libbinder: add makeDefaultRpcTransportCtxFactory

Add a new OS-specific function that creates a new
instance of the default RpcTransportCtxFactory.
This is needed because Android and Trusty have
different default transports: RpcTransportRaw and
RpcTransportTipcTrusty, respectively.

Bug: 230135749
Test: presubmit
Change-Id: I4abd443fe9a08c1fa0cc41dfca7ef1cdb69fe0fb
diff --git a/libs/binder/OS.cpp b/libs/binder/OS.cpp
index cc4a03b..24ce2bb 100644
--- a/libs/binder/OS.cpp
+++ b/libs/binder/OS.cpp
@@ -17,6 +17,7 @@
 #include "OS.h"
 
 #include <android-base/file.h>
+#include <binder/RpcTransportRaw.h>
 #include <string.h>
 
 using android::base::ErrnoError;
@@ -58,4 +59,8 @@
     return OK;
 }
 
+std::unique_ptr<RpcTransportCtxFactory> makeDefaultRpcTransportCtxFactory() {
+    return RpcTransportCtxFactoryRaw::make();
+}
+
 } // namespace android
diff --git a/libs/binder/OS.h b/libs/binder/OS.h
index d6e1c78..5ab8bab 100644
--- a/libs/binder/OS.h
+++ b/libs/binder/OS.h
@@ -20,6 +20,7 @@
 
 #include <android-base/result.h>
 #include <android-base/unique_fd.h>
+#include <binder/RpcTransport.h>
 #include <utils/Errors.h>
 
 namespace android {
@@ -30,4 +31,6 @@
 
 status_t dupFileDescriptor(int oldFd, int* newFd);
 
+std::unique_ptr<RpcTransportCtxFactory> makeDefaultRpcTransportCtxFactory();
+
 } // namespace android
diff --git a/libs/binder/RpcServer.cpp b/libs/binder/RpcServer.cpp
index 49be4dd..2efd113 100644
--- a/libs/binder/RpcServer.cpp
+++ b/libs/binder/RpcServer.cpp
@@ -55,7 +55,7 @@
 sp<RpcServer> RpcServer::make(std::unique_ptr<RpcTransportCtxFactory> rpcTransportCtxFactory) {
     // Default is without TLS.
     if (rpcTransportCtxFactory == nullptr)
-        rpcTransportCtxFactory = RpcTransportCtxFactoryRaw::make();
+        rpcTransportCtxFactory = makeDefaultRpcTransportCtxFactory();
     auto ctx = rpcTransportCtxFactory->newServerCtx();
     if (ctx == nullptr) return nullptr;
     return sp<RpcServer>::make(std::move(ctx));
diff --git a/libs/binder/RpcSession.cpp b/libs/binder/RpcSession.cpp
index 8ddfa93..eee28d6 100644
--- a/libs/binder/RpcSession.cpp
+++ b/libs/binder/RpcSession.cpp
@@ -68,7 +68,7 @@
 
 sp<RpcSession> RpcSession::make() {
     // Default is without TLS.
-    return make(RpcTransportCtxFactoryRaw::make());
+    return make(makeDefaultRpcTransportCtxFactory());
 }
 
 sp<RpcSession> RpcSession::make(std::unique_ptr<RpcTransportCtxFactory> rpcTransportCtxFactory) {
diff --git a/libs/binder/trusty/OS.cpp b/libs/binder/trusty/OS.cpp
index b21fe6a..1a76da5 100644
--- a/libs/binder/trusty/OS.cpp
+++ b/libs/binder/trusty/OS.cpp
@@ -20,6 +20,8 @@
 #include <lib/rand/rand.h>
 #endif
 
+#include <binder/RpcTransportTipcTrusty.h>
+
 #include "../OS.h"
 
 using android::base::Result;
@@ -46,4 +48,8 @@
     return INVALID_OPERATION;
 }
 
+std::unique_ptr<RpcTransportCtxFactory> makeDefaultRpcTransportCtxFactory() {
+    return RpcTransportCtxFactoryTipcTrusty::make();
+}
+
 } // namespace android