Introduce netd_client, a dynamic library that talks to netd.
The library exists outside bionic. It is dynamically loaded, to replace selected
standard socket syscalls with versions that talk to netd.
Change connect() to use the library if available.
(cherry picked from commit 3a6b627a14df8111b03e452f2df4b5f4938e0e49)
Change-Id: Ib6198e19dbc306521a26fcecfdf6e8424d163fc9
diff --git a/libc/bionic/NetdClient.cpp b/libc/bionic/NetdClient.cpp
new file mode 100644
index 0000000..56d8244
--- /dev/null
+++ b/libc/bionic/NetdClient.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2014 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 <private/NetdClient.h>
+#include <private/libc_logging.h>
+#include <pthread.h>
+
+#ifdef __i386__
+#define __socketcall __attribute__((__cdecl__))
+#else
+#define __socketcall
+#endif
+
+extern "C" __socketcall int __connect(int, const sockaddr*, socklen_t);
+
+NetdClientDispatch __netdClientDispatch __attribute__((aligned(32))) = {
+ __connect
+};
+
+#ifndef LIBC_STATIC
+
+#include <dlfcn.h>
+
+template <typename FunctionType>
+static void netdClientInitFunction(void* handle, const char* symbol, FunctionType* function) {
+ typedef void (*InitFunctionType)(FunctionType*);
+ InitFunctionType initFunction = reinterpret_cast<InitFunctionType>(dlsym(handle, symbol));
+ if (initFunction != NULL) {
+ initFunction(function);
+ }
+}
+
+static void netdClientInitImpl() {
+ void* netdClientHandle = dlopen("libnetd_client.so", RTLD_LAZY);
+ if (netdClientHandle == NULL) {
+ // If the library is not available, it's not an error. We'll just use
+ // default implementations of functions that it would've overridden.
+ return;
+ }
+ netdClientInitFunction(netdClientHandle, "netdClientInitConnect",
+ &__netdClientDispatch.connect);
+}
+
+static pthread_once_t netdClientInitOnce = PTHREAD_ONCE_INIT;
+
+#endif // LIBC_STATIC
+
+extern "C" __LIBC_HIDDEN__ void netdClientInit() {
+#ifndef LIBC_STATIC
+ if (pthread_once(&netdClientInitOnce, netdClientInitImpl)) {
+ __libc_format_log(ANDROID_LOG_ERROR, "netdClient",
+ "Unable to initialize netd_client component.");
+ }
+#endif // LIBC_STATIC
+}