LineageOS/android_packages_modules_Connectivity
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[BR11] Read data saver status from bpf

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Writing data saver status to bpf is supported on Android V or
later devices. Thus, read that from bpf if available.

Test: atest FrameworksNetTests:android.net.connectivity.android.net.BpfNetMapsReaderTest
Test: atest ConnectivityCoverageTests:android.net.connectivity.android.net.ConnectivityManagerTest
Fix: 310801259
Change-Id: Ibd2616328d83f72ee6d2665239c3a44379d1ebf5
This commit is contained in:
Junyu Lai
2023-11-14 15:44:37 +08:00
parent 8b61783b78
commit 9e88052fe7
4 changed files with 84 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

53
framework/src/android/net/BpfNetMapsReader.java
View File

@@ -17,6 +17,9 @@
package android.net;
import static android.net.BpfNetMapsConstants.CONFIGURATION_MAP_PATH;
import static android.net.BpfNetMapsConstants.DATA_SAVER_ENABLED;
import static android.net.BpfNetMapsConstants.DATA_SAVER_ENABLED_KEY;
import static android.net.BpfNetMapsConstants.DATA_SAVER_ENABLED_MAP_PATH;
import static android.net.BpfNetMapsConstants.HAPPY_BOX_MATCH;
import static android.net.BpfNetMapsConstants.PENALTY_BOX_MATCH;
import static android.net.BpfNetMapsConstants.UID_OWNER_MAP_PATH;
@@ -33,14 +36,15 @@ import android.os.Build;
import android.os.ServiceSpecificException;
import android.system.ErrnoException;
import android.system.Os;
import android.util.Log;
import com.android.internal.annotations.VisibleForTesting;
import com.android.modules.utils.build.SdkLevel;
import com.android.net.module.util.BpfMap;
import com.android.net.module.util.IBpfMap;
import com.android.net.module.util.Struct;
import com.android.net.module.util.Struct.S32;
import com.android.net.module.util.Struct.U32;
import com.android.net.module.util.Struct.U8;
/**
* A helper class to *read* java BpfMaps.
@@ -48,6 +52,8 @@ import com.android.net.module.util.Struct.U32;
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU) // BPF maps were only mainlined in T
public class BpfNetMapsReader {
private static final String TAG = BpfNetMapsReader.class.getSimpleName();
// Locally store the handle of bpf maps. The FileDescriptors are statically cached inside the
// BpfMap implementation.
@@ -57,6 +63,7 @@ public class BpfNetMapsReader {
// Bpf map to store per uid traffic control configurations.
// See {@link UidOwnerValue} for more detail.
private final IBpfMap<S32, UidOwnerValue> mUidOwnerMap;
private final IBpfMap<S32, U8> mDataSaverEnabledMap;
private final Dependencies mDeps;
// Bitmaps for calculating whether a given uid is blocked by firewall chains.
@@ -104,6 +111,7 @@ public class BpfNetMapsReader {
mDeps = deps;
mConfigurationMap = mDeps.getConfigurationMap();
mUidOwnerMap = mDeps.getUidOwnerMap();
mDataSaverEnabledMap = mDeps.getDataSaverEnabledMap();
}
/**
@@ -130,6 +138,16 @@ public class BpfNetMapsReader {
throw new IllegalStateException("Cannot open uid owner map", e);
}
}
/** Get the data saver enabled map. */
public IBpfMap<S32, U8> getDataSaverEnabledMap() {
try {
return new BpfMap<>(DATA_SAVER_ENABLED_MAP_PATH, BpfMap.BPF_F_RDONLY, S32.class,
U8.class);
} catch (ErrnoException e) {
throw new IllegalStateException("Cannot open data saver enabled map", e);
}
}
}
/**
@@ -171,12 +189,12 @@ public class BpfNetMapsReader {
* cause of the failure.
*/
public static boolean isChainEnabled(
final IBpfMap<Struct.S32, Struct.U32> configurationMap, final int chain) {
final IBpfMap<S32, U32> configurationMap, final int chain) {
throwIfPreT("isChainEnabled is not available on pre-T devices");
final long match = getMatchByFirewallChain(chain);
try {
final Struct.U32 config = configurationMap.getValue(UID_RULES_CONFIGURATION_KEY);
final U32 config = configurationMap.getValue(UID_RULES_CONFIGURATION_KEY);
return (config.val & match) != 0;
} catch (ErrnoException e) {
throw new ServiceSpecificException(e.errno,
@@ -195,14 +213,14 @@ public class BpfNetMapsReader {
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
public static int getUidRule(final IBpfMap<Struct.S32, UidOwnerValue> uidOwnerMap,
public static int getUidRule(final IBpfMap<S32, UidOwnerValue> uidOwnerMap,
final int chain, final int uid) {
throwIfPreT("getUidRule is not available on pre-T devices");
final long match = getMatchByFirewallChain(chain);
final boolean isAllowList = isFirewallAllowList(chain);
try {
final UidOwnerValue uidMatch = uidOwnerMap.getValue(new Struct.S32(uid));
final UidOwnerValue uidMatch = uidOwnerMap.getValue(new S32(uid));
final boolean isMatchEnabled = uidMatch != null && (uidMatch.rule & match) != 0;
return isMatchEnabled == isAllowList ? FIREWALL_RULE_ALLOW : FIREWALL_RULE_DENY;
} catch (ErrnoException e) {
@@ -249,4 +267,29 @@ public class BpfNetMapsReader {
if ((uidMatch & HAPPY_BOX_MATCH) != 0) return false;
return isDataSaverEnabled;
}
/**
* Get Data Saver enabled or disabled
*
* @return whether Data Saver is enabled or disabled.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
public boolean getDataSaverEnabled() {
throwIfPreT("getDataSaverEnabled is not available on pre-T devices");
// Note that this is not expected to be called until V given that it relies on the
// counterpart platform solution to set data saver status to bpf.
// See {@code NetworkManagementService#setDataSaverModeEnabled}.
if (!SdkLevel.isAtLeastV()) {
Log.wtf(TAG, "getDataSaverEnabled is not expected to be called on pre-V devices");
}
try {
return mDataSaverEnabledMap.getValue(DATA_SAVER_ENABLED_KEY).val == DATA_SAVER_ENABLED;
} catch (ErrnoException e) {
throw new ServiceSpecificException(e.errno, "Unable to get data saver: "
+ Os.strerror(e.errno));
}
}
}