Load Zygisk modules

This commit is contained in:
topjohnwu
2021-10-13 04:52:02 -07:00
parent 27814e3015
commit c8ac6c07b0
10 changed files with 366 additions and 120 deletions

View File

@@ -8,7 +8,7 @@
#include "zygisk.hpp"
#include "memory.hpp"
#include "api.hpp"
#include "module.hpp"
using namespace std;
using jni_hook::hash_map;
@@ -22,57 +22,13 @@ using xstring = jni_hook::string;
namespace {
enum {
DENY_FLAG,
UNMOUNT_FLAG,
FORK_AND_SPECIALIZE,
APP_SPECIALIZE,
SERVER_SPECIALIZE,
FLAG_MAX
};
struct AppSpecializeArgsImpl {
jint &uid;
jint &gid;
jintArray &gids;
jint &runtime_flags;
jint &mount_external;
jstring &se_info;
jstring &nice_name;
jstring &instruction_set;
jstring &app_data_dir;
/* Optional */
jboolean *is_child_zygote = nullptr;
jboolean *is_top_app = nullptr;
jobjectArray *pkg_data_info_list = nullptr;
jobjectArray *whitelisted_data_info_list = nullptr;
jboolean *mount_data_dirs = nullptr;
jboolean *mount_storage_dirs = nullptr;
AppSpecializeArgsImpl(
jint &uid, jint &gid, jintArray &gids, jint &runtime_flags,
jint &mount_external, jstring &se_info, jstring &nice_name,
jstring &instruction_set, jstring &app_data_dir) :
uid(uid), gid(gid), gids(gids), runtime_flags(runtime_flags),
mount_external(mount_external), se_info(se_info), nice_name(nice_name),
instruction_set(instruction_set), app_data_dir(app_data_dir) {}
};
struct ServerSpecializeArgsImpl {
jint &uid;
jint &gid;
jintArray &gids;
jint &runtime_flags;
jlong &permitted_capabilities;
jlong &effective_capabilities;
ServerSpecializeArgsImpl(
jint &uid, jint &gid, jintArray &gids, jint &runtime_flags,
jlong &permitted_capabilities, jlong &effective_capabilities) :
uid(uid), gid(gid), gids(gids), runtime_flags(runtime_flags),
permitted_capabilities(permitted_capabilities),
effective_capabilities(effective_capabilities) {}
};
#define DCL_PRE_POST(name) \
void name##_pre(); \
void name##_post();
@@ -88,14 +44,16 @@ struct HookContext {
int pid;
bitset<FLAG_MAX> flags;
AppInfo info;
vector<ZygiskModule> modules;
HookContext() : pid(-1), info{} {}
static void close_fds();
void toggle_unmount();
DCL_PRE_POST(fork)
DCL_PRE_POST(run_modules)
void run_modules_pre(const vector<int> &fds);
void run_modules_post();
DCL_PRE_POST(nativeForkAndSpecialize)
DCL_PRE_POST(nativeSpecializeAppProcess)
DCL_PRE_POST(nativeForkSystemServer)
@@ -184,7 +142,7 @@ DCL_HOOK_FUNC(int, 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 (g_ctx && g_ctx->flags[UNMOUNT_FLAG]) {
if (remote_request_unmount() == 0) {
LOGD("zygisk: mount namespace cleaned up\n");
}
@@ -267,13 +225,121 @@ DCL_HOOK_FUNC(void, setArgv0, void *self, const char *argv0, bool setProcName) {
// -----------------------------------------------------------------
void HookContext::run_modules_pre() { /* TODO */ }
void HookContext::run_modules_post() { /* TODO */ }
void hookJniNativeMethods(JNIEnv *env, const char *clz, JNINativeMethod *methods, int numMethods) {
auto class_map = jni_method_map->find(clz);
if (class_map == jni_method_map->end()) {
for (int i = 0; i < numMethods; ++i) {
methods[i].fnPtr = nullptr;
}
return;
}
vector<JNINativeMethod> hooks;
for (int i = 0; i < numMethods; ++i) {
auto method_map = class_map->second.find(methods[i].name);
if (method_map != class_map->second.end()) {
auto it = method_map->second.find(methods[i].signature);
if (it != method_map->second.end()) {
// Copy the JNINativeMethod
hooks.push_back(methods[i]);
// Save the original function pointer
methods[i].fnPtr = it->second;
// Do not allow double hook, remove method from map
method_map->second.erase(it);
continue;
}
}
// No matching method found, set fnPtr to null
methods[i].fnPtr = nullptr;
}
if (hooks.empty())
return;
old_jniRegisterNativeMethods(env, clz, hooks.data(), hooks.size());
}
bool ZygiskModule::registerModule(ApiTable *table, long *module) {
long ver = *module;
// Unsupported version
if (ver > ZYGISK_API_VERSION)
return false;
// Set the actual module_abi*
table->module->ver = module;
// Fill in API accordingly with module API version
table->v1.hookJniNativeMethods = &hookJniNativeMethods;
table->v1.pltHookRegister = [](const char *path, const char *symbol, void *n, void **o) {
xhook_register(path, symbol, n, o);
};
table->v1.pltHookExclude = [](const char *path, const char *symbol) {
xhook_ignore(path, symbol);
};
table->v1.pltHookCommit = []() { return xhook_refresh(0) == 0; };
table->v1.connectCompanion = [](ZygiskModule *m) { return m->connectCompanion(); };
table->v1.forceDenyListUnmount = [](auto) { ZygiskModule::forceDenyListUnmount(); };
return true;
}
int ZygiskModule::connectCompanion() {
// TODO
(void) id;
return -1;
}
void ZygiskModule::forceDenyListUnmount() {
if (g_ctx == nullptr)
return;
g_ctx->toggle_unmount();
}
void HookContext::run_modules_pre(const vector<int> &fds) {
char buf[256];
for (int i = 0; i < fds.size(); ++i) {
snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fds[i]);
if (void *h = dlopen(buf, RTLD_LAZY)) {
void (*module_entry)(void *, void *);
*(void **) &module_entry = dlsym(h, "zygisk_module_entry");
if (module_entry) {
modules.emplace_back(i);
auto api = new ApiTable(&modules.back());
module_entry(api, env);
}
}
close(fds[i]);
}
for (auto &m : modules) {
if (flags[APP_SPECIALIZE]) {
m.preAppSpecialize(args);
} else if (flags[SERVER_SPECIALIZE]) {
m.preServerSpecialize(server_args);
}
}
}
void HookContext::run_modules_post() {
for (auto &m : modules) {
if (flags[APP_SPECIALIZE]) {
m.postAppSpecialize(args);
} else if (flags[SERVER_SPECIALIZE]) {
m.postServerSpecialize(server_args);
}
}
}
void HookContext::close_fds() {
close(logd_fd.exchange(-1));
}
void HookContext::toggle_unmount() {
if (flags[APP_SPECIALIZE]) {
// TODO: Handle MOUNT_EXTERNAL_NONE
flags[UNMOUNT_FLAG] = args->mount_external != 0;
}
}
// -----------------------------------------------------------------
void HookContext::nativeSpecializeAppProcess_pre() {
@@ -286,14 +352,12 @@ void HookContext::nativeSpecializeAppProcess_pre() {
VLOG("zygisk: pre specialize [%s]\n", process);
}
remote_get_app_info(args->uid, process, &info);
/* TODO: Handle MOUNT_EXTERNAL_NONE */
if (args->mount_external != 0 && info.on_denylist) {
auto module_fds = remote_get_info(args->uid, process, &info);
if (info.on_denylist) {
LOGI("zygisk: [%s] is on the denylist\n", process);
flags[DENY_FLAG] = true;
toggle_unmount();
} else {
run_modules_pre();
run_modules_pre(module_fds);
}
}
@@ -305,7 +369,7 @@ void HookContext::nativeSpecializeAppProcess_post() {
}
env->ReleaseStringUTFChars(args->nice_name, process);
if (flags[DENY_FLAG]) {
if (info.on_denylist) {
self_unload();
} else {
run_modules_post();
@@ -325,7 +389,7 @@ void HookContext::nativeForkSystemServer_pre() {
flags[SERVER_SPECIALIZE] = true;
if (pid == 0) {
VLOG("zygisk: pre forkSystemServer\n");
run_modules_pre();
run_modules_pre(remote_get_info(1000, "system_server", &info));
close_fds();
}
}