(define (read-from-request reader)
  (let* ((req (current-request))
         (headers (request-headers (current-request)))
         (content-length (header-value 'content-length headers)))
    (cond ((and content-length (zero? content-length))
           "")
          ((not content-length)
           (error 'echo-service "Set content-length, sloppy client"))
          (else (call-with-input-string
                 (read-string content-length (request-port req))
                 reader)))))