sunet/scheme/httpd/response.scm

262 lines
8.0 KiB
Scheme

;;; This file is part of the Scheme Untergrund Networking package.
;;; Copyright (c) 1994 by Brian D. Carlstrom and Olin Shivers.
;;; Copyright (c) 2002 by Mike Sperber.
;;; For copyright information, see the file COPYING which comes with
;;; the distribution.
(define-record-type http-response :http-response
(make-response code message seconds mime extras body)
response?
(code response-code)
(message response-message)
(seconds response-seconds)
(mime response-mime)
(extras response-extras)
(body response-body))
;; This is mainly for nph-... CGI scripts.
;; This means that the body will output the entire MIME message, not
;; just the part after the headers.
(define-record-type http-nph-response :http-nph-response
(make-nph-response body)
nph-response?
(body nph-response-body))
(define-record-type http-writer-body :http-writer-body
(make-writer-body proc)
writer-body?
(proc writer-body-proc))
(define-record-type http-reader-writer-body :http-reader-writer-body
(make-reader-writer-body proc)
reader-writer-body?
(proc reader-writer-body-proc))
(define-record-type http-redirect-body :http-redirect-body
(make-redirect-body location)
redirect-body?
(location redirect-body-location))
(define (display-http-body body iport oport options)
(cond
((writer-body? body)
((writer-body-proc body) oport options))
((reader-writer-body? body)
((reader-writer-body-proc body) iport oport options))))
(define-finite-type status-code :http-status-code
(number message)
status-code?
status-codes
status-code-name
status-code-index
(number status-code-number)
(message status-code-message)
(
(ok 200 "OK")
(created 201 "Created")
(accepted 202 "Accepted")
(prov-info 203 "Provisional Information")
(no-content 204 "No Content")
(mult-choice 300 "Multiple Choices")
(moved-perm 301 "Moved Permanently")
(moved-temp 302 "Moved Temporarily")
(method 303 "Method (obsolete)")
(not-mod 304 "Not Modified")
(bad-request 400 "Bad Request")
(unauthorized 401 "Unauthorized")
(payment-req 402 "Payment Required")
(forbidden 403 "Forbidden")
(not-found 404 "Not Found")
(method-not-allowed 405 "Method Not Allowed")
(none-acceptable 406 "None Acceptable")
(proxy-auth-required 407 "Proxy Authentication Required")
(timeout 408 "Request Timeout")
(conflict 409 "Conflict")
(gone 410 "Gone")
(internal-error 500 "Internal Server Error")
(not-implemented 501 "Not Implemented")
(bad-gateway 502 "Bad Gateway")
(service-unavailable 503 "Service Unavailable")
(gateway-timeout 504 "Gateway Timeout")
(redirect -301 "Internal redirect")))
(define (name->status-code name)
(if (not (symbol? name))
(call-error name->status-code (list name))
(let loop ((i 0))
(cond ((= i (vector-length status-codes))
#f)
((eq? name
(status-code-name (vector-ref status-codes i)))
(vector-ref status-codes i))
(else
(loop (+ i 1)))))))
(define (number->status-code number)
(if (not (number? number))
(call-error number->status-code (list number))
(let loop ((i 0))
(cond ((= i (vector-length status-codes))
#f)
((= number
(status-code-number (vector-ref status-codes i)))
(vector-ref status-codes i))
(else
(loop (+ i 1)))))))
;;; (make-error-response status-code req [message . extras])
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; As a special case, request REQ is allowed to be #f, meaning we haven't
;;; even had a chance to parse and construct the request. This is only used
;;; for 400 BAD-REQUEST error report.
(define (make-error-response code req . args)
(let* ((message (and (pair? args) (car args)))
(extras (if (pair? args) (cdr args) '()))
(generic-title (lambda (port)
(title-html port
(status-code-message code))))
(send-message (lambda (port)
(if message
(format port "<BR>~%Further Information: ~A<BR>~%" message))))
(close-html (lambda (port)
(for-each (lambda (x) (format port "<BR>~s~%" x)) extras)
(write-string "</BODY>\n" port)))
(create-response
(lambda (headers writer-proc)
(make-response code
#f
(time)
"text/html"
headers
(make-writer-body writer-proc)))))
(cond
;; This error response requires two args: message is the new URI: field,
;; and the first EXTRA is the older Location: field.
((or (eq? code (status-code moved-temp))
(eq? code (status-code moved-perm)))
(create-response
(list (cons 'uri message)
(cons 'location (car extras)))
(lambda (port options)
(title-html port "Document moved")
(format port
"This document has ~A moved to a <A HREF=\"~A\">new location</A>.~%"
(if (eq? code (status-code moved-temp))
"temporarily"
"permanently")
message)
(close-html port))))
((eq? code (status-code bad-request))
(create-response
'()
(lambda (port options)
(generic-title port)
(write-string "<P>Client sent a query that this server could not understand.\n"
port)
(send-message port)
(close-html port))))
((eq? code (status-code unauthorized))
(create-response
(list (cons 'WWW-Authenticate message)) ; Vas is das?
;; Vas das is? See: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.47
;; message should be a challenge(?)
(lambda (port options)
(title-html port "Authorization Required")
(write-string "<P>Browser not authentication-capable or\n" port)
(write-string "authentication failed.\n" port)
(send-message port)
(close-html port))))
((eq? code (status-code forbidden))
(create-response
'()
(lambda (port options)
(title-html port "Request not allowed.")
(format port
"Your client does not have permission to perform a ~A~%"
(request-method req))
(format port "operation on url ~a.~%" (request-uri req))
(send-message port)
(close-html port))))
((eq? code (status-code not-found))
(create-response
'()
(lambda (port options)
(title-html port "URL not found")
(write-string
"<P>The requested URL was not found on this server.\n"
port)
(send-message port)
(close-html port))))
((eq? code (status-code internal-error))
(create-response
'()
(lambda (port options)
(generic-title port)
(format port "The server encountered an internal error or
misconfiguration and was unable to complete your request.
<P>
Please inform the server administrator, ~A, of the circumstances leading to
the error, and time it occured.~%"
(or (httpd-options-server-admin options)
"[no mail address available]"))
(send-message port)
(close-html port))))
((eq? code (status-code not-implemented))
(create-response
'()
(lambda (port options)
(generic-title port)
(format port "This server does not currently implement
the requested method (~A).~%"
(request-method req))
(send-message port)
(close-html port))))
((eq? code (status-code bad-gateway))
(create-response
'()
(lambda (port options)
(generic-title port)
(format port "An error occured while waiting for the
response of a gateway.~%")
(send-message port)
(close-html port)))))))
(define (title-html out message)
(format out "<HEAD>~%<TITLE>~%~A~%</TITLE>~%</HEAD>~%~%" message)
(format out "<BODY>~%<H1>~A</H1>~%" message))
;; Creates a redirect response. The server will serve the new file
;; indicated by NEW-LOCATION. NEW-LOCATION must be uri-encoded and
;; begin with a slash. This is intended for CGI scripts. Note that
;; the browser won't notice the redirect. Thus, it will keep the
;; original URL. For "real" redirections, use
;; (make-error-response (status-code moved-perm) req
;; "new-location" "new-location").
(define (make-redirect-response new-location)
(make-response
(status-code redirect)
#f
(time)
""
'()
(make-redirect-body new-location)))