1 /*
2 * Copyright (C) 2017 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 "vndksupport"
18
19 #include "linker.h"
20
21 #include <android/dlext.h>
22 #include <dlfcn.h>
23 #include <log/log.h>
24 #include <sys/types.h>
25 #include <unistd.h>
26
27 #include <initializer_list>
28
29 extern "C" android_namespace_t* android_get_exported_namespace(const char*);
30
31 namespace {
32
33 struct VendorNamespace {
34 android_namespace_t* ptr = nullptr;
35 const char* name = nullptr;
36 };
37
38 } // anonymous namespace
39
get_vendor_namespace()40 static VendorNamespace get_vendor_namespace() {
41 static VendorNamespace result = ([] {
42 for (const char* name : {"sphal", "vendor", "default"}) {
43 if (android_namespace_t* ns = android_get_exported_namespace(name)) {
44 return VendorNamespace{ns, name};
45 }
46 }
47 return VendorNamespace{};
48 })();
49 return result;
50 }
51
android_is_in_vendor_process()52 int android_is_in_vendor_process() {
53 // Special case init, since when init runs, ld.config.<ver>.txt hasn't been
54 // loaded (sysprop service isn't up for init to know <ver>).
55 if (getpid() == 1) {
56 return 0;
57 }
58
59 // In vendor process, 'vndk' namespace is not visible, whereas in system
60 // process, it is.
61 return android_get_exported_namespace("vndk") == nullptr;
62 }
63
android_load_sphal_library(const char * name,int flag)64 void* android_load_sphal_library(const char* name, int flag) {
65 VendorNamespace vendor_namespace = get_vendor_namespace();
66 if (vendor_namespace.ptr != nullptr) {
67 const android_dlextinfo dlextinfo = {
68 .flags = ANDROID_DLEXT_USE_NAMESPACE,
69 .library_namespace = vendor_namespace.ptr,
70 };
71 void* handle = android_dlopen_ext(name, flag, &dlextinfo);
72 if (!handle) {
73 ALOGE("Could not load %s from %s namespace: %s.", name, vendor_namespace.name,
74 dlerror());
75 }
76 return handle;
77 } else {
78 ALOGW("Loading %s from current namespace instead of sphal namespace.", name);
79 return dlopen(name, flag);
80 }
81 }
82
android_unload_sphal_library(void * handle)83 int android_unload_sphal_library(void* handle) {
84 return dlclose(handle);
85 }
86