Support multiple IPv4 / IPv6 addresses in MdnsResponse

If the mDNS service has multiple IPv4 / IPv6 addresses, only the
last added address will be present on the response. Since the
NsdServiceInfo supports multiple host addresses in Android U, the
MdnsResponse should also support multiple IPv4 / IPv6 addresses
in favor of providing accurate service info to clients.

Check cache flush flag on the response when adding a new address
record. Per RFC6762 10.2, clear all address records if the
cache-flush bit set.

Bug: 268586836
Test: atest FrameworksNetTests
Change-Id: I04548a3f16837939f3131b84c1033377ff81d521
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsResponse.java b/service-t/src/com/android/server/connectivity/mdns/MdnsResponse.java
index a6e3762..be2555b 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsResponse.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsResponse.java
@@ -25,6 +25,7 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
@@ -36,8 +37,8 @@
     private final List<MdnsPointerRecord> pointerRecords;
     private MdnsServiceRecord serviceRecord;
     private MdnsTextRecord textRecord;
-    private MdnsInetAddressRecord inet4AddressRecord;
-    private MdnsInetAddressRecord inet6AddressRecord;
+    @NonNull private List<MdnsInetAddressRecord> inet4AddressRecords;
+    @NonNull private List<MdnsInetAddressRecord> inet6AddressRecords;
     private long lastUpdateTime;
     private final int interfaceIndex;
     @Nullable private final Network network;
@@ -49,6 +50,8 @@
         lastUpdateTime = now;
         records = new LinkedList<>();
         pointerRecords = new LinkedList<>();
+        inet4AddressRecords = new ArrayList<>();
+        inet6AddressRecords = new ArrayList<>();
         this.interfaceIndex = interfaceIndex;
         this.network = network;
         this.serviceName = serviceName;
@@ -59,8 +62,8 @@
         pointerRecords = new ArrayList<>(base.pointerRecords);
         serviceRecord = base.serviceRecord;
         textRecord = base.textRecord;
-        inet4AddressRecord = base.inet4AddressRecord;
-        inet6AddressRecord = base.inet6AddressRecord;
+        inet4AddressRecords = new ArrayList<>(base.inet4AddressRecords);
+        inet6AddressRecords = new ArrayList<>(base.inet6AddressRecords);
         lastUpdateTime = base.lastUpdateTime;
         serviceName = base.serviceName;
         interfaceIndex = base.interfaceIndex;
@@ -94,8 +97,8 @@
             if (recordsAreSame(pointerRecord, pointerRecords.get(existing))) {
                 return false;
             }
-            pointerRecords.remove(existing);
-            records.remove(existing);
+            final MdnsRecord record = pointerRecords.remove(existing);
+            records.remove(record);
         }
         pointerRecords.add(pointerRecord);
         records.add(pointerRecord);
@@ -201,46 +204,60 @@
         return textRecord != null;
     }
 
-    /** Sets the IPv4 address record. */
-    public synchronized boolean setInet4AddressRecord(
-            @Nullable MdnsInetAddressRecord newInet4AddressRecord) {
-        if (recordsAreSame(this.inet4AddressRecord, newInet4AddressRecord)) {
-            return false;
+    /** Add the IPv4 address record. */
+    public synchronized boolean addInet4AddressRecord(
+            @NonNull MdnsInetAddressRecord newInet4AddressRecord) {
+        final int existing = inet4AddressRecords.indexOf(newInet4AddressRecord);
+        if (existing >= 0) {
+            if (recordsAreSame(newInet4AddressRecord, inet4AddressRecords.get(existing))) {
+                return false;
+            }
+            final MdnsRecord record = inet4AddressRecords.remove(existing);
+            records.remove(record);
         }
-        if (this.inet4AddressRecord != null) {
-            records.remove(this.inet4AddressRecord);
-            this.inet4AddressRecord = null;
-        }
-        if (newInet4AddressRecord != null && newInet4AddressRecord.getInet4Address() != null) {
-            this.inet4AddressRecord = newInet4AddressRecord;
-            records.add(this.inet4AddressRecord);
-        }
+        inet4AddressRecords.add(newInet4AddressRecord);
+        records.add(newInet4AddressRecord);
         return true;
     }
 
-    /** Gets the IPv4 address record. */
+    /** Gets the IPv4 address records. */
+    @NonNull
+    public synchronized List<MdnsInetAddressRecord> getInet4AddressRecords() {
+        return Collections.unmodifiableList(inet4AddressRecords);
+    }
+
+    /** Return the first IPv4 address record or null if no record. */
+    @Nullable
     public synchronized MdnsInetAddressRecord getInet4AddressRecord() {
-        return inet4AddressRecord;
+        return inet4AddressRecords.isEmpty() ? null : inet4AddressRecords.get(0);
     }
 
+    /** Check whether response has IPv4 address record */
     public synchronized boolean hasInet4AddressRecord() {
-        return inet4AddressRecord != null;
+        return !inet4AddressRecords.isEmpty();
     }
 
-    /** Sets the IPv6 address record. */
-    public synchronized boolean setInet6AddressRecord(
-            @Nullable MdnsInetAddressRecord newInet6AddressRecord) {
-        if (recordsAreSame(this.inet6AddressRecord, newInet6AddressRecord)) {
-            return false;
+    /** Clear all IPv4 address records */
+    synchronized void clearInet4AddressRecords() {
+        for (MdnsInetAddressRecord record : inet4AddressRecords) {
+            records.remove(record);
         }
-        if (this.inet6AddressRecord != null) {
-            records.remove(this.inet6AddressRecord);
-            this.inet6AddressRecord = null;
+        inet4AddressRecords.clear();
+    }
+
+    /** Sets the IPv6 address records. */
+    public synchronized boolean addInet6AddressRecord(
+            @NonNull MdnsInetAddressRecord newInet6AddressRecord) {
+        final int existing = inet6AddressRecords.indexOf(newInet6AddressRecord);
+        if (existing >= 0) {
+            if (recordsAreSame(newInet6AddressRecord, inet6AddressRecords.get(existing))) {
+                return false;
+            }
+            final MdnsRecord record = inet6AddressRecords.remove(existing);
+            records.remove(record);
         }
-        if (newInet6AddressRecord != null && newInet6AddressRecord.getInet6Address() != null) {
-            this.inet6AddressRecord = newInet6AddressRecord;
-            records.add(this.inet6AddressRecord);
-        }
+        inet6AddressRecords.add(newInet6AddressRecord);
+        records.add(newInet6AddressRecord);
         return true;
     }
 
@@ -260,13 +277,28 @@
         return network;
     }
 
-    /** Gets the IPv6 address record. */
-    public synchronized MdnsInetAddressRecord getInet6AddressRecord() {
-        return inet6AddressRecord;
+    /** Gets all IPv6 address records. */
+    public synchronized List<MdnsInetAddressRecord> getInet6AddressRecords() {
+        return Collections.unmodifiableList(inet6AddressRecords);
     }
 
+    /** Return the first IPv6 address record or null if no record. */
+    @Nullable
+    public synchronized MdnsInetAddressRecord getInet6AddressRecord() {
+        return inet6AddressRecords.isEmpty() ? null : inet6AddressRecords.get(0);
+    }
+
+    /** Check whether response has IPv6 address record */
     public synchronized boolean hasInet6AddressRecord() {
-        return inet6AddressRecord != null;
+        return !inet6AddressRecords.isEmpty();
+    }
+
+    /** Clear all IPv6 address records */
+    synchronized void clearInet6AddressRecords() {
+        for (MdnsInetAddressRecord record : inet6AddressRecords) {
+            records.remove(record);
+        }
+        inet6AddressRecords.clear();
     }
 
     /** Gets all of the records. */
@@ -283,22 +315,22 @@
         if (this.serviceRecord == null) return false;
         boolean dropAddressRecords = false;
 
-        if (this.inet4AddressRecord != null) {
+        for (MdnsInetAddressRecord inetAddressRecord : getInet4AddressRecords()) {
             if (!Arrays.equals(
-                    this.serviceRecord.getServiceHost(), this.inet4AddressRecord.getName())) {
+                    this.serviceRecord.getServiceHost(), inetAddressRecord.getName())) {
                 dropAddressRecords = true;
             }
         }
-        if (this.inet6AddressRecord != null) {
+        for (MdnsInetAddressRecord inetAddressRecord : getInet6AddressRecords()) {
             if (!Arrays.equals(
-                    this.serviceRecord.getServiceHost(), this.inet6AddressRecord.getName())) {
+                    this.serviceRecord.getServiceHost(), inetAddressRecord.getName())) {
                 dropAddressRecords = true;
             }
         }
 
         if (dropAddressRecords) {
-            setInet4AddressRecord(null);
-            setInet6AddressRecord(null);
+            clearInet4AddressRecords();
+            clearInet6AddressRecords();
             return true;
         }
         return false;
@@ -312,7 +344,7 @@
     public synchronized boolean isComplete() {
         return (serviceRecord != null)
                 && (textRecord != null)
-                && (inet4AddressRecord != null || inet6AddressRecord != null);
+                && (!inet4AddressRecords.isEmpty() || !inet6AddressRecords.isEmpty());
     }
 
     /**
@@ -378,13 +410,13 @@
             ++count;
         }
 
-        if (inet4AddressRecord != null) {
-            inet4AddressRecord.write(writer, now);
+        for (MdnsInetAddressRecord inetAddressRecord : inet4AddressRecords) {
+            inetAddressRecord.write(writer, now);
             ++count;
         }
 
-        if (inet6AddressRecord != null) {
-            inet6AddressRecord.write(writer, now);
+        for (MdnsInetAddressRecord inetAddressRecord : inet6AddressRecords) {
+            inetAddressRecord.write(writer, now);
             ++count;
         }
 
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java b/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
index 7878b0b..0151202 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsResponseDecoder.java
@@ -205,39 +205,79 @@
             }
         }
 
-        // Loop 3: find A and AAAA records, which reference the host name in the SRV record.
+        // Loop 3-1: find A and AAAA records and clear addresses if the cache-flush bit set, which
+        //           reference the host name in the SRV record.
+        final List<MdnsInetAddressRecord> inetRecords = new ArrayList<>();
         for (MdnsRecord record : records) {
             if (record instanceof MdnsInetAddressRecord) {
                 MdnsInetAddressRecord inetRecord = (MdnsInetAddressRecord) record;
+                inetRecords.add(inetRecord);
                 if (allowMultipleSrvRecordsPerHost) {
                     List<MdnsResponse> matchingResponses =
                             findResponsesWithHostName(responses, inetRecord.getName());
                     for (MdnsResponse response : matchingResponses) {
-                        if (assignInetRecord(response, inetRecord)) {
-                            modified.add(response);
+                        // Per RFC6762 10.2, clear all address records if the cache-flush bit set.
+                        // This bit, the cache-flush bit, tells neighboring hosts
+                        // that this is not a shared record type.  Instead of merging this new
+                        // record additively into the cache in addition to any previous records with
+                        // the same name, rrtype, and rrclass, all old records with that name,
+                        // rrtype, and rrclass that were received more than one second ago are
+                        // declared invalid, and marked to expire from the cache in one second.
+                        if (inetRecord.getCacheFlush()) {
+                            response.clearInet4AddressRecords();
+                            response.clearInet6AddressRecords();
                         }
                     }
                 } else {
                     MdnsResponse response =
                             findResponseWithHostName(responses, inetRecord.getName());
                     if (response != null) {
-                        if (assignInetRecord(response, inetRecord)) {
-                            modified.add(response);
+                        // Per RFC6762 10.2, clear all address records if the cache-flush bit set.
+                        // This bit, the cache-flush bit, tells neighboring hosts
+                        // that this is not a shared record type.  Instead of merging this new
+                        // record additively into the cache in addition to any previous records with
+                        // the same name, rrtype, and rrclass, all old records with that name,
+                        // rrtype, and rrclass that were received more than one second ago are
+                        // declared invalid, and marked to expire from the cache in one second.
+                        if (inetRecord.getCacheFlush()) {
+                            response.clearInet4AddressRecords();
+                            response.clearInet6AddressRecords();
                         }
                     }
                 }
             }
         }
 
+        // Loop 3-2: Assign addresses, which reference the host name in the SRV record.
+        for (MdnsInetAddressRecord inetRecord : inetRecords) {
+            if (allowMultipleSrvRecordsPerHost) {
+                List<MdnsResponse> matchingResponses =
+                        findResponsesWithHostName(responses, inetRecord.getName());
+                for (MdnsResponse response : matchingResponses) {
+                    if (assignInetRecord(response, inetRecord)) {
+                        modified.add(response);
+                    }
+                }
+            } else {
+                MdnsResponse response =
+                        findResponseWithHostName(responses, inetRecord.getName());
+                if (response != null) {
+                    if (assignInetRecord(response, inetRecord)) {
+                        modified.add(response);
+                    }
+                }
+            }
+        }
+
         return modified;
     }
 
     private static boolean assignInetRecord(
             MdnsResponse response, MdnsInetAddressRecord inetRecord) {
         if (inetRecord.getInet4Address() != null) {
-            return response.setInet4AddressRecord(inetRecord);
+            return response.addInet4AddressRecord(inetRecord);
         } else if (inetRecord.getInet6Address() != null) {
-            return response.setInet6AddressRecord(inetRecord);
+            return response.addInet6AddressRecord(inetRecord);
         }
         return false;
     }
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceInfo.java b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceInfo.java
index 938fc3f..606d3f8 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceInfo.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceInfo.java
@@ -57,8 +57,8 @@
                             source.createStringArrayList(),
                             source.createStringArray(),
                             source.readInt(),
-                            source.readString(),
-                            source.readString(),
+                            source.createStringArrayList(),
+                            source.createStringArrayList(),
                             source.createStringArrayList(),
                             source.createTypedArrayList(TextEntry.CREATOR),
                             source.readInt(),
@@ -76,10 +76,10 @@
     private final List<String> subtypes;
     private final String[] hostName;
     private final int port;
-    @Nullable
-    private final String ipv4Address;
-    @Nullable
-    private final String ipv6Address;
+    @NonNull
+    private final List<String> ipv4Addresses;
+    @NonNull
+    private final List<String> ipv6Addresses;
     final List<String> textStrings;
     @Nullable
     final List<TextEntry> textEntries;
@@ -105,8 +105,8 @@
                 subtypes,
                 hostName,
                 port,
-                ipv4Address,
-                ipv6Address,
+                List.of(ipv4Address),
+                List.of(ipv6Address),
                 textStrings,
                 /* textEntries= */ null,
                 /* interfaceIndex= */ INTERFACE_INDEX_UNSPECIFIED,
@@ -130,8 +130,8 @@
                 subtypes,
                 hostName,
                 port,
-                ipv4Address,
-                ipv6Address,
+                List.of(ipv4Address),
+                List.of(ipv6Address),
                 textStrings,
                 textEntries,
                 /* interfaceIndex= */ INTERFACE_INDEX_UNSPECIFIED,
@@ -160,8 +160,8 @@
                 subtypes,
                 hostName,
                 port,
-                ipv4Address,
-                ipv6Address,
+                List.of(ipv4Address),
+                List.of(ipv6Address),
                 textStrings,
                 textEntries,
                 interfaceIndex,
@@ -179,8 +179,8 @@
             @Nullable List<String> subtypes,
             String[] hostName,
             int port,
-            @Nullable String ipv4Address,
-            @Nullable String ipv6Address,
+            @NonNull List<String> ipv4Addresses,
+            @NonNull List<String> ipv6Addresses,
             @Nullable List<String> textStrings,
             @Nullable List<TextEntry> textEntries,
             int interfaceIndex,
@@ -193,8 +193,8 @@
         }
         this.hostName = hostName;
         this.port = port;
-        this.ipv4Address = ipv4Address;
-        this.ipv6Address = ipv6Address;
+        this.ipv4Addresses = new ArrayList<>(ipv4Addresses);
+        this.ipv6Addresses = new ArrayList<>(ipv6Addresses);
         this.textStrings = new ArrayList<>();
         if (textStrings != null) {
             this.textStrings.addAll(textStrings);
@@ -263,16 +263,41 @@
         return port;
     }
 
-    /** Returns the IPV4 address of this service instance. */
+    /** Returns the IPV4 addresses of this service instance. */
+    @NonNull
+    public List<String> getIpv4Addresses() {
+        return Collections.unmodifiableList(ipv4Addresses);
+    }
+
+    /**
+     * Returns the first IPV4 address of this service instance.
+     *
+     * @deprecated Use {@link #getIpv4Addresses()} to get the entire list of IPV4
+     * addresses for
+     * the host.
+     */
     @Nullable
+    @Deprecated
     public String getIpv4Address() {
-        return ipv4Address;
+        return ipv4Addresses.isEmpty() ? null : ipv4Addresses.get(0);
     }
 
     /** Returns the IPV6 address of this service instance. */
+    @NonNull
+    public List<String> getIpv6Addresses() {
+        return Collections.unmodifiableList(ipv6Addresses);
+    }
+
+    /**
+     * Returns the first IPV6 address of this service instance.
+     *
+     * @deprecated Use {@link #getIpv6Addresses()} to get the entire list of IPV6 addresses for
+     * the host.
+     */
     @Nullable
+    @Deprecated
     public String getIpv6Address() {
-        return ipv6Address;
+        return ipv6Addresses.isEmpty() ? null : ipv6Addresses.get(0);
     }
 
     /**
@@ -336,8 +361,8 @@
         out.writeStringList(subtypes);
         out.writeStringArray(hostName);
         out.writeInt(port);
-        out.writeString(ipv4Address);
-        out.writeString(ipv6Address);
+        out.writeStringList(ipv4Addresses);
+        out.writeStringList(ipv6Addresses);
         out.writeStringList(textStrings);
         out.writeTypedList(textEntries);
         out.writeInt(interfaceIndex);
@@ -346,13 +371,16 @@
 
     @Override
     public String toString() {
-        return String.format(
-                Locale.ROOT,
-                "Name: %s, subtypes: %s, ip: %s, port: %d",
-                serviceInstanceName,
-                TextUtils.join(",", subtypes),
-                ipv4Address,
-                port);
+        return "Name: " + serviceInstanceName
+                + ", type: " + TextUtils.join(".", serviceType)
+                + ", subtypes: " + TextUtils.join(",", subtypes)
+                + ", ip: " + ipv4Addresses
+                + ", ipv6: " + ipv6Addresses
+                + ", port: " + port
+                + ", interfaceIndex: " + interfaceIndex
+                + ", network: " + network
+                + ", textStrings: " + textStrings
+                + ", textEntries: " + textEntries;
     }
 
 
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
index f886948..df270bb 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsServiceTypeClient.java
@@ -115,15 +115,19 @@
             port = response.getServiceRecord().getServicePort();
         }
 
-        String ipv4Address = null;
-        String ipv6Address = null;
+        final List<String> ipv4Addresses = new ArrayList<>();
+        final List<String> ipv6Addresses = new ArrayList<>();
         if (response.hasInet4AddressRecord()) {
-            Inet4Address inet4Address = response.getInet4AddressRecord().getInet4Address();
-            ipv4Address = (inet4Address == null) ? null : inet4Address.getHostAddress();
+            for (MdnsInetAddressRecord inetAddressRecord : response.getInet4AddressRecords()) {
+                final Inet4Address inet4Address = inetAddressRecord.getInet4Address();
+                ipv4Addresses.add((inet4Address == null) ? null : inet4Address.getHostAddress());
+            }
         }
         if (response.hasInet6AddressRecord()) {
-            Inet6Address inet6Address = response.getInet6AddressRecord().getInet6Address();
-            ipv6Address = (inet6Address == null) ? null : inet6Address.getHostAddress();
+            for (MdnsInetAddressRecord inetAddressRecord : response.getInet6AddressRecords()) {
+                final Inet6Address inet6Address = inetAddressRecord.getInet6Address();
+                ipv6Addresses.add((inet6Address == null) ? null : inet6Address.getHostAddress());
+            }
         }
         String serviceInstanceName = response.getServiceInstanceName();
         if (serviceInstanceName == null) {
@@ -143,8 +147,8 @@
                 response.getSubtypes(),
                 hostName,
                 port,
-                ipv4Address,
-                ipv6Address,
+                ipv4Addresses,
+                ipv6Addresses,
                 textStrings,
                 textEntries,
                 response.getInterfaceIndex(),
diff --git a/tests/unit/java/com/android/server/NsdServiceTest.java b/tests/unit/java/com/android/server/NsdServiceTest.java
index 053212b..1fd4439 100644
--- a/tests/unit/java/com/android/server/NsdServiceTest.java
+++ b/tests/unit/java/com/android/server/NsdServiceTest.java
@@ -895,8 +895,8 @@
                 List.of(), /* subtypes */
                 new String[] {"android", "local"}, /* hostName */
                 12345, /* port */
-                IPV4_ADDRESS,
-                IPV6_ADDRESS,
+                List.of(IPV4_ADDRESS),
+                List.of(IPV6_ADDRESS),
                 List.of(), /* textStrings */
                 List.of(), /* textEntries */
                 1234, /* interfaceIndex */
@@ -915,8 +915,8 @@
                 null, /* subtypes */
                 null, /* hostName */
                 0, /* port */
-                null, /* ipv4Address */
-                null, /* ipv6Address */
+                List.of(), /* ipv4Address */
+                List.of(), /* ipv6Address */
                 null, /* textStrings */
                 null, /* textEntries */
                 1234, /* interfaceIndex */
@@ -992,8 +992,8 @@
                 List.of(), /* subtypes */
                 new String[]{"android", "local"}, /* hostName */
                 PORT,
-                IPV4_ADDRESS,
-                IPV6_ADDRESS,
+                List.of(IPV4_ADDRESS),
+                List.of(IPV6_ADDRESS),
                 List.of() /* textStrings */,
                 List.of(MdnsServiceInfo.TextEntry.fromBytes(new byte[]{
                         'k', 'e', 'y', '=', (byte) 0xFF, (byte) 0xFE})) /* textEntries */,
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
index d83c0dd..a80c078 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseDecoderTests.java
@@ -158,16 +158,16 @@
 
     // MDNS record for name "testhost1" with an IPv4 address of 10.1.2.3
     private static final byte[] DATAIN_IPV4_1 = HexDump.hexStringToByteArray(
-            "0974657374686f73743100000100010000007800040a010203");
+            "0974657374686f73743100000180010000007800040a010203");
     // MDNS record for name "testhost1" with an IPv4 address of 10.1.2.4
     private static final byte[] DATAIN_IPV4_2 = HexDump.hexStringToByteArray(
-            "0974657374686f73743100000100010000007800040a010204");
+            "0974657374686f73743100000180010000007800040a010204");
     // MDNS record w/name "testhost1" & IPv6 address of aabb:ccdd:1122:3344:a0b0:c0d0:1020:3040
     private static final byte[] DATAIN_IPV6_1 = HexDump.hexStringToByteArray(
-            "0974657374686f73743100001c0001000000780010aabbccdd11223344a0b0c0d010203040");
+            "0974657374686f73743100001c8001000000780010aabbccdd11223344a0b0c0d010203040");
     // MDNS record w/name "testhost1" & IPv6 address of aabb:ccdd:1122:3344:a0b0:c0d0:1020:3030
     private static final byte[] DATAIN_IPV6_2 = HexDump.hexStringToByteArray(
-            "0974657374686f73743100001c0001000000780010aabbccdd11223344a0b0c0d010203030");
+            "0974657374686f73743100001c8001000000780010aabbccdd11223344a0b0c0d010203030");
     // MDNS record w/name "test" & PTR to foo.bar.quxx
     private static final byte[] DATAIN_PTR_1 = HexDump.hexStringToByteArray(
             "047465737400000C000100001194000E03666F6F03626172047175787800");
@@ -295,15 +295,15 @@
         assertTrue(response.isComplete());
 
         response = new MdnsResponse(responses.valueAt(0));
-        response.setInet4AddressRecord(null);
+        response.clearInet4AddressRecords();
         assertFalse(response.isComplete());
 
-        response.setInet6AddressRecord(new MdnsInetAddressRecord(new String[] { "testhostname" },
+        response.addInet6AddressRecord(new MdnsInetAddressRecord(new String[] { "testhostname" },
                 0L /* receiptTimeMillis */, false /* cacheFlush */, 1234L /* ttlMillis */,
                 parseNumericAddress("2008:db1::123")));
         assertTrue(response.isComplete());
 
-        response.setInet6AddressRecord(null);
+        response.clearInet6AddressRecords();
         assertFalse(response.isComplete());
 
         response = new MdnsResponse(responses.valueAt(0));
@@ -356,10 +356,12 @@
         assertTrue(response2.isComplete());
 
         // And should both have the same IPv6 address:
-        assertEquals(parseNumericAddress("2605:a601:a846:5700:3e61:5ff:fe0c:89f8"),
-                response1.getInet6AddressRecord().getInet6Address());
-        assertEquals(parseNumericAddress("2605:a601:a846:5700:3e61:5ff:fe0c:89f8"),
-                response2.getInet6AddressRecord().getInet6Address());
+        assertTrue(response1.getInet6AddressRecords().stream().anyMatch(
+                record -> record.getInet6Address().equals(
+                        parseNumericAddress("2605:a601:a846:5700:3e61:5ff:fe0c:89f8"))));
+        assertTrue(response2.getInet6AddressRecords().stream().anyMatch(
+                record -> record.getInet6Address().equals(
+                        parseNumericAddress("2605:a601:a846:5700:3e61:5ff:fe0c:89f8"))));
     }
 
     @Test
@@ -514,9 +516,9 @@
             reader.skip(2); // skip record type indication.
             // Apply the right kind of record to the response.
             if (responseData.recordClass == MdnsInet4AddressRecord.class) {
-                response.setInet4AddressRecord(new MdnsInet4AddressRecord(name, reader));
+                response.addInet4AddressRecord(new MdnsInet4AddressRecord(name, reader));
             } else if (responseData.recordClass == MdnsInet6AddressRecord.class) {
-                response.setInet6AddressRecord(new MdnsInet6AddressRecord(name, reader));
+                response.addInet6AddressRecord(new MdnsInet6AddressRecord(name, reader));
             } else if (responseData.recordClass == MdnsPointerRecord.class) {
                 response.addPointerRecord(new MdnsPointerRecord(name, reader));
             } else if (responseData.recordClass == MdnsServiceRecord.class) {
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseTests.java
index 132a822..3f5e7a1 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseTests.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsResponseTests.java
@@ -108,10 +108,10 @@
                 0 /* serviceWeight */, 0 /* servicePort */, hostname));
         response.setTextRecord(new MdnsTextRecord(serviceName, 0L /* receiptTimeMillis */,
                 true /* cacheFlush */, recordsTtlMillis, emptyList() /* entries */));
-        response.setInet4AddressRecord(new MdnsInetAddressRecord(
+        response.addInet4AddressRecord(new MdnsInetAddressRecord(
                 hostname, 0L /* receiptTimeMillis */, true /* cacheFlush */,
                 recordsTtlMillis, parseNumericAddress("192.0.2.123")));
-        response.setInet6AddressRecord(new MdnsInetAddressRecord(
+        response.addInet6AddressRecord(new MdnsInetAddressRecord(
                 hostname, 0L /* receiptTimeMillis */, true /* cacheFlush */,
                 recordsTtlMillis, parseNumericAddress("2001:db8::123")));
         return response;
@@ -126,7 +126,7 @@
         MdnsInetAddressRecord record = new MdnsInetAddressRecord(name, MdnsRecord.TYPE_A, reader);
         MdnsResponse response = new MdnsResponse(0, TEST_SERVICE_NAME, INTERFACE_INDEX, mNetwork);
         assertFalse(response.hasInet4AddressRecord());
-        assertTrue(response.setInet4AddressRecord(record));
+        assertTrue(response.addInet4AddressRecord(record));
         assertEquals(response.getInet4AddressRecord(), record);
     }
 
@@ -140,7 +140,7 @@
                 new MdnsInetAddressRecord(name, MdnsRecord.TYPE_AAAA, reader);
         MdnsResponse response = new MdnsResponse(0, TEST_SERVICE_NAME, INTERFACE_INDEX, mNetwork);
         assertFalse(response.hasInet6AddressRecord());
-        assertTrue(response.setInet6AddressRecord(record));
+        assertTrue(response.addInet6AddressRecord(record));
         assertEquals(response.getInet6AddressRecord(), record);
     }
 
@@ -228,8 +228,8 @@
         final MdnsResponse response = makeCompleteResponse(TEST_TTL_MS);
 
         assertFalse(response.addPointerRecord(response.getPointerRecords().get(0)));
-        assertFalse(response.setInet6AddressRecord(response.getInet6AddressRecord()));
-        assertFalse(response.setInet4AddressRecord(response.getInet4AddressRecord()));
+        assertFalse(response.addInet6AddressRecord(response.getInet6AddressRecord()));
+        assertFalse(response.addInet4AddressRecord(response.getInet4AddressRecord()));
         assertFalse(response.setServiceRecord(response.getServiceRecord()));
         assertFalse(response.setTextRecord(response.getTextRecord()));
     }
@@ -245,12 +245,14 @@
         assertTrue(response.getRecords().stream().anyMatch(r ->
                 r == response.getPointerRecords().get(0)));
 
-        assertTrue(response.setInet6AddressRecord(ttlZeroResponse.getInet6AddressRecord()));
+        assertTrue(response.addInet6AddressRecord(ttlZeroResponse.getInet6AddressRecord()));
+        assertEquals(1, response.getInet6AddressRecords().size());
         assertEquals(0, response.getInet6AddressRecord().getTtl());
         assertTrue(response.getRecords().stream().anyMatch(r ->
                 r == response.getInet6AddressRecord()));
 
-        assertTrue(response.setInet4AddressRecord(ttlZeroResponse.getInet4AddressRecord()));
+        assertTrue(response.addInet4AddressRecord(ttlZeroResponse.getInet4AddressRecord()));
+        assertEquals(1, response.getInet4AddressRecords().size());
         assertEquals(0, response.getInet4AddressRecord().getTtl());
         assertTrue(response.getRecords().stream().anyMatch(r ->
                 r == response.getInet4AddressRecord()));
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java
index 76728cf..a4e03a8 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceInfoTest.java
@@ -177,8 +177,8 @@
                         List.of(),
                         new String[] {"my-host", "local"},
                         12345,
-                        "192.168.1.1",
-                        "2001::1",
+                        List.of("192.168.1.1"),
+                        List.of("2001::1"),
                         List.of(),
                         /* textEntries= */ null,
                         /* interfaceIndex= */ 20,
@@ -197,8 +197,8 @@
                         List.of(),
                         new String[] {"my-host", "local"},
                         12345,
-                        "192.168.1.1",
-                        "2001::1",
+                        List.of("192.168.1.1", "192.168.1.2"),
+                        List.of("2001::1", "2001::2"),
                         List.of("vn=Alphabet Inc.", "mn=Google Nest Hub Max", "id=12345"),
                         List.of(
                                 MdnsServiceInfo.TextEntry.fromString("vn=Google Inc."),
@@ -217,7 +217,9 @@
         assertArrayEquals(beforeParcel.getHostName(), afterParcel.getHostName());
         assertEquals(beforeParcel.getPort(), afterParcel.getPort());
         assertEquals(beforeParcel.getIpv4Address(), afterParcel.getIpv4Address());
+        assertEquals(beforeParcel.getIpv4Addresses(), afterParcel.getIpv4Addresses());
         assertEquals(beforeParcel.getIpv6Address(), afterParcel.getIpv6Address());
+        assertEquals(beforeParcel.getIpv6Addresses(), afterParcel.getIpv6Addresses());
         assertEquals(beforeParcel.getAttributes(), afterParcel.getAttributes());
         assertEquals(beforeParcel.getInterfaceIndex(), afterParcel.getInterfaceIndex());
         assertEquals(beforeParcel.getNetwork(), afterParcel.getNetwork());
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
index a5c6123..d9fa10f 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsServiceTypeClientTests.java
@@ -420,13 +420,13 @@
     }
 
     private static void verifyServiceInfo(MdnsServiceInfo serviceInfo, String serviceName,
-            String[] serviceType, String ipv4Address, String ipv6Address, int port,
+            String[] serviceType, List<String> ipv4Addresses, List<String> ipv6Addresses, int port,
             List<String> subTypes, Map<String, String> attributes, int interfaceIndex,
             Network network) {
         assertEquals(serviceName, serviceInfo.getServiceInstanceName());
         assertArrayEquals(serviceType, serviceInfo.getServiceType());
-        assertEquals(ipv4Address, serviceInfo.getIpv4Address());
-        assertEquals(ipv6Address, serviceInfo.getIpv6Address());
+        assertEquals(ipv4Addresses, serviceInfo.getIpv4Addresses());
+        assertEquals(ipv6Addresses, serviceInfo.getIpv6Addresses());
         assertEquals(port, serviceInfo.getPort());
         assertEquals(subTypes, serviceInfo.getSubtypes());
         for (String key : attributes.keySet()) {
@@ -449,8 +449,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(0),
                 "service-instance-1",
                 SERVICE_TYPE_LABELS,
-                /* ipv4Address= */ null,
-                /* ipv6Address= */ null,
+                /* ipv4Address= */ List.of(),
+                /* ipv6Address= */ List.of(),
                 /* port= */ 0,
                 /* subTypes= */ List.of(),
                 Collections.emptyMap(),
@@ -484,8 +484,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(0),
                 "service-instance-1",
                 SERVICE_TYPE_LABELS,
-                ipV4Address /* ipv4Address */,
-                null /* ipv6Address */,
+                List.of(ipV4Address) /* ipv4Address */,
+                List.of() /* ipv6Address */,
                 5353 /* port */,
                 Collections.singletonList("ABCDE") /* subTypes */,
                 Collections.singletonMap("key", null) /* attributes */,
@@ -539,8 +539,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(0),
                 "service-instance-1",
                 SERVICE_TYPE_LABELS,
-                null /* ipv4Address */,
-                ipV6Address /* ipv6Address */,
+                List.of() /* ipv4Address */,
+                List.of(ipV6Address) /* ipv6Address */,
                 5353 /* port */,
                 Collections.singletonList("ABCDE") /* subTypes */,
                 Collections.singletonMap("key", null) /* attributes */,
@@ -638,8 +638,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(0),
                 "service-instance-1",
                 SERVICE_TYPE_LABELS,
-                "192.168.1.1" /* ipv4Address */,
-                null /* ipv6Address */,
+                List.of("192.168.1.1") /* ipv4Address */,
+                List.of() /* ipv6Address */,
                 5353 /* port */,
                 Collections.singletonList("ABCDE") /* subTypes */,
                 Collections.singletonMap("key", null) /* attributes */,
@@ -834,8 +834,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(0),
                 serviceName,
                 SERVICE_TYPE_LABELS,
-                null /* ipv4Address */,
-                null /* ipv6Address */,
+                List.of() /* ipv4Address */,
+                List.of() /* ipv6Address */,
                 5353 /* port */,
                 Collections.singletonList(subtype) /* subTypes */,
                 Collections.singletonMap("key", null) /* attributes */,
@@ -847,8 +847,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(1),
                 serviceName,
                 SERVICE_TYPE_LABELS,
-                ipV4Address /* ipv4Address */,
-                null /* ipv6Address */,
+                List.of(ipV4Address) /* ipv4Address */,
+                List.of() /* ipv6Address */,
                 5353 /* port */,
                 Collections.singletonList(subtype) /* subTypes */,
                 Collections.singletonMap("key", null) /* attributes */,
@@ -860,8 +860,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(2),
                 serviceName,
                 SERVICE_TYPE_LABELS,
-                ipV4Address /* ipv4Address */,
-                ipV6Address /* ipv6Address */,
+                List.of(ipV4Address) /* ipv4Address */,
+                List.of(ipV6Address) /* ipv6Address */,
                 5354 /* port */,
                 Collections.singletonList(subtype) /* subTypes */,
                 Collections.singletonMap("key", "value") /* attributes */,
@@ -873,8 +873,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(3),
                 serviceName,
                 SERVICE_TYPE_LABELS,
-                ipV4Address /* ipv4Address */,
-                ipV6Address /* ipv6Address */,
+                List.of(ipV4Address) /* ipv4Address */,
+                List.of(ipV6Address) /* ipv6Address */,
                 5354 /* port */,
                 Collections.singletonList("ABCDE") /* subTypes */,
                 Collections.singletonMap("key", "value") /* attributes */,
@@ -886,8 +886,8 @@
         verifyServiceInfo(serviceInfoCaptor.getAllValues().get(4),
                 serviceName,
                 SERVICE_TYPE_LABELS,
-                ipV4Address /* ipv4Address */,
-                ipV6Address /* ipv6Address */,
+                List.of(ipV4Address) /* ipv4Address */,
+                List.of(ipV6Address) /* ipv6Address */,
                 5354 /* port */,
                 Collections.singletonList("ABCDE") /* subTypes */,
                 Collections.singletonMap("key", "value") /* attributes */,
@@ -982,8 +982,8 @@
         verifyServiceInfo(serviceInfoCaptor.getValue(),
                 instanceName,
                 SERVICE_TYPE_LABELS,
-                ipV4Address,
-                ipV6Address,
+                List.of(ipV4Address),
+                List.of(ipV6Address),
                 1234 /* port */,
                 Collections.emptyList() /* subTypes */,
                 Collections.emptyMap() /* attributes */,