From 7c0b79f00a17e0a284b519418655c539dc0f3940 Mon Sep 17 00:00:00 2001
From: Andrei Homescu <ahomescu@google.com>
Date: Thu, 30 Jun 2022 02:00:46 +0000
Subject: libbinder: separate OS-specific code from Utils.cpp

Separate the OS-specific functions setNonBlocking and
getRandomBytes from Utils.cpp into a separate OS-specific
OS.cpp file that other operating systems can override at
build time.

Bug: 224644083
Test: build Trusty
Change-Id: I2703fb81d4370b5f6264556ae57fdddb0573971a
---
 libs/binder/OS.cpp | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 libs/binder/OS.cpp

(limited to 'libs/binder/OS.cpp')

diff --git a/libs/binder/OS.cpp b/libs/binder/OS.cpp
new file mode 100644
index 0000000000..6eb72726f5
--- /dev/null
+++ b/libs/binder/OS.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2022 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.
+ */
+
+#include "OS.h"
+
+#include <android-base/file.h>
+#include <string.h>
+
+using android::base::ErrnoError;
+using android::base::Result;
+
+namespace android {
+
+Result<void> setNonBlocking(android::base::borrowed_fd fd) {
+    int flags = TEMP_FAILURE_RETRY(fcntl(fd.get(), F_GETFL));
+    if (flags == -1) {
+        return ErrnoError() << "Could not get flags for fd";
+    }
+    if (int ret = TEMP_FAILURE_RETRY(fcntl(fd.get(), F_SETFL, flags | O_NONBLOCK)); ret == -1) {
+        return ErrnoError() << "Could not set non-blocking flag for fd";
+    }
+    return {};
+}
+
+status_t getRandomBytes(uint8_t* data, size_t size) {
+    int ret = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY | O_CLOEXEC | O_NOFOLLOW));
+    if (ret == -1) {
+        return -errno;
+    }
+
+    base::unique_fd fd(ret);
+    if (!base::ReadFully(fd, data, size)) {
+        return -errno;
+    }
+    return OK;
+}
+
+} // namespace android
-- 
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