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#ifdef LIBC_STATIC
18#error NetdClient.cpp should NOT be included in static libc builds.
19#endif
20
21#include "private/libc_logging.h"
22#include "private/NetdClientDispatch.h"
23
24#include <dlfcn.h>
25#include <pthread.h>
26
27template <typename FunctionType>
28static void netdClientInitFunction(void* handle, const char* symbol, FunctionType* function) {
29    typedef void (*InitFunctionType)(FunctionType*);
30    InitFunctionType initFunction = reinterpret_cast<InitFunctionType>(dlsym(handle, symbol));
31    if (initFunction != NULL) {
32        initFunction(function);
33    }
34}
35
36static void netdClientInitImpl() {
37    void* netdClientHandle = dlopen("libnetd_client.so", RTLD_NOW);
38    if (netdClientHandle == NULL) {
39        // If the library is not available, it's not an error. We'll just use
40        // default implementations of functions that it would've overridden.
41        return;
42    }
43    netdClientInitFunction(netdClientHandle, "netdClientInitAccept4",
44                           &__netdClientDispatch.accept4);
45    netdClientInitFunction(netdClientHandle, "netdClientInitConnect",
46                           &__netdClientDispatch.connect);
47    netdClientInitFunction(netdClientHandle, "netdClientInitNetIdForResolv",
48                           &__netdClientDispatch.netIdForResolv);
49    netdClientInitFunction(netdClientHandle, "netdClientInitSocket", &__netdClientDispatch.socket);
50}
51
52static pthread_once_t netdClientInitOnce = PTHREAD_ONCE_INIT;
53
54extern "C" __LIBC_HIDDEN__ void netdClientInit() {
55    if (pthread_once(&netdClientInitOnce, netdClientInitImpl)) {
56        __libc_format_log(ANDROID_LOG_ERROR, "netdClient", "Failed to initialize netd_client");
57    }
58}
59