 print(DHCP_SUCCESS);
             } else {
                 print(DHCP_FAILURE);

@@ -18,7 +18,6 @@ package org.onosproject.dhcp.rest;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
-import com.google.common.collect.Lists;
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.MacAddress;
 import org.onosproject.dhcp.DhcpService;
@@ -36,8 +35,11 @@ import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Date;
 import java.util.Map;
 
+import static org.onosproject.dhcp.IpAssignment.AssignmentStatus.Option_Requested;
+
 /**
  * Manage DHCP address assignments.
  */
@@ -120,10 +122,15 @@ public class DhcpWebResource extends AbstractWebResource {
             JsonNode macID = jsonTree.get("mac");
             JsonNode ip = jsonTree.get("ip");
             if (macID != null && ip != null) {
+                IpAssignment ipAssignment = IpAssignment.builder()
+                        .ipAddress(Ip4Address.valueOf(ip.asText()))
+                        .leasePeriod(service.getLeaseTime())
+                        .timestamp(new Date())
+                        .assignmentStatus(Option_Requested)
+                        .build();
 
                 if (!service.setStaticMapping(MacAddress.valueOf(macID.asText()),
-                                              Ip4Address.valueOf(ip.asText()),
-                                              false, Lists.newArrayList())) {
+                                              ipAssignment)) {
                     throw new IllegalArgumentException("Static Mapping Failed. " +
                                                                "The IP maybe unavailable.");
                 }

@@ -28,6 +28,7 @@ import org.onlab.packet.Ip4Address;
 import org.onlab.packet.IpAddress;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.UDP;
+import org.onosproject.cfg.ComponentConfigAdapter;
 import org.onosproject.core.CoreServiceAdapter;
 import org.onosproject.dhcp.DhcpStore;
 import org.onosproject.dhcp.IpAssignment;
@@ -93,6 +94,7 @@ public class DhcpManagerTest {
         hostProviderService = new TestHostProviderService(new TestHostProvider());
         dhcpXManager.hostProviderService = hostProviderService;
         dhcpXManager.hostProviderRegistry = new TestHostRegistry();
+        dhcpXManager.componentConfigService = new TestComponentConfig();
         dhcpXManager.activate();
     }
 
@@ -228,8 +230,7 @@ public class DhcpManagerTest {
             return Ip4Address.valueOf(EXPECTED_IP);
         }
 
-        public boolean assignIP(HostId hostId, Ip4Address ipAddr, int leaseTime, boolean fromOpenStack,
-                                List<Ip4Address> addressList) {
+        public boolean assignIP(HostId hostId, IpAssignment ipAssignment) {
             return true;
         }
 
@@ -256,8 +257,7 @@ public class DhcpManagerTest {
             return map;
         }
 
-        public boolean assignStaticIP(MacAddress macID, Ip4Address ipAddr, boolean fromOpenStack,
-                                      List<Ip4Address> addressList) {
+        public boolean assignStaticIP(MacAddress macID, IpAssignment ipAssignment) {
             return true;
         }
 
@@ -327,6 +327,13 @@ public class DhcpManagerTest {
     }
 
     /**
+     * Mocks the ComponentConfigRegistry.
+     */
+    private class TestComponentConfig extends ComponentConfigAdapter {
+
+    }
+
+    /**
      * Mocks the HostProviderService.
      */
     private class TestHostProviderService extends AbstractProviderService<HostProvider>

@@ -9,14 +9,14 @@
         "router": "10.0.0.1",
         "domain": "10.0.0.1",
         "ttl": "63",
-        "lease": "300",
+        "lease": 300,
         "renew": "150",
-        "rebind": "200",
+        "rebind": 200,
         "delay": "3",
-        "timeout": "150",
+        "timeout": 150,
         "startip": "10.0.0.110",
         "endip": "10.0.0.130"
       }
     }
   }
-}
\ No newline at end of file
+}

@@ -15,7 +15,6 @@
  */
 package org.onosproject.openstacknetworking.switching;
 
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
 import org.apache.felix.scr.annotations.Activate;
@@ -26,9 +25,11 @@ import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.packet.Ethernet;
 import org.onlab.packet.Ip4Address;
+import org.onlab.packet.IpPrefix;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.core.CoreService;
 import org.onosproject.dhcp.DhcpService;
+import org.onosproject.dhcp.IpAssignment;
 import org.onosproject.event.AbstractEvent;
 import org.onosproject.net.Device;
 import org.onosproject.net.DeviceId;
@@ -61,13 +62,18 @@ import org.onosproject.openstacknetworking.OpenstackNetworkingConfig;
 import org.onosproject.openstacknetworking.OpenstackSwitchingService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import java.util.List;
+
+import java.util.Date;
 import java.util.Collection;
 import java.util.Map;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
 import static org.onlab.util.Tools.groupedThreads;
+import static org.onosproject.dhcp.IpAssignment.AssignmentStatus.Option_RangeNotEnforced;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 @Service
 @Component(immediate = true)
@@ -117,8 +123,9 @@ public class OpenstackSwitchingManager implements OpenstackSwitchingService {
     public static final String PORTNAME = "portName";
     private static final String ROUTER_INTERFACE = "network:router_interface";
     public static final String DEVICE_OWNER_GATEWAY = "network:router_gateway";
-    public static final String DNS_SERVER_IP = "8.8.8.8";
+    public static final Ip4Address DNS_SERVER_IP = Ip4Address.valueOf("8.8.8.8");
     private static final String FORWARD_SLASH = "/";
+    private static final int DHCP_INFINITE_LEASE = -1;
 
 
     private ApplicationId appId;
@@ -372,42 +379,41 @@ public class OpenstackSwitchingManager implements OpenstackSwitchingService {
     }
 
     private void registerDhcpInfo(OpenstackPort openstackPort) {
-        Ip4Address ip4Address, subnetMask, gatewayIPAddress, dhcpServer, domainServer;
-        OpenstackSubnet openstackSubnet;
+        checkNotNull(openstackPort);
+        checkArgument(!openstackPort.fixedIps().isEmpty());
 
-        ip4Address = (Ip4Address) openstackPort.fixedIps().values().stream().findFirst().orElse(null);
-
-        openstackSubnet = openstackService.subnets().stream()
+        OpenstackSubnet openstackSubnet = openstackService.subnets().stream()
                 .filter(n -> n.networkId().equals(openstackPort.networkId()))
-                .findFirst().get();
-
-        subnetMask = Ip4Address.valueOf(buildSubnetMask(openstackSubnet.cidr()));
-        gatewayIPAddress = Ip4Address.valueOf(openstackSubnet.gatewayIp());
-        dhcpServer = gatewayIPAddress;
-        // TODO: supports multiple DNS servers
-        if (openstackSubnet.dnsNameservers().isEmpty()) {
-            domainServer = Ip4Address.valueOf(DNS_SERVER_IP);
-        } else {
-            domainServer = openstackSubnet.dnsNameservers().get(0);
+                .findFirst().orElse(null);
+        if (openstackSubnet == null) {
+            log.warn("Failed to find subnet for {}", openstackPort);
+            return;
         }
-        List<Ip4Address> options = ImmutableList.of(subnetMask, dhcpServer, gatewayIPAddress, domainServer);
-
-        dhcpService.setStaticMapping(openstackPort.macAddress(), ip4Address, true, options);
-    }
 
-    private byte[] buildSubnetMask(String cidr) {
-        int prefix;
-        String[] parts = cidr.split(FORWARD_SLASH);
-        prefix = Integer.parseInt(parts[1]);
-        int mask = 0xffffffff << (32 - prefix);
-        byte[] bytes = new byte[]{(byte) (mask >>> 24),
-                (byte) (mask >> 16 & 0xff), (byte) (mask >> 8 & 0xff), (byte) (mask & 0xff)};
+        Ip4Address ipAddress = openstackPort.fixedIps().values().stream().findFirst().get();
+        IpPrefix subnetPrefix = IpPrefix.valueOf(openstackSubnet.cidr());
+        Ip4Address broadcast = Ip4Address.makeMaskedAddress(
+                ipAddress,
+                subnetPrefix.prefixLength());
 
-        return bytes;
+        // TODO: supports multiple DNS servers
+        Ip4Address domainServer = openstackSubnet.dnsNameservers().isEmpty() ?
+                DNS_SERVER_IP : openstackSubnet.dnsNameservers().get(0);
+
+        IpAssignment ipAssignment = IpAssignment.builder()
+                .ipAddress(ipAddress)
+                .leasePeriod(DHCP_INFINITE_LEASE)
+                .timestamp(new Date())
+                .subnetMask(Ip4Address.makeMaskPrefix(subnetPrefix.prefixLength()))
+                .broadcast(broadcast)
+                .domainServer(domainServer)
+                .assignmentStatus(Option_RangeNotEnforced)
+                .routerAddress(Ip4Address.valueOf(openstackSubnet.gatewayIp()))
+                .build();
+
+        dhcpService.setStaticMapping(openstackPort.macAddress(), ipAssignment);
     }
 
-
-
     private class InternalPacketProcessor implements PacketProcessor {
 
         @Override