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 #include "linker.h"
17
18 #include <android/dlext.h>
19 #include <dlfcn.h>
20
21 #define LOG_TAG "vndksupport"
22 #include <log/log.h>
23 #include <sys/types.h>
24 #include <unistd.h>
25
26 __attribute__((weak)) extern struct android_namespace_t* android_get_exported_namespace(const char*);
27 __attribute__((weak)) extern void* android_dlopen_ext(const char*, int, const android_dlextinfo*);
28
29 static const char* namespace_name = NULL;
30
get_vendor_namespace()31 static struct android_namespace_t* get_vendor_namespace() {
32 const char* namespace_names[] = {"sphal", "default", NULL};
33 static struct android_namespace_t* vendor_namespace = NULL;
34 if (vendor_namespace == NULL) {
35 int name_idx = 0;
36 while (namespace_names[name_idx] != NULL) {
37 if (android_get_exported_namespace != NULL) {
38 vendor_namespace = android_get_exported_namespace(namespace_names[name_idx]);
39 }
40 if (vendor_namespace != NULL) {
41 namespace_name = namespace_names[name_idx];
42 break;
43 }
44 name_idx++;
45 }
46 }
47 return vendor_namespace;
48 }
49
android_is_in_vendor_process()50 int android_is_in_vendor_process() {
51 // Special case init, since when init runs, ld.config.<ver>.txt hasn't been
52 // loaded (sysprop service isn't up for init to know <ver>).
53 if (getpid() == 1) {
54 return 0;
55 }
56 if (android_get_exported_namespace == NULL) {
57 ALOGD("android_get_exported_namespace() not available. Assuming system process.");
58 return 0;
59 }
60
61 // In vendor process, 'vndk' namespace is not visible, whereas in system
62 // process, it is.
63 return android_get_exported_namespace("vndk") == NULL;
64 }
65
android_load_sphal_library(const char * name,int flag)66 void* android_load_sphal_library(const char* name, int flag) {
67 struct android_namespace_t* vendor_namespace = get_vendor_namespace();
68 if (vendor_namespace != NULL) {
69 const android_dlextinfo dlextinfo = {
70 .flags = ANDROID_DLEXT_USE_NAMESPACE, .library_namespace = vendor_namespace,
71 };
72 void* handle = NULL;
73 if (android_dlopen_ext != NULL) {
74 handle = android_dlopen_ext(name, flag, &dlextinfo);
75 }
76 if (!handle) {
77 ALOGE("Could not load %s from %s namespace: %s.", name, namespace_name, dlerror());
78 }
79 return handle;
80 } else {
81 ALOGD("Loading %s from current namespace instead of sphal namespace.", name);
82 return dlopen(name, flag);
83 }
84 }
85
android_unload_sphal_library(void * handle)86 int android_unload_sphal_library(void* handle) {
87 return dlclose(handle);
88 }
89