Add three new IKE options in IkeSessionParamsUtils

This commit updates IkeSessionParamsUtils to be able
to encode/decode IkeSessionParams with IKE_OPTION_REKEY_MOBILITY,
IKE_OPTION_AUTOMATIC_ADDRESS_FAMILY_SELECTION and
IKE_OPTION_AUTOMATIC_NATT_KEEPALIVES.

This commit can also maintain compatibility with older T IPsec
modules that do not support the two IKE_OPTION_AUTOMATIC_ options

Bug: 242231517
Test: atest IkeSessionParamsUtilsTest
Change-Id: Icadbe98b3df3cf3a80f51dc1467eb99753d82216
diff --git a/core/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtils.java b/core/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtils.java
index be57372..d6f191e 100644
--- a/core/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtils.java
+++ b/core/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtils.java
@@ -37,6 +37,7 @@
 import android.net.ipsec.ike.IkeSessionParams.IkeConfigRequest;
 import android.os.PersistableBundle;
 import android.util.ArraySet;
+import android.util.Log;
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.server.vcn.util.PersistableBundleUtils;
@@ -58,6 +59,8 @@
  */
 @VisibleForTesting(visibility = Visibility.PRIVATE)
 public final class IkeSessionParamsUtils {
+    private static final String TAG = IkeSessionParamsUtils.class.getSimpleName();
+
     private static final String SERVER_HOST_NAME_KEY = "SERVER_HOST_NAME_KEY";
     private static final String SA_PROPOSALS_KEY = "SA_PROPOSALS_KEY";
     private static final String LOCAL_ID_KEY = "LOCAL_ID_KEY";
@@ -72,6 +75,13 @@
     private static final String NATT_KEEPALIVE_DELAY_SEC_KEY = "NATT_KEEPALIVE_DELAY_SEC_KEY";
     private static final String IKE_OPTIONS_KEY = "IKE_OPTIONS_KEY";
 
+    // TODO: b/243181760 Use the IKE API when they are exposed
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    public static final int IKE_OPTION_AUTOMATIC_ADDRESS_FAMILY_SELECTION = 6;
+
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    public static final int IKE_OPTION_AUTOMATIC_NATT_KEEPALIVES = 7;
+
     private static final Set<Integer> IKE_OPTIONS = new ArraySet<>();
 
     static {
@@ -80,6 +90,26 @@
         IKE_OPTIONS.add(IkeSessionParams.IKE_OPTION_MOBIKE);
         IKE_OPTIONS.add(IkeSessionParams.IKE_OPTION_FORCE_PORT_4500);
         IKE_OPTIONS.add(IkeSessionParams.IKE_OPTION_INITIAL_CONTACT);
+        IKE_OPTIONS.add(IkeSessionParams.IKE_OPTION_REKEY_MOBILITY);
+        IKE_OPTIONS.add(IKE_OPTION_AUTOMATIC_ADDRESS_FAMILY_SELECTION);
+        IKE_OPTIONS.add(IKE_OPTION_AUTOMATIC_NATT_KEEPALIVES);
+    }
+
+    /**
+     * Check if an IKE option is supported in the IPsec module installed on the device
+     *
+     * <p>This method ensures caller to safely access options that are added between dessert
+     * releases.
+     */
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    public static boolean isIkeOptionValid(int option) {
+        try {
+            new IkeSessionParams.Builder().addIkeOption(option);
+            return true;
+        } catch (IllegalArgumentException e) {
+            Log.d(TAG, "Option not supported; discarding: " + option);
+            return false;
+        }
     }
 
     /** Serializes an IkeSessionParams to a PersistableBundle. */
@@ -130,7 +160,7 @@
         // IKE_OPTION is defined in IKE module and added in the IkeSessionParams
         final List<Integer> enabledIkeOptions = new ArrayList<>();
         for (int option : IKE_OPTIONS) {
-            if (params.hasIkeOption(option)) {
+            if (isIkeOptionValid(option) && params.hasIkeOption(option)) {
                 enabledIkeOptions.add(option);
             }
         }
@@ -205,12 +235,16 @@
 
         // Clear IKE Options that are by default enabled
         for (int option : IKE_OPTIONS) {
-            builder.removeIkeOption(option);
+            if (isIkeOptionValid(option)) {
+                builder.removeIkeOption(option);
+            }
         }
 
         final int[] optionArray = in.getIntArray(IKE_OPTIONS_KEY);
         for (int option : optionArray) {
-            builder.addIkeOption(option);
+            if (isIkeOptionValid(option)) {
+                builder.addIkeOption(option);
+            }
         }
 
         return builder.build();
diff --git a/tests/vcn/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtilsTest.java b/tests/vcn/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtilsTest.java
index 3b201f9..e4add80 100644
--- a/tests/vcn/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtilsTest.java
+++ b/tests/vcn/java/android/net/vcn/persistablebundleutils/IkeSessionParamsUtilsTest.java
@@ -16,6 +16,9 @@
 
 package android.net.vcn.persistablebundleutils;
 
+import static android.net.vcn.persistablebundleutils.IkeSessionParamsUtils.IKE_OPTION_AUTOMATIC_ADDRESS_FAMILY_SELECTION;
+import static android.net.vcn.persistablebundleutils.IkeSessionParamsUtils.IKE_OPTION_AUTOMATIC_NATT_KEEPALIVES;
+import static android.net.vcn.persistablebundleutils.IkeSessionParamsUtils.isIkeOptionValid;
 import static android.system.OsConstants.AF_INET;
 import static android.system.OsConstants.AF_INET6;
 import static android.telephony.TelephonyManager.APPTYPE_USIM;
@@ -134,15 +137,37 @@
         verifyPersistableBundleEncodeDecodeIsLossless(params);
     }
 
+    private static IkeSessionParams.Builder createBuilderMinimumWithEap() throws Exception {
+        final X509Certificate serverCaCert = createCertFromPemFile("self-signed-ca.pem");
+
+        final byte[] eapId = "test@android.net".getBytes(StandardCharsets.US_ASCII);
+        final int subId = 1;
+        final EapSessionConfig eapConfig =
+                new EapSessionConfig.Builder()
+                        .setEapIdentity(eapId)
+                        .setEapSimConfig(subId, APPTYPE_USIM)
+                        .setEapAkaConfig(subId, APPTYPE_USIM)
+                        .build();
+        return createBuilderMinimum().setAuthEap(serverCaCert, eapConfig);
+    }
+
     @Test
     public void testEncodeDecodeParamsWithIkeOptions() throws Exception {
-        final IkeSessionParams params =
-                createBuilderMinimum()
+        final IkeSessionParams.Builder builder =
+                createBuilderMinimumWithEap()
                         .addIkeOption(IkeSessionParams.IKE_OPTION_ACCEPT_ANY_REMOTE_ID)
+                        .addIkeOption(IkeSessionParams.IKE_OPTION_EAP_ONLY_AUTH)
                         .addIkeOption(IkeSessionParams.IKE_OPTION_MOBIKE)
+                        .addIkeOption(IkeSessionParams.IKE_OPTION_FORCE_PORT_4500)
                         .addIkeOption(IkeSessionParams.IKE_OPTION_INITIAL_CONTACT)
-                        .build();
-        verifyPersistableBundleEncodeDecodeIsLossless(params);
+                        .addIkeOption(IkeSessionParams.IKE_OPTION_REKEY_MOBILITY);
+        if (isIkeOptionValid(IKE_OPTION_AUTOMATIC_ADDRESS_FAMILY_SELECTION)) {
+            builder.addIkeOption(IKE_OPTION_AUTOMATIC_ADDRESS_FAMILY_SELECTION);
+        }
+        if (isIkeOptionValid(IKE_OPTION_AUTOMATIC_NATT_KEEPALIVES)) {
+            builder.addIkeOption(IKE_OPTION_AUTOMATIC_NATT_KEEPALIVES);
+        }
+        verifyPersistableBundleEncodeDecodeIsLossless(builder.build());
     }
 
     private static InputStream openAssetsFile(String fileName) throws Exception {
@@ -176,19 +201,7 @@
 
     @Test
     public void testEncodeRecodeParamsWithEapAuth() throws Exception {
-        final X509Certificate serverCaCert = createCertFromPemFile("self-signed-ca.pem");
-
-        final byte[] eapId = "test@android.net".getBytes(StandardCharsets.US_ASCII);
-        final int subId = 1;
-        final EapSessionConfig eapConfig =
-                new EapSessionConfig.Builder()
-                        .setEapIdentity(eapId)
-                        .setEapSimConfig(subId, APPTYPE_USIM)
-                        .setEapAkaConfig(subId, APPTYPE_USIM)
-                        .build();
-
-        final IkeSessionParams params =
-                createBuilderMinimum().setAuthEap(serverCaCert, eapConfig).build();
+        final IkeSessionParams params = createBuilderMinimumWithEap().build();
         verifyPersistableBundleEncodeDecodeIsLossless(params);
     }
 }