Pass data usage limits to tethering offload code.

Bug: 29337859
Bug: 32163131
Test: builds
Test: OffloadControllerTest passes
Change-Id: I82d3bee030bafa8fe85855885b5fc3893e699181
diff --git a/services/core/java/com/android/server/NetworkManagementService.java b/services/core/java/com/android/server/NetworkManagementService.java
index 097202b..3d638be 100644
--- a/services/core/java/com/android/server/NetworkManagementService.java
+++ b/services/core/java/com/android/server/NetworkManagementService.java
@@ -1538,6 +1538,17 @@
             } catch (NativeDaemonConnectorException e) {
                 throw e.rethrowAsParcelableException();
             }
+
+            synchronized (mTetheringStatsProviders) {
+                for (ITetheringStatsProvider provider : mTetheringStatsProviders.keySet()) {
+                    try {
+                        provider.setInterfaceQuota(iface, quotaBytes);
+                    } catch (RemoteException e) {
+                        Log.e(TAG, "Problem setting tethering data limit on provider " +
+                                mTetheringStatsProviders.get(provider) + ": " + e);
+                    }
+                }
+            }
         }
     }
 
@@ -1564,6 +1575,17 @@
             } catch (NativeDaemonConnectorException e) {
                 throw e.rethrowAsParcelableException();
             }
+
+            synchronized (mTetheringStatsProviders) {
+                for (ITetheringStatsProvider provider : mTetheringStatsProviders.keySet()) {
+                    try {
+                        provider.setInterfaceQuota(iface, ITetheringStatsProvider.QUOTA_UNLIMITED);
+                    } catch (RemoteException e) {
+                        Log.e(TAG, "Problem removing tethering data limit on provider " +
+                                mTetheringStatsProviders.get(provider) + ": " + e);
+                    }
+                }
+            }
         }
     }
 
@@ -1823,6 +1845,11 @@
             }
             return stats;
         }
+
+        @Override
+        public void setInterfaceQuota(String iface, long quotaBytes) {
+            // Do nothing. netd is already informed of quota changes in setInterfaceQuota.
+        }
     }
 
     @Override
diff --git a/services/core/java/com/android/server/connectivity/tethering/OffloadController.java b/services/core/java/com/android/server/connectivity/tethering/OffloadController.java
index ccbac31..55e290a 100644
--- a/services/core/java/com/android/server/connectivity/tethering/OffloadController.java
+++ b/services/core/java/com/android/server/connectivity/tethering/OffloadController.java
@@ -73,9 +73,17 @@
     private Set<String> mLastLocalPrefixStrs;
 
     // Maps upstream interface names to offloaded traffic statistics.
+    // Always contains the latest value received from the hardware for each interface, regardless of
+    // whether offload is currently running on that interface.
     private HashMap<String, OffloadHardwareInterface.ForwardedStats>
             mForwardedStats = new HashMap<>();
 
+    // Maps upstream interface names to interface quotas.
+    // Always contains the latest value received from the framework for each interface, regardless
+    // of whether offload is currently running (or is even supported) on that interface. Only
+    // includes upstream interfaces that have a quota set.
+    private HashMap<String, Long> mInterfaceQuotas = new HashMap<>();
+
     public OffloadController(Handler h, OffloadHardwareInterface hwi,
             ContentResolver contentResolver, INetworkManagementService nms, SharedLog log) {
         mHandler = h;
@@ -195,6 +203,17 @@
 
             return stats;
         }
+
+        public void setInterfaceQuota(String iface, long quotaBytes) {
+            mHandler.post(() -> {
+                if (quotaBytes == ITetheringStatsProvider.QUOTA_UNLIMITED) {
+                    mInterfaceQuotas.remove(iface);
+                } else {
+                    mInterfaceQuotas.put(iface, quotaBytes);
+                }
+                maybeUpdateDataLimit(iface);
+            });
+        }
     }
 
     private void maybeUpdateStats(String iface) {
@@ -208,6 +227,22 @@
         mForwardedStats.get(iface).add(mHwInterface.getForwardedStats(iface));
     }
 
+    private boolean maybeUpdateDataLimit(String iface) {
+        // setDataLimit may only be called while offload is occuring on this upstream.
+        if (!started() ||
+                mUpstreamLinkProperties == null ||
+                !TextUtils.equals(iface, mUpstreamLinkProperties.getInterfaceName())) {
+            return true;
+        }
+
+        Long limit = mInterfaceQuotas.get(iface);
+        if (limit == null) {
+            limit = Long.MAX_VALUE;
+        }
+
+        return mHwInterface.setDataLimit(iface, limit);
+    }
+
     private void updateStatsForCurrentUpstream() {
         if (mUpstreamLinkProperties != null) {
             maybeUpdateStats(mUpstreamLinkProperties.getInterfaceName());
@@ -297,8 +332,21 @@
             }
         }
 
-        return mHwInterface.setUpstreamParameters(
+        boolean success = mHwInterface.setUpstreamParameters(
                 iface, v4addr, v4gateway, (v6gateways.isEmpty() ? null : v6gateways));
+
+        if (!success) {
+           return success;
+        }
+
+        // Data limits can only be set once offload is running on the upstream.
+        success = maybeUpdateDataLimit(iface);
+        if (!success) {
+            mLog.log("Setting data limit for " + iface + " failed, disabling offload.");
+            stop();
+        }
+
+        return success;
     }
 
     private boolean computeAndPushLocalPrefixes() {
diff --git a/services/core/java/com/android/server/connectivity/tethering/OffloadHardwareInterface.java b/services/core/java/com/android/server/connectivity/tethering/OffloadHardwareInterface.java
index 4df566f..86ff0a6 100644
--- a/services/core/java/com/android/server/connectivity/tethering/OffloadHardwareInterface.java
+++ b/services/core/java/com/android/server/connectivity/tethering/OffloadHardwareInterface.java
@@ -188,6 +188,27 @@
         return results.success;
     }
 
+    public boolean setDataLimit(String iface, long limit) {
+
+        final String logmsg = String.format("setDataLimit(%s, %d)", iface, limit);
+
+        final CbResults results = new CbResults();
+        try {
+            mOffloadControl.setDataLimit(
+                    iface, limit,
+                    (boolean success, String errMsg) -> {
+                        results.success = success;
+                        results.errMsg = errMsg;
+                    });
+        } catch (RemoteException e) {
+            record(logmsg, e);
+            return false;
+        }
+
+        record(logmsg, results);
+        return results.success;
+    }
+
     public boolean setUpstreamParameters(
             String iface, String v4addr, String v4gateway, ArrayList<String> v6gws) {
         iface = (iface != null) ? iface : NO_INTERFACE_NAME;