riju/backend/sandbox.js

51 lines
1.2 KiB
JavaScript

import { spawn } from "child_process";
import { promises as fs } from "fs";
import process from "process";
import { quote } from "shell-quote";
import { v4 as getUUID } from "uuid";
import { borrowUser } from "./users.js";
import {
privilegedSetup,
privilegedSpawn,
privilegedTeardown,
run,
} from "./util.js";
function die(msg) {
console.error(msg);
process.exit(1);
}
function log(msg) {
console.log(msg);
}
async function main() {
const sandboxScript = await fs.readFile("backend/sandbox.bash", "utf-8");
const lang = process.env.L;
if (!lang) {
die("environment variable unset: $L");
}
const uuid = getUUID();
const { uid, returnUser } = await borrowUser(log);
await run(privilegedSetup({ uid, uuid }), log);
const args = privilegedSpawn({ uid, uuid }, [
"bash",
"-c",
`exec env L='${lang}' bash --rcfile <(cat <<< ${quote([sandboxScript])})`,
]);
const proc = spawn(args[0], args.slice(1), {
stdio: "inherit",
});
await new Promise((resolve, reject) => {
proc.on("error", reject);
proc.on("close", resolve);
});
await run(privilegedTeardown({ uid, uuid }), log);
await returnUser();
}
main().catch(die);