LibreChat/api/server/middleware/logHeaders.js

const { logger } = require('@librechat/data-schemas');

/**
 * Middleware to log Forwarded Headers
 * @function
 * @param {ServerRequest} req - Express request object containing user information.
 * @param {ServerResponse} res - Express response object.
 * @param {import('express').NextFunction} next - Next middleware function.
 * @throws {Error} Throws an error if the user exceeds the concurrent request limit.
 */
const logHeaders = (req, res, next) => {
  try {
    const forwardedHeaders = {};
    if (req.headers['x-forwarded-for']) {
      forwardedHeaders['x-forwarded-for'] = req.headers['x-forwarded-for'];
    }
    if (req.headers['x-forwarded-host']) {
      forwardedHeaders['x-forwarded-host'] = req.headers['x-forwarded-host'];
    }
    if (req.headers['x-forwarded-proto']) {
      forwardedHeaders['x-forwarded-proto'] = req.headers['x-forwarded-proto'];
    }
    if (Object.keys(forwardedHeaders).length > 0) {
      logger.debug('X-Forwarded headers detected in OAuth request:', forwardedHeaders);
    }
  } catch (error) {
    logger.error('Error logging X-Forwarded headers:', error);
  }
  next();
};

module.exports = logHeaders;