companion object {
    /**
     * A DNS that uses [InetAddress.getAllByName] to ask the underlying operating system to
     * lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

    private class DnsSystem : Dns {
      override fun lookup(hostname: String): List<InetAddress> {
        try {

Eoin Fennessy <******@****.***> 1715615475 +0100

    var routeSelector = newRouteSelector(address)
    dns[PROXY_A_HOST] = dns.allocate(1)
    dns[PROXY_B_HOST] = dns.allocate(1)

    // Mark the ProxyA route as failed.
    val selection = routeSelector.next()
    dns.assertRequests(PROXY_A_HOST)
    val route = selection.next()
    assertRoute(route, address, proxyA, dns.lookup(PROXY_A_HOST, 0), PROXY_A_PORT)
    routeDatabase.failed(route)

import okhttp3.OkHttpClient

/**
 * Temporary registry of known DNS over HTTPS providers.
 *
 * https://github.com/curl/curl/wiki/DNS-over-HTTPS
 */
object DohProviders {
  private fun buildGoogle(bootstrapClient: OkHttpClient): DnsOverHttps {
    return DnsOverHttps.Builder()
      .client(bootstrapClient)
      .url("https://dns.google/dns-query".toHttpUrl())
      .bootstrapDnsHosts(getByIp("8.8.4.4"), getByIp("8.8.8.8"))

        continue
      }

      val dns = route?.address?.dns ?: defaultDns
      val auth =
        if (proxyAuthorization) {
          val proxyAddress = proxy.address() as InetSocketAddress
          Authenticator.requestPasswordAuthentication(
            proxyAddress.hostName,
            proxy.connectToInetAddress(url, dns),
            proxyAddress.port,
            url.scheme,

    .url("https://dns.google/dns-query".toHttpUrl())
    .bootstrapDnsHosts(InetAddress.getByName("8.8.4.4"), InetAddress.getByName("8.8.8.8"))
    .build()

  val client = bootstrapClient.newBuilder().dns(dns).build()
```

    const val TYPE_AAAA = 28

    /**
     * Adapt an AsyncDns implementation to Dns, waiting until onComplete is received
     * and returning results if available.
     */
    fun toDns(vararg asyncDns: AsyncDns): Dns =
      Dns { hostname ->
        val allAddresses = mutableListOf<InetAddress>()
        val allExceptions = mutableListOf<IOException>()
        val latch = CountDownLatch(asyncDns.size)

  private lateinit var dns: Dns
  private val cacheFs = FakeFileSystem()
  private val bootstrapClient =
    OkHttpClient.Builder()
      .protocols(listOf(Protocol.HTTP_2, Protocol.HTTP_1_1))
      .build()

  @BeforeEach
  fun setUp(server: MockWebServer) {
    this.server = server
    server.protocols = bootstrapClient.protocols
    dns = buildLocalhost(bootstrapClient, false)
  }

  @Test

    server.useHttps(handshakeCertificates.sslSocketFactory())

    val dns =
      Dns {
        Dns.SYSTEM.lookup(server.hostName)
      }

    val client =
      clientTestRule.newClientBuilder()
        .sslSocketFactory(
          handshakeCertificates.sslSocketFactory(),
          handshakeCertificates.trustManager,
        )
        .dns(dns)
        .build()

    server.enqueue(MockResponse())

import java.net.InetAddress
import java.net.UnknownHostException
import okhttp3.Dns

/**
 * Internal Bootstrap DNS implementation for handling initial connection to DNS over HTTPS server.
 *
 * Returns hardcoded results for the known host.
 */
internal class BootstrapDns(
  private val dnsHostname: String,
  private val dnsServers: List<InetAddress>,
) : Dns {
  @Throws(UnknownHostException::class)