Make CaptivePortalProbeSpec and CaptivePortalProbeResult as a library
These two classes were added to @SystemApi because they are used
both by NetworkMonitor and CaptivePortalLogin. However it turns
out they are not needed in the framework, so having them as a
library sounds better.
Change-Id: Iadf77ec5952b6da8812dc6d006a39bd4e93d2bd9
Fix: 129433264
Test: atest NetworkStackTests FrameworksNetTests
diff --git a/common/CaptivePortalProbeSpec.java b/common/CaptivePortalProbeSpec.java
new file mode 100644
index 0000000..bf983a5
--- /dev/null
+++ b/common/CaptivePortalProbeSpec.java
@@ -0,0 +1,195 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net.captiveportal;
+
+import static android.net.captiveportal.CaptivePortalProbeResult.PORTAL_CODE;
+import static android.net.captiveportal.CaptivePortalProbeResult.SUCCESS_CODE;
+
+import android.text.TextUtils;
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.text.ParseException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+/** @hide */
+public abstract class CaptivePortalProbeSpec {
+ private static final String TAG = CaptivePortalProbeSpec.class.getSimpleName();
+ private static final String REGEX_SEPARATOR = "@@/@@";
+ private static final String SPEC_SEPARATOR = "@@,@@";
+
+ private final String mEncodedSpec;
+ private final URL mUrl;
+
+ CaptivePortalProbeSpec(@NonNull String encodedSpec, @NonNull URL url) {
+ mEncodedSpec = checkNotNull(encodedSpec);
+ mUrl = checkNotNull(url);
+ }
+
+ /**
+ * Parse a {@link CaptivePortalProbeSpec} from a {@link String}.
+ *
+ * <p>The valid format is a URL followed by two regular expressions, each separated by "@@/@@".
+ * @throws MalformedURLException The URL has invalid format for {@link URL#URL(String)}.
+ * @throws ParseException The string is empty, does not match the above format, or a regular
+ * expression is invalid for {@link Pattern#compile(String)}.
+ * @hide
+ */
+ @VisibleForTesting
+ @NonNull
+ public static CaptivePortalProbeSpec parseSpec(@NonNull String spec) throws ParseException,
+ MalformedURLException {
+ if (TextUtils.isEmpty(spec)) {
+ throw new ParseException("Empty probe spec", 0 /* errorOffset */);
+ }
+
+ String[] splits = TextUtils.split(spec, REGEX_SEPARATOR);
+ if (splits.length != 3) {
+ throw new ParseException("Probe spec does not have 3 parts", 0 /* errorOffset */);
+ }
+
+ final int statusRegexPos = splits[0].length() + REGEX_SEPARATOR.length();
+ final int locationRegexPos = statusRegexPos + splits[1].length() + REGEX_SEPARATOR.length();
+ final Pattern statusRegex = parsePatternIfNonEmpty(splits[1], statusRegexPos);
+ final Pattern locationRegex = parsePatternIfNonEmpty(splits[2], locationRegexPos);
+
+ return new RegexMatchProbeSpec(spec, new URL(splits[0]), statusRegex, locationRegex);
+ }
+
+ @Nullable
+ private static Pattern parsePatternIfNonEmpty(@Nullable String pattern, int pos)
+ throws ParseException {
+ if (TextUtils.isEmpty(pattern)) {
+ return null;
+ }
+ try {
+ return Pattern.compile(pattern);
+ } catch (PatternSyntaxException e) {
+ throw new ParseException(
+ String.format("Invalid status pattern [%s]: %s", pattern, e),
+ pos /* errorOffset */);
+ }
+ }
+
+ /**
+ * Parse a {@link CaptivePortalProbeSpec} from a {@link String}, or return a fallback spec
+ * based on the status code of the provided URL if the spec cannot be parsed.
+ */
+ @Nullable
+ public static CaptivePortalProbeSpec parseSpecOrNull(@Nullable String spec) {
+ if (spec != null) {
+ try {
+ return parseSpec(spec);
+ } catch (ParseException | MalformedURLException e) {
+ Log.e(TAG, "Invalid probe spec: " + spec, e);
+ // Fall through
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Parse a config String to build an array of {@link CaptivePortalProbeSpec}.
+ *
+ * <p>Each spec is separated by @@,@@ and follows the format for {@link #parseSpec(String)}.
+ * <p>This method does not throw but ignores any entry that could not be parsed.
+ */
+ @NonNull
+ public static Collection<CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(
+ @NonNull String settingsVal) {
+ List<CaptivePortalProbeSpec> specs = new ArrayList<>();
+ if (settingsVal != null) {
+ for (String spec : TextUtils.split(settingsVal, SPEC_SEPARATOR)) {
+ try {
+ specs.add(parseSpec(spec));
+ } catch (ParseException | MalformedURLException e) {
+ Log.e(TAG, "Invalid probe spec: " + spec, e);
+ }
+ }
+ }
+
+ if (specs.isEmpty()) {
+ Log.e(TAG, String.format("could not create any validation spec from %s", settingsVal));
+ }
+ return specs;
+ }
+
+ /**
+ * Get the probe result from HTTP status and location header.
+ */
+ @NonNull
+ public abstract CaptivePortalProbeResult getResult(int status, @Nullable String locationHeader);
+
+ @NonNull
+ public String getEncodedSpec() {
+ return mEncodedSpec;
+ }
+
+ @NonNull
+ public URL getUrl() {
+ return mUrl;
+ }
+
+ /**
+ * Implementation of {@link CaptivePortalProbeSpec} that is based on configurable regular
+ * expressions for the HTTP status code and location header (if any). Matches indicate that
+ * the page is not a portal.
+ * This probe cannot fail: it always returns SUCCESS_CODE or PORTAL_CODE
+ */
+ private static class RegexMatchProbeSpec extends CaptivePortalProbeSpec {
+ @Nullable
+ final Pattern mStatusRegex;
+ @Nullable
+ final Pattern mLocationHeaderRegex;
+
+ RegexMatchProbeSpec(
+ String spec, URL url, Pattern statusRegex, Pattern locationHeaderRegex) {
+ super(spec, url);
+ mStatusRegex = statusRegex;
+ mLocationHeaderRegex = locationHeaderRegex;
+ }
+
+ @Override
+ public CaptivePortalProbeResult getResult(int status, String locationHeader) {
+ final boolean statusMatch = safeMatch(String.valueOf(status), mStatusRegex);
+ final boolean locationMatch = safeMatch(locationHeader, mLocationHeaderRegex);
+ final int returnCode = statusMatch && locationMatch ? SUCCESS_CODE : PORTAL_CODE;
+ return new CaptivePortalProbeResult(
+ returnCode, locationHeader, getUrl().toString(), this);
+ }
+ }
+
+ private static boolean safeMatch(@Nullable String value, @Nullable Pattern pattern) {
+ // No value is a match ("no location header" passes the location rule for non-redirects)
+ return pattern == null || TextUtils.isEmpty(value) || pattern.matcher(value).matches();
+ }
+
+ // Throws NullPointerException if the input is null.
+ private static <T> T checkNotNull(T object) {
+ if (object == null) throw new NullPointerException();
+ return object;
+ }
+}