binder: add openDeclaredPassthroughHal()

It handles dlopen()ing a declared native hal. This can replace
android_load_sphal_library to load declared native instance. The new API
also supports when instances are from APEX.

Bug: 316051788
Test: atest servicemanager_test
Test: atest vts_treble_vintf_vendor_test
Change-Id: I95b752253e0b550d38f0543ff56134d38d838855
diff --git a/libs/binder/ndk/include_platform/android/binder_manager.h b/libs/binder/ndk/include_platform/android/binder_manager.h
index 316a79c..b34b30d 100644
--- a/libs/binder/ndk/include_platform/android/binder_manager.h
+++ b/libs/binder/ndk/include_platform/android/binder_manager.h
@@ -243,6 +243,18 @@
         __INTRODUCED_IN(__ANDROID_API_U__);
 
 /**
+ * Opens a declared passthrough HAL.
+ *
+ * \param instance identifier of the passthrough service (e.g. "mapper")
+ * \param instance identifier of the implemenatation (e.g. "default")
+ * \param flag passed to dlopen()
+ */
+void* AServiceManager_openDeclaredPassthroughHal(const char* interface, const char* instance,
+                                                 int flag)
+        // TODO(b/302113279) use __INTRODUCED_LLNDK for vendor variants
+        __INTRODUCED_IN(__ANDROID_API_V__);
+
+/**
  * Prevent lazy services without client from shutting down their process
  *
  * This should only be used if it is every eventually set to false. If a
diff --git a/libs/binder/ndk/libbinder_ndk.map.txt b/libs/binder/ndk/libbinder_ndk.map.txt
index 0843a8e..de624e4 100644
--- a/libs/binder/ndk/libbinder_ndk.map.txt
+++ b/libs/binder/ndk/libbinder_ndk.map.txt
@@ -204,6 +204,7 @@
     APersistableBundle_getDoubleVectorKeys;
     APersistableBundle_getStringVectorKeys;
     APersistableBundle_getPersistableBundleKeys;
+    AServiceManager_openDeclaredPassthroughHal; # systemapi llndk
 };
 
 LIBBINDER_NDK_PLATFORM {
diff --git a/libs/binder/ndk/service_manager.cpp b/libs/binder/ndk/service_manager.cpp
index 3bfdc59..5529455 100644
--- a/libs/binder/ndk/service_manager.cpp
+++ b/libs/binder/ndk/service_manager.cpp
@@ -200,6 +200,13 @@
         callback(String8(updatableViaApex.value()).c_str(), context);
     }
 }
+void* AServiceManager_openDeclaredPassthroughHal(const char* interface, const char* instance,
+                                                 int flag) {
+    LOG_ALWAYS_FATAL_IF(interface == nullptr, "interface == nullptr");
+    LOG_ALWAYS_FATAL_IF(instance == nullptr, "instance == nullptr");
+
+    return openDeclaredPassthroughHal(String16(interface), String16(instance), flag);
+}
 void AServiceManager_forceLazyServicesPersist(bool persist) {
     auto serviceRegistrar = android::binder::LazyServiceRegistrar::getInstance();
     serviceRegistrar.forcePersist(persist);