hotspot2: anqp: add parsing support OSU Providers List ANQP element

Bug: 38351209
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: I14f26966b073e44291241bd69c4160b91a47e264

2 files changed, 232 insertions, 0 deletions

diff --git a/service/java/com/android/server/wifi/hotspot2/anqp/HSOsuProvidersElement.java b/service/java/com/android/server/wifi/hotspot2/anqp/HSOsuProvidersElement.java
new file mode 100644
index 000000000..146a44ca9
--- /dev/null
+++ b/service/java/com/android/server/wifi/hotspot2/anqp/HSOsuProvidersElement.java
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2017 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 com.android.server.wifi.hotspot2.anqp;
+
+import android.net.wifi.WifiSsid;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.net.ProtocolException;
+import java.nio.BufferUnderflowException;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * The OSU Providers List vendor specific ANQP Element,
+ * Wi-Fi Alliance Hotspot 2.0 (Release 2) Technical Specification - Version 5.00,
+ * section 4.8.
+ *
+ * Format:
+ *
+ * | OSU SSID Length | OSU SSID | Number of OSU Providers | Provider #1 | ...
+ *          1          variable             1                 variable
+ *
+ */
+public class HSOsuProvidersElement extends ANQPElement {
+    /**
+     * Maximum length for a SSID.  Refer to IEEE 802.11-2012 Section 8.4.2.2
+     * for more info.
+     */
+    @VisibleForTesting
+    public static final int MAXIMUM_OSU_SSID_LENGTH = 32;
+
+    private final WifiSsid mOsuSsid;
+    private final List<OsuProviderInfo> mProviders;
+
+    @VisibleForTesting
+    public HSOsuProvidersElement(WifiSsid osuSsid, List<OsuProviderInfo> providers) {
+        super(Constants.ANQPElementType.HSOSUProviders);
+        mOsuSsid = osuSsid;
+        mProviders = providers;
+    }
+
+    /**
+     * Parse a HSOsuProvidersElement from the given buffer.
+     *
+     * @param payload The buffer to read from
+     * @return {@link HSOsuProvidersElement}
+     * @throws BufferUnderflowException
+     * @throws ProtocolException
+     */
+    public static HSOsuProvidersElement parse(ByteBuffer payload)
+            throws ProtocolException {
+        int ssidLength = payload.get() & 0xFF;
+        if (ssidLength > MAXIMUM_OSU_SSID_LENGTH) {
+            throw new ProtocolException("Invalid SSID length: " + ssidLength);
+        }
+        byte[] ssidBytes = new byte[ssidLength];
+        payload.get(ssidBytes);
+
+        int numProviders = payload.get() & 0xFF;
+        List<OsuProviderInfo> providers = new ArrayList<>();
+        while (numProviders > 0) {
+            providers.add(OsuProviderInfo.parse(payload));
+            numProviders--;
+        }
+
+        return new HSOsuProvidersElement(WifiSsid.createFromByteArray(ssidBytes), providers);
+    }
+
+    public WifiSsid getOsuSsid() {
+        return mOsuSsid;
+    }
+
+    public List<OsuProviderInfo> getProviders() {
+        return Collections.unmodifiableList(mProviders);
+    }
+
+    @Override
+    public boolean equals(Object thatObject) {
+        if (this == thatObject) {
+            return true;
+        }
+        if (!(thatObject instanceof HSOsuProvidersElement)) {
+            return false;
+        }
+        HSOsuProvidersElement that = (HSOsuProvidersElement) thatObject;
+        return (mOsuSsid == null ? that.mOsuSsid == null : mOsuSsid.equals(that.mOsuSsid))
+                && (mProviders == null ? that.mProviders == null
+                        : mProviders.equals(that.mProviders));
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(mOsuSsid, mProviders);
+    }
+
+    @Override
+    public String toString() {
+        return "OSUProviders{" + "mOsuSsid=" + mOsuSsid + ", mProviders=" + mProviders + "}";
+    }
+}
diff --git a/tests/wifitests/src/com/android/server/wifi/hotspot2/anqp/HSOsuProvidersElementTest.java b/tests/wifitests/src/com/android/server/wifi/hotspot2/anqp/HSOsuProvidersElementTest.java
new file mode 100644
index 000000000..c4f73871b
--- /dev/null
+++ b/tests/wifitests/src/com/android/server/wifi/hotspot2/anqp/HSOsuProvidersElementTest.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2017 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 com.android.server.wifi.hotspot2.anqp;
+
+import static org.junit.Assert.assertEquals;
+
+import android.net.wifi.WifiSsid;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import org.junit.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.net.ProtocolException;
+import java.nio.BufferUnderflowException;
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Unit tests for {@link com.android.server.wifi.hotspot2.anqp.HSOsuProvidersElement}.
+ */
+@SmallTest
+public class HSOsuProvidersElementTest {
+    private static final byte[] TEST_OSU_SSID_BYTES = "Test SSID".getBytes(StandardCharsets.UTF_8);
+    private static final WifiSsid TEST_OSU_SSID =
+            WifiSsid.createFromByteArray(TEST_OSU_SSID_BYTES);
+    private static final List<OsuProviderInfo> TEST_PROVIDER_LIST =
+            Arrays.asList(OsuProviderInfoTestUtil.TEST_OSU_PROVIDER_INFO);
+
+    private static final HSOsuProvidersElement TEST_OSU_PROVIDERS_ELEMENT =
+            new HSOsuProvidersElement(TEST_OSU_SSID, TEST_PROVIDER_LIST);
+
+    /**
+     * Utility function for generating test data.
+     *
+     * @param osuSsidBytes The OSU SSID bytes
+     * @return byte[]
+     */
+    private static byte[] getTestData(byte[] osuSsidBytes) {
+        try {
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+            out.write((byte) osuSsidBytes.length);
+            out.write(osuSsidBytes);
+            out.write((byte) TEST_PROVIDER_LIST.size());
+            out.write(OsuProviderInfoTestUtil.TEST_OSU_PROVIDER_INFO_RAW_BYTES);
+            return out.toByteArray();
+        } catch (IOException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Verify that BufferUnderflowException will be thrown when parsing an empty buffer.
+     * @throws Exception
+     */
+    @Test(expected = BufferUnderflowException.class)
+    public void parseEmptyBuffer() throws Exception {
+        HSOsuProvidersElement.parse(ByteBuffer.allocate(0));
+    }
+
+    /**
+     * Verify that BufferUnderflowException will be thrown when parsing a truncated buffer
+     * (missing a byte at the end).
+     *
+     * @throws Exception
+     */
+    @Test(expected = BufferUnderflowException.class)
+    public void parseTruncatedBuffer() throws Exception {
+        ByteBuffer buffer = ByteBuffer.wrap(getTestData(TEST_OSU_SSID_BYTES));
+        buffer.limit(buffer.remaining() - 1);
+        HSOsuProvidersElement.parse(buffer);
+    }
+
+    /**
+     * Verify that ProtocolException will be thrown when parsing a buffer containing an
+     * invalid OSU SSID.
+     *
+     * @throws Exception
+     */
+    @Test(expected = ProtocolException.class)
+    public void parseBufferWithInvalidLength() throws Exception {
+        byte[] invalidSsidBytes = new byte[HSOsuProvidersElement.MAXIMUM_OSU_SSID_LENGTH + 1];
+        ByteBuffer buffer = ByteBuffer.wrap(getTestData(invalidSsidBytes));
+        HSOsuProvidersElement.parse(buffer);
+    }
+
+    /**
+     * Verify that an expected {@link HSOsuProvidersElement} will be returned when parsing a buffer
+     * containing pre-defined test data.
+     *
+     * @throws Exception
+     */
+    @Test
+    public void parseBufferWithTestData() throws Exception {
+        ByteBuffer buffer = ByteBuffer.wrap(getTestData(TEST_OSU_SSID_BYTES));
+        assertEquals(TEST_OSU_PROVIDERS_ELEMENT, HSOsuProvidersElement.parse(buffer));
+    }
+}