Send hostname and MTU options in DHCP ACK/OFFER
The hostname option is only sent when requested in the requested
parameters option. This matches current behavior.
Test: with aosp/763982, regression tests now all pass
atest FrameworksNetTest
Bug: b/109584964
Change-Id: I793173fa893750ddbe72be09f4c2d70e5b285837
diff --git a/services/net/java/android/net/dhcp/DhcpPacket.java b/services/net/java/android/net/dhcp/DhcpPacket.java
index 77a3e21..6ba7d94 100644
--- a/services/net/java/android/net/dhcp/DhcpPacket.java
+++ b/services/net/java/android/net/dhcp/DhcpPacket.java
@@ -1,5 +1,8 @@
package android.net.dhcp;
+import static android.net.util.NetworkConstants.IPV4_MAX_MTU;
+import static android.net.util.NetworkConstants.IPV4_MIN_MTU;
+
import android.annotation.Nullable;
import android.net.DhcpResults;
import android.net.LinkAddress;
@@ -381,6 +384,26 @@
}
/**
+ * Returns whether a parameter is included in the parameter request list option of this packet.
+ *
+ * <p>If there is no parameter request list option in the packet, false is returned.
+ *
+ * @param paramId ID of the parameter, such as {@link #DHCP_MTU} or {@link #DHCP_HOST_NAME}.
+ */
+ public boolean hasRequestedParam(byte paramId) {
+ if (mRequestedParams == null) {
+ return false;
+ }
+
+ for (byte reqParam : mRequestedParams) {
+ if (reqParam == paramId) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
* Creates a new L3 packet (including IP header) containing the
* DHCP udp packet. This method relies upon the delegated method
* finishPacket() to insert the per-packet contents.
@@ -696,7 +719,11 @@
addTlv(buf, DHCP_ROUTER, mGateways);
addTlv(buf, DHCP_DNS_SERVER, mDnsServers);
addTlv(buf, DHCP_DOMAIN_NAME, mDomainName);
+ addTlv(buf, DHCP_HOST_NAME, mHostName);
addTlv(buf, DHCP_VENDOR_INFO, mVendorInfo);
+ if (mMtu != null && Short.toUnsignedInt(mMtu) >= IPV4_MIN_MTU) {
+ addTlv(buf, DHCP_MTU, mMtu);
+ }
}
/**
@@ -1259,7 +1286,8 @@
boolean broadcast, Inet4Address serverIpAddr, Inet4Address relayIp,
Inet4Address yourIp, byte[] mac, Integer timeout, Inet4Address netMask,
Inet4Address bcAddr, List<Inet4Address> gateways, List<Inet4Address> dnsServers,
- Inet4Address dhcpServerIdentifier, String domainName, boolean metered) {
+ Inet4Address dhcpServerIdentifier, String domainName, String hostname, boolean metered,
+ short mtu) {
DhcpPacket pkt = new DhcpOfferPacket(
transactionId, (short) 0, broadcast, serverIpAddr, relayIp,
INADDR_ANY /* clientIp */, yourIp, mac);
@@ -1267,9 +1295,11 @@
pkt.mDnsServers = dnsServers;
pkt.mLeaseTime = timeout;
pkt.mDomainName = domainName;
+ pkt.mHostName = hostname;
pkt.mServerIdentifier = dhcpServerIdentifier;
pkt.mSubnetMask = netMask;
pkt.mBroadcastAddress = bcAddr;
+ pkt.mMtu = mtu;
if (metered) {
pkt.mVendorInfo = VENDOR_INFO_ANDROID_METERED;
}
@@ -1283,7 +1313,8 @@
boolean broadcast, Inet4Address serverIpAddr, Inet4Address relayIp, Inet4Address yourIp,
Inet4Address requestClientIp, byte[] mac, Integer timeout, Inet4Address netMask,
Inet4Address bcAddr, List<Inet4Address> gateways, List<Inet4Address> dnsServers,
- Inet4Address dhcpServerIdentifier, String domainName, boolean metered) {
+ Inet4Address dhcpServerIdentifier, String domainName, String hostname, boolean metered,
+ short mtu) {
DhcpPacket pkt = new DhcpAckPacket(
transactionId, (short) 0, broadcast, serverIpAddr, relayIp, requestClientIp, yourIp,
mac);
@@ -1291,9 +1322,11 @@
pkt.mDnsServers = dnsServers;
pkt.mLeaseTime = timeout;
pkt.mDomainName = domainName;
+ pkt.mHostName = hostname;
pkt.mSubnetMask = netMask;
pkt.mServerIdentifier = dhcpServerIdentifier;
pkt.mBroadcastAddress = bcAddr;
+ pkt.mMtu = mtu;
if (metered) {
pkt.mVendorInfo = VENDOR_INFO_ANDROID_METERED;
}
diff --git a/services/net/java/android/net/dhcp/DhcpServer.java b/services/net/java/android/net/dhcp/DhcpServer.java
index 2b3d577..cee6fa9 100644
--- a/services/net/java/android/net/dhcp/DhcpServer.java
+++ b/services/net/java/android/net/dhcp/DhcpServer.java
@@ -20,6 +20,7 @@
import static android.net.NetworkUtils.getPrefixMaskAsInet4Address;
import static android.net.TrafficStats.TAG_SYSTEM_DHCP_SERVER;
import static android.net.dhcp.DhcpPacket.DHCP_CLIENT;
+import static android.net.dhcp.DhcpPacket.DHCP_HOST_NAME;
import static android.net.dhcp.DhcpPacket.DHCP_SERVER;
import static android.net.dhcp.DhcpPacket.ENCAP_BOOTP;
import static android.net.dhcp.DhcpPacket.INFINITE_LEASE;
@@ -46,6 +47,7 @@
import android.os.SystemClock;
import android.system.ErrnoException;
import android.system.Os;
+import android.text.TextUtils;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.util.HexDump;
@@ -350,6 +352,19 @@
return isEmpty(request.mClientIp) && (request.mBroadcast || isEmpty(lease.getNetAddr()));
}
+ /**
+ * Get the hostname from a lease if non-empty and requested in the incoming request.
+ * @param request The incoming request.
+ * @return The hostname, or null if not requested or empty.
+ */
+ @Nullable
+ private static String getHostnameIfRequested(@NonNull DhcpPacket request,
+ @NonNull DhcpLease lease) {
+ return request.hasRequestedParam(DHCP_HOST_NAME) && !TextUtils.isEmpty(lease.getHostname())
+ ? lease.getHostname()
+ : null;
+ }
+
private boolean transmitOffer(@NonNull DhcpPacket request, @NonNull DhcpLease lease,
@NonNull MacAddress clientMac) {
final boolean broadcastFlag = getBroadcastFlag(request, lease);
@@ -358,12 +373,14 @@
getPrefixMaskAsInet4Address(mServingParams.serverAddr.getPrefixLength());
final Inet4Address broadcastAddr = getBroadcastAddress(
mServingParams.getServerInet4Addr(), mServingParams.serverAddr.getPrefixLength());
+ final String hostname = getHostnameIfRequested(request, lease);
final ByteBuffer offerPacket = DhcpPacket.buildOfferPacket(
ENCAP_BOOTP, request.mTransId, broadcastFlag, mServingParams.getServerInet4Addr(),
request.mRelayIp, lease.getNetAddr(), request.mClientMac, timeout, prefixMask,
broadcastAddr, new ArrayList<>(mServingParams.defaultRouters),
new ArrayList<>(mServingParams.dnsServers),
- mServingParams.getServerInet4Addr(), null /* domainName */, mServingParams.metered);
+ mServingParams.getServerInet4Addr(), null /* domainName */, hostname,
+ mServingParams.metered, (short) mServingParams.linkMtu);
return transmitOfferOrAckPacket(offerPacket, request, lease, clientMac, broadcastFlag);
}
@@ -374,13 +391,15 @@
// transmitOffer above
final boolean broadcastFlag = getBroadcastFlag(request, lease);
final int timeout = getLeaseTimeout(lease);
+ final String hostname = getHostnameIfRequested(request, lease);
final ByteBuffer ackPacket = DhcpPacket.buildAckPacket(ENCAP_BOOTP, request.mTransId,
broadcastFlag, mServingParams.getServerInet4Addr(), request.mRelayIp,
lease.getNetAddr(), request.mClientIp, request.mClientMac, timeout,
mServingParams.getPrefixMaskAsAddress(), mServingParams.getBroadcastAddress(),
new ArrayList<>(mServingParams.defaultRouters),
new ArrayList<>(mServingParams.dnsServers),
- mServingParams.getServerInet4Addr(), null /* domainName */, mServingParams.metered);
+ mServingParams.getServerInet4Addr(), null /* domainName */, hostname,
+ mServingParams.metered, (short) mServingParams.linkMtu);
return transmitOfferOrAckPacket(ackPacket, request, lease, clientMac, broadcastFlag);
}
diff --git a/tests/net/java/android/net/dhcp/DhcpPacketTest.java b/tests/net/java/android/net/dhcp/DhcpPacketTest.java
index 312b3d1..a592809 100644
--- a/tests/net/java/android/net/dhcp/DhcpPacketTest.java
+++ b/tests/net/java/android/net/dhcp/DhcpPacketTest.java
@@ -25,6 +25,7 @@
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
+import android.annotation.Nullable;
import android.net.DhcpResults;
import android.net.LinkAddress;
import android.net.NetworkUtils;
@@ -37,6 +38,7 @@
import java.io.ByteArrayOutputStream;
import java.net.Inet4Address;
import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
@@ -56,6 +58,8 @@
private static final Inet4Address NETMASK = getPrefixMaskAsInet4Address(PREFIX_LENGTH);
private static final Inet4Address BROADCAST_ADDR = getBroadcastAddress(
SERVER_ADDR, PREFIX_LENGTH);
+ private static final String HOSTNAME = "testhostname";
+ private static final short MTU = 1500;
// Use our own empty address instead of Inet4Address.ANY or INADDR_ANY to ensure that the code
// doesn't use == instead of equals when comparing addresses.
private static final Inet4Address ANY = (Inet4Address) v4Address("0.0.0.0");
@@ -960,7 +964,8 @@
assertTrue(msg, Arrays.equals(expected, actual));
}
- public void checkBuildOfferPacket(int leaseTimeSecs) throws Exception {
+ public void checkBuildOfferPacket(int leaseTimeSecs, @Nullable String hostname)
+ throws Exception {
final int renewalTime = (int) (Integer.toUnsignedLong(leaseTimeSecs) / 2);
final int rebindingTime = (int) (Integer.toUnsignedLong(leaseTimeSecs) * 875 / 1000);
final int transactionId = 0xdeadbeef;
@@ -971,7 +976,8 @@
CLIENT_MAC, leaseTimeSecs, NETMASK /* netMask */,
BROADCAST_ADDR /* bcAddr */, Collections.singletonList(SERVER_ADDR) /* gateways */,
Collections.singletonList(SERVER_ADDR) /* dnsServers */,
- SERVER_ADDR /* dhcpServerIdentifier */, null /* domainName */, false /* metered */);
+ SERVER_ADDR /* dhcpServerIdentifier */, null /* domainName */, hostname,
+ false /* metered */, MTU);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
// BOOTP headers
@@ -1027,12 +1033,22 @@
// Nameserver
bos.write(new byte[] { (byte) 0x06, (byte) 0x04 });
bos.write(SERVER_ADDR.getAddress());
+ // Hostname
+ if (hostname != null) {
+ bos.write(new byte[]{(byte) 0x0c, (byte) hostname.length()});
+ bos.write(hostname.getBytes(Charset.forName("US-ASCII")));
+ }
+ // MTU
+ bos.write(new byte[] { (byte) 0x1a, (byte) 0x02 });
+ bos.write(shortToByteArray(MTU));
// End options.
bos.write(0xff);
- final byte[] expected = bos.toByteArray();
- assertTrue((expected.length & 1) == 0);
+ if ((bos.size() & 1) != 0) {
+ bos.write(0x00);
+ }
+ final byte[] expected = bos.toByteArray();
final byte[] actual = new byte[packet.limit()];
packet.get(actual);
final String msg = "Expected:\n " + HexDump.dumpHexString(expected) +
@@ -1042,13 +1058,18 @@
@Test
public void testOfferPacket() throws Exception {
- checkBuildOfferPacket(3600);
- checkBuildOfferPacket(Integer.MAX_VALUE);
- checkBuildOfferPacket(0x80000000);
- checkBuildOfferPacket(INFINITE_LEASE);
+ checkBuildOfferPacket(3600, HOSTNAME);
+ checkBuildOfferPacket(Integer.MAX_VALUE, HOSTNAME);
+ checkBuildOfferPacket(0x80000000, HOSTNAME);
+ checkBuildOfferPacket(INFINITE_LEASE, HOSTNAME);
+ checkBuildOfferPacket(3600, null);
}
private static byte[] intToByteArray(int val) {
return ByteBuffer.allocate(4).putInt(val).array();
}
+
+ private static byte[] shortToByteArray(short val) {
+ return ByteBuffer.allocate(2).putShort(val).array();
+ }
}
diff --git a/tests/net/java/android/net/dhcp/DhcpServerTest.java b/tests/net/java/android/net/dhcp/DhcpServerTest.java
index 45a50d9..df34c73 100644
--- a/tests/net/java/android/net/dhcp/DhcpServerTest.java
+++ b/tests/net/java/android/net/dhcp/DhcpServerTest.java
@@ -17,6 +17,7 @@
package android.net.dhcp;
import static android.net.dhcp.DhcpPacket.DHCP_CLIENT;
+import static android.net.dhcp.DhcpPacket.DHCP_HOST_NAME;
import static android.net.dhcp.DhcpPacket.ENCAP_BOOTP;
import static android.net.dhcp.DhcpPacket.INADDR_ANY;
import static android.net.dhcp.DhcpPacket.INADDR_BROADCAST;
@@ -87,6 +88,7 @@
Arrays.asList(parseAddr("192.168.0.200"), parseAddr("192.168.0.201")));
private static final long TEST_LEASE_TIME_SECS = 3600L;
private static final int TEST_MTU = 1500;
+ private static final String TEST_HOSTNAME = "testhostname";
private static final int TEST_TRANSACTION_ID = 123;
private static final byte[] TEST_CLIENT_MAC_BYTES = new byte [] { 1, 2, 3, 4, 5, 6 };
@@ -96,7 +98,10 @@
private static final long TEST_CLOCK_TIME = 1234L;
private static final int TEST_LEASE_EXPTIME_SECS = 3600;
private static final DhcpLease TEST_LEASE = new DhcpLease(null, TEST_CLIENT_MAC,
- TEST_CLIENT_ADDR, TEST_LEASE_EXPTIME_SECS*1000L + TEST_CLOCK_TIME, null /* hostname */);
+ TEST_CLIENT_ADDR, TEST_LEASE_EXPTIME_SECS * 1000L + TEST_CLOCK_TIME,
+ null /* hostname */);
+ private static final DhcpLease TEST_LEASE_WITH_HOSTNAME = new DhcpLease(null, TEST_CLIENT_MAC,
+ TEST_CLIENT_ADDR, TEST_LEASE_EXPTIME_SECS * 1000L + TEST_CLOCK_TIME, TEST_HOSTNAME);
@NonNull @Mock
private Dependencies mDeps;
@@ -217,15 +222,17 @@
public void testRequest_Selecting_Ack() throws Exception {
when(mRepository.requestLease(isNull() /* clientId */, eq(TEST_CLIENT_MAC),
eq(INADDR_ANY) /* clientAddr */, eq(INADDR_ANY) /* relayAddr */,
- eq(TEST_CLIENT_ADDR) /* reqAddr */, eq(true) /* sidSet */, isNull() /* hostname */))
- .thenReturn(TEST_LEASE);
+ eq(TEST_CLIENT_ADDR) /* reqAddr */, eq(true) /* sidSet */, eq(TEST_HOSTNAME)))
+ .thenReturn(TEST_LEASE_WITH_HOSTNAME);
final DhcpRequestPacket request = makeRequestSelectingPacket();
+ request.mHostName = TEST_HOSTNAME;
+ request.mRequestedParams = new byte[] { DHCP_HOST_NAME };
mServer.processPacket(request, DHCP_CLIENT);
assertResponseSentTo(TEST_CLIENT_ADDR);
final DhcpAckPacket packet = assertAck(getPacket());
- assertMatchesTestLease(packet);
+ assertMatchesTestLease(packet, TEST_HOSTNAME);
}
@Test
@@ -270,14 +277,18 @@
* - other request states (init-reboot/renewing/rebinding)
*/
- private void assertMatchesTestLease(@NonNull DhcpPacket packet) {
+ private void assertMatchesTestLease(@NonNull DhcpPacket packet, @Nullable String hostname) {
assertMatchesClient(packet);
assertFalse(packet.hasExplicitClientId());
assertEquals(TEST_SERVER_ADDR, packet.mServerIdentifier);
assertEquals(TEST_CLIENT_ADDR, packet.mYourIp);
assertNotNull(packet.mLeaseTime);
assertEquals(TEST_LEASE_EXPTIME_SECS, (int) packet.mLeaseTime);
- assertNull(packet.mHostName);
+ assertEquals(hostname, packet.mHostName);
+ }
+
+ private void assertMatchesTestLease(@NonNull DhcpPacket packet) {
+ assertMatchesTestLease(packet, null);
}
private void assertMatchesClient(@NonNull DhcpPacket packet) {
