Add a new ssid field in NetworkCapabilities.

Clean cherry-pick of ag/3887737

Bug: 77891227
Test: frameworks-net
Change-Id: Icefe1657bca52b913a72b56705342a7285769658
Merged-In: Ia1f4e51b7c2e9118789242cf6d9e7576c4167cda
Merged-In: I6dd1aba6fde5a502b4a9145cf16393d8ce623c89

core/java/android/net/NetworkCapabilities.java

@@ -70,6 +70,7 @@ public final class NetworkCapabilities implements Parcelable {
             mUids = nc.mUids;
             mEstablishingVpnAppUid = nc.mEstablishingVpnAppUid;
             mUnwantedNetworkCapabilities = nc.mUnwantedNetworkCapabilities;
+            mSSID = nc.mSSID;
         }
     }
 
@@ -85,6 +86,7 @@ public final class NetworkCapabilities implements Parcelable {
         mSignalStrength = SIGNAL_STRENGTH_UNSPECIFIED;
         mUids = null;
         mEstablishingVpnAppUid = INVALID_UID;
+        mSSID = null;
     }
 
     /**
@@ -922,7 +924,7 @@ public final class NetworkCapabilities implements Parcelable {
     /**
      * Sets the signal strength. This is a signed integer, with higher values indicating a stronger
      * signal. The exact units are bearer-dependent. For example, Wi-Fi uses the same RSSI units
-     * reported by WifiManager.
+     * reported by wifi code.
      * <p>
      * Note that when used to register a network callback, this specifies the minimum acceptable
      * signal strength. When received as the state of an existing network it specifies the current
@@ -1054,7 +1056,7 @@ public final class NetworkCapabilities implements Parcelable {
     }
 
     /**
-     * Tests if the set of UIDs that this network applies to is the same of the passed set of UIDs.
+     * Tests if the set of UIDs that this network applies to is the same as the passed network.
      * <p>
      * This test only checks whether equal range objects are in both sets. It will
      * return false if the ranges are not exactly the same, even if the covered UIDs
@@ -1144,6 +1146,62 @@ public final class NetworkCapabilities implements Parcelable {
         mUids.addAll(nc.mUids);
     }
 
+
+    /**
+     * The SSID of the network, or null if not applicable or unknown.
+     * <p>
+     * This is filled in by wifi code.
+     * @hide
+     */
+    private String mSSID;
+
+    /**
+     * Sets the SSID of this network.
+     * @hide
+     */
+    public NetworkCapabilities setSSID(String ssid) {
+        mSSID = ssid;
+        return this;
+    }
+
+    /**
+     * Gets the SSID of this network, or null if none or unknown.
+     * @hide
+     */
+    public String getSSID() {
+        return mSSID;
+    }
+
+    /**
+     * Tests if the SSID of this network is the same as the SSID of the passed network.
+     * @hide
+     */
+    public boolean equalsSSID(NetworkCapabilities nc) {
+        return Objects.equals(mSSID, nc.mSSID);
+    }
+
+    /**
+     * Check if the SSID requirements of this object are matched by the passed object.
+     * @hide
+     */
+    public boolean satisfiedBySSID(NetworkCapabilities nc) {
+        return mSSID == null || mSSID.equals(nc.mSSID);
+    }
+
+    /**
+     * Combine SSIDs of the capabilities.
+     * <p>
+     * This is only legal if either the SSID of this object is null, or both SSIDs are
+     * equal.
+     * @hide
+     */
+    private void combineSSIDs(NetworkCapabilities nc) {
+        if (mSSID != null && !mSSID.equals(nc.mSSID)) {
+            throw new IllegalStateException("Can't combine two SSIDs");
+        }
+        setSSID(nc.mSSID);
+    }
+
     /**
      * Combine a set of Capabilities to this one.  Useful for coming up with the complete set.
      * <p>
@@ -1159,6 +1217,7 @@ public final class NetworkCapabilities implements Parcelable {
         combineSpecifiers(nc);
         combineSignalStrength(nc);
         combineUids(nc);
+        combineSSIDs(nc);
     }
 
     /**
@@ -1177,7 +1236,8 @@ public final class NetworkCapabilities implements Parcelable {
                 && (onlyImmutable || satisfiedByLinkBandwidths(nc))
                 && satisfiedBySpecifier(nc)
                 && (onlyImmutable || satisfiedBySignalStrength(nc))
-                && (onlyImmutable || satisfiedByUids(nc)));
+                && (onlyImmutable || satisfiedByUids(nc))
+                && (onlyImmutable || satisfiedBySSID(nc)));
     }
 
     /**
@@ -1266,7 +1326,8 @@ public final class NetworkCapabilities implements Parcelable {
                 && equalsLinkBandwidths(that)
                 && equalsSignalStrength(that)
                 && equalsSpecifier(that)
-                && equalsUids(that));
+                && equalsUids(that)
+                && equalsSSID(that));
     }
 
     @Override
@@ -1281,7 +1342,8 @@ public final class NetworkCapabilities implements Parcelable {
                 + (mLinkDownBandwidthKbps * 19)
                 + Objects.hashCode(mNetworkSpecifier) * 23
                 + (mSignalStrength * 29)
-                + Objects.hashCode(mUids) * 31;
+                + Objects.hashCode(mUids) * 31
+                + Objects.hashCode(mSSID) * 37;
     }
 
     @Override
@@ -1298,6 +1360,7 @@ public final class NetworkCapabilities implements Parcelable {
         dest.writeParcelable((Parcelable) mNetworkSpecifier, flags);
         dest.writeInt(mSignalStrength);
         dest.writeArraySet(mUids);
+        dest.writeString(mSSID);
     }
 
     public static final Creator<NetworkCapabilities> CREATOR =
@@ -1315,6 +1378,7 @@ public final class NetworkCapabilities implements Parcelable {
                 netCap.mSignalStrength = in.readInt();
                 netCap.mUids = (ArraySet<UidRange>) in.readArraySet(
                         null /* ClassLoader, null for default */);
+                netCap.mSSID = in.readString();
                 return netCap;
             }
             @Override
@@ -1365,6 +1429,10 @@ public final class NetworkCapabilities implements Parcelable {
             sb.append(" EstablishingAppUid: ").append(mEstablishingVpnAppUid);
         }
 
+        if (null != mSSID) {
+            sb.append(" SSID: ").append(mSSID);
+        }
+
         sb.append("]");
         return sb.toString();
     }

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

@@ -1354,7 +1354,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
         if (nai != null) {
             synchronized (nai) {
                 if (nai.networkCapabilities != null) {
-                    return networkCapabilitiesWithoutUidsUnlessAllowed(nai.networkCapabilities,
+                    return networkCapabilitiesRestrictedForCallerPermissions(
+                            nai.networkCapabilities,
                             Binder.getCallingPid(), Binder.getCallingUid());
                 }
             }
@@ -1368,10 +1369,12 @@ public class ConnectivityService extends IConnectivityManager.Stub
         return getNetworkCapabilitiesInternal(getNetworkAgentInfoForNetwork(network));
     }
 
-    private NetworkCapabilities networkCapabilitiesWithoutUidsUnlessAllowed(
+    private NetworkCapabilities networkCapabilitiesRestrictedForCallerPermissions(
             NetworkCapabilities nc, int callerPid, int callerUid) {
-        if (checkSettingsPermission(callerPid, callerUid)) return new NetworkCapabilities(nc);
+        final NetworkCapabilities newNc = new NetworkCapabilities(nc);
-        return new NetworkCapabilities(nc).setUids(null);
+        if (!checkSettingsPermission(callerPid, callerUid)) newNc.setUids(null);
+        if (!checkNetworkStackPermission(callerPid, callerUid)) newNc.setSSID(null);
+        return newNc;
     }
 
     private void restrictRequestUidsForCaller(NetworkCapabilities nc) {
@@ -1630,6 +1633,11 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 android.Manifest.permission.NETWORK_SETTINGS, pid, uid);
     }
 
+    private boolean checkNetworkStackPermission(int pid, int uid) {
+        return PERMISSION_GRANTED == mContext.checkPermission(
+                android.Manifest.permission.NETWORK_STACK, pid, uid);
+    }
+
     private void enforceTetherAccessPermission() {
         mContext.enforceCallingOrSelfPermission(
                 android.Manifest.permission.ACCESS_NETWORK_STATE,
@@ -4185,6 +4193,15 @@ public class ConnectivityService extends IConnectivityManager.Stub
         }
     }
 
+    // This checks that the passed capabilities either do not request a specific SSID, or the
+    // calling app has permission to do so.
+    private void ensureSufficientPermissionsForRequest(NetworkCapabilities nc,
+            int callerPid, int callerUid) {
+        if (null != nc.getSSID() && !checkNetworkStackPermission(callerPid, callerUid)) {
+            throw new SecurityException("Insufficient permissions to request a specific SSID");
+        }
+    }
+
     private ArrayList<Integer> getSignalStrengthThresholds(NetworkAgentInfo nai) {
         final SortedSet<Integer> thresholds = new TreeSet();
         synchronized (nai) {
@@ -4254,6 +4271,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
             enforceMeteredApnPolicy(networkCapabilities);
         }
         ensureRequestableCapabilities(networkCapabilities);
+        ensureSufficientPermissionsForRequest(networkCapabilities,
+                Binder.getCallingPid(), Binder.getCallingUid());
         // Set the UID range for this request to the single UID of the requester, or to an empty
         // set of UIDs if the caller has the appropriate permission and UIDs have not been set.
         // This will overwrite any allowed UIDs in the requested capabilities. Though there
@@ -4332,6 +4351,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
         enforceNetworkRequestPermissions(networkCapabilities);
         enforceMeteredApnPolicy(networkCapabilities);
         ensureRequestableCapabilities(networkCapabilities);
+        ensureSufficientPermissionsForRequest(networkCapabilities,
+                Binder.getCallingPid(), Binder.getCallingUid());
         ensureValidNetworkSpecifier(networkCapabilities);
         restrictRequestUidsForCaller(networkCapabilities);
 
@@ -4387,6 +4408,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
         }
 
         NetworkCapabilities nc = new NetworkCapabilities(networkCapabilities);
+        ensureSufficientPermissionsForRequest(networkCapabilities,
+                Binder.getCallingPid(), Binder.getCallingUid());
         restrictRequestUidsForCaller(nc);
         // Apps without the CHANGE_NETWORK_STATE permission can't use background networks, so
         // make all their listens include NET_CAPABILITY_FOREGROUND. That way, they will get
@@ -4413,6 +4436,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
             enforceAccessPermission();
         }
         ensureValidNetworkSpecifier(networkCapabilities);
+        ensureSufficientPermissionsForRequest(networkCapabilities,
+                Binder.getCallingPid(), Binder.getCallingUid());
 
         final NetworkCapabilities nc = new NetworkCapabilities(networkCapabilities);
         restrictRequestUidsForCaller(nc);
@@ -4984,7 +5009,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
             }
             case ConnectivityManager.CALLBACK_CAP_CHANGED: {
                 // networkAgent can't be null as it has been accessed a few lines above.
-                final NetworkCapabilities nc = networkCapabilitiesWithoutUidsUnlessAllowed(
+                final NetworkCapabilities nc = networkCapabilitiesRestrictedForCallerPermissions(
                         networkAgent.networkCapabilities, nri.mPid, nri.mUid);
                 putParcelable(bundle, nc);
                 break;

tests/net/java/android/net/NetworkCapabilitiesTest.java

@@ -40,12 +40,14 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import android.os.Parcel;
 import android.support.test.runner.AndroidJUnit4;
 import android.test.suitebuilder.annotation.SmallTest;
 import android.util.ArraySet;
 
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -54,6 +56,8 @@ import java.util.Set;
 @RunWith(AndroidJUnit4.class)
 @SmallTest
 public class NetworkCapabilitiesTest {
+    private static final String TEST_SSID = "TEST_SSID";
+
     @Test
     public void testMaybeMarkCapabilitiesRestricted() {
         // verify EIMS is restricted
@@ -268,6 +272,8 @@ public class NetworkCapabilitiesTest {
             .addCapability(NET_CAPABILITY_EIMS)
             .addCapability(NET_CAPABILITY_NOT_METERED);
         assertEqualsThroughMarshalling(netCap);
+        netCap.setSSID(TEST_SSID);
+        assertEqualsThroughMarshalling(netCap);
     }
 
     @Test
@@ -361,6 +367,21 @@ public class NetworkCapabilitiesTest {
         assertTrue(nc1.equalsNetCapabilities(nc2));
     }
 
+    @Test
+    public void testSSID() {
+        NetworkCapabilities nc1 = new NetworkCapabilities();
+        NetworkCapabilities nc2 = new NetworkCapabilities();
+        assertTrue(nc2.satisfiedBySSID(nc1));
+
+        nc1.setSSID(TEST_SSID);
+        assertTrue(nc2.satisfiedBySSID(nc1));
+        nc2.setSSID("different " + TEST_SSID);
+        assertFalse(nc2.satisfiedBySSID(nc1));
+
+        assertTrue(nc1.satisfiedByImmutableNetworkCapabilities(nc2));
+        assertFalse(nc1.satisfiedByNetworkCapabilities(nc2));
+    }
+
     @Test
     public void testCombineCapabilities() {
         NetworkCapabilities nc1 = new NetworkCapabilities();
@@ -382,6 +403,19 @@ public class NetworkCapabilitiesTest {
         // will never be satisfied.
         assertTrue(nc2.hasCapability(NET_CAPABILITY_NOT_ROAMING));
         assertTrue(nc2.hasUnwantedCapability(NET_CAPABILITY_NOT_ROAMING));
+
+        nc1.setSSID(TEST_SSID);
+        nc2.combineCapabilities(nc1);
+        assertTrue(TEST_SSID.equals(nc2.getSSID()));
+
+        // Because they now have the same SSID, the folllowing call should not throw
+        nc2.combineCapabilities(nc1);
+
+        nc1.setSSID("different " + TEST_SSID);
+        try {
+            nc2.combineCapabilities(nc1);
+            fail("Expected IllegalStateException: can't combine different SSIDs");
+        } catch (IllegalStateException expected) {}
     }
 
     @Test