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a9eeb2f4 AW |
1 | ;;; HTTP response objects |
2 | ||
3 | ;; Copyright (C) 2010 Free Software Foundation, Inc. | |
4 | ||
5 | ;; This library is free software; you can redistribute it and/or | |
6 | ;; modify it under the terms of the GNU Lesser General Public | |
7 | ;; License as published by the Free Software Foundation; either | |
8 | ;; version 3 of the License, or (at your option) any later version. | |
9 | ;; | |
10 | ;; This library is distributed in the hope that it will be useful, | |
11 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | ;; Lesser General Public License for more details. | |
14 | ;; | |
15 | ;; You should have received a copy of the GNU Lesser General Public | |
16 | ;; License along with this library; if not, write to the Free Software | |
17 | ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
18 | ;; 02110-1301 USA | |
19 | ||
20 | ;;; Code: | |
21 | ||
22 | (define-module (web response) | |
23 | #:use-module (rnrs bytevectors) | |
24 | #:use-module (rnrs io ports) | |
25 | #:use-module (ice-9 rdelim) | |
26 | #:use-module (srfi srfi-9) | |
27 | #:use-module (web http) | |
28 | #:export (response? | |
29 | response-version | |
30 | response-code | |
31 | response-reason-phrase | |
32 | response-headers | |
33 | response-port | |
34 | read-response | |
35 | build-response | |
3d959779 | 36 | extend-response |
c6371902 | 37 | adapt-response-version |
a9eeb2f4 AW |
38 | write-response |
39 | ||
40 | read-response-body/latin-1 | |
41 | write-response-body/latin-1 | |
42 | ||
43 | read-response-body/bytevector | |
44 | write-response-body/bytevector | |
45 | ||
46 | ;; General headers | |
47 | ;; | |
48 | response-cache-control | |
49 | response-connection | |
50 | response-date | |
51 | response-pragma | |
52 | response-trailer | |
53 | response-transfer-encoding | |
54 | response-upgrade | |
55 | response-via | |
56 | response-warning | |
57 | ||
58 | ;; Entity headers | |
59 | ;; | |
60 | response-allow | |
61 | response-content-encoding | |
62 | response-content-language | |
63 | response-content-length | |
64 | response-content-location | |
65 | response-content-md5 | |
66 | response-content-range | |
67 | response-content-type | |
68 | response-expires | |
69 | response-last-modified | |
70 | ||
71 | ;; Response headers | |
72 | ;; | |
73 | response-accept-ranges | |
74 | response-age | |
75 | response-etag | |
76 | response-location | |
77 | response-proxy-authenticate | |
78 | response-retry-after | |
79 | response-server | |
80 | response-vary | |
81 | response-www-authenticate)) | |
82 | ||
83 | ||
84 | (define-record-type <response> | |
85 | (make-response version code reason-phrase headers port) | |
86 | response? | |
87 | (version response-version) | |
88 | (code response-code) | |
89 | (reason-phrase %response-reason-phrase) | |
90 | (headers response-headers) | |
91 | (port response-port)) | |
92 | ||
93 | (define (bad-response message . args) | |
94 | (throw 'bad-response message args)) | |
95 | ||
e2d4bfea AW |
96 | (define (non-negative-integer? n) |
97 | (and (number? n) (>= n 0) (exact? n) (integer? n))) | |
98 | ||
99 | (define (validate-headers headers) | |
100 | (if (pair? headers) | |
101 | (let ((h (car headers))) | |
102 | (if (pair? h) | |
103 | (let ((k (car h)) (v (cdr h))) | |
104 | (if (symbol? k) | |
105 | (if (not (valid-header? k v)) | |
106 | (bad-response "Bad value for header ~a: ~s" k v)) | |
107 | (if (not (and (string? k) (string? v))) | |
108 | (bad-response "Unknown header not a pair of strings: ~s" | |
109 | h))) | |
110 | (validate-headers (cdr headers))) | |
111 | (bad-response "Header not a pair: ~a" h))) | |
112 | (if (not (null? headers)) | |
113 | (bad-response "Headers not a list: ~a" headers)))) | |
114 | ||
a9eeb2f4 | 115 | (define* (build-response #:key (version '(1 . 1)) (code 200) reason-phrase |
e2d4bfea | 116 | (headers '()) port (validate-headers? #t)) |
cc1e26c2 AW |
117 | "Construct an HTTP response object. If @var{validate-headers?} is true, |
118 | the headers are each run through their respective validators." | |
e2d4bfea AW |
119 | (cond |
120 | ((not (and (pair? version) | |
121 | (non-negative-integer? (car version)) | |
122 | (non-negative-integer? (cdr version)))) | |
123 | (bad-response "Bad version: ~a" version)) | |
124 | ((not (and (non-negative-integer? code) (< code 600))) | |
125 | (bad-response "Bad code: ~a" code)) | |
126 | ((and reason-phrase (not (string? reason-phrase))) | |
127 | (bad-response "Bad reason phrase" reason-phrase)) | |
128 | (else | |
129 | (if validate-headers? | |
130 | (validate-headers headers)))) | |
a9eeb2f4 AW |
131 | (make-response version code reason-phrase headers port)) |
132 | ||
3d959779 | 133 | (define (extend-response r k v . additional) |
cc1e26c2 AW |
134 | "Extend an HTTP response by setting additional HTTP headers @var{k}, |
135 | @var{v}. Returns a new HTTP response." | |
3d959779 AW |
136 | (let ((r (build-response #:version (response-version r) |
137 | #:code (response-code r) | |
138 | #:reason-phrase (%response-reason-phrase r) | |
139 | #:headers | |
140 | (assoc-set! (copy-tree (response-headers r)) | |
141 | k v) | |
142 | #:port (response-port r)))) | |
143 | (if (null? additional) | |
144 | r | |
145 | (apply extend-response r additional)))) | |
146 | ||
a9eeb2f4 AW |
147 | (define *reason-phrases* |
148 | '((100 . "Continue") | |
149 | (101 . "Switching Protocols") | |
150 | (200 . "OK") | |
151 | (201 . "Created") | |
152 | (202 . "Accepted") | |
153 | (203 . "Non-Authoritative Information") | |
154 | (204 . "No Content") | |
155 | (205 . "Reset Content") | |
156 | (206 . "Partial Content") | |
157 | (300 . "Multiple Choices") | |
158 | (301 . "Moved Permanently") | |
159 | (302 . "Found") | |
160 | (303 . "See Other") | |
161 | (304 . "Not Modified") | |
162 | (305 . "Use Proxy") | |
163 | (307 . "Temporary Redirect") | |
164 | (400 . "Bad Request") | |
165 | (401 . "Unauthorized") | |
166 | (402 . "Payment Required") | |
167 | (403 . "Forbidden") | |
168 | (404 . "Not Found") | |
169 | (405 . "Method Not Allowed") | |
170 | (406 . "Not Acceptable") | |
171 | (407 . "Proxy Authentication Required") | |
172 | (408 . "Request Timeout") | |
173 | (409 . "Conflict") | |
174 | (410 . "Gone") | |
175 | (411 . "Length Required") | |
176 | (412 . "Precondition Failed") | |
177 | (413 . "Request Entity Too Large") | |
178 | (414 . "Request-URI Too Long") | |
179 | (415 . "Unsupported Media Type") | |
180 | (416 . "Requested Range Not Satisfiable") | |
181 | (417 . "Expectation Failed") | |
182 | (500 . "Internal Server Error") | |
183 | (501 . "Not Implemented") | |
184 | (502 . "Bad Gateway") | |
185 | (503 . "Service Unavailable") | |
186 | (504 . "Gateway Timeout") | |
187 | (505 . "HTTP Version Not Supported"))) | |
188 | ||
189 | (define (code->reason-phrase code) | |
190 | (or (assv-ref *reason-phrases* code) | |
191 | "(Unknown)")) | |
192 | ||
193 | (define (response-reason-phrase response) | |
cc1e26c2 AW |
194 | "Return the reason phrase given in @var{response}, or the standard |
195 | reason phrase for the response's code." | |
a9eeb2f4 AW |
196 | (or (%response-reason-phrase response) |
197 | (code->reason-phrase (response-code response)))) | |
198 | ||
199 | (define (read-response port) | |
cc1e26c2 AW |
200 | "Read an HTTP response from @var{port}, optionally attaching the given |
201 | metadata, @var{meta}. | |
202 | ||
203 | As a side effect, sets the encoding on @var{port} to | |
204 | ISO-8859-1 (latin-1), so that reading one character reads one byte. See | |
205 | the discussion of character sets in \"HTTP Responses\" in the manual, | |
206 | for more information." | |
a9eeb2f4 AW |
207 | (set-port-encoding! port "ISO-8859-1") |
208 | (call-with-values (lambda () (read-response-line port)) | |
209 | (lambda (version code reason-phrase) | |
210 | (make-response version code reason-phrase (read-headers port) port)))) | |
211 | ||
c6371902 | 212 | (define (adapt-response-version response version) |
cc1e26c2 AW |
213 | "Adapt the given response to a different HTTP version. Returns a new |
214 | HTTP response. | |
215 | ||
216 | The idea is that many applications might just build a response for the | |
217 | default HTTP version, and this method could handle a number of | |
218 | programmatic transformations to respond to older HTTP versions (0.9 and | |
219 | 1.0). But currently this function is a bit heavy-handed, just updating | |
220 | the version field." | |
c6371902 AW |
221 | (build-response #:code (response-code response) |
222 | #:version version | |
223 | #:headers (response-headers response) | |
224 | #:port (response-port response))) | |
225 | ||
a9eeb2f4 | 226 | (define (write-response r port) |
cc1e26c2 AW |
227 | "Write the given HTTP response to @var{port}. |
228 | ||
229 | Returns a new response, whose @code{response-port} will continue writing | |
230 | on @var{port}, perhaps using some transfer encoding." | |
a9eeb2f4 AW |
231 | (write-response-line (response-version r) (response-code r) |
232 | (response-reason-phrase r) port) | |
233 | (write-headers (response-headers r) port) | |
234 | (display "\r\n" port) | |
235 | (if (eq? port (response-port r)) | |
236 | r | |
237 | (make-response (response-version r) (response-code r) | |
238 | (response-reason-phrase r) (response-headers r) port))) | |
239 | ||
240 | ;; Probably not what you want to use "in production". Relies on one byte | |
241 | ;; per char because we are in latin-1 encoding. | |
242 | ;; | |
243 | (define (read-response-body/latin-1 r) | |
cc1e26c2 AW |
244 | "Reads the response body from @var{r}, as a string. |
245 | ||
246 | Assumes that the response port has ISO-8859-1 encoding, so that the | |
247 | number of characters to read is the same as the | |
248 | @code{response-content-length}. Returns @code{#f} if there was no | |
249 | response body." | |
e46f69e2 AW |
250 | (cond |
251 | ((response-content-length r) => | |
252 | (lambda (nbytes) | |
253 | (let ((buf (make-string nbytes)) | |
254 | (port (response-port r))) | |
255 | (let lp ((i 0)) | |
256 | (cond | |
257 | ((< i nbytes) | |
258 | (let ((c (read-char port))) | |
259 | (cond | |
260 | ((eof-object? c) | |
261 | (bad-response "EOF while reading response body: ~a bytes of ~a" | |
262 | i nbytes)) | |
263 | (else | |
264 | (string-set! buf i c) | |
265 | (lp (1+ i)))))) | |
266 | (else buf)))))) | |
267 | (else #f))) | |
a9eeb2f4 AW |
268 | |
269 | ;; Likewise, assumes that body can be written in the latin-1 encoding, | |
cc1e26c2 | 270 | ;; and that the latin-1 encoding is what is expected by the client. |
a9eeb2f4 AW |
271 | ;; |
272 | (define (write-response-body/latin-1 r body) | |
cc1e26c2 AW |
273 | "Write @var{body}, a string encodable in ISO-8859-1, to the port |
274 | corresponding to the HTTP response @var{r}." | |
a9eeb2f4 AW |
275 | (display body (response-port r))) |
276 | ||
277 | (define (read-response-body/bytevector r) | |
cc1e26c2 AW |
278 | "Reads the response body from @var{r}, as a bytevector. Returns |
279 | @code{#f} if there was no response body." | |
a9eeb2f4 AW |
280 | (let ((nbytes (response-content-length r))) |
281 | (and nbytes | |
282 | (let ((bv (get-bytevector-n (response-port r) nbytes))) | |
283 | (if (= (bytevector-length bv) nbytes) | |
284 | bv | |
285 | (bad-response "EOF while reading response body: ~a bytes of ~a" | |
286 | (bytevector-length bv) nbytes)))))) | |
287 | ||
288 | (define (write-response-body/bytevector r bv) | |
cc1e26c2 AW |
289 | "Write @var{body}, a bytevector, to the port corresponding to the HTTP |
290 | response @var{r}." | |
a9eeb2f4 AW |
291 | (put-bytevector (response-port r) bv)) |
292 | ||
293 | (define-syntax define-response-accessor | |
294 | (lambda (x) | |
295 | (syntax-case x () | |
296 | ((_ field) | |
297 | #'(define-response-accessor field #f)) | |
298 | ((_ field def) (identifier? #'field) | |
299 | #`(define* (#,(datum->syntax | |
300 | #'field | |
301 | (symbol-append 'response- (syntax->datum #'field))) | |
302 | response | |
303 | #:optional (default def)) | |
304 | (cond | |
305 | ((assq 'field (response-headers response)) => cdr) | |
306 | (else default))))))) | |
307 | ||
308 | ;; General headers | |
309 | ;; | |
310 | (define-response-accessor cache-control '()) | |
311 | (define-response-accessor connection '()) | |
312 | (define-response-accessor date #f) | |
313 | (define-response-accessor pragma '()) | |
314 | (define-response-accessor trailer '()) | |
315 | (define-response-accessor transfer-encoding '()) | |
316 | (define-response-accessor upgrade '()) | |
317 | (define-response-accessor via '()) | |
318 | (define-response-accessor warning '()) | |
319 | ||
320 | ;; Entity headers | |
321 | ;; | |
322 | (define-response-accessor allow '()) | |
323 | (define-response-accessor content-encoding '()) | |
324 | (define-response-accessor content-language '()) | |
325 | (define-response-accessor content-length #f) | |
326 | (define-response-accessor content-location #f) | |
327 | (define-response-accessor content-md5 #f) | |
328 | (define-response-accessor content-range #f) | |
329 | (define-response-accessor content-type #f) | |
330 | (define-response-accessor expires #f) | |
331 | (define-response-accessor last-modified #f) | |
332 | ||
333 | ;; Response headers | |
334 | ;; | |
335 | (define-response-accessor accept-ranges #f) | |
336 | (define-response-accessor age #f) | |
337 | (define-response-accessor etag #f) | |
338 | (define-response-accessor location #f) | |
339 | (define-response-accessor proxy-authenticate #f) | |
340 | (define-response-accessor retry-after #f) | |
341 | (define-response-accessor server #f) | |
342 | (define-response-accessor vary '()) | |
343 | (define-response-accessor www-authenticate #f) |