mirror of
https://github.com/topjohnwu/Magisk.git
synced 2024-12-26 05:37:38 +00:00
436 lines
13 KiB
C++
436 lines
13 KiB
C++
#include <dlfcn.h>
|
|
#include <xhook.h>
|
|
#include <bitset>
|
|
|
|
#include <utils.hpp>
|
|
#include <flags.h>
|
|
#include <daemon.hpp>
|
|
|
|
#include "inject.hpp"
|
|
#include "memory.hpp"
|
|
#include "api.hpp"
|
|
|
|
using namespace std;
|
|
using jni_hook::hash_map;
|
|
using jni_hook::tree_map;
|
|
using xstring = jni_hook::string;
|
|
|
|
// Extreme verbose logging
|
|
#define VLOG(...) LOGD(__VA_ARGS__)
|
|
//#define VLOG(...)
|
|
|
|
namespace {
|
|
|
|
enum {
|
|
DENY_FLAG,
|
|
FORK_AND_SPECIALIZE,
|
|
APP_SPECIALIZE,
|
|
SERVER_SPECIALIZE,
|
|
FLAG_MAX
|
|
};
|
|
|
|
#define DCL_PRE_POST(name) \
|
|
void name##_pre(); \
|
|
void name##_post();
|
|
|
|
struct HookContext {
|
|
JNIEnv *env;
|
|
union {
|
|
SpecializeAppProcessArgs *args;
|
|
ForkSystemServerArgs *server_args;
|
|
void *raw_args;
|
|
};
|
|
const char *process;
|
|
int pid;
|
|
bitset<FLAG_MAX> flags;
|
|
|
|
HookContext() : pid(-1) {}
|
|
|
|
static void close_fds();
|
|
|
|
DCL_PRE_POST(fork)
|
|
DCL_PRE_POST(run_modules)
|
|
|
|
DCL_PRE_POST(nativeForkAndSpecialize)
|
|
DCL_PRE_POST(nativeSpecializeAppProcess)
|
|
DCL_PRE_POST(nativeForkSystemServer)
|
|
};
|
|
|
|
#undef DCL_PRE_POST
|
|
|
|
struct StringCmp {
|
|
using is_transparent = void;
|
|
bool operator()(string_view a, string_view b) const { return a < b; }
|
|
};
|
|
|
|
// Global variables
|
|
vector<tuple<const char *, const char *, void **>> *xhook_list;
|
|
map<string, vector<JNINativeMethod>, StringCmp> *jni_hook_list;
|
|
hash_map<xstring, tree_map<xstring, tree_map<xstring, void *>>> *jni_method_map;
|
|
|
|
// Current context
|
|
HookContext *g_ctx;
|
|
const JNINativeInterface *old_functions;
|
|
JNINativeInterface *new_functions;
|
|
|
|
#define HOOK_JNI(method) \
|
|
if (methods[i].name == #method##sv) { \
|
|
for (int j = 0; j < method##_methods_num; ++j) { \
|
|
if (strcmp(methods[i].signature, method##_methods[j].signature) == 0) { \
|
|
jni_hook_list->try_emplace(className).first->second.push_back(methods[i]); \
|
|
method##_orig = methods[i].fnPtr; \
|
|
newMethods[i] = method##_methods[j]; \
|
|
LOGI("zygisk: replaced %s#" #method "\n", className); \
|
|
--hook_cnt; \
|
|
break; \
|
|
} \
|
|
} \
|
|
continue; \
|
|
}
|
|
|
|
// JNI method hook definitions, auto generated
|
|
#include "jni_hooks.hpp"
|
|
|
|
#undef HOOK_JNI
|
|
|
|
jclass gClassRef;
|
|
jmethodID class_getName;
|
|
string get_class_name(JNIEnv *env, jclass clazz) {
|
|
if (!gClassRef) {
|
|
jclass cls = env->FindClass("java/lang/Class");
|
|
gClassRef = (jclass) env->NewGlobalRef(cls);
|
|
env->DeleteLocalRef(cls);
|
|
class_getName = env->GetMethodID(gClassRef, "getName", "()Ljava/lang/String;");
|
|
}
|
|
auto nameRef = (jstring) env->CallObjectMethod(clazz, class_getName);
|
|
const char *name = env->GetStringUTFChars(nameRef, nullptr);
|
|
string className(name);
|
|
env->ReleaseStringUTFChars(nameRef, name);
|
|
std::replace(className.begin(), className.end(), '.', '/');
|
|
return className;
|
|
}
|
|
|
|
// -----------------------------------------------------------------
|
|
|
|
#define DCL_HOOK_FUNC(ret, func, ...) \
|
|
ret (*old_##func)(__VA_ARGS__); \
|
|
ret new_##func(__VA_ARGS__)
|
|
|
|
jint env_RegisterNatives(
|
|
JNIEnv *env, jclass clazz, const JNINativeMethod *methods, jint numMethods) {
|
|
auto className = get_class_name(env, clazz);
|
|
VLOG("zygisk: JNIEnv->RegisterNatives [%s]\n", className.data());
|
|
auto newMethods = hookAndSaveJNIMethods(className.data(), methods, numMethods);
|
|
return old_functions->RegisterNatives(env, clazz, newMethods.get() ?: methods, numMethods);
|
|
}
|
|
|
|
DCL_HOOK_FUNC(int, jniRegisterNativeMethods,
|
|
JNIEnv *env, const char *className, const JNINativeMethod *methods, int numMethods) {
|
|
VLOG("zygisk: jniRegisterNativeMethods [%s]\n", className);
|
|
auto newMethods = hookAndSaveJNIMethods(className, methods, numMethods);
|
|
return old_jniRegisterNativeMethods(env, className, newMethods.get() ?: methods, numMethods);
|
|
}
|
|
|
|
// Skip actual fork and return cached result if applicable
|
|
DCL_HOOK_FUNC(int, fork) {
|
|
return (g_ctx && g_ctx->pid >= 0) ? g_ctx->pid : old_fork();
|
|
}
|
|
|
|
// This is the latest point where we can still connect to the magiskd main socket
|
|
DCL_HOOK_FUNC(int, selinux_android_setcontext,
|
|
uid_t uid, int isSystemServer, const char *seinfo, const char *pkgname) {
|
|
if (g_ctx && g_ctx->flags[DENY_FLAG]) {
|
|
if (remote_request_unmount() == 0) {
|
|
LOGD("zygisk: mount namespace cleaned up\n");
|
|
}
|
|
}
|
|
return old_selinux_android_setcontext(uid, isSystemServer, seinfo, pkgname);
|
|
}
|
|
|
|
// A place to clean things up before calling into zygote::ForkCommon/SpecializeCommon
|
|
DCL_HOOK_FUNC(void, android_log_close) {
|
|
HookContext::close_fds();
|
|
if (g_ctx && g_ctx->pid <= 0) {
|
|
// In child process, no longer be able to access to magiskd
|
|
android_logging();
|
|
}
|
|
old_android_log_close();
|
|
}
|
|
|
|
// -----------------------------------------------------------------
|
|
|
|
// The original android::AppRuntime virtual table
|
|
void **gAppRuntimeVTable;
|
|
|
|
// This method is a trampoline for hooking JNIEnv->RegisterNatives
|
|
void onVmCreated(void *self, JNIEnv* env) {
|
|
LOGD("zygisk: AppRuntime::onVmCreated\n");
|
|
|
|
// Restore virtual table
|
|
auto new_table = *reinterpret_cast<void***>(self);
|
|
*reinterpret_cast<void***>(self) = gAppRuntimeVTable;
|
|
delete[] new_table;
|
|
|
|
new_functions = new JNINativeInterface();
|
|
memcpy(new_functions, env->functions, sizeof(*new_functions));
|
|
new_functions->RegisterNatives = &env_RegisterNatives;
|
|
|
|
// Replace the function table in JNIEnv to hook RegisterNatives
|
|
old_functions = env->functions;
|
|
env->functions = new_functions;
|
|
}
|
|
|
|
template<int N>
|
|
void vtable_entry(void *self, JNIEnv* env) {
|
|
// The first invocation will be onVmCreated. It will also restore the vtable.
|
|
onVmCreated(self, env);
|
|
// Call original function
|
|
reinterpret_cast<decltype(&onVmCreated)>(gAppRuntimeVTable[N])(self, env);
|
|
}
|
|
|
|
// This method is a trampoline for swizzling android::AppRuntime vtable
|
|
bool swizzled = false;
|
|
DCL_HOOK_FUNC(void, setArgv0, void *self, const char *argv0, bool setProcName) {
|
|
if (swizzled) {
|
|
old_setArgv0(self, argv0, setProcName);
|
|
return;
|
|
}
|
|
|
|
LOGD("zygisk: AndroidRuntime::setArgv0\n");
|
|
|
|
// We don't know which entry is onVmCreated, so overwrite every one
|
|
// We also don't know the size of the vtable, but 8 is more than enough
|
|
auto new_table = new void*[8];
|
|
new_table[0] = reinterpret_cast<void*>(&vtable_entry<0>);
|
|
new_table[1] = reinterpret_cast<void*>(&vtable_entry<1>);
|
|
new_table[2] = reinterpret_cast<void*>(&vtable_entry<2>);
|
|
new_table[3] = reinterpret_cast<void*>(&vtable_entry<3>);
|
|
new_table[4] = reinterpret_cast<void*>(&vtable_entry<4>);
|
|
new_table[5] = reinterpret_cast<void*>(&vtable_entry<5>);
|
|
new_table[6] = reinterpret_cast<void*>(&vtable_entry<6>);
|
|
new_table[7] = reinterpret_cast<void*>(&vtable_entry<7>);
|
|
|
|
// Swizzle C++ vtable to hook virtual function
|
|
gAppRuntimeVTable = *reinterpret_cast<void***>(self);
|
|
*reinterpret_cast<void***>(self) = new_table;
|
|
swizzled = true;
|
|
|
|
old_setArgv0(self, argv0, setProcName);
|
|
}
|
|
|
|
#undef DCL_HOOK_FUNC
|
|
|
|
// -----------------------------------------------------------------
|
|
|
|
void HookContext::run_modules_pre() { /* TODO */ }
|
|
void HookContext::run_modules_post() { /* TODO */ }
|
|
|
|
void HookContext::close_fds() {
|
|
close(logd_fd.exchange(-1));
|
|
}
|
|
|
|
// -----------------------------------------------------------------
|
|
|
|
void HookContext::nativeSpecializeAppProcess_pre() {
|
|
g_ctx = this;
|
|
flags[APP_SPECIALIZE] = true;
|
|
process = env->GetStringUTFChars(args->nice_name, nullptr);
|
|
if (flags[FORK_AND_SPECIALIZE]) {
|
|
VLOG("zygisk: pre forkAndSpecialize [%s]\n", process);
|
|
} else {
|
|
VLOG("zygisk: pre specialize [%s]\n", process);
|
|
}
|
|
|
|
/* TODO: Handle MOUNT_EXTERNAL_NONE */
|
|
if (args->mount_external != 0 && remote_check_denylist(args->uid, process)) {
|
|
flags[DENY_FLAG] = true;
|
|
LOGI("zygisk: [%s] is on the denylist\n", process);
|
|
} else {
|
|
run_modules_pre();
|
|
}
|
|
}
|
|
|
|
void HookContext::nativeSpecializeAppProcess_post() {
|
|
if (flags[FORK_AND_SPECIALIZE]) {
|
|
VLOG("zygisk: post forkAndSpecialize [%s]\n", process);
|
|
} else {
|
|
VLOG("zygisk: post specialize [%s]\n", process);
|
|
}
|
|
|
|
env->ReleaseStringUTFChars(args->nice_name, process);
|
|
if (flags[DENY_FLAG]) {
|
|
self_unload();
|
|
} else {
|
|
run_modules_post();
|
|
}
|
|
g_ctx = nullptr;
|
|
}
|
|
|
|
void HookContext::nativeForkSystemServer_pre() {
|
|
fork_pre();
|
|
flags[SERVER_SPECIALIZE] = true;
|
|
if (pid == 0) {
|
|
VLOG("zygisk: pre forkSystemServer\n");
|
|
run_modules_pre();
|
|
close_fds();
|
|
}
|
|
}
|
|
|
|
void HookContext::nativeForkSystemServer_post() {
|
|
if (pid == 0) {
|
|
android_logging();
|
|
VLOG("zygisk: post forkSystemServer\n");
|
|
run_modules_post();
|
|
}
|
|
fork_post();
|
|
}
|
|
|
|
void HookContext::nativeForkAndSpecialize_pre() {
|
|
fork_pre();
|
|
flags[FORK_AND_SPECIALIZE] = true;
|
|
if (pid == 0) {
|
|
nativeSpecializeAppProcess_pre();
|
|
close_fds();
|
|
}
|
|
}
|
|
|
|
void HookContext::nativeForkAndSpecialize_post() {
|
|
if (pid == 0) {
|
|
android_logging();
|
|
nativeSpecializeAppProcess_post();
|
|
}
|
|
fork_post();
|
|
}
|
|
|
|
int sigmask(int how, int signum) {
|
|
sigset_t set;
|
|
sigemptyset(&set);
|
|
sigaddset(&set, signum);
|
|
return sigprocmask(how, &set, nullptr);
|
|
}
|
|
|
|
// Do our own fork before loading any 3rd party code
|
|
// First block SIGCHLD, unblock after original fork is done
|
|
void HookContext::fork_pre() {
|
|
g_ctx = this;
|
|
sigmask(SIG_BLOCK, SIGCHLD);
|
|
pid = old_fork();
|
|
}
|
|
|
|
// Unblock SIGCHLD in case the original method didn't
|
|
void HookContext::fork_post() {
|
|
sigmask(SIG_UNBLOCK, SIGCHLD);
|
|
g_ctx = nullptr;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
static bool hook_refresh() {
|
|
if (xhook_refresh(0) == 0) {
|
|
xhook_clear();
|
|
LOGI("zygisk: xhook success\n");
|
|
return true;
|
|
} else {
|
|
LOGE("zygisk: xhook failed\n");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static int hook_register(const char *path, const char *symbol, void *new_func, void **old_func) {
|
|
int ret = xhook_register(path, symbol, new_func, old_func);
|
|
if (ret != 0) {
|
|
LOGE("hook: Failed to register hook \"%s\"\n", symbol);
|
|
return ret;
|
|
}
|
|
xhook_list->emplace_back(path, symbol, old_func);
|
|
return 0;
|
|
}
|
|
|
|
#define XHOOK_REGISTER_SYM(PATH_REGEX, SYM, NAME) \
|
|
hook_register(PATH_REGEX, SYM, (void*) new_##NAME, (void **) &old_##NAME)
|
|
|
|
#define XHOOK_REGISTER(PATH_REGEX, NAME) \
|
|
XHOOK_REGISTER_SYM(PATH_REGEX, #NAME, NAME)
|
|
|
|
#define ANDROID_RUNTIME ".*/libandroid_runtime.so$"
|
|
#define APP_PROCESS "^/system/bin/app_process.*"
|
|
|
|
void hook_functions() {
|
|
#if MAGISK_DEBUG
|
|
xhook_enable_debug(1);
|
|
xhook_enable_sigsegv_protection(0);
|
|
#endif
|
|
default_new(xhook_list);
|
|
default_new(jni_hook_list);
|
|
default_new(jni_method_map);
|
|
|
|
XHOOK_REGISTER(ANDROID_RUNTIME, fork);
|
|
XHOOK_REGISTER(ANDROID_RUNTIME, selinux_android_setcontext);
|
|
XHOOK_REGISTER(ANDROID_RUNTIME, jniRegisterNativeMethods);
|
|
XHOOK_REGISTER_SYM(ANDROID_RUNTIME, "__android_log_close", android_log_close);
|
|
hook_refresh();
|
|
|
|
// Remove unhooked methods
|
|
xhook_list->erase(
|
|
std::remove_if(xhook_list->begin(), xhook_list->end(),
|
|
[](auto &t) { return *std::get<2>(t) == nullptr;}),
|
|
xhook_list->end());
|
|
|
|
if (old_jniRegisterNativeMethods == nullptr) {
|
|
LOGD("zygisk: jniRegisterNativeMethods not hooked, using fallback\n");
|
|
|
|
// android::AndroidRuntime::setArgv0(const char*, bool)
|
|
XHOOK_REGISTER_SYM(APP_PROCESS, "_ZN7android14AndroidRuntime8setArgv0EPKcb", setArgv0);
|
|
hook_refresh();
|
|
|
|
// We still need old_jniRegisterNativeMethods as other code uses it
|
|
// android::AndroidRuntime::registerNativeMethods(_JNIEnv*, const char*, const JNINativeMethod*, int)
|
|
constexpr char sig[] = "_ZN7android14AndroidRuntime21registerNativeMethodsEP7_JNIEnvPKcPK15JNINativeMethodi";
|
|
*(void **) &old_jniRegisterNativeMethods = dlsym(RTLD_DEFAULT, sig);
|
|
}
|
|
}
|
|
|
|
bool unhook_functions() {
|
|
bool success = true;
|
|
|
|
// Restore JNIEnv
|
|
if (g_ctx->env->functions == new_functions) {
|
|
g_ctx->env->functions = old_functions;
|
|
if (gClassRef) {
|
|
g_ctx->env->DeleteGlobalRef(gClassRef);
|
|
gClassRef = nullptr;
|
|
class_getName = nullptr;
|
|
}
|
|
}
|
|
|
|
// Do NOT call the destructor
|
|
operator delete(jni_method_map);
|
|
// Directly unmap the whole memory block
|
|
jni_hook::memory_block::release();
|
|
|
|
// Unhook JNI methods
|
|
for (const auto &[clz, methods] : *jni_hook_list) {
|
|
if (!methods.empty() && old_jniRegisterNativeMethods(
|
|
g_ctx->env, clz.data(), methods.data(), methods.size()) != 0) {
|
|
LOGE("zygisk: Failed to restore JNI hook of class [%s]\n", clz.data());
|
|
success = false;
|
|
}
|
|
}
|
|
delete jni_hook_list;
|
|
|
|
// Unhook xhook
|
|
for (const auto &[path, sym, old_func] : *xhook_list) {
|
|
if (xhook_register(path, sym, *old_func, nullptr) != 0) {
|
|
LOGE("zygisk: Failed to register xhook [%s]\n", sym);
|
|
success = false;
|
|
}
|
|
}
|
|
delete xhook_list;
|
|
if (!hook_refresh()) {
|
|
LOGE("zygisk: Failed to restore xhook\n");
|
|
success = false;
|
|
}
|
|
|
|
return success;
|
|
}
|