3 files changed, 22 insertions, 0 deletions
diff --git a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
index 7932d0f29c..0309d6ca53 100644
--- a/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
+++ b/libs/binder/include_rpc_unstable/binder_rpc_unstable.hpp
@@ -23,4 +23,13 @@ struct AIBinder;
 bool RunRpcServer(AIBinder* service, unsigned int port);
 AIBinder* RpcClient(unsigned int cid, unsigned int port);
 
+// Connect to an RPC server with preconnected file descriptors.
+//
+// requestFd should connect to the server and return a valid file descriptor, or
+// -1 if connection fails.
+//
+// param will be passed to requestFd. Callers can use param to pass contexts to
+// the requestFd function.
+AIBinder* RpcPreconnectedClient(int (*requestFd)(void* param), void* param);
+
 }
diff --git a/libs/binder/libbinder_rpc_unstable.cpp b/libs/binder/libbinder_rpc_unstable.cpp
index bcb13aebdd..304415a7ce 100644
--- a/libs/binder/libbinder_rpc_unstable.cpp
+++ b/libs/binder/libbinder_rpc_unstable.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <android-base/logging.h>
+#include <android-base/unique_fd.h>
 #include <android/binder_libbinder.h>
 #include <binder/RpcServer.h>
 #include <binder/RpcSession.h>
@@ -24,6 +25,7 @@ using android::RpcServer;
 using android::RpcSession;
 using android::status_t;
 using android::statusToString;
+using android::base::unique_fd;
 
 extern "C" {
 
@@ -52,4 +54,14 @@ AIBinder* RpcClient(unsigned int cid, unsigned int port) {
     }
     return AIBinder_fromPlatformBinder(session->getRootObject());
 }
+
+AIBinder* RpcPreconnectedClient(int (*requestFd)(void* param), void* param) {
+    auto session = RpcSession::make();
+    auto request = [=] { return unique_fd{requestFd(param)}; };
+    if (status_t status = session->setupPreconnectedClient(unique_fd{}, request); status != OK) {
+        LOG(ERROR) << "Failed to set up vsock client. error: " << statusToString(status).c_str();
+        return nullptr;
+    }
+    return AIBinder_fromPlatformBinder(session->getRootObject());
+}
 }
diff --git a/libs/binder/libbinder_rpc_unstable.map.txt b/libs/binder/libbinder_rpc_unstable.map.txt
index 3921a4dde8..1138786a64 100644
--- a/libs/binder/libbinder_rpc_unstable.map.txt
+++ b/libs/binder/libbinder_rpc_unstable.map.txt
@@ -2,6 +2,7 @@ LIBBINDER_RPC_UNSTABLE_SHIM { # platform-only
   global:
     RunRpcServer;
     RpcClient;
+    RpcPreconnectedClient;
   local:
     *;
 };