Magisk/jni/magiskhide.c
2016-12-11 05:10:48 +08:00

286 lines
6.6 KiB
C

#define _GNU_SOURCE
#include <string.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sched.h>
#include <pthread.h>
#include <unistd.h>
#include <signal.h>
#include <sys/mount.h>
#include <sys/inotify.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <sys/stat.h>
#define LOGFILE "/cache/magisk.log"
#define HIDELIST "/magisk/.core/magiskhide/hidelist"
FILE *logfile;
int i, list_size, pipefd[2];
char **hide_list = NULL;
pthread_mutex_t mutex;
char **file_to_str_arr(FILE *fp, int *size) {
int allocated = 16;
char *line = NULL, **array;
size_t len = 0;
ssize_t read;
array = (char **) malloc(sizeof(char*) * allocated);
*size = 0;
while ((read = getline(&line, &len, fp)) != -1) {
if (*size >= allocated) {
// Double our allocation and re-allocate
allocated *= 2;
array = (char **) realloc(array, sizeof(char*) * allocated);
}
// Remove end newline
if (line[read - 1] == '\n') {
line[read - 1] = '\0';
}
array[*size] = line;
line = NULL;
++(*size);
}
return array;
}
void lazy_unmount(const char* mountpoint) {
if (umount2(mountpoint, MNT_DETACH) != -1)
fprintf(logfile, "MagiskHide: Unmounted (%s)\n", mountpoint);
else
fprintf(logfile, "MagiskHide: Unmount Failed (%s)\n", mountpoint);
}
int hideMagisk() {
int pid;
char path[256], cache_block[256];
cache_block[0] = 0;
close(pipefd[1]);
while(1) {
read(pipefd[0], &pid, sizeof(pid));
if(pid == -1) break;
snprintf(path, 256, "/proc/%d/ns/mnt", pid);
int fd = open(path, O_RDONLY);
if(fd == -1) continue; // Maybe process died..
if(setns(fd, 0) == -1) {
fprintf(logfile, "MagiskHide: Unable to change namespace for pid=%d\n", pid);
continue;
}
snprintf(path, 256, "/proc/%d/mounts", pid);
FILE *mount_fp = fopen(path, "r");
if (mount_fp == NULL) {
fprintf(logfile, "MagiskHide: Error opening mount list!\n");
continue;
}
int mount_size;
char **mount_list = file_to_str_arr(mount_fp, &mount_size), mountpoint[256], cache_block[256];
// Find the cache block name if not found yet
if (strlen(cache_block) == 0) {
for(i = 0; i < mount_size; ++i) {
if (strstr(mount_list[i], " /cache ")) {
sscanf(mount_list[i], "%256s", cache_block);
break;
}
}
}
// First unmount the dummy skeletons and the cache mounts
for(i = mount_size - 1; i >= 0; --i) {
if (strstr(mount_list[i], "tmpfs /system/") || strstr(mount_list[i], "tmpfs /vendor/")
|| (strstr(mount_list[i], cache_block) && strstr(mount_list[i], "/system")) ) {
sscanf(mount_list[i], "%*s %256s", mountpoint);
lazy_unmount(mountpoint);
}
free(mount_list[i]);
}
// Free memory
free(mount_list);
// Re-read mount infos
fseek(mount_fp, 0, SEEK_SET);
mount_list = file_to_str_arr(mount_fp, &mount_size);
fclose(mount_fp);
// Unmount loop mounts
for(i = mount_size - 1; i >= 0; --i) {
if (strstr(mount_list[i], "/dev/block/loop")) {
sscanf(mount_list[i], "%*s %256s", mountpoint);
lazy_unmount(mountpoint);
}
free(mount_list[i]);
}
// Free memory
free(mount_list);
}
// Should never go here
return 1;
// Below are UID checks, not used now but I'll leave it here
// struct stat info;
// snprintf(path, 256, "/proc/%d", pid);
// if (stat(path, &info) == -1) {
// fprintf(logfile, "MagiskHide: Unable to get info for pid=%d\n", pid);
// return 1;
// }
// if (info.st_uid != uid) {
// fprintf(logfile, "MagiskHide: Incorrect uid=%d, expect uid=%d\n", info.st_uid, uid);
// return 1;
// }
}
void update_list(const char *listpath) {
FILE *hide_fp = fopen((char*) listpath, "r");
if (hide_fp == NULL) {
fprintf(logfile, "MagiskHide: Error opening hide list\n");
exit(1);
}
pthread_mutex_lock(&mutex);
if (hide_list) {
// Free memory
for(i = 0; i < list_size; ++i)
free(hide_list[i]);
free(hide_list);
}
hide_list = file_to_str_arr(hide_fp, &list_size);
pthread_mutex_unlock(&mutex);
fclose(hide_fp);
if (list_size) fprintf(logfile, "MagiskHide: Update process/package list:\n");
for(i = 0; i < list_size; i++)
fprintf(logfile, "MagiskHide: [%s]\n", hide_list[i]);
}
void quit_pthread(int sig) {
// Free memory
for(i = 0; i < list_size; ++i)
free(hide_list[i]);
free(hide_list);
pthread_exit(NULL);
}
void *monitor_list(void *path) {
char* listpath = (char*) path;
signal(SIGQUIT, quit_pthread);
int inotifyFd = -1;
char buffer[512];
while(1) {
if (inotifyFd == -1 || read(inotifyFd, buffer, 512) == -1) {
close(inotifyFd);
inotifyFd = inotify_init();
if (inotifyFd == -1) {
fprintf(logfile, "MagiskHide: Unable to watch %s\n", listpath);
exit(1);
}
if (inotify_add_watch(inotifyFd, (char*) listpath, IN_MODIFY) == -1) {
fprintf(logfile, "MagiskHide: Unable to watch %s\n", listpath);
exit(1);
}
}
update_list(listpath);
}
return NULL;
}
void run_as_daemon() {
switch(fork()) {
case -1:
exit(-1);
case 0:
if (setsid() < 0)
exit(-1);
close(STDIN_FILENO);
close(STDOUT_FILENO);
close(STDERR_FILENO);
break;
default:
exit(0);
}
}
int main(int argc, char **argv, char **envp) {
run_as_daemon();
logfile = fopen(LOGFILE, "a+");
setbuf(logfile, NULL);
// Fork a child to handle namespace switches and unmounts
pipe(pipefd);
switch(fork()) {
case -1:
exit(-1);
case 0:
return hideMagisk();
default:
break;
}
close(pipefd[0]);
// Start a thread to constantly check the hide list
pthread_t list_monitor;
pthread_mutex_init(&mutex, NULL);
pthread_create(&list_monitor, NULL, monitor_list, HIDELIST);
char buffer[512];
FILE *p = popen("while true; do logcat -b events -v raw -s am_proc_start; sleep 1; done", "r");
while(!feof(p)) {
//Format of am_proc_start is (as of Android 5.1 and 6.0)
//UserID, pid, unix uid, processName, hostingType, hostingName
fgets(buffer, sizeof(buffer), p);
char *pos = buffer;
while(1) {
pos = strchr(pos, ',');
if(pos == NULL)
break;
pos[0] = ' ';
}
int user, pid, uid;
char processName[256], hostingType[16], hostingName[256];
int ret = sscanf(buffer, "[%d %d %d %256s %16s %256s]",
&user, &pid, &uid,
processName, hostingType, hostingName);
if(ret != 6)
continue;
for (i = 0; i < list_size; ++i) {
if(strstr(processName, hide_list[i])) {
fprintf(logfile, "MagiskHide: Disabling for process=%s, PID=%d, UID=%d\n", processName, pid, uid);
write(pipefd[1], &pid, sizeof(pid));
}
}
}
// Close the logcat monitor
pclose(p);
// Close the config list monitor
pthread_kill(list_monitor, SIGQUIT);
pthread_mutex_destroy(&mutex);
// Terminate our children
i = -1;
write(pipefd[1], &i, sizeof(i));
fprintf(logfile, "MagiskHide: Cannot read from logcat, abort...\n");
fclose(logfile);
return 1;
}