Merge "Captive portal: better detect empty responses" (af8e7498) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/connectivity/NetworkMonitor.java

+20 −13

Original line number	Diff line number	Diff line
		@@ -809,19 +809,26 @@ public class NetworkMonitor extends StateMachine {
		// portal. If it is considered a captive portal, a different sign-in URL
		// is needed (i.e. can't browse a 204). This could be the result of an HTTP
		// proxy server.

		if (httpResponseCode == 200) {
		if (probeType == ValidationProbeEvent.PROBE_PAC) {
		validationLog("PAC fetch 200 response interpreted as 204 response.");
		httpResponseCode = 204;
		} else if (urlConnection.getContentLengthLong() == 0) {
		// Consider 200 response with "Content-length=0" to not be a captive portal.
		// There's no point in considering this a captive portal as the user cannot
		// sign-in to an empty page. Probably the result of a broken transparent proxy.
		// See http://b/9972012.
		if (httpResponseCode == 200 && urlConnection.getContentLength() == 0) {
		validationLog(
		"200 response with Content-length=0 interpreted as 204 response.");
		httpResponseCode = 204;
		} else if (urlConnection.getContentLengthLong() == -1) {
		// When no Content-length (default value == -1), attempt to read a byte from the
		// response. Do not use available() as it is unreliable. See http://b/33498325.
		if (urlConnection.getInputStream().read() == -1) {
		validationLog("Empty 200 response interpreted as 204 response.");
		httpResponseCode = 204;
		}

		if (httpResponseCode == 200 && probeType == ValidationProbeEvent.PROBE_PAC) {
		validationLog("PAC fetch 200 response interpreted as 204 response.");
		httpResponseCode = 204;
		}
		}
		} catch (IOException e) {
		validationLog("Probably not a portal: exception " + e);