feat(quota): add downloadable traffic quota with local/OSS/share metering

2026-02-17 16:52:26 +08:00
parent b0e89df5c4
commit 2629237f9e
5 changed files with 750 additions and 84 deletions
--- a/backend/server.js
+++ b/backend/server.js
@@ -80,6 +80,37 @@ const SHOULD_USE_SECURE_COOKIES =
  COOKIE_SECURE_MODE === 'true' ||
  (process.env.NODE_ENV === 'production' && COOKIE_SECURE_MODE !== 'false');

+function getResolvedStorageRoot() {
+  const configuredRoot = process.env.STORAGE_ROOT;
+  if (!configuredRoot) {
+    return path.join(__dirname, 'storage');
+  }
+  return path.isAbsolute(configuredRoot)
+    ? configuredRoot
+    : path.resolve(__dirname, configuredRoot);
+}
+
+function getLocalUserStorageDir(userId) {
+  return path.join(getResolvedStorageRoot(), `user_${userId}`);
+}
+
+function syncLocalStorageUsageFromDisk(userId, currentUsed = 0) {
+  const userStorageDir = getLocalUserStorageDir(userId);
+  if (!fs.existsSync(userStorageDir)) {
+    fs.mkdirSync(userStorageDir, { recursive: true, mode: 0o755 });
+  }
+
+  const actualUsed = getUserDirectorySize(userStorageDir);
+  const normalizedCurrentUsed = Number(currentUsed) || 0;
+
+  if (actualUsed !== normalizedCurrentUsed) {
+    UserDB.update(userId, { local_storage_used: actualUsed });
+    console.log(`[本地存储] 已校准用户 ${userId} 本地用量: ${normalizedCurrentUsed} -> ${actualUsed}`);
+  }
+
+  return actualUsed;
+}
+
 if (process.env.NODE_ENV === 'production' && COOKIE_SECURE_MODE !== 'true') {
  console.warn('[安全警告] 生产环境建议设置 COOKIE_SECURE=true，以避免会话Cookie在HTTP下传输');
 }
@@ -597,6 +628,74 @@ function normalizeOssQuota(rawQuota) {
  return parsedQuota;
 }

+function normalizeDownloadTrafficQuota(rawQuota) {
+  const parsedQuota = Number(rawQuota);
+  if (!Number.isFinite(parsedQuota) || parsedQuota <= 0) {
+    return 0; // 0 表示不限流量
+  }
+  return Math.floor(parsedQuota);
+}
+
+function normalizeDownloadTrafficUsed(rawUsed, quota = 0) {
+  const parsedUsed = Number(rawUsed);
+  const normalizedUsed = Number.isFinite(parsedUsed) && parsedUsed > 0
+    ? Math.floor(parsedUsed)
+    : 0;
+  if (quota > 0) {
+    return Math.min(normalizedUsed, quota);
+  }
+  return normalizedUsed;
+}
+
+function getDownloadTrafficState(user) {
+  const quota = normalizeDownloadTrafficQuota(user?.download_traffic_quota);
+  const used = normalizeDownloadTrafficUsed(user?.download_traffic_used, quota);
+  return {
+    quota,
+    used,
+    isUnlimited: quota <= 0,
+    remaining: quota > 0 ? Math.max(0, quota - used) : Number.POSITIVE_INFINITY
+  };
+}
+
+const applyDownloadTrafficUsageTransaction = db.transaction((userId, bytesToAdd) => {
+  const user = UserDB.findById(userId);
+  if (!user) {
+    return null;
+  }
+
+  const trafficState = getDownloadTrafficState(user);
+  if (bytesToAdd <= 0) {
+    return {
+      quota: trafficState.quota,
+      usedBefore: trafficState.used,
+      usedAfter: trafficState.used,
+      added: 0
+    };
+  }
+
+  const nextUsed = trafficState.isUnlimited
+    ? trafficState.used + bytesToAdd
+    : Math.min(trafficState.quota, trafficState.used + bytesToAdd);
+
+  UserDB.update(userId, { download_traffic_used: nextUsed });
+
+  return {
+    quota: trafficState.quota,
+    usedBefore: trafficState.used,
+    usedAfter: nextUsed,
+    added: Math.max(0, nextUsed - trafficState.used)
+  };
+});
+
+function applyDownloadTrafficUsage(userId, bytesToAdd) {
+  const parsedBytes = Number(bytesToAdd);
+  if (!Number.isFinite(parsedBytes) || parsedBytes <= 0) {
+    return null;
+  }
+  return applyDownloadTrafficUsageTransaction(userId, Math.floor(parsedBytes));
+}
+
 // 构建用于存储客户端的用户对象（自动尝试解密 OSS Secret）
 function buildStorageUserContext(user, overrides = {}) {
  if (!user) {
@@ -2052,6 +2151,11 @@ app.post('/api/login',
        });
      }

+      // 本地存储用量校准：防止目录被外部清理后仍显示旧用量
+      if ((user.current_storage_type || 'oss') === 'local') {
+        user.local_storage_used = syncLocalStorageUsageFromDisk(user.id, user.local_storage_used);
+      }
+
      const token = generateToken(user);
      const refreshToken = generateRefreshToken(user);

@@ -2104,6 +2208,11 @@ app.post('/api/login',
          local_storage_used: user.local_storage_used || 0,
          oss_storage_quota: normalizeOssQuota(user.oss_storage_quota),
          storage_used: user.storage_used || 0,
+          download_traffic_quota: normalizeDownloadTrafficQuota(user.download_traffic_quota),
+          download_traffic_used: normalizeDownloadTrafficUsed(
+            user.download_traffic_used,
+            normalizeDownloadTrafficQuota(user.download_traffic_quota)
+          ),
          // OSS配置来源（重要：用于前端判断是否使用OSS直连上传）
          oss_config_source: SettingsDB.hasUnifiedOssConfig() ? 'unified' : (user.has_oss_config ? 'personal' : 'none')
        }
@@ -2169,8 +2278,15 @@ app.post('/api/logout', (req, res) => {

 // 获取当前用户信息
 app.get('/api/user/profile', authMiddleware, (req, res) => {
+  const userPayload = { ...req.user };
+
+  // 本地存储用量校准：避免“有占用但目录为空”的显示错乱
+  if ((userPayload.current_storage_type || 'oss') === 'local') {
+    userPayload.local_storage_used = syncLocalStorageUsageFromDisk(userPayload.id, userPayload.local_storage_used);
+  }
+
  // 不返回敏感信息（密码和 OSS 密钥）
-  const { password, oss_access_key_secret, ...safeUser } = req.user;
+  const { password, oss_access_key_secret, ...safeUser } = userPayload;

  // 检查是否使用统一 OSS 配置
  const hasUnifiedConfig = SettingsDB.hasUnifiedOssConfig();
@@ -2800,8 +2916,19 @@ app.post('/api/user/switch-storage',
        }
      }

-      // 更新存储类型
-      UserDB.update(req.user.id, { current_storage_type: storage_type });
+      // 更新存储类型（切到本地时同步校准本地用量）
+      const updates = { current_storage_type: storage_type };
+      if (storage_type === 'local') {
+        const latestUser = UserDB.findById(req.user.id);
+        if (latestUser) {
+          updates.local_storage_used = syncLocalStorageUsageFromDisk(
+            latestUser.id,
+            latestUser.local_storage_used
+          );
+        }
+      }
+
+      UserDB.update(req.user.id, updates);

      res.json({
        success: true,
@@ -3580,6 +3707,23 @@ app.get('/api/files/download-url', authMiddleware, async (req, res) => {
    });
  }

+  // 开启下载流量配额后，禁止发放直连 URL（避免绕过后端计量）
+  const latestUser = UserDB.findById(req.user.id);
+  if (!latestUser) {
+    return res.status(401).json({
+      success: false,
+      message: '用户不存在'
+    });
+  }
+
+  const trafficState = getDownloadTrafficState(latestUser);
+  if (!trafficState.isUnlimited) {
+    return res.status(403).json({
+      success: false,
+      message: '当前账号已启用下载流量限制，请使用系统下载入口'
+    });
+  }
+
  // 检查用户是否配置了 OSS（包括个人配置和系统级统一配置）
  const hasUnifiedConfig = SettingsDB.hasUnifiedOssConfig();
  if (!req.user.has_oss_config && !hasUnifiedConfig) {
@@ -3788,6 +3932,15 @@ app.get('/api/files/download', authMiddleware, async (req, res) => {
  const filePath = req.query.path;
  let storage;
  let storageEnded = false; // 防止重复关闭
+  let transferFinalized = false; // 防止重复结算
+  let downloadedBytes = 0;
+  let responseBodyStartSocketBytes = 0;
+
+  // Express 会将 HEAD 映射到 GET 处理器，这里显式拒绝，避免误触发下载计量
+  if (req.method === 'HEAD') {
+    res.setHeader('Allow', 'GET');
+    return res.status(405).end();
+  }

  // 安全关闭存储连接的辅助函数
  const safeEndStorage = async () => {
@@ -3801,6 +3954,39 @@ app.get('/api/files/download', authMiddleware, async (req, res) => {
    }
  };

+  const finalizeTransfer = async (reason = '') => {
+    if (transferFinalized) {
+      return;
+    }
+    transferFinalized = true;
+
+    try {
+      const socketBytesWritten = Number(res.socket?.bytesWritten);
+      const socketBodyBytes = Number.isFinite(socketBytesWritten) && socketBytesWritten > responseBodyStartSocketBytes
+        ? Math.floor(socketBytesWritten - responseBodyStartSocketBytes)
+        : 0;
+      const billableBytes = socketBodyBytes > 0
+        ? Math.min(downloadedBytes, socketBodyBytes)
+        : downloadedBytes;
+
+      if (billableBytes > 0) {
+        const usageResult = applyDownloadTrafficUsage(req.user.id, billableBytes);
+        if (usageResult) {
+          const quotaText = usageResult.quota > 0 ? formatFileSize(usageResult.quota) : '不限';
+          console.log(
+            `[下载流量] 用户 ${req.user.id} 新增 ${formatFileSize(usageResult.added)}，` +
+            `累计 ${formatFileSize(usageResult.usedAfter)} / ${quotaText} ` +
+            `(reason=${reason || 'unknown'}, streamed=${downloadedBytes}, socket=${socketBodyBytes})`
+          );
+        }
+      }
+    } catch (error) {
+      console.error(`[下载流量] 结算失败: user=${req.user.id}, bytes=${downloadedBytes}`, error);
+    }
+
+    await safeEndStorage();
+  };
+
  if (!filePath) {
    return res.status(400).json({
      success: false,
@@ -3818,26 +4004,66 @@ app.get('/api/files/download', authMiddleware, async (req, res) => {
  }

  try {
+    const latestUser = UserDB.findById(req.user.id);
+    if (!latestUser) {
+      return res.status(401).json({
+        success: false,
+        message: '用户不存在'
+      });
+    }
+    const trafficState = getDownloadTrafficState(latestUser);
+
    // 使用统一存储接口
    const { StorageInterface } = require('./storage');
    const storageInterface = new StorageInterface(req.user);
    storage = await storageInterface.connect();

    // 获取文件名
-    const fileName = filePath.split('/').pop();
+    const fileName = normalizedPath.split('/').pop() || 'download.bin';

    // 先获取文件信息（获取文件大小）
-    const fileStats = await storage.stat(filePath);
-    const fileSize = fileStats.size;
+    const fileStats = await storage.stat(normalizedPath);
+    const fileSize = Math.max(0, Number(fileStats?.size) || 0);
    console.log('[下载] 文件: ' + fileName + ', 大小: ' + fileSize + ' 字节');

+    if (!trafficState.isUnlimited && fileSize > trafficState.remaining) {
+      await safeEndStorage();
+      return res.status(403).json({
+        success: false,
+        message: `下载流量不足：文件 ${formatFileSize(fileSize)}，剩余 ${formatFileSize(trafficState.remaining)}`
+      });
+    }
+
    // 设置响应头（包含文件大小，浏览器可显示下载进度）
    res.setHeader('Content-Type', 'application/octet-stream');
    res.setHeader('Content-Length', fileSize);
+    // 关闭 Nginx 代理缓冲，避免上游提前读完整文件导致流量计量失真
+    res.setHeader('X-Accel-Buffering', 'no');
    res.setHeader('Content-Disposition', 'attachment; filename="' + encodeURIComponent(fileName) + '"; filename*=UTF-8\'\'' + encodeURIComponent(fileName));
+    if (typeof res.flushHeaders === 'function') {
+      res.flushHeaders();
+    }
+    responseBodyStartSocketBytes = Number(res.socket?.bytesWritten) || 0;

    // 创建文件流并传输（流式下载，服务器不保存临时文件）
-    const stream = await storage.createReadStream(filePath);
+    const stream = await storage.createReadStream(normalizedPath);
+
+    stream.on('data', (chunk) => {
+      if (!chunk) return;
+      downloadedBytes += Buffer.isBuffer(chunk) ? chunk.length : Buffer.byteLength(chunk);
+    });
+
+    res.on('finish', () => {
+      finalizeTransfer('finish').catch(err => {
+        console.error('下载完成后资源释放失败:', err);
+      });
+    });
+
+    res.on('close', () => {
+      finalizeTransfer('close').catch(err => {
+        console.error('下载连接关闭后资源释放失败:', err);
+      });
+    });

    stream.on('error', (error) => {
      console.error('文件流错误:', error);
@@ -3847,14 +4073,9 @@ app.get('/api/files/download', authMiddleware, async (req, res) => {
          message: getSafeErrorMessage(error, '下载文件失败，请稍后重试', '下载文件')
        });
      }
-      // 发生错误时关闭存储连接
-      safeEndStorage();
-    });
-
-    // 在传输完成后关闭存储连接
-    stream.on('close', () => {
-      console.log('[下载] 文件传输完成，关闭存储连接');
-      safeEndStorage();
+      finalizeTransfer('stream_error').catch(err => {
+        console.error('流错误后资源释放失败:', err);
+      });
    });

    stream.pipe(res);
@@ -3863,7 +4084,7 @@ app.get('/api/files/download', authMiddleware, async (req, res) => {
    console.error('下载文件失败:', error);

    // 如果stream还未创建或发生错误，关闭storage连接
-    await safeEndStorage();
+    await finalizeTransfer('catch_error');
    if (!res.headersSent) {
      res.status(500).json({
        success: false,
@@ -4783,9 +5004,10 @@ app.post('/api/share/:code/download-url', shareRateLimitMiddleware, async (req,
    }

    const storageType = share.storage_type || 'oss';
+    const ownerTrafficState = getDownloadTrafficState(shareOwner);

-    // 本地存储模式：返回后端下载 URL（短期 token，避免在 URL 中传密码）
-    if (storageType !== 'oss') {
+    // 本地存储，或分享者启用了下载流量上限：统一走后端下载（便于计量）
+    if (storageType !== 'oss' || !ownerTrafficState.isUnlimited) {
      let downloadUrl = `${getSecureBaseUrl(req)}/api/share/${code}/download-file?path=${encodeURIComponent(normalizedFilePath)}`;

      if (share.share_password) {
@@ -4800,7 +5022,8 @@ app.post('/api/share/:code/download-url', shareRateLimitMiddleware, async (req,
      return res.json({
        success: true,
        downloadUrl,
-        direct: false
+        direct: false,
+        quotaLimited: !ownerTrafficState.isUnlimited
      });
    }

@@ -4845,8 +5068,7 @@ app.post('/api/share/:code/download-url', shareRateLimitMiddleware, async (req,
  }
 });

-// 分享文件下载（支持本地存储，公开API，需要分享码和密码验证）
-// 注意：OSS 模式请使用 /api/share/:code/download-url 获取直连下载链接
+// 分享文件下载（支持本地存储和 OSS，公开 API，需要分享码和密码验证）
 app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req, res) => {
  const { code } = req.params;
  const rawFilePath = typeof req.query?.path === 'string' ? req.query.path : '';
@@ -4854,6 +5076,16 @@ app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req,
  const filePath = normalizeVirtualPath(rawFilePath);
  let storage;
  let storageEnded = false; // 防止重复关闭
+  let transferFinalized = false; // 防止重复结算
+  let downloadedBytes = 0;
+  let responseBodyStartSocketBytes = 0;
+  let shareOwnerId = null;
+
+  // Express 会将 HEAD 映射到 GET 处理器，这里显式拒绝，避免误触发下载计量
+  if (req.method === 'HEAD') {
+    res.setHeader('Allow', 'GET');
+    return res.status(405).end();
+  }

  // 安全关闭存储连接的辅助函数
  const safeEndStorage = async () => {
@@ -4867,6 +5099,39 @@ app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req,
    }
  };

+  const finalizeTransfer = async (reason = '') => {
+    if (transferFinalized) {
+      return;
+    }
+    transferFinalized = true;
+
+    try {
+      if (shareOwnerId && downloadedBytes > 0) {
+        const socketBytesWritten = Number(res.socket?.bytesWritten);
+        const socketBodyBytes = Number.isFinite(socketBytesWritten) && socketBytesWritten > responseBodyStartSocketBytes
+          ? Math.floor(socketBytesWritten - responseBodyStartSocketBytes)
+          : 0;
+        const billableBytes = socketBodyBytes > 0
+          ? Math.min(downloadedBytes, socketBodyBytes)
+          : downloadedBytes;
+
+        const usageResult = applyDownloadTrafficUsage(shareOwnerId, billableBytes);
+        if (usageResult) {
+          const quotaText = usageResult.quota > 0 ? formatFileSize(usageResult.quota) : '不限';
+          console.log(
+            `[分享下载流量] 用户 ${shareOwnerId} 新增 ${formatFileSize(usageResult.added)}，` +
+            `累计 ${formatFileSize(usageResult.usedAfter)} / ${quotaText} ` +
+            `(reason=${reason || 'unknown'}, streamed=${downloadedBytes}, socket=${socketBodyBytes})`
+          );
+        }
+      }
+    } catch (error) {
+      console.error(`[分享下载流量] 结算失败: user=${shareOwnerId}, bytes=${downloadedBytes}`, error);
+    }
+
+    await safeEndStorage();
+  };
+
  if (!filePath) {
    return res.status(400).json({
      success: false,
@@ -4935,6 +5200,8 @@ app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req,
        message: '分享者不存在'
      });
    }
+    shareOwnerId = shareOwner.id;
+    const ownerTrafficState = getDownloadTrafficState(shareOwner);

    // 使用统一存储接口，根据分享的storage_type选择存储后端
    // 注意：必须使用分享创建时记录的 storage_type，而不是分享者当前的存储类型
@@ -4959,17 +5226,48 @@ app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req,
    const fileSize = fileStats.size;
    console.log(`[分享下载] 文件: ${fileName}, 大小: ${fileSize} 字节`);

+    if (!ownerTrafficState.isUnlimited && fileSize > ownerTrafficState.remaining) {
+      await safeEndStorage();
+      return res.status(403).json({
+        success: false,
+        message: `分享者下载流量不足：文件 ${formatFileSize(fileSize)}，剩余 ${formatFileSize(ownerTrafficState.remaining)}`
+      });
+    }
+
    // 增加下载次数
    ShareDB.incrementDownloadCount(code);

    // 设置响应头（包含文件大小，浏览器可显示下载进度）
    res.setHeader('Content-Type', 'application/octet-stream');
    res.setHeader('Content-Length', fileSize);
+    // 关闭 Nginx 代理缓冲，减少代理预读导致的计量偏差
+    res.setHeader('X-Accel-Buffering', 'no');
    res.setHeader('Content-Disposition', `attachment; filename="${encodeURIComponent(fileName)}"; filename*=UTF-8''${encodeURIComponent(fileName)}`);
+    if (typeof res.flushHeaders === 'function') {
+      res.flushHeaders();
+    }
+    responseBodyStartSocketBytes = Number(res.socket?.bytesWritten) || 0;

    // 创建文件流并传输（流式下载，服务器不保存临时文件）
    const stream = await storage.createReadStream(filePath);

+    stream.on('data', (chunk) => {
+      if (!chunk) return;
+      downloadedBytes += Buffer.isBuffer(chunk) ? chunk.length : Buffer.byteLength(chunk);
+    });
+
+    res.on('finish', () => {
+      finalizeTransfer('finish').catch(err => {
+        console.error('分享下载完成后资源释放失败:', err);
+      });
+    });
+
+    res.on('close', () => {
+      finalizeTransfer('close').catch(err => {
+        console.error('分享下载连接关闭后资源释放失败:', err);
+      });
+    });
+
    stream.on('error', (error) => {
      console.error('文件流错误:', error);
      if (!res.headersSent) {
@@ -4978,14 +5276,9 @@ app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req,
          message: getSafeErrorMessage(error, '下载文件失败，请稍后重试', '分享下载')
        });
      }
-      // 发生错误时关闭存储连接
-      safeEndStorage();
-    });
-
-    // 在传输完成后关闭存储连接
-    stream.on('close', () => {
-      console.log('[分享下载] 文件传输完成，关闭存储连接');
-      safeEndStorage();
+      finalizeTransfer('stream_error').catch(err => {
+        console.error('分享下载流错误后资源释放失败:', err);
+      });
    });

    stream.pipe(res);
@@ -4998,8 +5291,8 @@ app.get('/api/share/:code/download-file', shareRateLimitMiddleware, async (req,
        message: getSafeErrorMessage(error, '下载文件失败，请稍后重试', '分享下载')
      });
    }
-    // 如果发生错误，关闭存储连接
-    await safeEndStorage();
+    // 如果发生错误，结算并关闭存储连接
+    await finalizeTransfer('catch_error');
  }
 });

@@ -5423,7 +5716,7 @@ app.get('/api/admin/health-check', authMiddleware, adminMiddleware, async (req,
    });

    // 7. 存储目录检查
-    const storageRoot = process.env.STORAGE_ROOT || path.join(__dirname, 'storage');
+    const storageRoot = getResolvedStorageRoot();
    let storageStatus = 'pass';
    let storageMessage = `存储目录正常: ${storageRoot}`;
    try {
@@ -5629,7 +5922,7 @@ app.post('/api/admin/wal-checkpoint',
 app.get('/api/admin/storage-stats', authMiddleware, adminMiddleware, async (req, res) => {
  try {
    // 获取本地存储目录（与 storage.js 保持一致）
-    const localStorageDir = process.env.STORAGE_ROOT || path.join(__dirname, 'storage');
+    const localStorageDir = getResolvedStorageRoot();

    // 确保存储目录存在
    if (!fs.existsSync(localStorageDir)) {
@@ -5740,7 +6033,12 @@ app.get('/api/admin/users', authMiddleware, adminMiddleware, (req, res) => {
        local_storage_quota: u.local_storage_quota || DEFAULT_LOCAL_STORAGE_QUOTA_BYTES,
        local_storage_used: u.local_storage_used || 0,
        oss_storage_quota: normalizeOssQuota(u.oss_storage_quota),
-        storage_used: u.storage_used || 0
+        storage_used: u.storage_used || 0,
+        download_traffic_quota: normalizeDownloadTrafficQuota(u.download_traffic_quota),
+        download_traffic_used: normalizeDownloadTrafficUsed(
+          u.download_traffic_used,
+          normalizeDownloadTrafficQuota(u.download_traffic_quota)
+        )
      }))
    });
  } catch (error) {
@@ -6209,7 +6507,7 @@ app.delete('/api/admin/users/:id',
    // 1. 删除本地存储文件（如果用户使用了本地存储）
    const storagePermission = user.storage_permission || 'oss_only';
    if (storagePermission === 'local_only' || storagePermission === 'user_choice') {
-      const storageRoot = process.env.STORAGE_ROOT || path.join(__dirname, 'storage');
+      const storageRoot = getResolvedStorageRoot();
      const userStorageDir = path.join(storageRoot, `user_${userId}`);

      if (fs.existsSync(userStorageDir)) {
@@ -6295,6 +6593,10 @@ app.delete('/api/admin/users/:id',

 // 辅助函数：计算目录大小
 function getUserDirectorySize(dirPath) {
+  if (!dirPath || !fs.existsSync(dirPath)) {
+    return 0;
+  }
+
  let totalSize = 0;

  function calculateSize(currentPath) {
@@ -6325,7 +6627,8 @@ app.post('/api/admin/users/:id/storage-permission',
  [
    body('storage_permission').isIn(['local_only', 'oss_only', 'user_choice']).withMessage('无效的存储权限'),
    body('local_storage_quota').optional({ nullable: true }).isInt({ min: 1048576, max: 10995116277760 }).withMessage('本地配额必须在 1MB 到 10TB 之间'),
-    body('oss_storage_quota').optional({ nullable: true }).isInt({ min: 1048576, max: 10995116277760 }).withMessage('OSS配额必须在 1MB 到 10TB 之间')
+    body('oss_storage_quota').optional({ nullable: true }).isInt({ min: 1048576, max: 10995116277760 }).withMessage('OSS配额必须在 1MB 到 10TB 之间'),
+    body('download_traffic_quota').optional({ nullable: true }).isInt({ min: 0, max: 10995116277760 }).withMessage('下载流量配额必须在 0 到 10TB 之间（0表示不限）')
  ],
  (req, res) => {
    const errors = validationResult(req);
@@ -6338,7 +6641,7 @@ app.post('/api/admin/users/:id/storage-permission',

    try {
      const { id } = req.params;
-      const { storage_permission, local_storage_quota, oss_storage_quota } = req.body;
+      const { storage_permission, local_storage_quota, oss_storage_quota, download_traffic_quota } = req.body;

      // 参数验证：验证 ID 格式
      const userId = parseInt(id, 10);
@@ -6361,6 +6664,11 @@ app.post('/api/admin/users/:id/storage-permission',
        updates.oss_storage_quota = parseInt(oss_storage_quota, 10);
      }

+      // 如果提供了下载流量配额，更新配额（单位：字节，0 表示不限）
+      if (download_traffic_quota !== undefined && download_traffic_quota !== null) {
+        updates.download_traffic_quota = parseInt(download_traffic_quota, 10);
+      }
+
      // 根据权限设置自动调整存储类型
      const user = UserDB.findById(userId);
      if (!user) {
@@ -6370,6 +6678,17 @@ app.post('/api/admin/users/:id/storage-permission',
        });
      }

+      // 如果管理员把配额调小，已用流量不能超过新配额
+      if (
+        updates.download_traffic_quota !== undefined &&
+        updates.download_traffic_quota > 0
+      ) {
+        updates.download_traffic_used = normalizeDownloadTrafficUsed(
+          user.download_traffic_used,
+          updates.download_traffic_quota
+        );
+      }
+
      if (storage_permission === 'local_only') {
        updates.current_storage_type = 'local';
      } else if (storage_permission === 'oss_only') {