[AWARE] Support multiple NAN data interfaces (NDI)

Support all the NAN data-interfaces which the firmware supports -
based on the returned capability.

- Create the data-interfaces
- Assign data-paths to data-interfaces based on constraints of
  unique [(src mac, dst mac), security config] tuples. I.e. a
  single data-interface can only have a single security configuration
  to a specific destination interface.

Bug: 63635857
Test: unit tests + integrated test suite
Change-Id: I4a21f3b025e8164673366e22da062d536d588148

3 files changed, 41 insertions, 11 deletions

diff --git a/service/java/com/android/server/wifi/aware/WifiAwareDataPathStateManager.java b/service/java/com/android/server/wifi/aware/WifiAwareDataPathStateManager.java
index 16888c81e..efeca655b 100644
--- a/service/java/com/android/server/wifi/aware/WifiAwareDataPathStateManager.java
+++ b/service/java/com/android/server/wifi/aware/WifiAwareDataPathStateManager.java
@@ -60,10 +60,11 @@ import java.net.SocketException;
 import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
 
 /**
  * Manages Aware data-path lifetime: interface creation/deletion, data-path setup and tear-down.
@@ -323,6 +324,8 @@ public class WifiAwareDataPathStateManager {
              * - The discovery session (pub/sub ID) must match.
              * - The peer MAC address (if specified - i.e. non-null) must match. A null peer MAC ==
              *   accept (otherwise matching) requests from any peer MAC.
+             * - The request must be pending (i.e. we could have completed requests for the same
+             *   parameters)
              */
             if (entry.getValue().pubSubId != 0 && entry.getValue().pubSubId != pubSubId) {
                 continue;
@@ -333,6 +336,11 @@ public class WifiAwareDataPathStateManager {
                 continue;
             }
 
+            if (entry.getValue().state
+                    != AwareNetworkRequestInformation.STATE_RESPONDER_WAIT_FOR_REQUEST) {
+                continue;
+            }
+
             networkSpecifier = entry.getKey();
             nnri = entry.getValue();
             break;
@@ -884,18 +892,43 @@ public class WifiAwareDataPathStateManager {
     }
 
     /**
-     * Select one of the existing interfaces for the new network request.
+     * Select one of the existing interfaces for the new network request. A request is canonical
+     * (otherwise it wouldn't be executed).
      *
-     * TODO: for now there is only a single interface - simply pick it.
+     * Construct a list of all interfaces currently used to communicate to the peer. The remaining
+     * interfaces are available for use for this request - if none are left then the request should
+     * fail (signaled to the caller by returning a null).
      */
     private String selectInterfaceForRequest(AwareNetworkRequestInformation req) {
-        Iterator<String> it = mInterfaces.iterator();
-        if (it.hasNext()) {
-            return it.next();
+        SortedSet<String> potential = new TreeSet<>(mInterfaces);
+        Set<String> used = new HashSet<>();
+
+        if (VDBG) {
+            Log.v(TAG, "selectInterfaceForRequest: req=" + req + ", mNetworkRequestsCache="
+                    + mNetworkRequestsCache);
         }
 
-        Log.e(TAG, "selectInterfaceForRequest: req=" + req + " - but no interfaces available!");
+        for (AwareNetworkRequestInformation nnri : mNetworkRequestsCache.values()) {
+            if (nnri == req) {
+                continue;
+            }
+
+            if (Arrays.equals(req.peerDiscoveryMac, nnri.peerDiscoveryMac)) {
+                used.add(nnri.interfaceName);
+            }
+        }
+
+        if (VDBG) {
+            Log.v(TAG, "selectInterfaceForRequest: potential=" + potential + ", used=" + used);
+        }
+
+        for (String ifName: potential) {
+            if (!used.contains(ifName)) {
+                return ifName;
+            }
+        }
 
+        Log.e(TAG, "selectInterfaceForRequest: req=" + req + " - no interfaces available!");
         return null;
     }
 
diff --git a/service/java/com/android/server/wifi/aware/WifiAwareNativeCallback.java b/service/java/com/android/server/wifi/aware/WifiAwareNativeCallback.java
index 2f424db4c..2121160bb 100644
--- a/service/java/com/android/server/wifi/aware/WifiAwareNativeCallback.java
+++ b/service/java/com/android/server/wifi/aware/WifiAwareNativeCallback.java
@@ -167,10 +167,6 @@ public class WifiAwareNativeCallback extends IWifiNanIfaceEventCallback.Stub imp
                     capabilities.maxSubscribeInterfaceAddresses;
             frameworkCapabilities.supportedCipherSuites = capabilities.supportedCipherSuites;
 
-            // TODO (b/63635857): enable framework support of >1 NDI
-            // Until then: force corresponding capability to 1.
-            frameworkCapabilities.maxNdiInterfaces = 1;
-
             mWifiAwareStateManager.onCapabilitiesUpdateResponse(id, frameworkCapabilities);
         } else {
             Log.e(TAG, "notifyCapabilitiesResponse: error code=" + status.status + " ("
diff --git a/service/java/com/android/server/wifi/aware/WifiAwareShellCommand.java b/service/java/com/android/server/wifi/aware/WifiAwareShellCommand.java
index 41eef6960..a2f604686 100644
--- a/service/java/com/android/server/wifi/aware/WifiAwareShellCommand.java
+++ b/service/java/com/android/server/wifi/aware/WifiAwareShellCommand.java
@@ -55,6 +55,7 @@ public class WifiAwareShellCommand extends ShellCommand {
                 for (DelegatedShellCommand dsc: mDelegatedCommands.values()) {
                     dsc.onReset();
                 }
+                return 0;
             } else {
                 DelegatedShellCommand delegatedCmd = null;
                 if (!TextUtils.isEmpty(cmd)) {