Refactor VPN proxy client implementation

src/server/singboxRuntime.ts

@@ -0,0 +1,108 @@
+import crypto from 'node:crypto';
+import fs from 'node:fs';
+import { spawn, spawnSync, type ChildProcess } from 'node:child_process';
+import { setGatewayInterception } from './gatewayRouting.js';
+import { HarborError } from '../shared/errors.js';
+
+export function createSingboxRuntime({
+  configPath,
+  gateway = false,
+  tproxyChain = '',
+}: {
+  configPath: string;
+  gateway?: boolean;
+  tproxyChain?: string;
+}) {
+  let child: ChildProcess | null = null;
+  let configHash = '';
+  let startedAt: string | null = null;
+
+  const state = () => ({ running: Boolean(child), startedAt });
+
+  async function stop() {
+    if (gateway) setGatewayInterception(false, tproxyChain);
+    if (!child) {
+      configHash = '';
+      startedAt = null;
+      return state();
+    }
+
+    const current = child;
+    child = null;
+    configHash = '';
+    startedAt = null;
+    await new Promise<void>((resolve) => {
+      const timeout = setTimeout(() => {
+        current.kill('SIGKILL');
+        resolve();
+      }, 4000);
+      current.once('exit', () => {
+        clearTimeout(timeout);
+        resolve();
+      });
+      current.kill('SIGTERM');
+    });
+    return state();
+  }
+
+  async function apply({ force = false } = {}) {
+    if (!fs.existsSync(configPath)) {
+      await stop();
+      return state();
+    }
+
+    const check = spawnSync('sing-box', ['check', '-c', configPath], { encoding: 'utf8' });
+    if (check.status !== 0) {
+      throw new HarborError('CONFIG_INVALID', {
+        cause: new Error((check.stderr || check.stdout || check.error?.message || 'sing-box check failed').trim()),
+      });
+    }
+
+    const nextHash = crypto.createHash('sha256').update(fs.readFileSync(configPath)).digest('hex');
+    if (!force && child && nextHash === configHash) return state();
+
+    await stop();
+    let current: ChildProcess;
+    try {
+      current = spawn('sing-box', ['run', '-c', configPath], {
+        stdio: ['ignore', 'inherit', 'inherit'],
+      });
+      await new Promise<void>((resolve, reject) => {
+        current.once('spawn', resolve);
+        current.once('error', reject);
+      });
+    } catch (cause) {
+      throw new HarborError('PROCESS_START_FAILED', { cause });
+    }
+    child = current;
+    configHash = nextHash;
+    startedAt = new Date().toISOString();
+    try {
+      if (gateway) setGatewayInterception(true, tproxyChain);
+    } catch (error) {
+      current.kill('SIGTERM');
+      child = null;
+      configHash = '';
+      startedAt = null;
+      throw new HarborError('PROCESS_START_FAILED', { cause: error });
+    }
+    current.once('exit', () => {
+      if (child !== current) return;
+      child = null;
+      configHash = '';
+      startedAt = null;
+      if (gateway) setGatewayInterception(false, tproxyChain);
+    });
+    return state();
+  }
+
+  return {
+    get running() { return Boolean(child); },
+    get startedAt() { return startedAt; },
+    refresh: async () => state(),
+    apply,
+    restart: () => apply({ force: true }),
+    stop,
+    shutdown: stop,
+  };
+}