DO NOT MERGE NetworkMonitor: send one DNS probe per web probe
This patch changes sligthly the two web probes mechanism for captive
portal detection and network validation so that DNS resolution is always
done for both probes.
In general the target web servers of the two parallel HTTP and HTTPS probes
are now different. This introduces a bias in the latency measurement of
th HTTPS probe since this latency will also include DNS resolution in
general.
Test: manual verification + $ runtest frameworks-net
Bug: 32198726
(cherry picked from commit ab61e7c324b24e46829495bc2597e42ea907c53d)
Change-Id: Ic83c3f8f46d32269bca1b90ae192ef648d5df6c3
diff --git a/services/core/java/com/android/server/connectivity/NetworkMonitor.java b/services/core/java/com/android/server/connectivity/NetworkMonitor.java
index 209ea64..5e98859 100644
--- a/services/core/java/com/android/server/connectivity/NetworkMonitor.java
+++ b/services/core/java/com/android/server/connectivity/NetworkMonitor.java
@@ -707,48 +707,13 @@
long startTime = SystemClock.elapsedRealtime();
- // Pre-resolve the captive portal server host so we can log it.
- // Only do this if HttpURLConnection is about to, to avoid any potentially
- // unnecessary resolution.
- String hostToResolve = null;
+ final CaptivePortalProbeResult result;
if (pacUrl != null) {
- hostToResolve = pacUrl.getHost();
- } else if (proxyInfo != null) {
- hostToResolve = proxyInfo.getHost();
- } else {
- hostToResolve = httpUrl.getHost();
- }
-
- if (!TextUtils.isEmpty(hostToResolve)) {
- String probeName = ValidationProbeEvent.getProbeName(ValidationProbeEvent.PROBE_DNS);
- final Stopwatch dnsTimer = new Stopwatch().start();
- int dnsResult;
- long dnsLatency;
- try {
- InetAddress[] addresses = mNetworkAgentInfo.network.getAllByName(hostToResolve);
- dnsResult = ValidationProbeEvent.DNS_SUCCESS;
- dnsLatency = dnsTimer.stop();
- final StringBuffer connectInfo = new StringBuffer(", " + hostToResolve + "=");
- for (InetAddress address : addresses) {
- connectInfo.append(address.getHostAddress());
- if (address != addresses[addresses.length-1]) connectInfo.append(",");
- }
- validationLog(probeName + " OK " + dnsLatency + "ms" + connectInfo);
- } catch (UnknownHostException e) {
- dnsResult = ValidationProbeEvent.DNS_FAILURE;
- dnsLatency = dnsTimer.stop();
- validationLog(probeName + " FAIL " + dnsLatency + "ms, " + hostToResolve);
- }
- logValidationProbe(dnsLatency, ValidationProbeEvent.PROBE_DNS, dnsResult);
- }
-
- CaptivePortalProbeResult result;
- if (pacUrl != null) {
- result = sendHttpProbe(pacUrl, ValidationProbeEvent.PROBE_PAC);
+ result = sendDnsAndHttpProbes(null, pacUrl, ValidationProbeEvent.PROBE_PAC);
} else if (mUseHttps) {
- result = sendParallelHttpProbes(httpsUrl, httpUrl, fallbackUrl);
+ result = sendParallelHttpProbes(proxyInfo, httpsUrl, httpUrl, fallbackUrl);
} else {
- result = sendHttpProbe(httpUrl, ValidationProbeEvent.PROBE_HTTP);
+ result = sendDnsAndHttpProbes(proxyInfo, httpUrl, ValidationProbeEvent.PROBE_HTTP);
}
long endTime = SystemClock.elapsedRealtime();
@@ -761,8 +726,50 @@
}
/**
- * Do a URL fetch on a known server to see if we get the data we expect.
- * Returns HTTP response code.
+ * Do a DNS resolution and URL fetch on a known web server to see if we get the data we expect.
+ * @return a CaptivePortalProbeResult inferred from the HTTP response.
+ */
+ private CaptivePortalProbeResult sendDnsAndHttpProbes(ProxyInfo proxy, URL url, int probeType) {
+ // Pre-resolve the captive portal server host so we can log it.
+ // Only do this if HttpURLConnection is about to, to avoid any potentially
+ // unnecessary resolution.
+ final String host = (proxy != null) ? proxy.getHost() : url.getHost();
+ sendDnsProbe(host);
+ return sendHttpProbe(url, probeType);
+ }
+
+ /** Do a DNS resolution of the given server. */
+ private void sendDnsProbe(String host) {
+ if (TextUtils.isEmpty(host)) {
+ return;
+ }
+
+ final String name = ValidationProbeEvent.getProbeName(ValidationProbeEvent.PROBE_DNS);
+ final Stopwatch watch = new Stopwatch().start();
+ int result;
+ String connectInfo;
+ try {
+ InetAddress[] addresses = mNetworkAgentInfo.network.getAllByName(host);
+ result = ValidationProbeEvent.DNS_SUCCESS;
+ StringBuffer buffer = new StringBuffer(host).append("=");
+ for (InetAddress address : addresses) {
+ buffer.append(address.getHostAddress());
+ if (address != addresses[addresses.length-1]) buffer.append(",");
+ }
+ connectInfo = buffer.toString();
+ } catch (UnknownHostException e) {
+ result = ValidationProbeEvent.DNS_FAILURE;
+ connectInfo = host;
+ }
+ final long latency = watch.stop();
+ String resultString = (ValidationProbeEvent.DNS_SUCCESS == result) ? "OK" : "FAIL";
+ validationLog(String.format("%s %s %dms, %s", name, resultString, latency, connectInfo));
+ logValidationProbe(latency, ValidationProbeEvent.PROBE_DNS, result);
+ }
+
+ /**
+ * Do a URL fetch on a known web server to see if we get the data we expect.
+ * @return a CaptivePortalProbeResult inferred from the HTTP response.
*/
@VisibleForTesting
protected CaptivePortalProbeResult sendHttpProbe(URL url, int probeType) {
@@ -829,7 +836,7 @@
}
private CaptivePortalProbeResult sendParallelHttpProbes(
- URL httpsUrl, URL httpUrl, URL fallbackUrl) {
+ ProxyInfo proxy, URL httpsUrl, URL httpUrl, URL fallbackUrl) {
// Number of probes to wait for. If a probe completes with a conclusive answer
// it shortcuts the latch immediately by forcing the count to 0.
final CountDownLatch latch = new CountDownLatch(2);
@@ -849,9 +856,10 @@
@Override
public void run() {
if (mIsHttps) {
- mResult = sendHttpProbe(httpsUrl, ValidationProbeEvent.PROBE_HTTPS);
+ mResult =
+ sendDnsAndHttpProbes(proxy, httpsUrl, ValidationProbeEvent.PROBE_HTTPS);
} else {
- mResult = sendHttpProbe(httpUrl, ValidationProbeEvent.PROBE_HTTP);
+ mResult = sendDnsAndHttpProbes(proxy, httpUrl, ValidationProbeEvent.PROBE_HTTP);
}
if ((mIsHttps && mResult.isSuccessful()) || (!mIsHttps && mResult.isPortal())) {
// Stop waiting immediately if https succeeds or if http finds a portal.