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-rw-r--r--packages/Tethering/src/android/net/ip/IpServer.java8
-rw-r--r--packages/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java76
2 files changed, 57 insertions, 27 deletions
diff --git a/packages/Tethering/src/android/net/ip/IpServer.java b/packages/Tethering/src/android/net/ip/IpServer.java
index 336124dc1b90..52d59fcdc19b 100644
--- a/packages/Tethering/src/android/net/ip/IpServer.java
+++ b/packages/Tethering/src/android/net/ip/IpServer.java
@@ -616,7 +616,7 @@ public class IpServer extends StateMachine {
if (VDBG) Log.d(TAG, "configureIPv4(" + enabled + ")");
if (enabled) {
- mIpv4Address = requestIpv4Address();
+ mIpv4Address = requestIpv4Address(true /* useLastAddress */);
}
if (mIpv4Address == null) {
@@ -661,14 +661,14 @@ public class IpServer extends StateMachine {
return configureDhcp(enabled, mIpv4Address, mStaticIpv4ClientAddr);
}
- private LinkAddress requestIpv4Address() {
+ private LinkAddress requestIpv4Address(final boolean useLastAddress) {
if (mStaticIpv4ServerAddr != null) return mStaticIpv4ServerAddr;
if (mInterfaceType == TetheringManager.TETHERING_BLUETOOTH) {
return new LinkAddress(BLUETOOTH_IFACE_ADDR);
}
- return mPrivateAddressCoordinator.requestDownstreamAddress(this);
+ return mPrivateAddressCoordinator.requestDownstreamAddress(this, useLastAddress);
}
private boolean startIPv6() {
@@ -957,7 +957,7 @@ public class IpServer extends StateMachine {
}
final LinkAddress deprecatedLinkAddress = mIpv4Address;
- mIpv4Address = requestIpv4Address();
+ mIpv4Address = requestIpv4Address(false);
if (mIpv4Address == null) {
mLog.e("Fail to request a new downstream prefix");
return;
diff --git a/packages/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java b/packages/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java
index b285849f9edf..6276c4e2aa7d 100644
--- a/packages/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java
+++ b/packages/Tethering/src/com/android/networkstack/tethering/PrivateAddressCoordinator.java
@@ -16,7 +16,9 @@
package com.android.networkstack.tethering;
import static android.net.NetworkCapabilities.TRANSPORT_VPN;
+import static android.net.TetheringManager.TETHERING_BLUETOOTH;
import static android.net.TetheringManager.TETHERING_WIFI_P2P;
+import static android.net.util.PrefixUtils.asIpPrefix;
import static java.util.Arrays.asList;
@@ -26,9 +28,9 @@ import android.net.IpPrefix;
import android.net.LinkAddress;
import android.net.Network;
import android.net.ip.IpServer;
-import android.net.util.PrefixUtils;
import android.util.ArrayMap;
import android.util.ArraySet;
+import android.util.SparseArray;
import androidx.annotation.Nullable;
@@ -58,9 +60,6 @@ public class PrivateAddressCoordinator {
private static final int MAX_UBYTE = 256;
private static final int BYTE_MASK = 0xff;
- // reserved for bluetooth tethering.
- private static final int BLUETOOTH_RESERVED = 44;
- private static final int WIFI_P2P_RESERVED = 49;
private static final byte DEFAULT_ID = (byte) 42;
// Upstream monitor would be stopped when tethering is down. When tethering restart, downstream
@@ -75,9 +74,12 @@ public class PrivateAddressCoordinator {
// Tethering use 192.168.0.0/16 that has 256 contiguous class C network numbers.
private static final String DEFAULT_TETHERING_PREFIX = "192.168.0.0/16";
private static final String LEGACY_WIFI_P2P_IFACE_ADDRESS = "192.168.49.1/24";
+ private static final String LEGACY_BLUETOOTH_IFACE_ADDRESS = "192.168.44.1/24";
private final IpPrefix mTetheringPrefix;
private final ConnectivityManager mConnectivityMgr;
private final TetheringConfiguration mConfig;
+ // keyed by downstream type(TetheringManager.TETHERING_*).
+ private final SparseArray<LinkAddress> mCachedAddresses;
public PrivateAddressCoordinator(Context context, TetheringConfiguration config) {
mDownstreams = new ArraySet<>();
@@ -86,6 +88,10 @@ public class PrivateAddressCoordinator {
mConnectivityMgr = (ConnectivityManager) context.getSystemService(
Context.CONNECTIVITY_SERVICE);
mConfig = config;
+ mCachedAddresses = new SparseArray<>();
+ // Reserved static addresses for bluetooth and wifi p2p.
+ mCachedAddresses.put(TETHERING_BLUETOOTH, new LinkAddress(LEGACY_BLUETOOTH_IFACE_ADDRESS));
+ mCachedAddresses.put(TETHERING_WIFI_P2P, new LinkAddress(LEGACY_WIFI_P2P_IFACE_ADDRESS));
}
/**
@@ -94,7 +100,8 @@ public class PrivateAddressCoordinator {
* UpstreamNetworkState must have an already populated LinkProperties.
*/
public void updateUpstreamPrefix(final UpstreamNetworkState ns) {
- // Do not support VPN as upstream
+ // Do not support VPN as upstream. Normally, networkCapabilities is not expected to be null,
+ // but just checking to be sure.
if (ns.networkCapabilities != null && ns.networkCapabilities.hasTransport(TRANSPORT_VPN)) {
removeUpstreamPrefix(ns.network);
return;
@@ -116,7 +123,7 @@ public class PrivateAddressCoordinator {
for (LinkAddress address : linkAddresses) {
if (!address.isIpv4()) continue;
- list.add(PrefixUtils.asIpPrefix(address));
+ list.add(asIpPrefix(address));
}
return list;
@@ -155,21 +162,23 @@ public class PrivateAddressCoordinator {
mUpstreamPrefixMap.removeAll(toBeRemoved);
}
- private boolean isReservedSubnet(final int subnet) {
- return subnet == BLUETOOTH_RESERVED || subnet == WIFI_P2P_RESERVED;
- }
-
/**
* Pick a random available address and mark its prefix as in use for the provided IpServer,
* returns null if there is no available address.
*/
@Nullable
- public LinkAddress requestDownstreamAddress(final IpServer ipServer) {
+ public LinkAddress requestDownstreamAddress(final IpServer ipServer, boolean useLastAddress) {
if (mConfig.shouldEnableWifiP2pDedicatedIp()
&& ipServer.interfaceType() == TETHERING_WIFI_P2P) {
return new LinkAddress(LEGACY_WIFI_P2P_IFACE_ADDRESS);
}
+ final LinkAddress cachedAddress = mCachedAddresses.get(ipServer.interfaceType());
+ if (useLastAddress && cachedAddress != null
+ && !isConflictWithUpstream(asIpPrefix(cachedAddress))) {
+ return cachedAddress;
+ }
+
// Address would be 192.168.[subAddress]/24.
final byte[] bytes = mTetheringPrefix.getRawAddress();
final int subAddress = getRandomSubAddr();
@@ -177,9 +186,8 @@ public class PrivateAddressCoordinator {
bytes[3] = getSanitizedAddressSuffix(subAddress, (byte) 0, (byte) 1, (byte) 0xff);
for (int i = 0; i < MAX_UBYTE; i++) {
final int newSubNet = (subNet + i) & BYTE_MASK;
- if (isReservedSubnet(newSubNet)) continue;
-
bytes[2] = (byte) newSubNet;
+
final InetAddress addr;
try {
addr = InetAddress.getByAddress(bytes);
@@ -187,20 +195,23 @@ public class PrivateAddressCoordinator {
throw new IllegalStateException("Invalid address, shouldn't happen.", e);
}
- final IpPrefix prefix = new IpPrefix(addr, PREFIX_LENGTH);
- // Check whether this prefix is in use.
- if (isDownstreamPrefixInUse(prefix)) continue;
- // Check whether this prefix is conflict with any current upstream network.
- if (isConflictWithUpstream(prefix)) continue;
+ if (isConflict(new IpPrefix(addr, PREFIX_LENGTH))) continue;
mDownstreams.add(ipServer);
- return new LinkAddress(addr, PREFIX_LENGTH);
+ final LinkAddress newAddress = new LinkAddress(addr, PREFIX_LENGTH);
+ mCachedAddresses.put(ipServer.interfaceType(), newAddress);
+ return newAddress;
}
// No available address.
return null;
}
+ private boolean isConflict(final IpPrefix prefix) {
+ // Check whether this prefix is in use or conflict with any current upstream network.
+ return isDownstreamPrefixInUse(prefix) || isConflictWithUpstream(prefix);
+ }
+
/** Get random sub address value. Return value is in 0 ~ 0xffff. */
@VisibleForTesting
public int getRandomSubAddr() {
@@ -244,13 +255,24 @@ public class PrivateAddressCoordinator {
return prefix1.contains(prefix2.getAddress());
}
- private boolean isDownstreamPrefixInUse(final IpPrefix source) {
+ // InUse Prefixes are prefixes of mCachedAddresses which are active downstream addresses, last
+ // downstream addresses(reserved for next time) and static addresses(e.g. bluetooth, wifi p2p).
+ private boolean isDownstreamPrefixInUse(final IpPrefix prefix) {
// This class always generates downstream prefixes with the same prefix length, so
// prefixes cannot be contained in each other. They can only be equal to each other.
+ for (int i = 0; i < mCachedAddresses.size(); i++) {
+ if (prefix.equals(asIpPrefix(mCachedAddresses.valueAt(i)))) return true;
+ }
+
+ // IpServer may use manually-defined address (mStaticIpv4ServerAddr) which does not include
+ // in mCachedAddresses.
for (IpServer downstream : mDownstreams) {
- final IpPrefix prefix = getDownstreamPrefix(downstream);
- if (source.equals(prefix)) return true;
+ final IpPrefix target = getDownstreamPrefix(downstream);
+ if (target == null) continue;
+
+ if (isConflictPrefix(prefix, target)) return true;
}
+
return false;
}
@@ -258,7 +280,7 @@ public class PrivateAddressCoordinator {
final LinkAddress address = downstream.getAddress();
if (address == null) return null;
- return PrefixUtils.asIpPrefix(address);
+ return asIpPrefix(address);
}
void dump(final IndentingPrintWriter pw) {
@@ -268,11 +290,19 @@ public class PrivateAddressCoordinator {
pw.println(mUpstreamPrefixMap.keyAt(i) + " - " + mUpstreamPrefixMap.valueAt(i));
}
pw.decreaseIndent();
+
pw.println("mDownstreams:");
pw.increaseIndent();
for (IpServer ipServer : mDownstreams) {
pw.println(ipServer.interfaceType() + " - " + ipServer.getAddress());
}
pw.decreaseIndent();
+
+ pw.println("mCachedAddresses:");
+ pw.increaseIndent();
+ for (int i = 0; i < mCachedAddresses.size(); i++) {
+ pw.println(mCachedAddresses.keyAt(i) + " - " + mCachedAddresses.valueAt(i));
+ }
+ pw.decreaseIndent();
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-03 07:16:30 +0000