MarcoBuster/Magisk
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Right now there are three threads (process)
1. Main thread in parent: monitor logcat
2. Second thread in parent: monitor hidelist
3. Children: switch namespace and unmounts
This commit is contained in:
topjohnwu 2016-12-11 04:56:01 +08:00
parent 70e332b9e8
commit 8d6d619eed
1 changed files with 91 additions and 77 deletions
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84
jni/magiskhide.c
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@ -18,8 +18,8 @@
#define HIDELIST "/magisk/.core/magiskhide/hidelist"
FILE *logfile;
int i, list_size;
char **hide_list = NULL, cache_block[256];
int i, list_size, pipefd[2];
char **hide_list = NULL;
pthread_mutex_t mutex;
char **file_to_str_arr(FILE *fp, int *size) {
@ -55,34 +55,28 @@ void lazy_unmount(const char* mountpoint) {
fprintf(logfile, "MagiskHide: Unmount Failed (%s)\n", mountpoint);
}
//WARNING: Calling this will change our current namespace
//We don't care because we don't want to run from here anyway
int hideMagisk(int pid, int uid) {
// struct stat info;
char path[256];
// 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;
// }
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) return 2; // Maybe process died..
if(fd == -1) continue; // Maybe process died..
if(setns(fd, 0) == -1) {
fprintf(logfile, "MagiskHide: Unable to change namespace for pid=%d\n", pid);
return 3;
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");
return 4;
continue;
}
int mount_size;
@ -102,7 +96,7 @@ int hideMagisk(int pid, int uid) {
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], "%256s %256s", mountpoint, mountpoint);
sscanf(mount_list[i], "%*s %256s", mountpoint);
lazy_unmount(mountpoint);
}
free(mount_list[i]);
@ -118,15 +112,31 @@ int hideMagisk(int pid, int uid) {
// Unmount loop mounts
for(i = mount_size - 1; i >= 0; --i) {
if (strstr(mount_list[i], "/dev/block/loop")) {
sscanf(mount_list[i], "%256s %256s", mountpoint, mountpoint);
sscanf(mount_list[i], "%*s %256s", mountpoint);
lazy_unmount(mountpoint);
}
free(mount_list[i]);
}
// Free memory
free(mount_list);
}
return 0;
// 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) {
@ -202,11 +212,18 @@ int main(int argc, char **argv, char **envp) {
logfile = fopen(LOGFILE, "a+");
setbuf(logfile, NULL);
// Set cache block to null
cache_block[0] = 0;
// Fork a child to handle namespace switches and unmounts
pipe(pipefd);
forkpid = fork();
if (forkpid < 0)
return 1;
if (forkpid == 0)
return hideMagisk();
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);
@ -238,25 +255,22 @@ int main(int argc, char **argv, char **envp) {
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);
forkpid = fork();
if (forkpid < 0)
break;
if (forkpid == 0) {
hideMagisk(pid, uid);
return 0;
}
waitpid(forkpid, NULL, 0);
kill(forkpid, SIGTERM);
break;
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);