racket/collects/web-server/http/cookie-parse.ss
Jay McCarthy bebc7f50ef cookie debugging
svn: r13876
2009-02-27 21:49:42 +00:00

149 lines
5.0 KiB
Scheme

#lang scheme
(require web-server/http/request-structs
net/cookie
web-server/private/util
scheme/contract)
(define-struct client-cookie
(name value domain path)
#:transparent)
(provide/contract
[struct client-cookie
([name string?]
[value string?]
[domain (or/c false/c valid-domain?)]
[path (or/c false/c string?)])]
[request-cookies (request? . -> . (listof client-cookie?))])
;; ============================================================
;; utilities for retrieving cookies
(require parser-tools/lex
parser-tools/yacc
(prefix-in : parser-tools/lex-sre))
#|
cookie = "Cookie:" cookie-version
1*((";" | ",") cookie-value)
cookie-value = NAME "=" VALUE [";" path] [";" domain]
cookie-version = "$Version" "=" value
NAME = attr
VALUE = value
path = "$Path" "=" value
domain = "$Domain" "=" value
|#
(define-lex-abbrevs
(tspecial (:or (char-set "()<>@,;:\\\"/[]?={}") whitespace #\tab))
(token-char (:- any-char tspecial iso-control)))
(define-tokens regular (TOKEN QUOTED-STRING))
(define-empty-tokens keywords (EQUALS SEMI COMMA PATH DOMAIN VERSION EOF))
(define cookie-lexer
(lexer-src-pos
[(eof) (token-EOF)]
[whitespace (return-without-pos (cookie-lexer input-port))]
["=" (token-EQUALS)]
[";" (token-SEMI)]
["," (token-COMMA)]
["$Path" (token-PATH)]
["$Domain" (token-DOMAIN)]
["$Version" (token-VERSION)]
[(:: #\" (:* (:or (:~ #\") "\\\"")) #\")
(token-QUOTED-STRING (substring lexeme 1 (- (string-length lexeme) 1)))]
[(:+ token-char) (token-TOKEN lexeme)]))
(define current-source-name (make-parameter #f))
(define (make-srcloc start-pos end-pos)
(list (current-source-name)
(position-line start-pos)
(position-col start-pos)
(position-offset start-pos)
(- (position-offset end-pos) (position-offset start-pos))))
(define assoc-list-parser
(parser (src-pos)
(start cookie)
(tokens regular keywords)
(grammar (cookie [(VERSION EQUALS rhs separator items) $5]
[(items) $1])
(items [(item separator items) (cons $1 $3)]
[(item) (list $1)])
(separator
[(COMMA) #t]
[(SEMI) #t])
(item [(lhs EQUALS rhs) (cons $1 $3)])
(lhs [(DOMAIN) 'domain]
[(PATH) 'path]
[(TOKEN) $1])
(rhs [(TOKEN) $1]
[(QUOTED-STRING) $1]))
(end EOF)
(error (lambda (tok-ok? tok-name tok-value start-pos end-pos)
(raise-syntax-error
'assoc-list-parser
(format
(if tok-ok?
"Did not expect token ~a"
"Invalid token ~a")
tok-name)
(datum->syntax #f tok-value (make-srcloc start-pos end-pos)))))))
(define (do-parse str)
(with-handlers ([exn:fail?
(λ (e) empty)])
(with-input-from-string
str
(λ ()
(let ([ip (current-input-port)])
(port-count-lines! ip)
(parameterize ([current-source-name (object-name ip)])
(raw->cookies (assoc-list-parser (λ () (cookie-lexer ip))))))))))
;; raw->cookies : flat-property-list -> (listof cookie)
(define (raw->cookies associations)
;; get-cookie-setter : symbol -> cookie string -> cookie
;; gets a setter for the given property
(define (get-cookie-setter property-name)
(case property-name
[(domain)
(λ (c x)
(struct-copy client-cookie c
[domain x]))]
[(path)
(λ (c x)
(struct-copy client-cookie c
[path x]))]
[else
(λ (c x) c)]))
(unless (and (pair? associations) (string? (car (car associations))))
(error 'raw->cookies "expected a non-empty association list headed by a cookie"))
(let loop ([l (cdr associations)]
[c (make-client-cookie (car (car associations))
(cdr (car associations))
#f #f)])
(cond
[(null? l) (list c)]
[(string? (car (car l)))
(cons c (loop (cdr l) (make-client-cookie
(car (car l))
(cdr (car l))
#f #f)))]
[else
(loop (cdr l)
((get-cookie-setter (car (car l))) c (cdr (car l))))])))
;; request-cookies* : request -> (listof cookie)
(define (request-cookies req)
(define hdrs (request-headers/raw req))
(apply append
(map (compose do-parse bytes->string/utf-8 header-value)
(filter (lambda (h)
(bytes-ci=? #"Cookie" (header-field h)))
hdrs))))