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
27 template <typename FunctionType>
netdClientInitFunction(void * handle,const char * symbol,FunctionType * function)28 static 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
netdClientInitImpl()36 static 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
52 static pthread_once_t netdClientInitOnce = PTHREAD_ONCE_INIT;
53
netdClientInit()54 extern "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