android: add experimental option to force all connections to use IPv6

library/common/config/config.cc

@@ -78,6 +78,7 @@ const char* brotli_config_insert = R"(
 // clang-format off
 const std::string config_header = R"(
 !ignore default_defs:
+- &android_force_ipv6 false
 - &connect_timeout 30s
 - &dns_fail_base_interval 2s
 - &dns_fail_max_interval 10s
@@ -513,6 +514,7 @@ stats_sinks: *stats_sinks
  disallow_global_stats: true
  reloadable_features:
  allow_multiple_dns_addresses: *dns_multiple_addresses
+ android_always_use_v6: *android_force_ipv6
  http2_delay_keepalive_timeout: *h2_delay_keepalive_timeout
 )"
 // Needed due to warning in

library/java/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java

@@ -42,6 +42,7 @@ public enum TrustChainVerification {
  public final Boolean enableBrotli;
  public final Boolean enableHappyEyeballs;
  public final Boolean enableInterfaceBinding;
+ public final Boolean forceIPv6;
  public final Integer h2ConnectionKeepaliveIdleIntervalMilliseconds;
  public final Integer h2ConnectionKeepaliveTimeoutSeconds;
  public final Boolean h2ExtendKeepaliveTimeout;
@@ -82,6 +83,7 @@ public enum TrustChainVerification {
  * @param enableBrotli whether to enable response brotli decompression.
  * @param enableHappyEyeballs whether to enable RFC 6555 handling for IPv4/IPv6.
  * @param enableInterfaceBinding whether to allow interface binding.
+ * @param forceIPv6 whether to force connections to use IPv6.
  * @param h2ConnectionKeepaliveIdleIntervalMilliseconds rate in milliseconds seconds to send h2
  * pings on stream creation.
  * @param h2ConnectionKeepaliveTimeoutSeconds rate in seconds to timeout h2 pings.
@@ -108,12 +110,12 @@ public EnvoyConfiguration(
  String dnsPreresolveHostnames, List<String> dnsFallbackNameservers,
  Boolean dnsFilterUnroutableFamilies, boolean enableDrainPostDnsRefresh, boolean enableHttp3,
  boolean enableGzip, boolean enableBrotli, boolean enableHappyEyeballs,
- boolean enableInterfaceBinding, int h2ConnectionKeepaliveIdleIntervalMilliseconds,
- int h2ConnectionKeepaliveTimeoutSeconds, boolean h2ExtendKeepaliveTimeout,
- List<String> h2RawDomains, int maxConnectionsPerHost, int statsFlushSeconds,
- int streamIdleTimeoutSeconds, int perTryIdleTimeoutSeconds, String appVersion, String appId,
- TrustChainVerification trustChainVerification, String virtualClusters,
- List<EnvoyNativeFilterConfig> nativeFilterChain,
+ boolean enableInterfaceBinding, boolean forceIPv6,
+ int h2ConnectionKeepaliveIdleIntervalMilliseconds, int h2ConnectionKeepaliveTimeoutSeconds,
+ boolean h2ExtendKeepaliveTimeout, List<String> h2RawDomains, int maxConnectionsPerHost,
+ int statsFlushSeconds, int streamIdleTimeoutSeconds, int perTryIdleTimeoutSeconds,
+ String appVersion, String appId, TrustChainVerification trustChainVerification,
+ String virtualClusters, List<EnvoyNativeFilterConfig> nativeFilterChain,
  List<EnvoyHTTPFilterFactory> httpPlatformFilterFactories,
  Map<String, EnvoyStringAccessor> stringAccessors,
  Map<String, EnvoyKeyValueStore> keyValueStores) {
@@ -135,6 +137,7 @@ public EnvoyConfiguration(
  this.enableBrotli = enableBrotli;
  this.enableHappyEyeballs = enableHappyEyeballs;
  this.enableInterfaceBinding = enableInterfaceBinding;
+ this.forceIPv6 = forceIPv6;
  this.h2ConnectionKeepaliveIdleIntervalMilliseconds =
  h2ConnectionKeepaliveIdleIntervalMilliseconds;
  this.h2ConnectionKeepaliveTimeoutSeconds = h2ConnectionKeepaliveTimeoutSeconds;
@@ -250,6 +253,7 @@ String resolveTemplate(final String configTemplate, final String platformFilterT
  enableDrainPostDnsRefresh ? "true" : "false"))
  .append(String.format("- &enable_interface_binding %s\n",
  enableInterfaceBinding ? "true" : "false"))
+ .append(String.format("- &android_force_ipv6 %s\n", forceIPv6 ? "true" : "false"))
  .append(String.format("- &h2_connection_keepalive_idle_interval %ss\n",
  h2ConnectionKeepaliveIdleIntervalMilliseconds / 1000.0))
  .append(String.format("- &h2_connection_keepalive_timeout %ss\n",

library/java/org/chromium/net/impl/NativeCronetEngineBuilderImpl.java

@@ -48,6 +48,7 @@ public class NativeCronetEngineBuilderImpl extends CronetEngineBuilderImpl {
  private boolean mEnableGzip = true;
  private boolean mEnableHappyEyeballs = false;
  private boolean mEnableInterfaceBinding = false;
+ private boolean mForceIPv6 = false;
  private int mH2ConnectionKeepaliveIdleIntervalMilliseconds = 100000000;
  private int mH2ConnectionKeepaliveTimeoutSeconds = 10;
  private boolean mH2ExtendKeepaliveTimeout = false;
@@ -108,10 +109,10 @@ private EnvoyConfiguration createEnvoyConfiguration() {
  mDnsQueryTimeoutSeconds, mDnsMinRefreshSeconds, mDnsPreresolveHostnames,
  mDnsFallbackNameservers, mEnableDnsFilterUnroutableFamilies, mEnableDrainPostDnsRefresh,
  mEnableHttp3, mEnableGzip, brotliEnabled(), mEnableHappyEyeballs, mEnableInterfaceBinding,
- mH2ConnectionKeepaliveIdleIntervalMilliseconds, mH2ConnectionKeepaliveTimeoutSeconds,
- mH2ExtendKeepaliveTimeout, mH2RawDomains, mMaxConnectionsPerHost, mStatsFlushSeconds,
- mStreamIdleTimeoutSeconds, mPerTryIdleTimeoutSeconds, mAppVersion, mAppId,
- mTrustChainVerification, mVirtualClusters, nativeFilterChain, platformFilterChain,
- stringAccessors, keyValueStores);
+ mForceIPv6, mH2ConnectionKeepaliveIdleIntervalMilliseconds,
+ mH2ConnectionKeepaliveTimeoutSeconds, mH2ExtendKeepaliveTimeout, mH2RawDomains,
+ mMaxConnectionsPerHost, mStatsFlushSeconds, mStreamIdleTimeoutSeconds,
+ mPerTryIdleTimeoutSeconds, mAppVersion, mAppId, mTrustChainVerification, mVirtualClusters,
+ nativeFilterChain, platformFilterChain, stringAccessors, keyValueStores);
  }
 }

library/kotlin/io/envoyproxy/envoymobile/EngineBuilder.kt

@@ -46,6 +46,7 @@ open class EngineBuilder(
  private var enableGzip = true
  private var enableBrotli = false
  private var enableInterfaceBinding = false
+ private var forceIPv6 = false
  private var h2ConnectionKeepaliveIdleIntervalMilliseconds = 1
  private var h2ConnectionKeepaliveTimeoutSeconds = 10
  private var h2ExtendKeepaliveTimeout = false
@@ -284,6 +285,19 @@ open class EngineBuilder(
  return this
  }
 
+ /**
+ * Specify whether to remap IPv4 addresses to the IPv6 space and always force connections
+ * to use IPv6. Note this is an experimental option and should be enabled with caution.
+ *
+ * @param forceIPv6 whether to force connections to use IPv6.
+ *
+ * @return This builder.
+ */
+ fun forceIPv6(forceIPv6: Boolean): EngineBuilder {
+ this.forceIPv6 = forceIPv6
+ return this
+ }
+
  /**
  * Add a rate at which to ping h2 connections on new stream creation if the connection has
  * sat idle. Defaults to 1 millisecond which effectively enables h2 ping functionality
@@ -571,6 +585,7 @@ open class EngineBuilder(
  enableBrotli,
  enableHappyEyeballs,
  enableInterfaceBinding,
+ forceIPv6,
  h2ConnectionKeepaliveIdleIntervalMilliseconds,
  h2ConnectionKeepaliveTimeoutSeconds,
  h2ExtendKeepaliveTimeout,

test/java/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt

@@ -60,6 +60,7 @@ class EnvoyConfigurationTest {
  enableBrotli: Boolean = false,
  enableHappyEyeballs: Boolean = false,
  enableInterfaceBinding: Boolean = false,
+ forceIPv6: Boolean = false,
  h2ConnectionKeepaliveIdleIntervalMilliseconds: Int = 222,
  h2ConnectionKeepaliveTimeoutSeconds: Int = 333,
  h2ExtendKeepaliveTimeout: Boolean = false,
@@ -92,6 +93,7 @@ class EnvoyConfigurationTest {
  enableBrotli,
  enableHappyEyeballs,
  enableInterfaceBinding,
+ forceIPv6,
  h2ConnectionKeepaliveIdleIntervalMilliseconds,
  h2ConnectionKeepaliveTimeoutSeconds,
  h2ExtendKeepaliveTimeout,
@@ -139,6 +141,9 @@ class EnvoyConfigurationTest {
  // Interface Binding
  assertThat(resolvedTemplate).contains("&enable_interface_binding false")
 
+ // Forcing IPv6
+ assertThat(resolvedTemplate).contains("&android_force_ipv6 false")
+
  // H2 Ping
  assertThat(resolvedTemplate).contains("&h2_connection_keepalive_idle_interval 0.222s")
  assertThat(resolvedTemplate).contains("&h2_connection_keepalive_timeout 333s")
@@ -192,6 +197,7 @@ class EnvoyConfigurationTest {
  enableGzip = false,
  enableBrotli = true,
  enableInterfaceBinding = true,
+ forceIPv6 = true,
  h2ExtendKeepaliveTimeout = true
  )
 
@@ -219,6 +225,9 @@ class EnvoyConfigurationTest {
 
  // Interface Binding
  assertThat(resolvedTemplate).contains("&enable_interface_binding true")
+
+ // Forcing IPv6
+ assertThat(resolvedTemplate).contains("&android_force_ipv6 true")
  }
 
  @Test

test/kotlin/apps/experimental/MainActivity.kt

@@ -57,6 +57,7 @@ class MainActivity : Activity() {
  .addPlatformFilter(::AsyncDemoFilter)
  .h2ExtendKeepaliveTimeout(true)
  .enableInterfaceBinding(true)
+ .forceIPv6(true)
  .addNativeFilter("envoy.filters.http.buffer", "{\"@type\":\"type.googleapis.com/envoy.extensions.filters.http.buffer.v3.Buffer\",\"max_request_bytes\":5242880}")
  .addStringAccessor("demo-accessor", { "PlatformString" })
  .addKeyValueStore("demo-kv-store", SharedPreferencesStore(preferences))