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Commit 1881ae03 authored by Lorenzo Colitti's avatar Lorenzo Colitti
Browse files

Stop using NetworkState internally in ConnectivityService. 

NetworkState is used by many methods that take or return legacy
network types. It is used because it contains most of the state
related to a network.

This code is not easy to follow and is more expensive than it
needs to be: most of the methods that construct a NetworkState
only really need one of its members (e.g., LinkProperties, or
NetworkInfo), but constructing a NetworkState requires making
defensive copies of all its other members as well.

- Instead of using NetworkState, use NetworkAgentInfo, which
  already contains all the same data.
- Replace calls to getUnfilteredActiveNetworkState with calls to
  getNetworkAgentInfoForUid. When getUnfilteredActiveNetworkState
  returned NetworkState.EMPTY, return a null nai, which causes
  any caller to see return null LinkProperties/NetworkInfo/etc.
- Rename filterNetworkStateForUid to getFilteredNetworkInfo,
  because that's the only thing it actually filters.
- Rename getFilteredNetworkInfo to getFilteredNetworkInfoForType
  to avoid having two methods with the same name perform two
  different operations. That method was only introduced recently
  in aosp/1552503, so it's probably fine to rename it.

Bug: 174123988
Test: passes existing ConnectivityServiceTest
Change-Id: Idfb5e149967266a442b268de6f13a521884dbb8f
parent 2d23f530

services/core/java/com/android/server/ConnectivityService.java

+46 −52
Original line number Diff line number Diff line
@@ -1403,7 +1403,7 @@ public class ConnectivityService extends IConnectivityManager.Stub 
        return null;

    }



    private NetworkState getUnfilteredActiveNetworkState(int uid) {

    private NetworkAgentInfo getNetworkAgentInfoForUid(int uid) {

        NetworkAgentInfo nai = getDefaultNetworkForUid(uid);



        final Network[] networks = getVpnUnderlyingNetworks(uid);
@@ -1419,12 +1419,7 @@ public class ConnectivityService extends IConnectivityManager.Stub 
                nai = null;

            }

        }



        if (nai != null) {

            return nai.getNetworkState();

        } else {

            return NetworkState.EMPTY;

        }

        return nai;

    }



    /**
@@ -1477,24 +1472,28 @@ public class ConnectivityService extends IConnectivityManager.Stub 
                "%s %d(%d) on netId %d", action, nri.mUid, requestId, net.getNetId()));

    }



    private void filterNetworkInfo(@NonNull NetworkInfo networkInfo,

            @NonNull NetworkCapabilities nc, int uid, boolean ignoreBlocked) {

        if (isNetworkWithCapabilitiesBlocked(nc, uid, ignoreBlocked)) {

            networkInfo.setDetailedState(DetailedState.BLOCKED, null, null);

        }

        networkInfo.setDetailedState(

                getLegacyLockdownState(networkInfo.getDetailedState()),

                "" /* reason */, null /* extraInfo */);

    }



    /**

     * Apply any relevant filters to {@link NetworkState} for the given UID. For

     * Apply any relevant filters to the specified {@link NetworkInfo} for the given UID. For

     * example, this may mark the network as {@link DetailedState#BLOCKED} based

     * on {@link #isNetworkWithCapabilitiesBlocked}.

     */

    private void filterNetworkStateForUid(NetworkState state, int uid, boolean ignoreBlocked) {

        if (state == null || state.networkInfo == null || state.linkProperties == null) return;

        filterNetworkInfo(state.networkInfo, state.networkCapabilities, uid, ignoreBlocked);

    @NonNull

    private NetworkInfo filterNetworkInfo(@NonNull NetworkInfo networkInfo, int type,

            @NonNull NetworkCapabilities nc, int uid, boolean ignoreBlocked) {

        NetworkInfo filtered = new NetworkInfo(networkInfo);

        filtered.setType(type);

        final DetailedState state = isNetworkWithCapabilitiesBlocked(nc, uid, ignoreBlocked)

                ? DetailedState.BLOCKED

                : filtered.getDetailedState();

        filtered.setDetailedState(getLegacyLockdownState(state),

                "" /* reason */, null /* extraInfo */);

        return filtered;

    }



    private NetworkInfo getFilteredNetworkInfo(NetworkAgentInfo nai, int uid,

            boolean ignoreBlocked) {

        return filterNetworkInfo(nai.networkInfo, nai.networkInfo.getType(),

                nai.networkCapabilities, uid, ignoreBlocked);

    }



    /**
@@ -1508,10 +1507,11 @@ public class ConnectivityService extends IConnectivityManager.Stub 
    public NetworkInfo getActiveNetworkInfo() {

        enforceAccessPermission();

        final int uid = mDeps.getCallingUid();

        final NetworkState state = getUnfilteredActiveNetworkState(uid);

        filterNetworkStateForUid(state, uid, false);

        maybeLogBlockedNetworkInfo(state.networkInfo, uid);

        return state.networkInfo;

        final NetworkAgentInfo nai = getNetworkAgentInfoForUid(uid);

        if (nai == null) return null;

        final NetworkInfo networkInfo = getFilteredNetworkInfo(nai, uid, false);

        maybeLogBlockedNetworkInfo(networkInfo, uid);

        return networkInfo;

    }



    @Override
@@ -1546,9 +1546,9 @@ public class ConnectivityService extends IConnectivityManager.Stub 
    @Override

    public NetworkInfo getActiveNetworkInfoForUid(int uid, boolean ignoreBlocked) {

        PermissionUtils.enforceNetworkStackPermission(mContext);

        final NetworkState state = getUnfilteredActiveNetworkState(uid);

        filterNetworkStateForUid(state, uid, ignoreBlocked);

        return state.networkInfo;

        final NetworkAgentInfo nai = getNetworkAgentInfoForUid(uid);

        if (nai == null) return null;

        return getFilteredNetworkInfo(nai, uid, ignoreBlocked);

    }



    /** Returns a NetworkInfo object for a network that doesn't exist. */
@@ -1567,7 +1567,7 @@ public class ConnectivityService extends IConnectivityManager.Stub 
        return info;

    }



    private NetworkInfo getFilteredNetworkInfo(int networkType, int uid) {

    private NetworkInfo getFilteredNetworkInfoForType(int networkType, int uid) {

        if (!mLegacyTypeTracker.isTypeSupported(networkType)) {

            return null;

        }
@@ -1575,10 +1575,8 @@ public class ConnectivityService extends IConnectivityManager.Stub 
        if (nai == null) {

            return makeFakeNetworkInfo(networkType, uid);

        }

        final NetworkInfo info = new NetworkInfo(nai.networkInfo);

        info.setType(networkType);

        filterNetworkInfo(info, nai.networkCapabilities, uid, false);

        return info;

        return filterNetworkInfo(nai.networkInfo, networkType, nai.networkCapabilities, uid,

                false);

    }



    @Override
@@ -1588,27 +1586,23 @@ public class ConnectivityService extends IConnectivityManager.Stub 
        if (getVpnUnderlyingNetworks(uid) != null) {

            // A VPN is active, so we may need to return one of its underlying networks. This

            // information is not available in LegacyTypeTracker, so we have to get it from

            // getUnfilteredActiveNetworkState.

            final NetworkState state = getUnfilteredActiveNetworkState(uid);

            if (state.networkInfo != null && state.networkInfo.getType() == networkType) {

                filterNetworkStateForUid(state, uid, false);

                return state.networkInfo;

            // getNetworkAgentInfoForUid.

            final NetworkAgentInfo nai = getNetworkAgentInfoForUid(uid);

            if (nai == null) return null;

            final NetworkInfo networkInfo = getFilteredNetworkInfo(nai, uid, false);

            if (networkInfo.getType() == networkType) {

                return networkInfo;

            }

        }

        return getFilteredNetworkInfo(networkType, uid);

        return getFilteredNetworkInfoForType(networkType, uid);

    }



    @Override

    public NetworkInfo getNetworkInfoForUid(Network network, int uid, boolean ignoreBlocked) {

        enforceAccessPermission();

        final NetworkAgentInfo nai = getNetworkAgentInfoForNetwork(network);

        if (nai != null) {

            final NetworkState state = nai.getNetworkState();

            filterNetworkStateForUid(state, uid, ignoreBlocked);

            return state.networkInfo;

        } else {

            return null;

        }

        if (nai == null) return null;

        return getFilteredNetworkInfo(nai, uid, ignoreBlocked);

    }



    @Override
@@ -1636,11 +1630,11 @@ public class ConnectivityService extends IConnectivityManager.Stub 
            return null;

        }

        final int uid = mDeps.getCallingUid();

        if (!isNetworkWithCapabilitiesBlocked(nai.networkCapabilities, uid, false)) {

            return nai.network;

        }

        if (isNetworkWithCapabilitiesBlocked(nai.networkCapabilities, uid, false)) {

            return null;

        }

        return nai.network;

    }



    @Override

    public Network[] getAllNetworks() {
@@ -1728,9 +1722,9 @@ public class ConnectivityService extends IConnectivityManager.Stub 
    public LinkProperties getActiveLinkProperties() {

        enforceAccessPermission();

        final int uid = mDeps.getCallingUid();

        NetworkState state = getUnfilteredActiveNetworkState(uid);

        if (state.linkProperties == null) return null;

        return linkPropertiesRestrictedForCallerPermissions(state.linkProperties,

        NetworkAgentInfo nai = getNetworkAgentInfoForUid(uid);

        if (nai == null) return null;

        return linkPropertiesRestrictedForCallerPermissions(nai.linkProperties,

                Binder.getCallingPid(), uid);

    }