binder: Add FD support to RPC Binder

Bug: 185909244
Test: TH
Change-Id: Ic4fc1b1edfe9d69984e785553cd1aaca97a07da3
diff --git a/libs/binder/RpcSession.cpp b/libs/binder/RpcSession.cpp
index 7ba08ed..41842a7 100644
--- a/libs/binder/RpcSession.cpp
+++ b/libs/binder/RpcSession.cpp
@@ -129,6 +129,14 @@
     return mProtocolVersion;
 }
 
+void RpcSession::setFileDescriptorTransportMode(FileDescriptorTransportMode mode) {
+    mFileDescriptorTransportMode = mode;
+}
+
+RpcSession::FileDescriptorTransportMode RpcSession::getFileDescriptorTransportMode() {
+    return mFileDescriptorTransportMode;
+}
+
 status_t RpcSession::setupUnixDomainClient(const char* path) {
     return setupSocketClient(UnixSocketAddress(path));
 }
@@ -606,6 +614,7 @@
     RpcConnectionHeader header{
             .version = mProtocolVersion.value_or(RPC_WIRE_PROTOCOL_VERSION),
             .options = 0,
+            .fileDescriptorTransportMode = static_cast<uint8_t>(mFileDescriptorTransportMode),
             .sessionIdSize = static_cast<uint16_t>(sessionId.size()),
     };
 
@@ -614,8 +623,8 @@
     }
 
     iovec headerIov{&header, sizeof(header)};
-    auto sendHeaderStatus =
-            server->interruptableWriteFully(mShutdownTrigger.get(), &headerIov, 1, std::nullopt);
+    auto sendHeaderStatus = server->interruptableWriteFully(mShutdownTrigger.get(), &headerIov, 1,
+                                                            std::nullopt, nullptr);
     if (sendHeaderStatus != OK) {
         ALOGE("Could not write connection header to socket: %s",
               statusToString(sendHeaderStatus).c_str());
@@ -625,8 +634,9 @@
     if (sessionId.size() > 0) {
         iovec sessionIov{const_cast<void*>(static_cast<const void*>(sessionId.data())),
                          sessionId.size()};
-        auto sendSessionIdStatus = server->interruptableWriteFully(mShutdownTrigger.get(),
-                                                                   &sessionIov, 1, std::nullopt);
+        auto sendSessionIdStatus =
+                server->interruptableWriteFully(mShutdownTrigger.get(), &sessionIov, 1,
+                                                std::nullopt, nullptr);
         if (sendSessionIdStatus != OK) {
             ALOGE("Could not write session ID ('%s') to socket: %s",
                   base::HexString(sessionId.data(), sessionId.size()).c_str(),