Allow MAC addresses to configure IP configurations

This allows the behavior to align with how MAC addresses can configure
network capabilities in config.xml. Ethernet interfaces can be
configured in the following format "<interface name|mac address>;
[Network Capabilities];[IP config];[Override Transport]", however for IP
 configurations within EthernetTracker the mac address was not
 considered.

Additionally, this CL fixes lapses in the retrieval of network
capabilities by mac address as well (e.g. within isRestrictedInterface,
network capabilities were only retrieved by the interface name rather
than the interface name and the mac address)

Test: atest FrameworksNetTests
Bug: 142259350
Change-Id: I211dd6466abcdbb1de3ca512a65214ed9e249969

2 files changed, 90 insertions, 48 deletions

diff --git a/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java b/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
index b8689d6f17..92f19531fb 100644
--- a/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
+++ b/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
@@ -108,7 +108,11 @@ public class EthernetServiceImpl extends IEthernetManager.Stub {
             PermissionUtils.enforceRestrictedNetworkPermission(mContext, TAG);
         }
 
-        return new IpConfiguration(mTracker.getIpConfiguration(iface));
+        // This causes thread-unsafe access on mIpConfigurations which might
+        // race with calls to EthernetManager#updateConfiguration().
+        // EthernetManager#getConfiguration() has been marked as
+        // @UnsupportedAppUsage since Android R.
+        return mTracker.getIpConfiguration(iface);
     }
 
     /**
diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index 71f289e5c2..a60592fac2 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -31,8 +31,6 @@ import android.net.INetd;
 import android.net.ITetheredInterfaceCallback;
 import android.net.InterfaceConfigurationParcel;
 import android.net.IpConfiguration;
-import android.net.IpConfiguration.IpAssignment;
-import android.net.IpConfiguration.ProxySettings;
 import android.net.LinkAddress;
 import android.net.NetworkCapabilities;
 import android.net.StaticIpConfiguration;
@@ -111,6 +109,7 @@ public class EthernetTracker {
     /** Mapping between {iface name | mac address} -> {NetworkCapabilities} */
     private final ConcurrentHashMap<String, NetworkCapabilities> mNetworkCapabilities =
             new ConcurrentHashMap<>();
+    /** Mapping between {iface name | mac address} -> {IpConfiguration} */
     private final ConcurrentHashMap<String, IpConfiguration> mIpConfigurations =
             new ConcurrentHashMap<>();
 
@@ -298,7 +297,7 @@ public class EthernetTracker {
     }
 
     private IpConfiguration getIpConfigurationForCallback(String iface, int state) {
-        return (state == EthernetManager.STATE_ABSENT) ? null : getOrCreateIpConfiguration(iface);
+        return (state == EthernetManager.STATE_ABSENT) ? null : getIpConfiguration(iface);
     }
 
     private void ensureRunningOnEthernetServiceThread() {
@@ -391,8 +390,83 @@ public class EthernetTracker {
         mHandler.post(() -> setInterfaceAdministrativeState(iface, enabled, cb));
     }
 
-    IpConfiguration getIpConfiguration(String iface) {
-        return mIpConfigurations.get(iface);
+    private @Nullable String getHwAddress(String iface) {
+        if (getInterfaceRole(iface) == EthernetManager.ROLE_SERVER) {
+            return mTetheringInterfaceHwAddr;
+        }
+
+        return mFactory.getHwAddress(iface);
+    }
+
+    /**
+     * Get the IP configuration of the interface, or the default if the interface doesn't exist.
+     * @param iface the name of the interface to retrieve.
+     *
+     * @return The IP configuration
+     */
+    public IpConfiguration getIpConfiguration(String iface) {
+        return getIpConfiguration(iface, getHwAddress(iface));
+    }
+
+    private IpConfiguration getIpConfiguration(String iface, @Nullable String hwAddress) {
+        // Look up Ip configuration first by ifname, then by MAC address.
+        IpConfiguration ipConfig = mIpConfigurations.get(iface);
+        if (ipConfig != null) {
+            return ipConfig;
+        }
+
+        if (hwAddress == null) {
+            // should never happen.
+            Log.wtf(TAG, "No hardware address for interface " + iface);
+        } else {
+            ipConfig = mIpConfigurations.get(hwAddress);
+        }
+
+        if (ipConfig == null) {
+            ipConfig = new IpConfiguration.Builder().build();
+        }
+
+        return ipConfig;
+    }
+
+    private NetworkCapabilities getNetworkCapabilities(String iface) {
+        return getNetworkCapabilities(iface, getHwAddress(iface));
+    }
+
+    private NetworkCapabilities getNetworkCapabilities(String iface, @Nullable String hwAddress) {
+        // Look up network capabilities first by ifname, then by MAC address.
+        NetworkCapabilities networkCapabilities = mNetworkCapabilities.get(iface);
+        if (networkCapabilities != null) {
+            return networkCapabilities;
+        }
+
+        if (hwAddress == null) {
+            // should never happen.
+            Log.wtf(TAG, "No hardware address for interface " + iface);
+        } else {
+            networkCapabilities = mNetworkCapabilities.get(hwAddress);
+        }
+
+        if (networkCapabilities != null) {
+            return networkCapabilities;
+        }
+
+        final NetworkCapabilities.Builder builder = createNetworkCapabilities(
+                false /* clear default capabilities */, null, null)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_CONGESTED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VCN_MANAGED);
+
+        if (isValidTestInterface(iface)) {
+            builder.addTransportType(NetworkCapabilities.TRANSPORT_TEST);
+        } else {
+            builder.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
+        }
+
+        return builder.build();
     }
 
     @VisibleForTesting(visibility = PACKAGE)
@@ -433,8 +507,8 @@ public class EthernetTracker {
      * NET_CAPABILITY_NOT_RESTRICTED) capability. Otherwise, returns false.
      */
     boolean isRestrictedInterface(String iface) {
-        final NetworkCapabilities nc = mNetworkCapabilities.get(iface);
-        return nc != null && !nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED);
+        final NetworkCapabilities nc = getNetworkCapabilities(iface);
+        return !nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED);
     }
 
     void addListener(IEthernetServiceListener listener, boolean canUseRestrictedNetworks) {
@@ -623,17 +697,9 @@ public class EthernetTracker {
             return;
         }
 
-        NetworkCapabilities nc = mNetworkCapabilities.get(iface);
-        if (nc == null) {
-            // Try to resolve using mac address
-            nc = mNetworkCapabilities.get(hwAddress);
-            if (nc == null) {
-                final boolean isTestIface = iface.matches(TEST_IFACE_REGEXP);
-                nc = createDefaultNetworkCapabilities(isTestIface);
-            }
-        }
+        final NetworkCapabilities nc = getNetworkCapabilities(iface, hwAddress);
+        final IpConfiguration ipConfiguration = getIpConfiguration(iface, hwAddress);
 
-        IpConfiguration ipConfiguration = getOrCreateIpConfiguration(iface);
         Log.d(TAG, "Tracking interface in client mode: " + iface);
         mFactory.addInterface(iface, hwAddress, ipConfiguration, nc);
 
@@ -773,25 +839,6 @@ public class EthernetTracker {
         return new EthernetTrackerConfig(configString.split(";", /* limit of tokens */ 4));
     }
 
-    private static NetworkCapabilities createDefaultNetworkCapabilities(boolean isTestIface) {
-        NetworkCapabilities.Builder builder = createNetworkCapabilities(
-                false /* clear default capabilities */, null, null)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_CONGESTED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VCN_MANAGED);
-
-        if (isTestIface) {
-            builder.addTransportType(NetworkCapabilities.TRANSPORT_TEST);
-        } else {
-            builder.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
-        }
-
-        return builder.build();
-    }
-
     /**
      * Parses a static list of network capabilities
      *
@@ -926,15 +973,6 @@ public class EthernetTracker {
         return new IpConfiguration.Builder().setStaticIpConfiguration(staticIpConfig).build();
     }
 
-    private IpConfiguration getOrCreateIpConfiguration(String iface) {
-        IpConfiguration ret = mIpConfigurations.get(iface);
-        if (ret != null) return ret;
-        ret = new IpConfiguration();
-        ret.setIpAssignment(IpAssignment.DHCP);
-        ret.setProxySettings(ProxySettings.NONE);
-        return ret;
-    }
-
     private boolean isValidEthernetInterface(String iface) {
         return iface.matches(mIfaceMatch) || isValidTestInterface(iface);
     }
@@ -1021,7 +1059,7 @@ public class EthernetTracker {
             pw.println("IP Configurations:");
             pw.increaseIndent();
             for (String iface : mIpConfigurations.keySet()) {
-                pw.println(iface + ": " + mIpConfigurations.get(iface));
+                pw.println(iface + ": " + getIpConfiguration(iface));
             }
             pw.decreaseIndent();
             pw.println();
@@ -1029,7 +1067,7 @@ public class EthernetTracker {
             pw.println("Network Capabilities:");
             pw.increaseIndent();
             for (String iface : mNetworkCapabilities.keySet()) {
-                pw.println(iface + ": " + mNetworkCapabilities.get(iface));
+                pw.println(iface + ": " + getNetworkCapabilities(iface));
             }
             pw.decreaseIndent();
             pw.println();