mirror of
https://github.com/topjohnwu/Magisk.git
synced 2024-11-25 02:55:33 +00:00
278 lines
6.8 KiB
C
278 lines
6.8 KiB
C
/* proc_monitor.c - Monitor am_proc_start events and unmount
|
|
*
|
|
* We monitor the logcat am_proc_start events. When a target starts up,
|
|
* we pause it ASAP, and fork a new process to join its mount namespace
|
|
* and do all the unmounting/mocking
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <signal.h>
|
|
#include <pthread.h>
|
|
#include <sys/types.h>
|
|
#include <sys/wait.h>
|
|
#include <sys/mount.h>
|
|
|
|
#include "magisk.h"
|
|
#include "utils.h"
|
|
#include "magiskhide.h"
|
|
|
|
static int zygote_num;
|
|
static char init_ns[32], zygote_ns[2][32], cache_block[256];
|
|
static int log_pid, log_fd, target_pid;
|
|
static char *buffer;
|
|
|
|
// Workaround for the lack of pthread_cancel
|
|
static void quit_pthread(int sig) {
|
|
err_handler = do_nothing;
|
|
LOGD("proc_monitor: running cleanup\n");
|
|
destroy_list();
|
|
free(buffer);
|
|
hideEnabled = 0;
|
|
// Kill the logging if needed
|
|
if (log_pid > 0) {
|
|
kill(log_pid, SIGTERM);
|
|
waitpid(log_pid, NULL, 0);
|
|
close(log_fd);
|
|
}
|
|
// Resume process if possible
|
|
if (target_pid > 0)
|
|
kill(target_pid, SIGCONT);
|
|
pthread_mutex_destroy(&hide_lock);
|
|
pthread_mutex_destroy(&file_lock);
|
|
LOGD("proc_monitor: terminating...\n");
|
|
pthread_exit(NULL);
|
|
}
|
|
|
|
static void proc_monitor_err() {
|
|
LOGD("proc_monitor: error occured, stopping magiskhide services\n");
|
|
quit_pthread(SIGUSR1);
|
|
}
|
|
|
|
static int read_namespace(const int pid, char* target, const size_t size) {
|
|
char path[32];
|
|
snprintf(path, sizeof(path), "/proc/%d/ns/mnt", pid);
|
|
if (access(path, R_OK) == -1)
|
|
return 1;
|
|
xreadlink(path, target, size);
|
|
return 0;
|
|
}
|
|
|
|
static void store_zygote_ns(int pid) {
|
|
if (zygote_num == 2) return;
|
|
do {
|
|
usleep(500);
|
|
read_namespace(pid, zygote_ns[zygote_num], 32);
|
|
} while (strcmp(zygote_ns[zygote_num], init_ns) == 0);
|
|
++zygote_num;
|
|
}
|
|
|
|
static void lazy_unmount(const char* mountpoint) {
|
|
if (umount2(mountpoint, MNT_DETACH) != -1)
|
|
LOGD("hide_daemon: Unmounted (%s)\n", mountpoint);
|
|
else
|
|
LOGD("hide_daemon: Unmount Failed (%s)\n", mountpoint);
|
|
}
|
|
|
|
static void hide_daemon_err() {
|
|
LOGD("hide_daemon: error occured, stopping magiskhide services\n");
|
|
_exit(-1);
|
|
}
|
|
|
|
static void hide_daemon(int pid) {
|
|
LOGD("hide_daemon: start unmount for pid=[%d]\n", pid);
|
|
// When an error occurs, report its failure to main process
|
|
err_handler = hide_daemon_err;
|
|
|
|
char *line;
|
|
struct vector mount_list;
|
|
|
|
manage_selinux();
|
|
relink_sbin();
|
|
clean_magisk_props();
|
|
|
|
if (switch_mnt_ns(pid))
|
|
return;
|
|
|
|
snprintf(buffer, PATH_MAX, "/proc/%d/mounts", pid);
|
|
vec_init(&mount_list);
|
|
file_to_vector(buffer, &mount_list);
|
|
|
|
// Find the cache block name if not found yet
|
|
if (cache_block[0] == '\0') {
|
|
vec_for_each(&mount_list, line) {
|
|
if (strstr(line, " /cache ")) {
|
|
sscanf(line, "%256s", cache_block);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// First unmount dummy skeletons, /sbin links, cache mounts, and mirrors
|
|
vec_for_each(&mount_list, line) {
|
|
if (strstr(line, "tmpfs /system") || strstr(line, "tmpfs /vendor") || strstr(line, "tmpfs /sbin")
|
|
|| (strstr(line, cache_block) && (strstr(line, " /system") || strstr(line, " /vendor")))
|
|
|| strstr(line, MIRRDIR)) {
|
|
sscanf(line, "%*s %4096s", buffer);
|
|
lazy_unmount(buffer);
|
|
}
|
|
free(line);
|
|
}
|
|
vec_destroy(&mount_list);
|
|
|
|
// Re-read mount infos
|
|
snprintf(buffer, PATH_MAX, "/proc/%d/mounts", pid);
|
|
vec_init(&mount_list);
|
|
file_to_vector(buffer, &mount_list);
|
|
|
|
// Unmount any loop mounts and dummy mounts
|
|
vec_for_each(&mount_list, line) {
|
|
if (strstr(line, "/dev/block/loop") || strstr(line, DUMMDIR)) {
|
|
sscanf(line, "%*s %4096s", buffer);
|
|
lazy_unmount(buffer);
|
|
}
|
|
free(line);
|
|
}
|
|
|
|
// Free uo memory
|
|
vec_destroy(&mount_list);
|
|
}
|
|
|
|
void proc_monitor() {
|
|
// Register the cancel signal
|
|
struct sigaction act;
|
|
memset(&act, 0, sizeof(act));
|
|
act.sa_handler = quit_pthread;
|
|
sigaction(SIGUSR1, &act, NULL);
|
|
|
|
// The error handler should stop magiskhide services
|
|
err_handler = proc_monitor_err;
|
|
log_pid = target_pid = -1;
|
|
|
|
buffer = xmalloc(PATH_MAX);
|
|
cache_block[0] = '\0';
|
|
|
|
// Get the mount namespace of init
|
|
if (read_namespace(1, init_ns, 32)) {
|
|
LOGE("proc_monitor: Your kernel doesn't support mount namespace :(\n");
|
|
proc_monitor_err();
|
|
}
|
|
LOGI("proc_monitor: init ns=%s\n", init_ns);
|
|
|
|
// Get the mount namespace of zygote
|
|
zygote_num = 0;
|
|
while(!zygote_num) {
|
|
// Check zygote every 2 secs
|
|
sleep(2);
|
|
ps_filter_proc_name("zygote", store_zygote_ns);
|
|
}
|
|
ps_filter_proc_name("zygote64", store_zygote_ns);
|
|
|
|
switch(zygote_num) {
|
|
case 1:
|
|
LOGI("proc_monitor: zygote ns=%s\n", zygote_ns[0]);
|
|
break;
|
|
case 2:
|
|
LOGI("proc_monitor: zygote ns=%s zygote64 ns=%s\n", zygote_ns[0], zygote_ns[1]);
|
|
break;
|
|
}
|
|
|
|
while (1) {
|
|
// Clear previous logcat buffer
|
|
char *const restart[] = { "logcat", "-b", "events", "-c", NULL };
|
|
log_pid = run_command(0, NULL, "/system/bin/logcat", restart);
|
|
if (log_pid > 0)
|
|
waitpid(log_pid, NULL, 0);
|
|
|
|
// Monitor am_proc_start
|
|
char *const command[] = { "logcat", "-b", "events", "-v", "raw", "-s", "am_proc_start", NULL };
|
|
log_fd = -1;
|
|
log_pid = run_command(0, &log_fd, "/system/bin/logcat", command);
|
|
|
|
if (log_pid < 0) continue;
|
|
if (kill(log_pid, 0)) continue;
|
|
|
|
while(fdgets(buffer, PATH_MAX, log_fd)) {
|
|
int pid, ret, comma = 0;
|
|
char *pos = buffer, *line, processName[256];
|
|
|
|
while(1) {
|
|
pos = strchr(pos, ',');
|
|
if(pos == NULL)
|
|
break;
|
|
pos[0] = ' ';
|
|
++comma;
|
|
}
|
|
|
|
if (comma == 6)
|
|
ret = sscanf(buffer, "[%*d %d %*d %*d %256s", &pid, processName);
|
|
else
|
|
ret = sscanf(buffer, "[%*d %d %*d %256s", &pid, processName);
|
|
|
|
if(ret != 2)
|
|
continue;
|
|
|
|
ret = 0;
|
|
|
|
// Critical region
|
|
pthread_mutex_lock(&hide_lock);
|
|
vec_for_each(hide_list, line) {
|
|
if (strcmp(processName, line) == 0) {
|
|
target_pid = pid;
|
|
while(1) {
|
|
ret = 1;
|
|
for (int i = 0; i < zygote_num; ++i) {
|
|
read_namespace(target_pid, buffer, 32);
|
|
if (strcmp(buffer, zygote_ns[i]) == 0) {
|
|
usleep(50);
|
|
ret = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (ret) break;
|
|
}
|
|
|
|
// Send pause signal ASAP
|
|
if (kill(target_pid, SIGSTOP) == -1) continue;
|
|
|
|
LOGI("proc_monitor: %s (PID=%d ns=%s)\n", processName, target_pid, buffer);
|
|
|
|
/*
|
|
* The setns system call do not support multithread processes
|
|
* We have to fork a new process, setns, then do the unmounts
|
|
*/
|
|
int hide_pid = fork();
|
|
switch(hide_pid) {
|
|
case -1:
|
|
PLOGE("fork");
|
|
return;
|
|
case 0:
|
|
hide_daemon(target_pid);
|
|
_exit(0);
|
|
default:
|
|
break;
|
|
}
|
|
|
|
// Wait till the unmount process is done
|
|
waitpid(hide_pid, &ret, 0);
|
|
if (WEXITSTATUS(ret))
|
|
quit_pthread(SIGUSR1);
|
|
|
|
// All done, send resume signal
|
|
kill(target_pid, SIGCONT);
|
|
target_pid = -1;
|
|
break;
|
|
}
|
|
}
|
|
pthread_mutex_unlock(&hide_lock);
|
|
}
|
|
|
|
// For some reason it went here, restart logging
|
|
kill(log_pid, SIGTERM);
|
|
waitpid(log_pid, NULL, 0);
|
|
close(log_fd);
|
|
}
|
|
}
|