diff options
| -rw-r--r-- | services/net/java/android/net/dhcp/DhcpPacket.java | 24 | ||||
| -rw-r--r-- | services/tests/servicestests/Android.mk | 1 | ||||
| -rw-r--r-- | services/tests/servicestests/src/android/net/dhcp/DhcpPacketTest.java | 116 |
3 files changed, 135 insertions, 6 deletions
diff --git a/services/net/java/android/net/dhcp/DhcpPacket.java b/services/net/java/android/net/dhcp/DhcpPacket.java index a232a6e..d41629d 100644 --- a/services/net/java/android/net/dhcp/DhcpPacket.java +++ b/services/net/java/android/net/dhcp/DhcpPacket.java @@ -611,10 +611,22 @@ abstract class DhcpPacket { /** * Reads a string of specified length from the buffer. */ - private static String readAsciiString(ByteBuffer buf, int byteCount) { + private static String readAsciiString(ByteBuffer buf, int byteCount, boolean nullOk) { byte[] bytes = new byte[byteCount]; buf.get(bytes); - return new String(bytes, 0, bytes.length, StandardCharsets.US_ASCII); + int length = bytes.length; + if (!nullOk) { + // Stop at the first null byte. This is because some DHCP options (e.g., the domain + // name) are passed to netd via FrameworkListener, which refuses arguments containing + // null bytes. We don't do this by default because vendorInfo is an opaque string which + // could in theory contain null bytes. + for (length = 0; length < bytes.length; length++) { + if (bytes[length] == 0) { + break; + } + } + } + return new String(bytes, 0, length, StandardCharsets.US_ASCII); } /** @@ -797,7 +809,7 @@ abstract class DhcpPacket { break; case DHCP_HOST_NAME: expectedLen = optionLen; - hostName = readAsciiString(packet, optionLen); + hostName = readAsciiString(packet, optionLen, false); break; case DHCP_MTU: expectedLen = 2; @@ -805,7 +817,7 @@ abstract class DhcpPacket { break; case DHCP_DOMAIN_NAME: expectedLen = optionLen; - domainName = readAsciiString(packet, optionLen); + domainName = readAsciiString(packet, optionLen, false); break; case DHCP_BROADCAST_ADDRESS: bcAddr = readIpAddress(packet); @@ -834,7 +846,7 @@ abstract class DhcpPacket { break; case DHCP_MESSAGE: expectedLen = optionLen; - message = readAsciiString(packet, optionLen); + message = readAsciiString(packet, optionLen, false); break; case DHCP_MAX_MESSAGE_SIZE: expectedLen = 2; @@ -850,7 +862,7 @@ abstract class DhcpPacket { break; case DHCP_VENDOR_CLASS_ID: expectedLen = optionLen; - vendorId = readAsciiString(packet, optionLen); + vendorId = readAsciiString(packet, optionLen, true); break; case DHCP_CLIENT_IDENTIFIER: { // Client identifier byte[] id = new byte[optionLen]; diff --git a/services/tests/servicestests/Android.mk b/services/tests/servicestests/Android.mk index f25fc62..33979b1 100644 --- a/services/tests/servicestests/Android.mk +++ b/services/tests/servicestests/Android.mk @@ -10,6 +10,7 @@ LOCAL_SRC_FILES := $(call all-java-files-under, src) LOCAL_STATIC_JAVA_LIBRARIES := \ services.core \ services.devicepolicy \ + services.net \ easymocklib \ guava \ mockito-target diff --git a/services/tests/servicestests/src/android/net/dhcp/DhcpPacketTest.java b/services/tests/servicestests/src/android/net/dhcp/DhcpPacketTest.java new file mode 100644 index 0000000..2658937 --- /dev/null +++ b/services/tests/servicestests/src/android/net/dhcp/DhcpPacketTest.java @@ -0,0 +1,116 @@ +/* + * Copyright (C) 2015 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.dhcp; + +import android.net.NetworkUtils; +import android.system.OsConstants; +import android.test.suitebuilder.annotation.SmallTest; +import junit.framework.TestCase; + +import java.net.Inet4Address; +import java.nio.ByteBuffer; + +import static android.net.dhcp.DhcpPacket.*; + + +public class DhcpPacketTest extends TestCase { + + private static Inet4Address SERVER_ADDR = + (Inet4Address) NetworkUtils.numericToInetAddress("192.0.2.1"); + private static Inet4Address CLIENT_ADDR = + (Inet4Address) NetworkUtils.numericToInetAddress("192.0.2.234"); + private static byte[] CLIENT_MAC = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05 }; + + class TestDhcpPacket extends DhcpPacket { + private byte mType; + // TODO: Make this a map of option numbers to bytes instead. + private byte[] mDomainBytes, mVendorInfoBytes; + + public TestDhcpPacket(byte type, byte[] domainBytes, byte[] vendorInfoBytes) { + super(0xdeadbeef, INADDR_ANY, CLIENT_ADDR, INADDR_ANY, INADDR_ANY, CLIENT_MAC, true); + mType = type; + mDomainBytes = domainBytes; + mVendorInfoBytes = vendorInfoBytes; + } + + public ByteBuffer buildPacket(int encap, short unusedDestUdp, short unusedSrcUdp) { + ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH); + fillInPacket(encap, CLIENT_ADDR, SERVER_ADDR, + DHCP_CLIENT, DHCP_SERVER, result, DHCP_BOOTREPLY, false); + return result; + } + + public void finishPacket(ByteBuffer buffer) { + addTlv(buffer, DHCP_MESSAGE_TYPE, mType); + if (mDomainBytes != null) { + addTlv(buffer, DHCP_DOMAIN_NAME, mDomainBytes); + } + if (mVendorInfoBytes != null) { + addTlv(buffer, DHCP_VENDOR_CLASS_ID, mVendorInfoBytes); + } + addTlvEnd(buffer); + } + + // Convenience method. + public ByteBuffer build() { + // ENCAP_BOOTP packets don't contain ports, so just pass in 0. + ByteBuffer pkt = buildPacket(ENCAP_BOOTP, (short) 0, (short) 0); + pkt.flip(); + return pkt; + } + } + + private void assertDomainAndVendorInfoParses( + String expectedDomain, byte[] domainBytes, + String expectedVendorInfo, byte[] vendorInfoBytes) { + ByteBuffer packet = new TestDhcpPacket(DHCP_MESSAGE_TYPE_OFFER, + domainBytes, vendorInfoBytes).build(); + DhcpPacket offerPacket = DhcpPacket.decodeFullPacket(packet, ENCAP_BOOTP); + assertEquals(expectedDomain, offerPacket.mDomainName); + assertEquals(expectedVendorInfo, offerPacket.mVendorId); + } + + @SmallTest + public void testDomainName() throws Exception { + byte[] nullByte = new byte[] { 0x00 }; + byte[] twoNullBytes = new byte[] { 0x00, 0x00 }; + byte[] nonNullDomain = new byte[] { + (byte) 'g', (byte) 'o', (byte) 'o', (byte) '.', (byte) 'g', (byte) 'l' + }; + byte[] trailingNullDomain = new byte[] { + (byte) 'g', (byte) 'o', (byte) 'o', (byte) '.', (byte) 'g', (byte) 'l', 0x00 + }; + byte[] embeddedNullsDomain = new byte[] { + (byte) 'g', (byte) 'o', (byte) 'o', 0x00, 0x00, (byte) 'g', (byte) 'l' + }; + byte[] metered = "ANDROID_METERED".getBytes("US-ASCII"); + + byte[] meteredEmbeddedNull = metered.clone(); + meteredEmbeddedNull[7] = (char) 0; + + byte[] meteredTrailingNull = metered.clone(); + meteredTrailingNull[meteredTrailingNull.length - 1] = (char) 0; + + assertDomainAndVendorInfoParses("", nullByte, "\u0000", nullByte); + assertDomainAndVendorInfoParses("", twoNullBytes, "\u0000\u0000", twoNullBytes); + assertDomainAndVendorInfoParses("goo.gl", nonNullDomain, "ANDROID_METERED", metered); + assertDomainAndVendorInfoParses("goo", embeddedNullsDomain, + "ANDROID\u0000METERED", meteredEmbeddedNull); + assertDomainAndVendorInfoParses("goo.gl", trailingNullDomain, + "ANDROID_METERE\u0000", meteredTrailingNull); + } +} |