1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "FileDescriptor"
18
19#include "JniConstants.h"
20
21#include <sys/socket.h>
22#include <sys/types.h>
23
24static jboolean FileDescriptor_isSocket(JNIEnv*, jclass, jint fd) {
25  // If getsockopt succeeds, we know we're dealing with a socket.
26  // This is the cheapest way we know of to test whether an fd is a socket.
27  int option;
28  socklen_t option_length = sizeof(option);
29  return TEMP_FAILURE_RETRY(getsockopt(fd, SOL_SOCKET, SO_DEBUG, &option, &option_length)) == 0;
30}
31
32static JNINativeMethod gMethods[] = {
33  NATIVE_METHOD(FileDescriptor, isSocket, "(I)Z"),
34};
35void register_java_io_FileDescriptor(JNIEnv* env) {
36  jniRegisterNativeMethods(env, "java/io/FileDescriptor", gMethods, NELEM(gMethods));
37}
38