Magisk/native/jni/magiskhide/hide_policy.cpp
2021-01-10 19:27:54 -08:00

135 lines
4.0 KiB
C++

#include <sys/mount.h>
#include <magisk.hpp>
#include <utils.hpp>
#include <selinux.hpp>
#include <resetprop.hpp>
#include "magiskhide.hpp"
using namespace std;
static const char *prop_key[] =
{ "ro.boot.vbmeta.device_state", "ro.boot.verifiedbootstate", "ro.boot.flash.locked",
"ro.boot.veritymode", "ro.boot.warranty_bit", "ro.warranty_bit",
"ro.debuggable", "ro.secure", "ro.build.type", "ro.build.tags",
"ro.vendor.boot.warranty_bit", "ro.vendor.warranty_bit",
"vendor.boot.vbmeta.device_state", nullptr };
static const char *prop_val[] =
{ "locked", "green", "1",
"enforcing", "0", "0",
"0", "1", "user", "release-keys",
"0", "0",
"locked", nullptr };
static const char *late_prop_key[] =
{ "vendor.boot.verifiedbootstate", nullptr };
static const char *late_prop_val[] =
{ "green", nullptr };
void hide_sensitive_props() {
LOGI("hide: Hiding sensitive props\n");
for (int i = 0; prop_key[i]; ++i) {
auto value = getprop(prop_key[i]);
if (!value.empty() && value != prop_val[i])
setprop(prop_key[i], prop_val[i], false);
}
// Hide that we booted from recovery when magisk is in recovery mode
auto bootmode = getprop("ro.bootmode");
if (!bootmode.empty() && str_contains(bootmode, "recovery"))
setprop("ro.bootmode", "unknown", false);
bootmode = getprop("ro.boot.mode");
if (!bootmode.empty() && str_contains(bootmode, "recovery"))
setprop("ro.boot.mode", "unknown", false);
bootmode = getprop("vendor.boot.mode");
if (!bootmode.empty() && str_contains(bootmode, "recovery"))
setprop("vendor.boot.mode", "unknown", false);
// Xiaomi cross region flash
auto hwc = getprop("ro.boot.hwc");
if (!hwc.empty() && str_contains(hwc, "CN"))
setprop("ro.boot.hwc", "GLOBAL", false);
auto hwcountry = getprop("ro.boot.hwcountry");
if (!hwcountry.empty() && str_contains(hwcountry, "China"))
setprop("ro.boot.hwcountry", "GLOBAL", false);
auto selinux = getprop("ro.build.selinux");
if (!selinux.empty())
delprop("ro.build.selinux");
}
void hide_late_sensitive_props() {
LOGI("hide: Hiding sensitive props (late)\n");
for (int i = 0; late_prop_key[i]; ++i) {
auto value = getprop(late_prop_key[i]);
if (!value.empty() && value != late_prop_val[i])
setprop(late_prop_key[i], late_prop_val[i], false);
}
}
static void lazy_unmount(const char* mountpoint) {
if (umount2(mountpoint, MNT_DETACH) != -1)
LOGD("hide: Unmounted (%s)\n", mountpoint);
}
#if ENABLE_PTRACE_MONITOR
void hide_daemon(int pid) {
if (fork_dont_care() == 0) {
hide_unmount(pid);
// Send resume signal
kill(pid, SIGCONT);
_exit(0);
}
}
#endif
#define TMPFS_MNT(dir) (mentry->mnt_type == "tmpfs"sv && \
strncmp(mentry->mnt_dir, "/" #dir, sizeof("/" #dir) - 1) == 0)
void hide_unmount(int pid) {
if (pid > 0 && switch_mnt_ns(pid))
return;
LOGD("hide: handling PID=[%d]\n", pid);
char val;
int fd = xopen(SELINUX_ENFORCE, O_RDONLY);
xxread(fd, &val, sizeof(val));
close(fd);
// Permissive
if (val == '0') {
chmod(SELINUX_ENFORCE, 0640);
chmod(SELINUX_POLICY, 0440);
}
vector<string> targets;
// Unmount dummy skeletons and /sbin links
targets.push_back(MAGISKTMP);
parse_mnt("/proc/self/mounts", [&](mntent *mentry) {
if (TMPFS_MNT(system) || TMPFS_MNT(vendor) || TMPFS_MNT(product) || TMPFS_MNT(system_ext))
targets.emplace_back(mentry->mnt_dir);
return true;
});
for (auto &s : reversed(targets))
lazy_unmount(s.data());
targets.clear();
// Unmount all Magisk created mounts
parse_mnt("/proc/self/mounts", [&](mntent *mentry) {
if (strstr(mentry->mnt_fsname, BLOCKDIR))
targets.emplace_back(mentry->mnt_dir);
return true;
});
for (auto &s : reversed(targets))
lazy_unmount(s.data());
}