Magisk/native/jni/core/scripting.cpp
2021-01-11 02:19:10 -08:00

207 lines
5.3 KiB
C++

#include <string>
#include <vector>
#include <sys/wait.h>
#include <magisk.hpp>
#include <utils.hpp>
#include <selinux.hpp>
#include "core.hpp"
using namespace std;
#define BBEXEC_CMD bbpath(), "sh"
static const char *bbpath() {
static string path;
if (path.empty())
path = MAGISKTMP + "/" BBPATH "/busybox";
return path.data();
}
static void set_script_env() {
setenv("ASH_STANDALONE", "1", 1);
char new_path[4096];
sprintf(new_path, "%s:%s", getenv("PATH"), MAGISKTMP.data());
setenv("PATH", new_path, 1);
};
void exec_script(const char *script) {
exec_t exec {
.pre_exec = set_script_env,
.fork = fork_no_orphan
};
exec_command_sync(exec, BBEXEC_CMD, script);
}
static timespec pfs_timeout;
#define PFS_SETUP() \
if (pfs) { \
if (int pid = xfork()) { \
if (pid < 0) \
return; \
/* In parent process, simply wait for child to finish */ \
waitpid(pid, nullptr, 0); \
return; \
} \
timer_pid = xfork(); \
if (timer_pid == 0) { \
/* In timer process, count down */ \
clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &pfs_timeout, nullptr); \
exit(0); \
} \
}
#define PFS_WAIT() \
if (pfs) { \
/* If we ran out of time, don't block */ \
if (timer_pid < 0) \
continue; \
if (int pid = waitpid(-1, nullptr, 0); pid == timer_pid) { \
LOGW("* post-fs-data scripts blocking phase timeout\n"); \
timer_pid = -1; \
} \
}
#define PFS_DONE() \
if (pfs) { \
if (timer_pid > 0) \
kill(timer_pid, SIGKILL); \
exit(0); \
}
void exec_common_scripts(const char *stage) {
LOGI("* Running %s.d scripts\n", stage);
char path[4096];
char *name = path + sprintf(path, SECURE_DIR "/%s.d", stage);
auto dir = xopen_dir(path);
if (!dir) return;
bool pfs = stage == "post-fs-data"sv;
int timer_pid = -1;
if (pfs) {
// Setup timer
clock_gettime(CLOCK_MONOTONIC, &pfs_timeout);
pfs_timeout.tv_sec += POST_FS_DATA_SCRIPT_MAX_TIME;
}
PFS_SETUP()
*(name++) = '/';
int dfd = dirfd(dir.get());
for (dirent *entry; (entry = xreaddir(dir.get()));) {
if (entry->d_type == DT_REG) {
if (faccessat(dfd, entry->d_name, X_OK, 0) != 0)
continue;
LOGI("%s.d: exec [%s]\n", stage, entry->d_name);
strcpy(name, entry->d_name);
exec_t exec {
.pre_exec = set_script_env,
.fork = pfs ? xfork : fork_dont_care
};
exec_command(exec, BBEXEC_CMD, path);
PFS_WAIT()
}
}
PFS_DONE()
}
// Return if a > b
static bool timespec_larger(timespec *a, timespec *b) {
if (a->tv_sec != b->tv_sec)
return a->tv_sec > b->tv_sec;
return a->tv_nsec > b->tv_nsec;
}
void exec_module_scripts(const char *stage, const vector<string> &module_list) {
LOGI("* Running module %s scripts\n", stage);
if (module_list.empty())
return;
bool pfs = stage == "post-fs-data"sv;
if (pfs) {
timespec now{};
clock_gettime(CLOCK_MONOTONIC, &now);
// If we had already timed out, treat it as service mode
if (timespec_larger(&now, &pfs_timeout))
pfs = false;
}
int timer_pid = -1;
PFS_SETUP()
char path[4096];
for (auto &m : module_list) {
const char* module = m.data();
sprintf(path, MODULEROOT "/%s/%s.sh", module, stage);
if (access(path, F_OK) == -1)
continue;
LOGI("%s: exec [%s.sh]\n", module, stage);
exec_t exec {
.pre_exec = set_script_env,
.fork = pfs ? xfork : fork_dont_care
};
exec_command(exec, BBEXEC_CMD, path);
PFS_WAIT()
}
PFS_DONE()
}
constexpr char install_script[] = R"EOF(
APK=%s
log -t Magisk "apk_install: $APK"
log -t Magisk "apk_install: $(pm install -r $APK 2>&1)"
rm -f $APK
)EOF";
void install_apk(const char *apk) {
setfilecon(apk, "u:object_r:" SEPOL_FILE_TYPE ":s0");
exec_t exec {
.fork = fork_no_orphan
};
char cmds[sizeof(install_script) + 4096];
sprintf(cmds, install_script, apk);
exec_command_sync(exec, "/system/bin/sh", "-c", cmds);
}
[[noreturn]] __printflike(2, 3)
static void abort(FILE *fp, const char *fmt, ...) {
va_list valist;
va_start(valist, fmt);
vfprintf(fp, fmt, valist);
fprintf(fp, "\n\n");
va_end(valist);
exit(1);
}
constexpr char install_module_script[] = R"EOF(
exec $(magisk --path)/.magisk/busybox/busybox sh -c '
. /data/adb/magisk/util_functions.sh
install_module
exit 0'
)EOF";
void install_module(const char *file) {
if (getuid() != 0)
abort(stderr, "Run this command with root");
if (access(DATABIN, F_OK) ||
access(DATABIN "/busybox", X_OK) ||
access(DATABIN "/util_functions.sh", F_OK))
abort(stderr, "Incomplete Magisk install");
if (access(file, F_OK))
abort(stderr, "'%s' does not exist", file);
setenv("OUTFD", "1", 1);
setenv("ZIPFILE", file, 1);
setenv("ASH_STANDALONE", "1", 1);
int fd = xopen("/dev/null", O_RDONLY);
xdup2(fd, STDERR_FILENO);
close(fd);
const char *argv[] = { "/system/bin/sh", "-c", install_module_script, nullptr };
execve(argv[0], (char **) argv, environ);
abort(stdout, "Failed to execute BusyBox shell");
}