| /* |
| * 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. |
| */ |
| |
| // Uncomment for verbose logging. |
| // #define LOG_NDEBUG 0 |
| #define LOG_TAG "webviewchromiumloader" |
| |
| #include <dlfcn.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <sys/mman.h> |
| #include <sys/prctl.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| |
| #include <jni.h> |
| #include <android/dlext.h> |
| #include <nativeloader/native_loader.h> |
| #include <utils/Log.h> |
| |
| #define NELEM(x) ((int) (sizeof(x) / sizeof((x)[0]))) |
| |
| namespace android { |
| namespace { |
| |
| void* gReservedAddress = NULL; |
| size_t gReservedSize = 0; |
| |
| jint LIBLOAD_SUCCESS; |
| jint LIBLOAD_FAILED_TO_OPEN_RELRO_FILE; |
| jint LIBLOAD_FAILED_TO_LOAD_LIBRARY; |
| jint LIBLOAD_FAILED_JNI_CALL; |
| jint LIBLOAD_FAILED_TO_FIND_NAMESPACE; |
| |
| jboolean DoReserveAddressSpace(jlong size) { |
| size_t vsize = static_cast<size_t>(size); |
| |
| void* addr = mmap(NULL, vsize, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
| if (addr == MAP_FAILED) { |
| ALOGE("Failed to reserve %zd bytes of address space for future load of " |
| "libwebviewchromium.so: %s", |
| vsize, strerror(errno)); |
| return JNI_FALSE; |
| } |
| prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, addr, vsize, "libwebview reservation"); |
| gReservedAddress = addr; |
| gReservedSize = vsize; |
| ALOGV("Reserved %zd bytes at %p", vsize, addr); |
| return JNI_TRUE; |
| } |
| |
| jboolean DoCreateRelroFile(JNIEnv* env, const char* lib, const char* relro, |
| jobject clazzLoader) { |
| // Try to unlink the old file, since if this is being called, the old one is |
| // obsolete. |
| if (unlink(relro) != 0 && errno != ENOENT) { |
| // If something went wrong other than the file not existing, log a warning |
| // but continue anyway in the hope that we can successfully overwrite the |
| // existing file with rename() later. |
| ALOGW("Failed to unlink old file %s: %s", relro, strerror(errno)); |
| } |
| static const char tmpsuffix[] = ".XXXXXX"; |
| char relro_tmp[strlen(relro) + sizeof(tmpsuffix)]; |
| strlcpy(relro_tmp, relro, sizeof(relro_tmp)); |
| strlcat(relro_tmp, tmpsuffix, sizeof(relro_tmp)); |
| int tmp_fd = TEMP_FAILURE_RETRY(mkstemp(relro_tmp)); |
| if (tmp_fd == -1) { |
| ALOGE("Failed to create temporary file %s: %s", relro_tmp, strerror(errno)); |
| return JNI_FALSE; |
| } |
| android_namespace_t* ns = |
| android::FindNamespaceByClassLoader(env, clazzLoader); |
| if (ns == NULL) { |
| ALOGE("Failed to find classloader namespace"); |
| return JNI_FALSE; |
| } |
| android_dlextinfo extinfo; |
| extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS | ANDROID_DLEXT_WRITE_RELRO | |
| ANDROID_DLEXT_USE_NAMESPACE | |
| ANDROID_DLEXT_RESERVED_ADDRESS_RECURSIVE; |
| extinfo.reserved_addr = gReservedAddress; |
| extinfo.reserved_size = gReservedSize; |
| extinfo.relro_fd = tmp_fd; |
| extinfo.library_namespace = ns; |
| void* handle = android_dlopen_ext(lib, RTLD_NOW, &extinfo); |
| int close_result = close(tmp_fd); |
| if (handle == NULL) { |
| ALOGE("Failed to load library %s: %s", lib, dlerror()); |
| unlink(relro_tmp); |
| return JNI_FALSE; |
| } |
| if (close_result != 0 || |
| chmod(relro_tmp, S_IRUSR | S_IRGRP | S_IROTH) != 0 || |
| rename(relro_tmp, relro) != 0) { |
| ALOGE("Failed to update relro file %s: %s", relro, strerror(errno)); |
| unlink(relro_tmp); |
| return JNI_FALSE; |
| } |
| ALOGV("Created relro file %s for library %s", relro, lib); |
| return JNI_TRUE; |
| } |
| |
| jint DoLoadWithRelroFile(JNIEnv* env, const char* lib, const char* relro, |
| jobject clazzLoader) { |
| int relro_fd = TEMP_FAILURE_RETRY(open(relro, O_RDONLY)); |
| if (relro_fd == -1) { |
| ALOGW("Failed to open relro file %s: %s", relro, strerror(errno)); |
| return LIBLOAD_FAILED_TO_OPEN_RELRO_FILE; |
| } |
| android_namespace_t* ns = |
| android::FindNamespaceByClassLoader(env, clazzLoader); |
| if (ns == NULL) { |
| ALOGE("Failed to find classloader namespace"); |
| return LIBLOAD_FAILED_TO_FIND_NAMESPACE; |
| } |
| android_dlextinfo extinfo; |
| extinfo.flags = ANDROID_DLEXT_RESERVED_ADDRESS | ANDROID_DLEXT_USE_RELRO | |
| ANDROID_DLEXT_USE_NAMESPACE | |
| ANDROID_DLEXT_RESERVED_ADDRESS_RECURSIVE; |
| extinfo.reserved_addr = gReservedAddress; |
| extinfo.reserved_size = gReservedSize; |
| extinfo.relro_fd = relro_fd; |
| extinfo.library_namespace = ns; |
| void* handle = android_dlopen_ext(lib, RTLD_NOW, &extinfo); |
| close(relro_fd); |
| if (handle == NULL) { |
| ALOGE("Failed to load library %s: %s", lib, dlerror()); |
| return LIBLOAD_FAILED_TO_LOAD_LIBRARY; |
| } |
| ALOGV("Loaded library %s with relro file %s", lib, relro); |
| return LIBLOAD_SUCCESS; |
| } |
| |
| /******************************************************************************/ |
| /* JNI wrappers - handle string lifetimes and 32/64 ABI choice */ |
| /******************************************************************************/ |
| |
| jboolean ReserveAddressSpace(JNIEnv*, jclass, jlong size) { |
| return DoReserveAddressSpace(size); |
| } |
| |
| jboolean CreateRelroFile(JNIEnv* env, jclass, jstring lib, jstring relro, |
| jobject clazzLoader) { |
| jboolean ret = JNI_FALSE; |
| const char* lib_utf8 = env->GetStringUTFChars(lib, NULL); |
| if (lib_utf8 != NULL) { |
| const char* relro_utf8 = env->GetStringUTFChars(relro, NULL); |
| if (relro_utf8 != NULL) { |
| ret = DoCreateRelroFile(env, lib_utf8, relro_utf8, clazzLoader); |
| env->ReleaseStringUTFChars(relro, relro_utf8); |
| } |
| env->ReleaseStringUTFChars(lib, lib_utf8); |
| } |
| return ret; |
| } |
| |
| jint LoadWithRelroFile(JNIEnv* env, jclass, jstring lib, jstring relro, |
| jobject clazzLoader) { |
| jint ret = LIBLOAD_FAILED_JNI_CALL; |
| const char* lib_utf8 = env->GetStringUTFChars(lib, NULL); |
| if (lib_utf8 != NULL) { |
| const char* relro_utf8 = env->GetStringUTFChars(relro, NULL); |
| if (relro_utf8 != NULL) { |
| ret = DoLoadWithRelroFile(env, lib_utf8, relro_utf8, clazzLoader); |
| env->ReleaseStringUTFChars(relro, relro_utf8); |
| } |
| env->ReleaseStringUTFChars(lib, lib_utf8); |
| } |
| return ret; |
| } |
| |
| const char kWebViewFactoryClassName[] = "android/webkit/WebViewFactory"; |
| const char kWebViewLibraryLoaderClassName[] = |
| "android/webkit/WebViewLibraryLoader"; |
| const JNINativeMethod kJniMethods[] = { |
| { "nativeReserveAddressSpace", "(J)Z", |
| reinterpret_cast<void*>(ReserveAddressSpace) }, |
| { "nativeCreateRelroFile", |
| "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/ClassLoader;)Z", |
| reinterpret_cast<void*>(CreateRelroFile) }, |
| { "nativeLoadWithRelroFile", |
| "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/ClassLoader;)I", |
| reinterpret_cast<void*>(LoadWithRelroFile) }, |
| }; |
| |
| } // namespace |
| |
| void RegisterWebViewFactory(JNIEnv* env) { |
| // If either of these fail, it will set an exception that will be thrown on |
| // return, so no need to handle errors here. |
| jclass clazz = env->FindClass(kWebViewFactoryClassName); |
| if (clazz) { |
| LIBLOAD_SUCCESS = env->GetStaticIntField( |
| clazz, |
| env->GetStaticFieldID(clazz, "LIBLOAD_SUCCESS", "I")); |
| |
| LIBLOAD_FAILED_TO_OPEN_RELRO_FILE = env->GetStaticIntField( |
| clazz, |
| env->GetStaticFieldID(clazz, "LIBLOAD_FAILED_TO_OPEN_RELRO_FILE", "I")); |
| |
| LIBLOAD_FAILED_TO_LOAD_LIBRARY = env->GetStaticIntField( |
| clazz, |
| env->GetStaticFieldID(clazz, "LIBLOAD_FAILED_TO_LOAD_LIBRARY", "I")); |
| |
| LIBLOAD_FAILED_JNI_CALL = env->GetStaticIntField( |
| clazz, |
| env->GetStaticFieldID(clazz, "LIBLOAD_FAILED_JNI_CALL", "I")); |
| |
| LIBLOAD_FAILED_TO_FIND_NAMESPACE = env->GetStaticIntField( |
| clazz, |
| env->GetStaticFieldID(clazz, "LIBLOAD_FAILED_TO_FIND_NAMESPACE", "I")); |
| } |
| } |
| |
| void RegisterWebViewLibraryLoader(JNIEnv* env) { |
| // If either of these fail, it will set an exception that will be thrown on |
| // return, so no need to handle errors here. |
| jclass clazz = env->FindClass(kWebViewLibraryLoaderClassName); |
| if (clazz) { |
| env->RegisterNatives(clazz, kJniMethods, NELEM(kJniMethods)); |
| } |
| } |
| |
| } // namespace android |
| |
| JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void*) { |
| JNIEnv* env = NULL; |
| if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) { |
| ALOGE("GetEnv failed"); |
| return JNI_ERR; |
| } |
| android::RegisterWebViewFactory(env); |
| // Ensure there isn't a pending Java exception before registering methods from |
| // WebViewLibraryLoader |
| if (!env->ExceptionCheck()) { |
| android::RegisterWebViewLibraryLoader(env); |
| } |
| return JNI_VERSION_1_6; |
| } |