Magisk/native/jni/core/daemon.cpp
2019-02-10 04:18:50 -05:00

188 lines
4.1 KiB
C++

/* daemon.c - Magisk Daemon
*
* Start the daemon and wait for requests
* Connect the daemon and send requests through sockets
*/
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <pthread.h>
#include <signal.h>
#include <sys/un.h>
#include <sys/types.h>
#include <sys/mount.h>
#include <magisk.h>
#include <utils.h>
#include <daemon.h>
#include <selinux.h>
#include <db.h>
#include <resetprop.h>
#include <flags.h>
int SDK_INT = -1;
struct stat SERVER_STAT;
static void verify_client(int client, pid_t pid) {
// Verify caller is the same as server
char path[32];
sprintf(path, "/proc/%d/exe", pid);
struct stat st{};
stat(path, &st);
if (st.st_dev != SERVER_STAT.st_dev || st.st_ino != SERVER_STAT.st_ino) {
close(client);
pthread_exit(nullptr);
}
}
static void *request_handler(void *args) {
int client = *((int *) args);
delete (int *) args;
struct ucred credential;
get_client_cred(client, &credential);
if (credential.uid != 0)
verify_client(client, credential.pid);
int req = read_int(client);
switch (req) {
case MAGISKHIDE:
case POST_FS_DATA:
case LATE_START:
case BOOT_COMPLETE:
case SQLITE_CMD:
if (credential.uid != 0) {
write_int(client, ROOT_REQUIRED);
close(client);
return nullptr;
}
default:
break;
}
switch (req) {
case MAGISKHIDE:
magiskhide_handler(client);
break;
case SUPERUSER:
su_daemon_handler(client, &credential);
break;
case CHECK_VERSION:
write_string(client, xstr(MAGISK_VERSION) ":MAGISK");
close(client);
break;
case CHECK_VERSION_CODE:
write_int(client, MAGISK_VER_CODE);
close(client);
break;
case POST_FS_DATA:
post_fs_data(client);
break;
case LATE_START:
late_start(client);
break;
case BOOT_COMPLETE:
boot_complete(client);
break;
case SQLITE_CMD:
exec_sql(client);
close(client);
break;
default:
close(client);
break;
}
return nullptr;
}
static void main_daemon() {
android_logging();
setsid();
setcon("u:r:" SEPOL_PROC_DOMAIN ":s0");
int fd = xopen("/dev/null", O_RDWR | O_CLOEXEC);
xdup2(fd, STDOUT_FILENO);
xdup2(fd, STDERR_FILENO);
close(fd);
fd = xopen("/dev/zero", O_RDWR | O_CLOEXEC);
xdup2(fd, STDIN_FILENO);
close(fd);
LOGI("Magisk v" xstr(MAGISK_VERSION) "(" xstr(MAGISK_VER_CODE) ") daemon started\n");
// Get server stat
stat("/proc/self/exe", &SERVER_STAT);
// Get API level
parse_prop_file("/system/build.prop", [](auto key, auto val) -> bool {
if (strcmp(key, "ro.build.version.sdk") == 0) {
LOGI("* Device API level: %s\n", val);
SDK_INT = atoi(val);
return false;
}
return true;
});
struct sockaddr_un sun;
socklen_t len = setup_sockaddr(&sun, MAIN_SOCKET);
fd = xsocket(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
if (xbind(fd, (struct sockaddr*) &sun, len))
exit(1);
xlisten(fd, 10);
// Change process name
strcpy(argv0, "magiskd");
// Block all signals
sigset_t block_set;
sigfillset(&block_set);
pthread_sigmask(SIG_SETMASK, &block_set, nullptr);
// Loop forever to listen for requests
while(true) {
int *client = new int;
*client = xaccept4(fd, nullptr, nullptr, SOCK_CLOEXEC);
pthread_t thread;
xpthread_create(&thread, nullptr, request_handler, client);
// Detach the thread, we will never join it
pthread_detach(thread);
}
}
int switch_mnt_ns(int pid) {
char mnt[32];
snprintf(mnt, sizeof(mnt), "/proc/%d/ns/mnt", pid);
if(access(mnt, R_OK) == -1) return 1; // Maybe process died..
int fd, ret;
fd = xopen(mnt, O_RDONLY);
if (fd < 0) return 1;
// Switch to its namespace
ret = xsetns(fd, 0);
close(fd);
return ret;
}
int connect_daemon() {
struct sockaddr_un sun;
socklen_t len = setup_sockaddr(&sun, MAIN_SOCKET);
int fd = xsocket(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0);
if (connect(fd, (struct sockaddr*) &sun, len)) {
if (getuid() != UID_ROOT || getgid() != UID_ROOT) {
fprintf(stderr, "No daemon is currently running!\n");
exit(1);
}
LOGD("client: launching new main daemon process\n");
if (fork_dont_care() == 0) {
close(fd);
main_daemon();
}
while (connect(fd, (struct sockaddr*) &sun, len))
usleep(10000);
}
return fd;
}