Binder unique_fd
Test: mma
Bug: 302723053
Change-Id: I52f14cadb027b3f854946d5315dce3d23aa21b19
diff --git a/libs/binder/FdUtils.h b/libs/binder/FdUtils.h
new file mode 100644
index 0000000..52ae487
--- /dev/null
+++ b/libs/binder/FdUtils.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <binder/unique_fd.h>
+
+#if defined(_WIN32) || defined(__TRUSTY__)
+// Pipe and Socketpair are missing there
+#elif !defined(BINDER_NO_LIBBASE)
+
+namespace android::binder {
+using android::base::Pipe;
+using android::base::Socketpair;
+} // namespace android::binder
+
+#else // BINDER_NO_LIBBASE
+
+#include <sys/socket.h>
+
+namespace android::binder {
+
+// Inline functions, so that they can be used header-only.
+
+// See pipe(2).
+// This helper hides the details of converting to unique_fd, and also hides the
+// fact that macOS doesn't support O_CLOEXEC or O_NONBLOCK directly.
+inline bool Pipe(unique_fd* read, unique_fd* write, int flags = O_CLOEXEC) {
+ int pipefd[2];
+
+#if defined(__APPLE__)
+ if (flags & ~(O_CLOEXEC | O_NONBLOCK)) {
+ return false;
+ }
+ if (pipe(pipefd) != 0) {
+ return false;
+ }
+
+ if (flags & O_CLOEXEC) {
+ if (fcntl(pipefd[0], F_SETFD, FD_CLOEXEC) != 0 ||
+ fcntl(pipefd[1], F_SETFD, FD_CLOEXEC) != 0) {
+ close(pipefd[0]);
+ close(pipefd[1]);
+ return false;
+ }
+ }
+ if (flags & O_NONBLOCK) {
+ if (fcntl(pipefd[0], F_SETFL, O_NONBLOCK) != 0 ||
+ fcntl(pipefd[1], F_SETFL, O_NONBLOCK) != 0) {
+ close(pipefd[0]);
+ close(pipefd[1]);
+ return false;
+ }
+ }
+#else
+ if (pipe2(pipefd, flags) != 0) {
+ return false;
+ }
+#endif
+
+ read->reset(pipefd[0]);
+ write->reset(pipefd[1]);
+ return true;
+}
+
+// See socketpair(2).
+// This helper hides the details of converting to unique_fd.
+inline bool Socketpair(int domain, int type, int protocol, unique_fd* left, unique_fd* right) {
+ int sockfd[2];
+ if (socketpair(domain, type, protocol, sockfd) != 0) {
+ return false;
+ }
+ left->reset(sockfd[0]);
+ right->reset(sockfd[1]);
+ return true;
+}
+
+// See socketpair(2).
+// This helper hides the details of converting to unique_fd.
+inline bool Socketpair(int type, unique_fd* left, unique_fd* right) {
+ return Socketpair(AF_UNIX, type, 0, left, right);
+}
+
+} // namespace android::binder
+
+#endif // BINDER_NO_LIBBASE