mirror of
https://github.com/topjohnwu/Magisk.git
synced 2024-11-24 10:35:26 +00:00
431 lines
12 KiB
C++
431 lines
12 KiB
C++
#include <libgen.h>
|
|
#include <dlfcn.h>
|
|
#include <sys/prctl.h>
|
|
#include <android/log.h>
|
|
|
|
#include <utils.hpp>
|
|
#include <daemon.hpp>
|
|
#include <magisk.hpp>
|
|
#include <db.hpp>
|
|
|
|
#include "zygisk.hpp"
|
|
#include "module.hpp"
|
|
#include "deny/deny.hpp"
|
|
|
|
using namespace std;
|
|
|
|
void *self_handle = nullptr;
|
|
|
|
static int zygisk_log(int prio, const char *fmt, va_list ap);
|
|
|
|
#define zlog(prio) [](auto fmt, auto ap){ return zygisk_log(ANDROID_LOG_##prio, fmt, ap); }
|
|
static void zygisk_logging() {
|
|
log_cb.d = zlog(DEBUG);
|
|
log_cb.i = zlog(INFO);
|
|
log_cb.w = zlog(WARN);
|
|
log_cb.e = zlog(ERROR);
|
|
log_cb.ex = nop_ex;
|
|
}
|
|
|
|
static char *first_stage_path = nullptr;
|
|
void unload_first_stage() {
|
|
if (first_stage_path) {
|
|
unmap_all(first_stage_path);
|
|
free(first_stage_path);
|
|
first_stage_path = nullptr;
|
|
}
|
|
}
|
|
|
|
// Make sure /proc/self/environ is sanitized
|
|
// Filter env and reset MM_ENV_END
|
|
static void sanitize_environ() {
|
|
char *cur = environ[0];
|
|
|
|
for (int i = 0; environ[i]; ++i) {
|
|
// Copy all env onto the original stack
|
|
int len = strlen(environ[i]);
|
|
memmove(cur, environ[i], len + 1);
|
|
environ[i] = cur;
|
|
cur += len + 1;
|
|
}
|
|
|
|
prctl(PR_SET_MM, PR_SET_MM_ENV_END, cur, 0, 0);
|
|
}
|
|
|
|
__attribute__((destructor))
|
|
static void zygisk_cleanup_wait() {
|
|
if (self_handle) {
|
|
// Wait 10us to make sure none of our code is executing
|
|
timespec ts = { .tv_sec = 0, .tv_nsec = 10000L };
|
|
nanosleep(&ts, nullptr);
|
|
}
|
|
}
|
|
|
|
#define SECOND_STAGE_PTR "ZYGISK_PTR"
|
|
|
|
static void second_stage_entry(void *handle, const char *tmp, char *path) {
|
|
self_handle = handle;
|
|
MAGISKTMP = tmp;
|
|
unsetenv(INJECT_ENV_2);
|
|
unsetenv(SECOND_STAGE_PTR);
|
|
|
|
zygisk_logging();
|
|
ZLOGD("inject 2nd stage\n");
|
|
hook_functions();
|
|
|
|
// First stage will be unloaded before the first fork
|
|
first_stage_path = path;
|
|
}
|
|
|
|
static void first_stage_entry() {
|
|
android_logging();
|
|
ZLOGD("inject 1st stage\n");
|
|
|
|
char *ld = getenv("LD_PRELOAD");
|
|
char tmp[128];
|
|
strlcpy(tmp, getenv("MAGISKTMP"), sizeof(tmp));
|
|
char *path;
|
|
if (char *c = strrchr(ld, ':')) {
|
|
*c = '\0';
|
|
setenv("LD_PRELOAD", ld, 1); // Restore original LD_PRELOAD
|
|
path = strdup(c + 1);
|
|
} else {
|
|
unsetenv("LD_PRELOAD");
|
|
path = strdup(ld);
|
|
}
|
|
unsetenv(INJECT_ENV_1);
|
|
unsetenv("MAGISKTMP");
|
|
sanitize_environ();
|
|
|
|
char *num = strrchr(path, '.') - 1;
|
|
|
|
// Update path to 2nd stage lib
|
|
*num = '2';
|
|
|
|
// Load second stage
|
|
setenv(INJECT_ENV_2, "1", 1);
|
|
void *handle = dlopen(path, RTLD_LAZY);
|
|
remap_all(path);
|
|
|
|
// Revert path to 1st stage lib
|
|
*num = '1';
|
|
|
|
// Run second stage entry
|
|
char *env = getenv(SECOND_STAGE_PTR);
|
|
decltype(&second_stage_entry) second_stage;
|
|
sscanf(env, "%p", &second_stage);
|
|
second_stage(handle, tmp, path);
|
|
}
|
|
|
|
__attribute__((constructor))
|
|
static void zygisk_init() {
|
|
if (getenv(INJECT_ENV_2)) {
|
|
// Return function pointer to first stage
|
|
char buf[128];
|
|
snprintf(buf, sizeof(buf), "%p", &second_stage_entry);
|
|
setenv(SECOND_STAGE_PTR, buf, 1);
|
|
} else if (getenv(INJECT_ENV_1)) {
|
|
first_stage_entry();
|
|
}
|
|
}
|
|
|
|
// The following code runs in zygote/app process
|
|
|
|
static int zygisk_log(int prio, const char *fmt, va_list ap) {
|
|
// If we don't have log pipe set, ask magiskd for it
|
|
// This could happen multiple times in zygote because it was closed to prevent crashing
|
|
if (logd_fd < 0) {
|
|
// Change logging temporarily to prevent infinite recursion and stack overflow
|
|
android_logging();
|
|
if (int fd = connect_daemon(); fd >= 0) {
|
|
write_int(fd, ZYGISK_REQUEST);
|
|
write_int(fd, ZYGISK_GET_LOG_PIPE);
|
|
if (read_int(fd) == 0) {
|
|
logd_fd = recv_fd(fd);
|
|
}
|
|
close(fd);
|
|
}
|
|
zygisk_logging();
|
|
}
|
|
|
|
sigset_t mask;
|
|
sigset_t orig_mask;
|
|
bool sig = false;
|
|
// Make sure SIGPIPE won't crash zygote
|
|
if (logd_fd >= 0) {
|
|
sig = true;
|
|
sigemptyset(&mask);
|
|
sigaddset(&mask, SIGPIPE);
|
|
pthread_sigmask(SIG_BLOCK, &mask, &orig_mask);
|
|
}
|
|
int ret = magisk_log(prio, fmt, ap);
|
|
if (sig) {
|
|
timespec ts{};
|
|
sigtimedwait(&mask, nullptr, &ts);
|
|
pthread_sigmask(SIG_SETMASK, &orig_mask, nullptr);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static inline bool should_load_modules(int flags) {
|
|
return (flags & UNMOUNT_MASK) != UNMOUNT_MASK &&
|
|
(flags & PROCESS_IS_MAGISK_APP) != PROCESS_IS_MAGISK_APP;
|
|
}
|
|
|
|
int remote_get_info(int uid, const char *process, uint32_t *flags, vector<int> &fds) {
|
|
if (int fd = connect_daemon(); fd >= 0) {
|
|
write_int(fd, ZYGISK_REQUEST);
|
|
write_int(fd, ZYGISK_GET_INFO);
|
|
|
|
write_int(fd, uid);
|
|
write_string(fd, process);
|
|
xxread(fd, flags, sizeof(*flags));
|
|
if (should_load_modules(*flags)) {
|
|
fds = recv_fds(fd);
|
|
}
|
|
return fd;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
// The following code runs in magiskd
|
|
|
|
static vector<int> get_module_fds(bool is_64_bit) {
|
|
vector<int> fds;
|
|
// All fds passed to send_fds have to be valid file descriptors.
|
|
// To workaround this issue, send over STDOUT_FILENO as an indicator of an
|
|
// invalid fd as it will always be /dev/null in magiskd
|
|
if (is_64_bit) {
|
|
#if defined(__LP64__)
|
|
std::transform(module_list->begin(), module_list->end(), std::back_inserter(fds),
|
|
[](const module_info &info) { return info.z64 < 0 ? STDOUT_FILENO : info.z64; });
|
|
#endif
|
|
} else {
|
|
std::transform(module_list->begin(), module_list->end(), std::back_inserter(fds),
|
|
[](const module_info &info) { return info.z32 < 0 ? STDOUT_FILENO : info.z32; });
|
|
}
|
|
return fds;
|
|
}
|
|
|
|
static bool get_exe(int pid, char *buf, size_t sz) {
|
|
snprintf(buf, sz, "/proc/%d/exe", pid);
|
|
return xreadlink(buf, buf, sz) > 0;
|
|
}
|
|
|
|
static pthread_mutex_t zygiskd_lock = PTHREAD_MUTEX_INITIALIZER;
|
|
static int zygiskd_sockets[] = { -1, -1 };
|
|
#define zygiskd_socket zygiskd_sockets[is_64_bit]
|
|
|
|
static void connect_companion(int client, bool is_64_bit) {
|
|
mutex_guard g(zygiskd_lock);
|
|
|
|
if (zygiskd_socket >= 0) {
|
|
// Make sure the socket is still valid
|
|
pollfd pfd = { zygiskd_socket, 0, 0 };
|
|
poll(&pfd, 1, 0);
|
|
if (pfd.revents) {
|
|
// Any revent means error
|
|
close(zygiskd_socket);
|
|
zygiskd_socket = -1;
|
|
}
|
|
}
|
|
if (zygiskd_socket < 0) {
|
|
int fds[2];
|
|
socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, fds);
|
|
zygiskd_socket = fds[0];
|
|
if (fork_dont_care() == 0) {
|
|
string exe = MAGISKTMP + "/magisk" + (is_64_bit ? "64" : "32");
|
|
// This fd has to survive exec
|
|
fcntl(fds[1], F_SETFD, 0);
|
|
char buf[16];
|
|
snprintf(buf, sizeof(buf), "%d", fds[1]);
|
|
execl(exe.data(), "zygisk", "companion", buf, (char *) nullptr);
|
|
exit(-1);
|
|
}
|
|
close(fds[1]);
|
|
vector<int> module_fds = get_module_fds(is_64_bit);
|
|
send_fds(zygiskd_socket, module_fds.data(), module_fds.size());
|
|
// Wait for ack
|
|
if (read_int(zygiskd_socket) != 0) {
|
|
LOGE("zygiskd startup error\n");
|
|
return;
|
|
}
|
|
}
|
|
send_fd(zygiskd_socket, client);
|
|
}
|
|
|
|
static timespec last_zygote_start;
|
|
static int zygote_start_counts[] = { 0, 0 };
|
|
#define zygote_start_count zygote_start_counts[is_64_bit]
|
|
#define zygote_started (zygote_start_counts[0] + zygote_start_counts[1])
|
|
#define zygote_start_reset(val) { zygote_start_counts[0] = val; zygote_start_counts[1] = val; }
|
|
|
|
static void setup_files(int client, const sock_cred *cred) {
|
|
LOGD("zygisk: setup files for pid=[%d]\n", cred->pid);
|
|
|
|
char buf[256];
|
|
if (!get_exe(cred->pid, buf, sizeof(buf))) {
|
|
write_int(client, 1);
|
|
return;
|
|
}
|
|
|
|
bool is_64_bit = str_ends(buf, "64");
|
|
|
|
if (!zygote_started) {
|
|
// First zygote launch, record time
|
|
clock_gettime(CLOCK_MONOTONIC, &last_zygote_start);
|
|
}
|
|
|
|
if (zygote_start_count) {
|
|
// This zygote ABI had started before, kill existing zygiskd
|
|
close(zygiskd_sockets[0]);
|
|
close(zygiskd_sockets[1]);
|
|
zygiskd_sockets[0] = -1;
|
|
zygiskd_sockets[1] = -1;
|
|
}
|
|
++zygote_start_count;
|
|
|
|
if (zygote_start_count >= 5) {
|
|
// Bootloop prevention
|
|
timespec ts;
|
|
clock_gettime(CLOCK_MONOTONIC, &ts);
|
|
if (ts.tv_sec - last_zygote_start.tv_sec > 60) {
|
|
// This is very likely manual soft reboot
|
|
memcpy(&last_zygote_start, &ts, sizeof(ts));
|
|
zygote_start_reset(1);
|
|
} else {
|
|
// If any zygote relaunched more than 5 times within a minute,
|
|
// don't do any setups further to prevent bootloop.
|
|
zygote_start_reset(999);
|
|
write_int(client, 1);
|
|
return;
|
|
}
|
|
}
|
|
|
|
write_int(client, 0);
|
|
send_fd(client, is_64_bit ? app_process_64 : app_process_32);
|
|
|
|
string path = MAGISKTMP + "/" ZYGISKBIN "/zygisk." + basename(buf);
|
|
cp_afc(buf, (path + ".1.so").data());
|
|
cp_afc(buf, (path + ".2.so").data());
|
|
write_string(client, MAGISKTMP);
|
|
}
|
|
|
|
static void magiskd_passthrough(int client) {
|
|
bool is_64_bit = read_int(client);
|
|
write_int(client, 0);
|
|
send_fd(client, is_64_bit ? app_process_64 : app_process_32);
|
|
}
|
|
|
|
atomic<int> cached_manager_app_id = -1;
|
|
|
|
extern bool uid_granted_root(int uid);
|
|
static void get_process_info(int client, const sock_cred *cred) {
|
|
int uid = read_int(client);
|
|
string process = read_string(client);
|
|
|
|
uint32_t flags = 0;
|
|
|
|
// This function is called on every single zygote process specialization,
|
|
// so performance is critical. get_manager_app_id() is expensive as it goes
|
|
// through a SQLite query and potentially multiple filesystem stats, so we
|
|
// really want to cache the app ID value. inotify will invalidate the app ID
|
|
// cache for us.
|
|
|
|
int manager_app_id = cached_manager_app_id;
|
|
|
|
if (manager_app_id < 0) {
|
|
manager_app_id = get_manager_app_id();
|
|
cached_manager_app_id = manager_app_id;
|
|
}
|
|
|
|
if (to_app_id(uid) == manager_app_id) {
|
|
flags |= PROCESS_IS_MAGISK_APP;
|
|
}
|
|
if (denylist_enforced) {
|
|
flags |= DENYLIST_ENFORCING;
|
|
}
|
|
if (is_deny_target(uid, process)) {
|
|
flags |= PROCESS_ON_DENYLIST;
|
|
}
|
|
if (uid_granted_root(uid)) {
|
|
flags |= PROCESS_GRANTED_ROOT;
|
|
}
|
|
|
|
xwrite(client, &flags, sizeof(flags));
|
|
|
|
if (should_load_modules(flags)) {
|
|
char buf[256];
|
|
get_exe(cred->pid, buf, sizeof(buf));
|
|
vector<int> fds = get_module_fds(str_ends(buf, "64"));
|
|
send_fds(client, fds.data(), fds.size());
|
|
}
|
|
|
|
// The following will only happen for system_server
|
|
int slots = read_int(client);
|
|
int id = 0;
|
|
for (int i = 0; i < slots; ++i) {
|
|
dynamic_bitset::slot_type l = 0;
|
|
xxread(client, &l, sizeof(l));
|
|
dynamic_bitset::slot_bits bits(l);
|
|
for (int j = 0; id < module_list->size(); ++j, ++id) {
|
|
if (!bits[j]) {
|
|
// Either not a zygisk module, or incompatible
|
|
char buf[4096];
|
|
snprintf(buf, sizeof(buf), MODULEROOT "/%s/zygisk",
|
|
module_list->operator[](id).name.data());
|
|
if (int dirfd = open(buf, O_RDONLY | O_CLOEXEC); dirfd >= 0) {
|
|
close(xopenat(dirfd, "unloaded", O_CREAT | O_RDONLY, 0644));
|
|
close(dirfd);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void send_log_pipe(int fd) {
|
|
// There is race condition here, but we can't really do much about it...
|
|
if (logd_fd >= 0) {
|
|
write_int(fd, 0);
|
|
send_fd(fd, logd_fd);
|
|
} else {
|
|
write_int(fd, 1);
|
|
}
|
|
}
|
|
|
|
static void get_moddir(int client) {
|
|
int id = read_int(client);
|
|
char buf[4096];
|
|
snprintf(buf, sizeof(buf), MODULEROOT "/%s", module_list->operator[](id).name.data());
|
|
int dfd = xopen(buf, O_RDONLY | O_CLOEXEC);
|
|
send_fd(client, dfd);
|
|
close(dfd);
|
|
}
|
|
|
|
void zygisk_handler(int client, const sock_cred *cred) {
|
|
int code = read_int(client);
|
|
char buf[256];
|
|
switch (code) {
|
|
case ZYGISK_SETUP:
|
|
setup_files(client, cred);
|
|
break;
|
|
case ZYGISK_PASSTHROUGH:
|
|
magiskd_passthrough(client);
|
|
break;
|
|
case ZYGISK_GET_INFO:
|
|
get_process_info(client, cred);
|
|
break;
|
|
case ZYGISK_GET_LOG_PIPE:
|
|
send_log_pipe(client);
|
|
break;
|
|
case ZYGISK_CONNECT_COMPANION:
|
|
get_exe(cred->pid, buf, sizeof(buf));
|
|
connect_companion(client, str_ends(buf, "64"));
|
|
break;
|
|
case ZYGISK_GET_MODDIR:
|
|
get_moddir(client);
|
|
break;
|
|
}
|
|
close(client);
|
|
}
|