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/*
* Copyright (C) 2022 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;
import static android.net.BpfNetMapsConstants.CONFIGURATION_MAP_PATH;
import static android.net.BpfNetMapsConstants.COOKIE_TAG_MAP_PATH;
import static android.net.BpfNetMapsConstants.CURRENT_STATS_MAP_CONFIGURATION_KEY;
import static android.net.BpfNetMapsConstants.DATA_SAVER_DISABLED;
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.IIF_MATCH;
import static android.net.BpfNetMapsConstants.INGRESS_DISCARD_MAP_PATH;
import static android.net.BpfNetMapsConstants.LOCKDOWN_VPN_MATCH;
import static android.net.BpfNetMapsConstants.PENALTY_BOX_MATCH;
import static android.net.BpfNetMapsConstants.UID_OWNER_MAP_PATH;
import static android.net.BpfNetMapsConstants.UID_PERMISSION_MAP_PATH;
import static android.net.BpfNetMapsConstants.UID_RULES_CONFIGURATION_KEY;
import static android.net.BpfNetMapsUtils.getMatchByFirewallChain;
import static android.net.BpfNetMapsUtils.isFirewallAllowList;
import static android.net.BpfNetMapsUtils.matchToString;
import static android.net.ConnectivityManager.FIREWALL_RULE_ALLOW;
import static android.net.ConnectivityManager.FIREWALL_RULE_DENY;
import static android.net.INetd.PERMISSION_INTERNET;
import static android.net.INetd.PERMISSION_NONE;
import static android.net.INetd.PERMISSION_UNINSTALLED;
import static android.net.INetd.PERMISSION_UPDATE_DEVICE_STATS;
import static android.system.OsConstants.EINVAL;
import static android.system.OsConstants.ENODEV;
import static android.system.OsConstants.ENOENT;
import static android.system.OsConstants.EOPNOTSUPP;
import static com.android.server.ConnectivityStatsLog.NETWORK_BPF_MAP_INFO;
import android.app.StatsManager;
import android.content.Context;
import android.net.BpfNetMapsReader;
import android.net.INetd;
import android.net.UidOwnerValue;
import android.os.Build;
import android.os.RemoteException;
import android.os.ServiceSpecificException;
import android.system.ErrnoException;
import android.system.Os;
import android.util.ArraySet;
import android.util.IndentingPrintWriter;
import android.util.Log;
import android.util.Pair;
import android.util.StatsEvent;
import androidx.annotation.RequiresApi;
import com.android.internal.annotations.VisibleForTesting;
import com.android.modules.utils.BackgroundThread;
import com.android.modules.utils.build.SdkLevel;
import com.android.net.module.util.BpfDump;
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;
import com.android.net.module.util.bpf.CookieTagMapKey;
import com.android.net.module.util.bpf.CookieTagMapValue;
import com.android.net.module.util.bpf.IngressDiscardKey;
import com.android.net.module.util.bpf.IngressDiscardValue;
import java.io.FileDescriptor;
import java.io.IOException;
import java.net.InetAddress;
import java.util.Arrays;
import java.util.List;
import java.util.Set;
import java.util.StringJoiner;
/**
* BpfNetMaps is responsible for providing traffic controller relevant functionality.
*
* {@hide}
*/
public class BpfNetMaps {
static {
if (SdkLevel.isAtLeastT()) {
System.loadLibrary("service-connectivity");
}
}
private static final String TAG = "BpfNetMaps";
private final INetd mNetd;
private final Dependencies mDeps;
// Use legacy netd for releases before T.
private static boolean sInitialized = false;
// Lock for sConfigurationMap entry for UID_RULES_CONFIGURATION_KEY.
// This entry is not accessed by others.
// BpfNetMaps acquires this lock while sequence of read, modify, and write.
private static final Object sUidRulesConfigBpfMapLock = new Object();
// Lock for sConfigurationMap entry for CURRENT_STATS_MAP_CONFIGURATION_KEY.
// BpfNetMaps acquires this lock while sequence of read, modify, and write.
// BpfNetMaps is an only writer of this entry.
private static final Object sCurrentStatsMapConfigLock = new Object();
private static final long UID_RULES_DEFAULT_CONFIGURATION = 0;
private static final long STATS_SELECT_MAP_A = 0;
private static final long STATS_SELECT_MAP_B = 1;
private static IBpfMap<S32, U32> sConfigurationMap = null;
// BpfMap for UID_OWNER_MAP_PATH. This map is not accessed by others.
private static IBpfMap<S32, UidOwnerValue> sUidOwnerMap = null;
private static IBpfMap<S32, U8> sUidPermissionMap = null;
private static IBpfMap<CookieTagMapKey, CookieTagMapValue> sCookieTagMap = null;
// TODO: Add BOOL class and replace U8?
private static IBpfMap<S32, U8> sDataSaverEnabledMap = null;
private static IBpfMap<IngressDiscardKey, IngressDiscardValue> sIngressDiscardMap = null;
private static final List<Pair<Integer, String>> PERMISSION_LIST = Arrays.asList(
Pair.create(PERMISSION_INTERNET, "PERMISSION_INTERNET"),
Pair.create(PERMISSION_UPDATE_DEVICE_STATS, "PERMISSION_UPDATE_DEVICE_STATS")
);
/**
* Set configurationMap for test.
*/
@VisibleForTesting
public static void setConfigurationMapForTest(IBpfMap<S32, U32> configurationMap) {
sConfigurationMap = configurationMap;
}
/**
* Set uidOwnerMap for test.
*/
@VisibleForTesting
public static void setUidOwnerMapForTest(IBpfMap<S32, UidOwnerValue> uidOwnerMap) {
sUidOwnerMap = uidOwnerMap;
}
/**
* Set uidPermissionMap for test.
*/
@VisibleForTesting
public static void setUidPermissionMapForTest(IBpfMap<S32, U8> uidPermissionMap) {
sUidPermissionMap = uidPermissionMap;
}
/**
* Set cookieTagMap for test.
*/
@VisibleForTesting
public static void setCookieTagMapForTest(
IBpfMap<CookieTagMapKey, CookieTagMapValue> cookieTagMap) {
sCookieTagMap = cookieTagMap;
}
/**
* Set dataSaverEnabledMap for test.
*/
@VisibleForTesting
public static void setDataSaverEnabledMapForTest(IBpfMap<S32, U8> dataSaverEnabledMap) {
sDataSaverEnabledMap = dataSaverEnabledMap;
}
/**
* Set ingressDiscardMap for test.
*/
@VisibleForTesting
public static void setIngressDiscardMapForTest(
IBpfMap<IngressDiscardKey, IngressDiscardValue> ingressDiscardMap) {
sIngressDiscardMap = ingressDiscardMap;
}
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static IBpfMap<S32, U32> getConfigurationMap() {
try {
return new BpfMap<>(
CONFIGURATION_MAP_PATH, S32.class, U32.class);
} catch (ErrnoException e) {
throw new IllegalStateException("Cannot open netd configuration map", e);
}
}
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static IBpfMap<S32, UidOwnerValue> getUidOwnerMap() {
try {
return new BpfMap<>(
UID_OWNER_MAP_PATH, S32.class, UidOwnerValue.class);
} catch (ErrnoException e) {
throw new IllegalStateException("Cannot open uid owner map", e);
}
}
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static IBpfMap<S32, U8> getUidPermissionMap() {
try {
return new BpfMap<>(
UID_PERMISSION_MAP_PATH, S32.class, U8.class);
} catch (ErrnoException e) {
throw new IllegalStateException("Cannot open uid permission map", e);
}
}
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static IBpfMap<CookieTagMapKey, CookieTagMapValue> getCookieTagMap() {
try {
return new BpfMap<>(COOKIE_TAG_MAP_PATH,
CookieTagMapKey.class, CookieTagMapValue.class);
} catch (ErrnoException e) {
throw new IllegalStateException("Cannot open cookie tag map", e);
}
}
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static IBpfMap<S32, U8> getDataSaverEnabledMap() {
try {
return new BpfMap<>(
DATA_SAVER_ENABLED_MAP_PATH, S32.class, U8.class);
} catch (ErrnoException e) {
throw new IllegalStateException("Cannot open data saver enabled map", e);
}
}
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static IBpfMap<IngressDiscardKey, IngressDiscardValue> getIngressDiscardMap() {
try {
return new BpfMap<>(INGRESS_DISCARD_MAP_PATH,
IngressDiscardKey.class, IngressDiscardValue.class);
} catch (ErrnoException e) {
throw new IllegalStateException("Cannot open ingress discard map", e);
}
}
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static void initBpfMaps() {
if (sConfigurationMap == null) {
sConfigurationMap = getConfigurationMap();
}
try {
sConfigurationMap.updateEntry(UID_RULES_CONFIGURATION_KEY,
new U32(UID_RULES_DEFAULT_CONFIGURATION));
} catch (ErrnoException e) {
throw new IllegalStateException("Failed to initialize uid rules configuration", e);
}
try {
sConfigurationMap.updateEntry(CURRENT_STATS_MAP_CONFIGURATION_KEY,
new U32(STATS_SELECT_MAP_A));
} catch (ErrnoException e) {
throw new IllegalStateException("Failed to initialize current stats configuration", e);
}
if (sUidOwnerMap == null) {
sUidOwnerMap = getUidOwnerMap();
}
try {
sUidOwnerMap.clear();
} catch (ErrnoException e) {
throw new IllegalStateException("Failed to initialize uid owner map", e);
}
if (sUidPermissionMap == null) {
sUidPermissionMap = getUidPermissionMap();
}
if (sCookieTagMap == null) {
sCookieTagMap = getCookieTagMap();
}
if (sDataSaverEnabledMap == null) {
sDataSaverEnabledMap = getDataSaverEnabledMap();
}
try {
sDataSaverEnabledMap.updateEntry(DATA_SAVER_ENABLED_KEY, new U8(DATA_SAVER_DISABLED));
} catch (ErrnoException e) {
throw new IllegalStateException("Failed to initialize data saver configuration", e);
}
if (sIngressDiscardMap == null) {
sIngressDiscardMap = getIngressDiscardMap();
}
try {
sIngressDiscardMap.clear();
} catch (ErrnoException e) {
throw new IllegalStateException("Failed to initialize ingress discard map", e);
}
}
/**
* Initializes the class if it is not already initialized. This method will open maps but not
* cause any other effects. This method may be called multiple times on any thread.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private static synchronized void ensureInitialized(final Context context) {
if (sInitialized) return;
initBpfMaps();
sInitialized = true;
}
/**
* Dependencies of BpfNetMaps, for injection in tests.
*/
@VisibleForTesting
public static class Dependencies {
/**
* Get interface index.
*/
public int getIfIndex(final String ifName) {
return Os.if_nametoindex(ifName);
}
/**
* Get interface name
*/
public String getIfName(final int ifIndex) {
return Os.if_indextoname(ifIndex);
}
/**
* Synchronously call in to kernel to synchronize_rcu()
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public int synchronizeKernelRCU() {
try {
BpfMap.synchronizeKernelRCU();
} catch (ErrnoException e) {
return -e.errno;
}
return 0;
}
/**
* Build Stats Event for NETWORK_BPF_MAP_INFO atom
*/
public StatsEvent buildStatsEvent(final int cookieTagMapSize, final int uidOwnerMapSize,
final int uidPermissionMapSize) {
return ConnectivityStatsLog.buildStatsEvent(NETWORK_BPF_MAP_INFO, cookieTagMapSize,
uidOwnerMapSize, uidPermissionMapSize);
}
}
/** Constructor used after T that doesn't need to use netd anymore. */
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public BpfNetMaps(final Context context) {
this(context, null);
if (!SdkLevel.isAtLeastT()) throw new IllegalArgumentException("BpfNetMaps need to use netd before T");
}
public BpfNetMaps(final Context context, final INetd netd) {
this(context, netd, new Dependencies());
}
@VisibleForTesting
public BpfNetMaps(final Context context, final INetd netd, final Dependencies deps) {
if (SdkLevel.isAtLeastT()) {
ensureInitialized(context);
}
mNetd = netd;
mDeps = deps;
}
private void maybeThrow(final int err, final String msg) {
if (err != 0) {
throw new ServiceSpecificException(err, msg + ": " + Os.strerror(err));
}
}
private void throwIfPreT(final String msg) {
if (!SdkLevel.isAtLeastT()) {
throw new UnsupportedOperationException(msg);
}
}
private void removeRule(final int uid, final long match, final String caller) {
try {
synchronized (sUidOwnerMap) {
final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new S32(uid));
if (oldMatch == null) {
throw new ServiceSpecificException(ENOENT,
"sUidOwnerMap does not have entry for uid: " + uid);
}
final UidOwnerValue newMatch = new UidOwnerValue(
(match == IIF_MATCH) ? 0 : oldMatch.iif,
oldMatch.rule & ~match
);
if (newMatch.rule == 0) {
sUidOwnerMap.deleteEntry(new S32(uid));
} else {
sUidOwnerMap.updateEntry(new S32(uid), newMatch);
}
}
} catch (ErrnoException e) {
throw new ServiceSpecificException(e.errno,
caller + " failed to remove rule: " + Os.strerror(e.errno));
}
}
private void addRule(final int uid, final long match, final int iif, final String caller) {
if (match != IIF_MATCH && iif != 0) {
throw new ServiceSpecificException(EINVAL,
"Non-interface match must have zero interface index");
}
try {
synchronized (sUidOwnerMap) {
final UidOwnerValue oldMatch = sUidOwnerMap.getValue(new S32(uid));
final UidOwnerValue newMatch;
if (oldMatch != null) {
newMatch = new UidOwnerValue(
(match == IIF_MATCH) ? iif : oldMatch.iif,
oldMatch.rule | match
);
} else {
newMatch = new UidOwnerValue(
iif,
match
);
}
sUidOwnerMap.updateEntry(new S32(uid), newMatch);
}
} catch (ErrnoException e) {
throw new ServiceSpecificException(e.errno,
caller + " failed to add rule: " + Os.strerror(e.errno));
}
}
private void addRule(final int uid, final long match, final String caller) {
addRule(uid, match, 0 /* iif */, caller);
}
/**
* Add naughty app bandwidth rule for specific app
*
* @param uid uid of target app
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void addNaughtyApp(final int uid) {
throwIfPreT("addNaughtyApp is not available on pre-T devices");
addRule(uid, PENALTY_BOX_MATCH, "addNaughtyApp");
}
/**
* Remove naughty app bandwidth rule for specific app
*
* @param uid uid of target app
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void removeNaughtyApp(final int uid) {
throwIfPreT("removeNaughtyApp is not available on pre-T devices");
removeRule(uid, PENALTY_BOX_MATCH, "removeNaughtyApp");
}
/**
* Add nice app bandwidth rule for specific app
*
* @param uid uid of target app
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void addNiceApp(final int uid) {
throwIfPreT("addNiceApp is not available on pre-T devices");
addRule(uid, HAPPY_BOX_MATCH, "addNiceApp");
}
/**
* Remove nice app bandwidth rule for specific app
*
* @param uid uid of target app
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void removeNiceApp(final int uid) {
throwIfPreT("removeNiceApp is not available on pre-T devices");
removeRule(uid, HAPPY_BOX_MATCH, "removeNiceApp");
}
/**
* Set target firewall child chain
*
* @param childChain target chain to enable
* @param enable whether to enable or disable child chain.
* @throws UnsupportedOperationException if called on pre-T devices.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void setChildChain(final int childChain, final boolean enable) {
throwIfPreT("setChildChain is not available on pre-T devices");
final long match = getMatchByFirewallChain(childChain);
try {
synchronized (sUidRulesConfigBpfMapLock) {
final U32 config = sConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY);
final long newConfig = enable ? (config.val | match) : (config.val & ~match);
sConfigurationMap.updateEntry(UID_RULES_CONFIGURATION_KEY, new U32(newConfig));
}
} catch (ErrnoException e) {
throw new ServiceSpecificException(e.errno,
"Unable to set child chain: " + Os.strerror(e.errno));
}
}
/**
* Get the specified firewall chain's status.
*
* @param childChain target chain
* @return {@code true} if chain is enabled, {@code false} if chain is not enabled.
* @throws UnsupportedOperationException if called on pre-T devices.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*
* @deprecated Use {@link BpfNetMapsReader#isChainEnabled} instead.
*/
// TODO: Migrate the callers to use {@link BpfNetMapsReader#isChainEnabled} instead.
@Deprecated
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public boolean isChainEnabled(final int childChain) {
return BpfNetMapsReader.isChainEnabled(sConfigurationMap, childChain);
}
private Set<Integer> asSet(final int[] uids) {
final Set<Integer> uidSet = new ArraySet<>();
for (final int uid : uids) {
uidSet.add(uid);
}
return uidSet;
}
/**
* Replaces the contents of the specified UID-based firewall chain.
* Enables the chain for specified uids and disables the chain for non-specified uids.
*
* @param chain Target chain.
* @param uids The list of UIDs to allow/deny.
* @throws UnsupportedOperationException if called on pre-T devices.
* @throws IllegalArgumentException if {@code chain} is not a valid chain.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void replaceUidChain(final int chain, final int[] uids) {
throwIfPreT("replaceUidChain is not available on pre-T devices");
final long match;
try {
match = getMatchByFirewallChain(chain);
} catch (ServiceSpecificException e) {
// Throws IllegalArgumentException to keep the behavior of
// ConnectivityManager#replaceFirewallChain API
throw new IllegalArgumentException("Invalid firewall chain: " + chain);
}
final Set<Integer> uidSet = asSet(uids);
final Set<Integer> uidSetToRemoveRule = new ArraySet<>();
try {
synchronized (sUidOwnerMap) {
sUidOwnerMap.forEach((uid, config) -> {
// config could be null if there is a concurrent entry deletion.
// http://b/220084230. But sUidOwnerMap update must be done while holding a
// lock, so this should not happen.
if (config == null) {
Log.wtf(TAG, "sUidOwnerMap entry was deleted while holding a lock");
} else if (!uidSet.contains((int) uid.val) && (config.rule & match) != 0) {
uidSetToRemoveRule.add((int) uid.val);
}
});
for (final int uid : uidSetToRemoveRule) {
removeRule(uid, match, "replaceUidChain");
}
for (final int uid : uids) {
addRule(uid, match, "replaceUidChain");
}
}
} catch (ErrnoException | ServiceSpecificException e) {
Log.e(TAG, "replaceUidChain failed: " + e);
}
}
/**
* Set firewall rule for uid
*
* @param childChain target chain
* @param uid uid to allow/deny
* @param firewallRule either FIREWALL_RULE_ALLOW or FIREWALL_RULE_DENY
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void setUidRule(final int childChain, final int uid, final int firewallRule) {
throwIfPreT("setUidRule is not available on pre-T devices");
final long match = getMatchByFirewallChain(childChain);
final boolean isAllowList = isFirewallAllowList(childChain);
final boolean add = (firewallRule == FIREWALL_RULE_ALLOW && isAllowList)
|| (firewallRule == FIREWALL_RULE_DENY && !isAllowList);
if (add) {
addRule(uid, match, "setUidRule");
} else {
removeRule(uid, match, "setUidRule");
}
}
/**
* Get firewall rule of specified firewall chain on specified uid.
*
* @param childChain target chain
* @param uid target uid
* @return either FIREWALL_RULE_ALLOW or FIREWALL_RULE_DENY
* @throws UnsupportedOperationException if called on pre-T devices.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*
* @deprecated use {@link BpfNetMapsReader#getUidRule} instead.
*/
// TODO: Migrate the callers to use {@link BpfNetMapsReader#getUidRule} instead.
public int getUidRule(final int childChain, final int uid) {
return BpfNetMapsReader.getUidRule(sUidOwnerMap, childChain, uid);
}
private Set<Integer> getUidsMatchEnabled(final int childChain) throws ErrnoException {
final long match = getMatchByFirewallChain(childChain);
Set<Integer> uids = new ArraySet<>();
synchronized (sUidOwnerMap) {
sUidOwnerMap.forEach((uid, val) -> {
if (val == null) {
Log.wtf(TAG, "sUidOwnerMap entry was deleted while holding a lock");
} else {
if ((val.rule & match) != 0) {
uids.add(uid.val);
}
}
});
}
return uids;
}
/**
* Get uids that has FIREWALL_RULE_ALLOW on allowlist chain.
* Allowlist means the firewall denies all by default, uids must be explicitly allowed.
*
* Note that uids that has FIREWALL_RULE_DENY on allowlist chain can not be computed from the
* bpf map, since all the uids that does not have explicit FIREWALL_RULE_ALLOW rule in bpf map
* are determined to have FIREWALL_RULE_DENY.
*
* @param childChain target chain
* @return Set of uids
*/
public Set<Integer> getUidsWithAllowRuleOnAllowListChain(final int childChain)
throws ErrnoException {
if (!isFirewallAllowList(childChain)) {
throw new IllegalArgumentException("getUidsWithAllowRuleOnAllowListChain is called with"
+ " denylist chain:" + childChain);
}
// Corresponding match is enabled for uids that has FIREWALL_RULE_ALLOW on allowlist chain.
return getUidsMatchEnabled(childChain);
}
/**
* Get uids that has FIREWALL_RULE_DENY on denylist chain.
* Denylist means the firewall allows all by default, uids must be explicitly denyed
*
* Note that uids that has FIREWALL_RULE_ALLOW on denylist chain can not be computed from the
* bpf map, since all the uids that does not have explicit FIREWALL_RULE_DENY rule in bpf map
* are determined to have the FIREWALL_RULE_ALLOW.
*
* @param childChain target chain
* @return Set of uids
*/
public Set<Integer> getUidsWithDenyRuleOnDenyListChain(final int childChain)
throws ErrnoException {
if (isFirewallAllowList(childChain)) {
throw new IllegalArgumentException("getUidsWithDenyRuleOnDenyListChain is called with"
+ " allowlist chain:" + childChain);
}
// Corresponding match is enabled for uids that has FIREWALL_RULE_DENY on denylist chain.
return getUidsMatchEnabled(childChain);
}
/**
* Add ingress interface filtering rules to a list of UIDs
*
* For a given uid, once a filtering rule is added, the kernel will only allow packets from the
* allowed interface and loopback to be sent to the list of UIDs.
*
* Calling this method on one or more UIDs with an existing filtering rule but a different
* interface name will result in the filtering rule being updated to allow the new interface
* instead. Otherwise calling this method will not affect existing rules set on other UIDs.
*
* @param ifName the name of the interface on which the filtering rules will allow packets to
* be received.
* @param uids an array of UIDs which the filtering rules will be set
* @throws RemoteException when netd has crashed.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
public void addUidInterfaceRules(final String ifName, final int[] uids) throws RemoteException {
if (!SdkLevel.isAtLeastT()) {
mNetd.firewallAddUidInterfaceRules(ifName, uids);
return;
}
// Null ifName is a wildcard to allow apps to receive packets on all interfaces and
// ifIndex is set to 0.
final int ifIndex;
if (ifName == null) {
ifIndex = 0;
} else {
ifIndex = mDeps.getIfIndex(ifName);
if (ifIndex == 0) {
throw new ServiceSpecificException(ENODEV,
"Failed to get index of interface " + ifName);
}
}
for (final int uid : uids) {
try {
addRule(uid, IIF_MATCH, ifIndex, "addUidInterfaceRules");
} catch (ServiceSpecificException e) {
Log.e(TAG, "addRule failed uid=" + uid + " ifName=" + ifName + ", " + e);
}
}
}
/**
* Remove ingress interface filtering rules from a list of UIDs
*
* Clear the ingress interface filtering rules from the list of UIDs which were previously set
* by addUidInterfaceRules(). Ignore any uid which does not have filtering rule.
*
* @param uids an array of UIDs from which the filtering rules will be removed
* @throws RemoteException when netd has crashed.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
public void removeUidInterfaceRules(final int[] uids) throws RemoteException {
if (!SdkLevel.isAtLeastT()) {
mNetd.firewallRemoveUidInterfaceRules(uids);
return;
}
for (final int uid : uids) {
try {
removeRule(uid, IIF_MATCH, "removeUidInterfaceRules");
} catch (ServiceSpecificException e) {
Log.e(TAG, "removeRule failed uid=" + uid + ", " + e);
}
}
}
/**
* Update lockdown rule for uid
*
* @param uid target uid to add/remove the rule
* @param add {@code true} to add the rule, {@code false} to remove the rule.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void updateUidLockdownRule(final int uid, final boolean add) {
throwIfPreT("updateUidLockdownRule is not available on pre-T devices");
if (add) {
addRule(uid, LOCKDOWN_VPN_MATCH, "updateUidLockdownRule");
} else {
removeRule(uid, LOCKDOWN_VPN_MATCH, "updateUidLockdownRule");
}
}
/**
* Request netd to change the current active network stats map.
*
* @throws UnsupportedOperationException if called on pre-T devices.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void swapActiveStatsMap() {
throwIfPreT("swapActiveStatsMap is not available on pre-T devices");
try {
synchronized (sCurrentStatsMapConfigLock) {
final long config = sConfigurationMap.getValue(
CURRENT_STATS_MAP_CONFIGURATION_KEY).val;
final long newConfig = (config == STATS_SELECT_MAP_A)
? STATS_SELECT_MAP_B : STATS_SELECT_MAP_A;
sConfigurationMap.updateEntry(CURRENT_STATS_MAP_CONFIGURATION_KEY,
new U32(newConfig));
}
} catch (ErrnoException e) {
throw new ServiceSpecificException(e.errno, "Failed to swap active stats map");
}
// After changing the config, it's needed to make sure all the current running eBPF
// programs are finished and all the CPUs are aware of this config change before the old
// map is modified. So special hack is needed here to wait for the kernel to do a
// synchronize_rcu(). Once the kernel called synchronize_rcu(), the updated config will
// be available to all cores and the next eBPF programs triggered inside the kernel will
// use the new map configuration. So once this function returns it is safe to modify the
// old stats map without concerning about race between the kernel and userspace.
final int err = mDeps.synchronizeKernelRCU();
maybeThrow(err, "synchronizeKernelRCU failed");
}
/**
* Assigns android.permission.INTERNET and/or android.permission.UPDATE_DEVICE_STATS to the uids
* specified. Or remove all permissions from the uids.
*
* @param permissions The permission to grant, it could be either PERMISSION_INTERNET and/or
* PERMISSION_UPDATE_DEVICE_STATS. If the permission is NO_PERMISSIONS, then
* revoke all permissions for the uids.
* @param uids uid of users to grant permission
* @throws RemoteException when netd has crashed.
*/
public void setNetPermForUids(final int permissions, final int[] uids) throws RemoteException {
if (!SdkLevel.isAtLeastT()) {
mNetd.trafficSetNetPermForUids(permissions, uids);
return;
}
// Remove the entry if package is uninstalled or uid has only INTERNET permission.
if (permissions == PERMISSION_UNINSTALLED || permissions == PERMISSION_INTERNET) {
for (final int uid : uids) {
try {
sUidPermissionMap.deleteEntry(new S32(uid));
} catch (ErrnoException e) {
Log.e(TAG, "Failed to remove uid " + uid + " from permission map: " + e);
}
}
return;
}
for (final int uid : uids) {
try {
sUidPermissionMap.updateEntry(new S32(uid), new U8((short) permissions));
} catch (ErrnoException e) {
Log.e(TAG, "Failed to set permission "
+ permissions + " to uid " + uid + ": " + e);
}
}
}
/**
* Set Data Saver enabled or disabled
*
* @param enable whether Data Saver is enabled or disabled.
* @throws UnsupportedOperationException if called on pre-T devices.
* @throws ServiceSpecificException in case of failure, with an error code indicating the
* cause of the failure.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void setDataSaverEnabled(boolean enable) {
throwIfPreT("setDataSaverEnabled is not available on pre-T devices");
try {
final short config = enable ? DATA_SAVER_ENABLED : DATA_SAVER_DISABLED;
sDataSaverEnabledMap.updateEntry(DATA_SAVER_ENABLED_KEY, new U8(config));
} catch (ErrnoException e) {
throw new ServiceSpecificException(e.errno, "Unable to set data saver: "
+ Os.strerror(e.errno));
}
}
/**
* Set ingress discard rule
*
* @param address target address to set the ingress discard rule
* @param iface allowed interface
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void setIngressDiscardRule(final InetAddress address, final String iface) {
throwIfPreT("setIngressDiscardRule is not available on pre-T devices");
final int ifIndex = mDeps.getIfIndex(iface);
if (ifIndex == 0) {
Log.e(TAG, "Failed to get if index, skip setting ingress discard rule for " + address
+ "(" + iface + ")");
return;
}
try {
sIngressDiscardMap.updateEntry(new IngressDiscardKey(address),
new IngressDiscardValue(ifIndex, ifIndex));
} catch (ErrnoException e) {
Log.e(TAG, "Failed to set ingress discard rule for " + address + "("
+ iface + "), " + e);
}
}
/**
* Remove ingress discard rule
*
* @param address target address to remove the ingress discard rule
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void removeIngressDiscardRule(final InetAddress address) {
throwIfPreT("removeIngressDiscardRule is not available on pre-T devices");
try {
sIngressDiscardMap.deleteEntry(new IngressDiscardKey(address));
} catch (ErrnoException e) {
Log.e(TAG, "Failed to remove ingress discard rule for " + address + ", " + e);
}
}
/** Register callback for statsd to pull atom. */
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void setPullAtomCallback(final Context context) {
throwIfPreT("setPullAtomCallback is not available on pre-T devices");
final StatsManager statsManager = context.getSystemService(StatsManager.class);
statsManager.setPullAtomCallback(NETWORK_BPF_MAP_INFO, null /* metadata */,
BackgroundThread.getExecutor(), this::pullBpfMapInfoAtom);
}
private <K extends Struct, V extends Struct> int getMapSize(IBpfMap<K, V> map)
throws ErrnoException {
// forEach could restart iteration from the beginning if there is a concurrent entry
// deletion. netd and skDestroyListener could delete CookieTagMap entry concurrently.
// So using Set to count the number of entry in the map.
Set<K> keySet = new ArraySet<>();
map.forEach((k, v) -> keySet.add(k));
return keySet.size();
}
/** Callback for StatsManager#setPullAtomCallback */
@VisibleForTesting
public int pullBpfMapInfoAtom(final int atomTag, final List<StatsEvent> data) {
if (atomTag != NETWORK_BPF_MAP_INFO) {
Log.e(TAG, "Unexpected atom tag: " + atomTag);
return StatsManager.PULL_SKIP;
}
try {
data.add(mDeps.buildStatsEvent(getMapSize(sCookieTagMap), getMapSize(sUidOwnerMap),
getMapSize(sUidPermissionMap)));
} catch (ErrnoException e) {
Log.e(TAG, "Failed to pull NETWORK_BPF_MAP_INFO atom: " + e);
return StatsManager.PULL_SKIP;
}
return StatsManager.PULL_SUCCESS;
}
private String permissionToString(int permissionMask) {
if (permissionMask == PERMISSION_NONE) {
return "PERMISSION_NONE";
}
if (permissionMask == PERMISSION_UNINSTALLED) {
// PERMISSION_UNINSTALLED should never appear in the map
return "PERMISSION_UNINSTALLED error!";
}
final StringJoiner sj = new StringJoiner(" ");
for (Pair<Integer, String> permission: PERMISSION_LIST) {
final int permissionFlag = permission.first;
final String permissionName = permission.second;
if ((permissionMask & permissionFlag) != 0) {
sj.add(permissionName);
permissionMask &= ~permissionFlag;
}
}
if (permissionMask != 0) {
sj.add("PERMISSION_UNKNOWN(" + permissionMask + ")");
}
return sj.toString();
}
private void dumpOwnerMatchConfig(final IndentingPrintWriter pw) {
try {
final long match = sConfigurationMap.getValue(UID_RULES_CONFIGURATION_KEY).val;
pw.println("current ownerMatch configuration: " + match + " " + matchToString(match));
} catch (ErrnoException e) {
pw.println("Failed to read ownerMatch configuration: " + e);
}
}
private void dumpCurrentStatsMapConfig(final IndentingPrintWriter pw) {
try {
final long config = sConfigurationMap.getValue(CURRENT_STATS_MAP_CONFIGURATION_KEY).val;
final String currentStatsMap =
(config == STATS_SELECT_MAP_A) ? "SELECT_MAP_A" : "SELECT_MAP_B";
pw.println("current statsMap configuration: " + config + " " + currentStatsMap);
} catch (ErrnoException e) {
pw.println("Falied to read current statsMap configuration: " + e);
}
}
private void dumpDataSaverConfig(final IndentingPrintWriter pw) {
try {
final short config = sDataSaverEnabledMap.getValue(DATA_SAVER_ENABLED_KEY).val;
// Any non-zero value converted from short to boolean is true by convention.
pw.println("sDataSaverEnabledMap: " + (config != DATA_SAVER_DISABLED));
} catch (ErrnoException e) {
pw.println("Failed to read data saver configuration: " + e);
}
}
/**
* Dump BPF maps
*
* @param pw print writer
* @param fd file descriptor to output
* @param verbose verbose dump flag, if true dump the BpfMap contents
* @throws IOException when file descriptor is invalid.
* @throws ServiceSpecificException when the method is called on an unsupported device.
*/
@RequiresApi(Build.VERSION_CODES.TIRAMISU)
public void dump(final IndentingPrintWriter pw, final FileDescriptor fd, boolean verbose)
throws IOException, ServiceSpecificException {
if (!SdkLevel.isAtLeastT()) {
throw new ServiceSpecificException(
EOPNOTSUPP, "dumpsys connectivity trafficcontroller dump not available on pre-T"
+ " devices, use dumpsys netd trafficcontroller instead.");
}
pw.println("TrafficController"); // required by CTS testDumpBpfNetMaps
pw.println();
if (verbose) {
pw.println();
pw.println("BPF map content:");
pw.increaseIndent();
dumpOwnerMatchConfig(pw);
dumpCurrentStatsMapConfig(pw);
pw.println();
// TODO: Remove CookieTagMap content dump
// NetworkStatsService also dumps CookieTagMap and NetworkStatsService is a right place
// to dump CookieTagMap. But the TagSocketTest in CTS depends on this dump so the tests
// need to be updated before remove the dump from BpfNetMaps.
BpfDump.dumpMap(sCookieTagMap, pw, "sCookieTagMap",
(key, value) -> "cookie=" + key.socketCookie
+ " tag=0x" + Long.toHexString(value.tag)
+ " uid=" + value.uid);
BpfDump.dumpMap(sUidOwnerMap, pw, "sUidOwnerMap",
(uid, match) -> {
if ((match.rule & IIF_MATCH) != 0) {
// TODO: convert interface index to interface name by IfaceIndexNameMap
return uid.val + " " + matchToString(match.rule) + " " + match.iif;
} else {
return uid.val + " " + matchToString(match.rule);
}
});
BpfDump.dumpMap(sUidPermissionMap, pw, "sUidPermissionMap",
(uid, permission) -> uid.val + " " + permissionToString(permission.val));
BpfDump.dumpMap(sIngressDiscardMap, pw, "sIngressDiscardMap",
(key, value) -> "[" + key.dstAddr + "]: "
+ value.iif1 + "(" + mDeps.getIfName(value.iif1) + "), "
+ value.iif2 + "(" + mDeps.getIfName(value.iif2) + ")");
dumpDataSaverConfig(pw);
pw.decreaseIndent();
}
}
}