Merge "Reference DataSaver setting from BPF map on V+ only" into main am: 86b95d40

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2861608



Change-Id: Ia1d888c88c48e50fcfab624fd28f75e847524a53
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

DnsResolver/DnsBpfHelper.cpp

@@ -62,16 +62,24 @@ base::Result<bool> DnsBpfHelper::isUidNetworkingBlocked(uid_t uid, bool metered)
   if (isBlockedByUidRules(enabledRules.value(), uidRules)) return true;
 
   // For data saver.
-  if (!metered) return false;
+  // DataSaverEnabled map on V+ platforms is the only reliable source of information about the
+  // current data saver status. While ConnectivityService offers two ways to update this map for U
+  // and V+, the U- platform implementation can have delays, potentially leading to inaccurate
+  // results. Conversely, the V+ platform implementation is synchronized with the actual data saver
+  // state, making it a trustworthy source. Since this library primarily serves DNS resolvers,
+  // relying solely on V+ data prevents erroneous blocking of DNS queries.
+  if (android::modules::sdklevel::IsAtLeastV() && metered) {
+    // The background data setting (PENALTY_BOX_MATCH) and unrestricted data usage setting
+    // (HAPPY_BOX_MATCH) for individual apps override the system wide Data Saver setting.
+    if (uidRules & PENALTY_BOX_MATCH) return true;
+    if (uidRules & HAPPY_BOX_MATCH) return false;
 
-  // The background data setting (PENALTY_BOX_MATCH) and unrestricted data usage setting
-  // (HAPPY_BOX_MATCH) for individual apps override the system wide Data Saver setting.
-  if (uidRules & PENALTY_BOX_MATCH) return true;
-  if (uidRules & HAPPY_BOX_MATCH) return false;
+    auto dataSaverSetting = mDataSaverEnabledMap.readValue(DATA_SAVER_ENABLED_KEY);
+    RETURN_IF_RESULT_NOT_OK(dataSaverSetting);
+    return dataSaverSetting.value();
+  }
 
-  auto dataSaverSetting = mDataSaverEnabledMap.readValue(DATA_SAVER_ENABLED_KEY);
-  RETURN_IF_RESULT_NOT_OK(dataSaverSetting);
-  return dataSaverSetting.value();
+  return false;
 }
 
 }  // namespace net