You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

257 lines
8.8 KiB

/*
* 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) {
ALOGE("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;
}