WifiServiceImpl: act on interface ip mode changes

When Connectivity service notifies WifiService of interface ip mode
changes, we should use them to update our registered LOHS requestors.
When the LOHS is ready to use, we will be notified about the LOCAL_ONLY
mode and trigger the onStarted callback.  If tethering starts, we should
notify the requestors via the onFailed call with an INCOMPATIBLE_MODE
error.  In the unlikely case of an IP failure, we should also trigger
the onFailed callback with the GENERIC error.

This CL also adds tests and handling for cases where additional LOHS
requests are added after the hotspot is already up and running.

Bug: 31466854
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: I1c6a25eca7b23f161ea4403a980292e82968c4c1

1 files changed, 109 insertions, 13 deletions

diff --git a/service/java/com/android/server/wifi/WifiServiceImpl.java b/service/java/com/android/server/wifi/WifiServiceImpl.java
index ce9784d2e..4e8bbd9c2 100644
--- a/service/java/com/android/server/wifi/WifiServiceImpl.java
+++ b/service/java/com/android/server/wifi/WifiServiceImpl.java
@@ -203,12 +203,12 @@ public class WifiServiceImpl extends IWifiManager.Stub {
 
     private WifiPermissionsUtil mWifiPermissionsUtil;
 
-    private final ConcurrentHashMap<String, Integer> mIfaceIpModes;
-
     @GuardedBy("mLocalOnlyHotspotRequests")
     private final HashMap<Integer, LocalOnlyHotspotRequestInfo> mLocalOnlyHotspotRequests;
     @GuardedBy("mLocalOnlyHotspotRequests")
     private WifiConfiguration mLocalOnlyHotspotConfig = null;
+    @GuardedBy("mLocalOnlyHotspotRequests")
+    private final ConcurrentHashMap<String, Integer> mIfaceIpModes;
 
     /**
      * Callback for use with LocalOnlyHotspot to unregister requesting applications upon death.
@@ -856,12 +856,65 @@ public class WifiServiceImpl extends IWifiManager.Stub {
         // NETWORK_STACK is a signature only permission.
         enforceNetworkStackPermission();
 
-        Integer previousMode = mIfaceIpModes.put(ifaceName, mode);
-        Slog.d(TAG, "updateInterfaceIpState: ifaceName=" + ifaceName + " mode=" + mode
-                + " previous mode= " + previousMode);
+        // hand off the work to our handler thread
+        mClientHandler.post(() -> {
+            updateInterfaceIpStateInternal(ifaceName, mode);
+        });
+    }
 
-        // TODO: check the mode when startLOHS comes in in case it is already active
-        // TODO: if mode == LOCAL_ONLY, trigger onStarted callbacks
+    private void updateInterfaceIpStateInternal(String ifaceName, int mode) {
+        // update interface IP state related to tethering and hotspot
+        synchronized (mLocalOnlyHotspotRequests) {
+            // update the mode tracker here - we clear out state below
+            Integer previousMode = WifiManager.IFACE_IP_MODE_UNSPECIFIED;
+            if (ifaceName != null) {
+                previousMode = mIfaceIpModes.put(ifaceName, mode);
+            }
+            Slog.d(TAG, "updateInterfaceIpState: ifaceName=" + ifaceName + " mode=" + mode
+                    + " previous mode= " + previousMode);
+
+            switch (mode) {
+                case WifiManager.IFACE_IP_MODE_LOCAL_ONLY:
+                    // first make sure we have registered requests..  otherwise clean up
+                    if (mLocalOnlyHotspotRequests.isEmpty()) {
+                        // we don't have requests...  stop the hotspot
+                        stopSoftAp();
+                        updateInterfaceIpStateInternal(null, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
+                        return;
+                    }
+                    // LOHS is ready to go!  Call our registered requestors!
+                    sendHotspotStartedMessageToAllLOHSRequestInfoEntriesLocked();
+                    break;
+                case WifiManager.IFACE_IP_MODE_TETHERED:
+                    // we have tethered an interface. we don't really act on this now other than if
+                    // we have LOHS requests, and this is an issue.  return incompatible mode for
+                    // onFailed for the registered requestors since this can result from a race
+                    // between a tether request and a hotspot request (tethering wins).
+                    sendHotspotFailedMessageToAllLOHSRequestInfoEntriesLocked(
+                            LocalOnlyHotspotCallback.ERROR_INCOMPATIBLE_MODE);
+                    mLocalOnlyHotspotRequests.clear();
+                    break;
+                case WifiManager.IFACE_IP_MODE_CONFIGURATION_ERROR:
+                    // there was an error setting up the hotspot...  trigger onFailed for the
+                    // registered LOHS requestors
+                    sendHotspotFailedMessageToAllLOHSRequestInfoEntriesLocked(
+                            LocalOnlyHotspotCallback.ERROR_GENERIC);
+                    mLocalOnlyHotspotRequests.clear();
+                    updateInterfaceIpStateInternal(null, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
+                    break;
+                case WifiManager.IFACE_IP_MODE_UNSPECIFIED:
+                    if (ifaceName == null) {
+                        // interface name is null, this is due to softap teardown.  clear all
+                        // entries for now.
+                        // TODO: Deal with individual interfaces when we receive updates for them
+                        mIfaceIpModes.clear();
+                        return;
+                    }
+                    break;
+                default:
+                    mLog.trace("updateInterfaceIpStateInternal: unknown mode %").c(mode).flush();
+            }
+        }
     }
 
     /**
@@ -953,6 +1006,9 @@ public class WifiServiceImpl extends IWifiManager.Stub {
                 // holding the required lock: send message to requestors and clear the list
                 sendHotspotFailedMessageToAllLOHSRequestInfoEntriesLocked(
                         errorToReport);
+                // also need to clear interface ip state - send null for now since we don't know
+                // what interface (and we have one anyway)
+                updateInterfaceIpStateInternal(null, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
             }
             return;
         }
@@ -960,8 +1016,18 @@ public class WifiServiceImpl extends IWifiManager.Stub {
         if (currentState == WIFI_AP_STATE_DISABLING || currentState == WIFI_AP_STATE_DISABLED) {
             // softap is shutting down or is down...  let requestors know via the onStopped call
             synchronized (mLocalOnlyHotspotRequests) {
-                // holding the required lock: send message to requestors and clear the list
-                sendHotspotStoppedMessageToAllLOHSRequestInfoEntriesLocked();
+                // if we are currently in hotspot mode, then trigger onStopped for registered
+                // requestors, otherwise something odd happened and we should clear state
+                if (mIfaceIpModes.contains(WifiManager.IFACE_IP_MODE_LOCAL_ONLY)) {
+                    // holding the required lock: send message to requestors and clear the list
+                    sendHotspotStoppedMessageToAllLOHSRequestInfoEntriesLocked();
+                } else {
+                    // LOHS not active: report an error (still holding the required lock)
+                    sendHotspotFailedMessageToAllLOHSRequestInfoEntriesLocked(ERROR_GENERIC);
+                }
+                // also clear interface ip state - send null for now since we don't know what
+                // interface (and we only have one anyway)
+                updateInterfaceIpState(null, WifiManager.IFACE_IP_MODE_UNSPECIFIED);
             }
             return;
         }
@@ -1078,10 +1144,40 @@ public class WifiServiceImpl extends IWifiManager.Stub {
         // check current mode to see if we can start localOnlyHotspot
         boolean apDisabled =
                 mWifiStateMachine.syncGetWifiApState() == WifiManager.WIFI_AP_STATE_DISABLED;
-        if (!apDisabled) {
-            // Tethering is enabled, cannot start LocalOnlyHotspot
-            mLog.trace("Cannot start localOnlyHotspot when WiFi Tethering is active.");
-            return LocalOnlyHotspotCallback.ERROR_INCOMPATIBLE_MODE;
+
+        synchronized (mLocalOnlyHotspotRequests) {
+            if (!apDisabled && mLocalOnlyHotspotRequests.isEmpty()) {
+                // Tethering is enabled, cannot start LocalOnlyHotspot
+                mLog.trace("Cannot start localOnlyHotspot when WiFi Tethering is active.");
+                return LocalOnlyHotspotCallback.ERROR_INCOMPATIBLE_MODE;
+            }
+
+            // does this caller already have a request?
+            LocalOnlyHotspotRequestInfo request = mLocalOnlyHotspotRequests.get(uid);
+            if (request != null) {
+                mLog.trace("caller already has an active request");
+                throw new IllegalStateException(
+                        "Caller already has an active LocalOnlyHotspot request");
+            }
+
+            // now create the new LOHS request info object
+            request = new LocalOnlyHotspotRequestInfo(binder, messenger,
+                    new LocalOnlyRequestorCallback());
+            // TODO: move this below when start is implemented
+            mLocalOnlyHotspotRequests.put(uid, request);
+
+            // check if LOHS is already active, if so, record the request and trigger the callback
+            if (mIfaceIpModes.contains(WifiManager.IFACE_IP_MODE_LOCAL_ONLY)) {
+                try {
+                    Slog.d(TAG, "LOHS already up, send started");
+                    request.sendHotspotStartedMessage(mLocalOnlyHotspotConfig);
+                    // TODO: move this return value out of the try when start is implemented
+                    return LocalOnlyHotspotCallback.REQUEST_REGISTERED;
+                } catch (RemoteException e) {
+                    mLocalOnlyHotspotRequests.remove(uid);
+                    return LocalOnlyHotspotCallback.ERROR_GENERIC;
+                }
+            }
         }
 
         throw new UnsupportedOperationException("LocalOnlyHotspot is still in development");