1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
|
/*
This file is part of TALER
Copyright (C) 2019, 2020 Taler Systems SA
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file mhd_legal.c
* @brief API for returning legal documents based on client language
* and content type preferences
* @author Christian Grothoff
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <gnunet/gnunet_json_lib.h>
#include <jansson.h>
#include <microhttpd.h>
#include "taler_util.h"
#include "taler_mhd_lib.h"
/**
* How long should browsers/proxies cache the "legal" replies?
*/
#define MAX_TERMS_CACHING GNUNET_TIME_UNIT_DAYS
/**
* Entry in the terms-of-service array.
*/
struct Terms
{
/**
* Kept in a DLL.
*/
struct Terms *prev;
/**
* Kept in a DLL.
*/
struct Terms *next;
/**
* Mime type of the terms.
*/
const char *mime_type;
/**
* The terms (NOT 0-terminated!), mmap()'ed. Do not free,
* use munmap() instead.
*/
void *terms;
/**
* The desired language.
*/
char *language;
/**
* deflated @e terms, to return if client supports deflate compression.
* malloc()'ed. NULL if @e terms does not compress.
*/
void *compressed_terms;
/**
* Number of bytes in @e terms.
*/
size_t terms_size;
/**
* Number of bytes in @e compressed_terms.
*/
size_t compressed_terms_size;
/**
* Sorting key by format preference in case
* everything else is equal. Higher is preferred.
*/
unsigned int priority;
};
/**
* Prepared responses for legal documents
* (terms of service, privacy policy).
*/
struct TALER_MHD_Legal
{
/**
* DLL of terms of service.
*/
struct Terms *terms_head;
/**
* DLL of terms of service.
*/
struct Terms *terms_tail;
/**
* Etag to use for the terms of service (= version).
*/
char *terms_etag;
};
/**
* Check if @a mime matches the @a accept_pattern.
*
* @param accept_pattern a mime pattern like "text/plain"
* or "image/STAR"
* @param mime the mime type to match
* @return true if @a mime matches the @a accept_pattern
*/
static bool
mime_matches (const char *accept_pattern,
const char *mime)
{
const char *da = strchr (accept_pattern, '/');
const char *dm = strchr (mime, '/');
if ( (NULL == da) ||
(NULL == dm) )
return (0 == strcmp ("*", accept_pattern));
return
( ( (1 == da - accept_pattern) &&
('*' == *accept_pattern) ) ||
( (da - accept_pattern == dm - mime) &&
(0 == strncasecmp (accept_pattern,
mime,
da - accept_pattern)) ) ) &&
( (0 == strcmp (da, "/*")) ||
(0 == strcasecmp (da,
dm)) );
}
bool
TALER_MHD_xmime_matches (const char *accept_pattern,
const char *mime)
{
char *ap = GNUNET_strdup (accept_pattern);
char *sptr;
for (const char *tok = strtok_r (ap, ";", &sptr);
NULL != tok;
tok = strtok_r (NULL, ";", &sptr))
{
if (mime_matches (tok,
mime))
{
GNUNET_free (ap);
return true;
}
}
GNUNET_free (ap);
return false;
}
MHD_RESULT
TALER_MHD_reply_legal (struct MHD_Connection *conn,
struct TALER_MHD_Legal *legal)
{
struct MHD_Response *resp;
struct Terms *t;
struct GNUNET_TIME_Absolute a;
struct GNUNET_TIME_Timestamp m;
char dat[128];
a = GNUNET_TIME_relative_to_absolute (MAX_TERMS_CACHING);
m = GNUNET_TIME_absolute_to_timestamp (a);
TALER_MHD_get_date_string (m.abs_time,
dat);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Setting 'Expires' header to '%s'\n",
dat);
if (NULL != legal)
{
const char *etag;
etag = MHD_lookup_connection_value (conn,
MHD_HEADER_KIND,
MHD_HTTP_HEADER_IF_NONE_MATCH);
if ( (NULL != etag) &&
(NULL != legal->terms_etag) &&
(0 == strcasecmp (etag,
legal->terms_etag)) )
{
MHD_RESULT ret;
resp = MHD_create_response_from_buffer (0,
NULL,
MHD_RESPMEM_PERSISTENT);
TALER_MHD_add_global_headers (resp);
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_EXPIRES,
dat));
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_ETAG,
legal->terms_etag));
ret = MHD_queue_response (conn,
MHD_HTTP_NOT_MODIFIED,
resp);
GNUNET_break (MHD_YES == ret);
MHD_destroy_response (resp);
return ret;
}
}
t = NULL;
if (NULL != legal)
{
const char *mime;
const char *lang;
mime = MHD_lookup_connection_value (conn,
MHD_HEADER_KIND,
MHD_HTTP_HEADER_ACCEPT);
if (NULL == mime)
mime = "text/html";
lang = MHD_lookup_connection_value (conn,
MHD_HEADER_KIND,
MHD_HTTP_HEADER_ACCEPT_LANGUAGE);
if (NULL == lang)
lang = "en";
/* Find best match: must match mime type (if possible), and if
mime type matches, ideally also language */
for (struct Terms *p = legal->terms_head;
NULL != p;
p = p->next)
{
if ( (NULL == t) ||
(TALER_MHD_xmime_matches (mime,
p->mime_type)) )
{
if ( (NULL == t) ||
(! TALER_MHD_xmime_matches (mime,
t->mime_type)) ||
(TALER_language_matches (lang,
p->language) >
TALER_language_matches (lang,
t->language) ) )
t = p;
}
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Best match for %s/%s: %s / %s\n",
lang,
mime,
(NULL != t) ? t->mime_type : "<none>",
(NULL != t) ? t->language : "<none>");
}
if (NULL == t)
{
/* Default terms of service if none are configured */
static struct Terms none = {
.mime_type = "text/plain",
.terms = "not configured",
.language = "en",
.terms_size = strlen ("not configured")
};
t = &none;
}
/* try to compress the response */
resp = NULL;
if (MHD_YES ==
TALER_MHD_can_compress (conn))
{
resp = MHD_create_response_from_buffer (t->compressed_terms_size,
t->compressed_terms,
MHD_RESPMEM_PERSISTENT);
if (MHD_NO ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_CONTENT_ENCODING,
"deflate"))
{
GNUNET_break (0);
MHD_destroy_response (resp);
resp = NULL;
}
}
if (NULL == resp)
{
/* could not generate compressed response, return uncompressed */
resp = MHD_create_response_from_buffer (t->terms_size,
(void *) t->terms,
MHD_RESPMEM_PERSISTENT);
}
TALER_MHD_add_global_headers (resp);
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_EXPIRES,
dat));
/* Set cache control headers: our response varies depending on these headers */
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_VARY,
MHD_HTTP_HEADER_ACCEPT_LANGUAGE ","
MHD_HTTP_HEADER_ACCEPT ","
MHD_HTTP_HEADER_ACCEPT_ENCODING));
/* Information is always public, revalidate after 10 days */
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_CACHE_CONTROL,
"public max-age=864000"));
if (NULL != legal)
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_ETAG,
legal->terms_etag));
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_CONTENT_TYPE,
t->mime_type));
{
MHD_RESULT ret;
ret = MHD_queue_response (conn,
MHD_HTTP_OK,
resp);
MHD_destroy_response (resp);
return ret;
}
}
/**
* Load all the terms of service from @a path under language @a lang
* from file @a name
*
* @param[in,out] legal where to write the result
* @param path where the terms are found
* @param lang which language directory to crawl
* @param name specific file to access
*/
static void
load_terms (struct TALER_MHD_Legal *legal,
const char *path,
const char *lang,
const char *name)
{
static struct MimeMap
{
const char *ext;
const char *mime;
unsigned int priority;
} mm[] = {
{ .ext = ".html", .mime = "text/html", .priority = 100 },
{ .ext = ".htm", .mime = "text/html", .priority = 99 },
{ .ext = ".txt", .mime = "text/plain", .priority = 50 },
{ .ext = ".pdf", .mime = "application/pdf", .priority = 25 },
{ .ext = ".jpg", .mime = "image/jpeg" },
{ .ext = ".jpeg", .mime = "image/jpeg" },
{ .ext = ".png", .mime = "image/png" },
{ .ext = ".gif", .mime = "image/gif" },
{ .ext = ".epub", .mime = "application/epub+zip", .priority = 10 },
{ .ext = ".xml", .mime = "text/xml", .priority = 10 },
{ .ext = NULL, .mime = NULL }
};
const char *ext = strrchr (name, '.');
const char *mime;
unsigned int priority;
if (NULL == ext)
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Unsupported file `%s' in directory `%s/%s': lacks extension\n",
name,
path,
lang);
return;
}
if ( (NULL == legal->terms_etag) ||
(0 != strncmp (legal->terms_etag,
name,
ext - name - 1)) )
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Filename `%s' does not match Etag `%s' in directory `%s/%s'. Ignoring it.\n",
name,
legal->terms_etag,
path,
lang);
return;
}
mime = NULL;
for (unsigned int i = 0; NULL != mm[i].ext; i++)
if (0 == strcasecmp (mm[i].ext,
ext))
{
mime = mm[i].mime;
priority = mm[i].priority;
break;
}
if (NULL == mime)
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Unsupported file extension `%s' of file `%s' in directory `%s/%s'\n",
ext,
name,
path,
lang);
return;
}
/* try to read the file with the terms of service */
{
struct stat st;
char *fn;
int fd;
GNUNET_asprintf (&fn,
"%s/%s/%s",
path,
lang,
name);
fd = open (fn, O_RDONLY);
if (-1 == fd)
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"open",
fn);
GNUNET_free (fn);
return;
}
if (0 != fstat (fd, &st))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"fstat",
fn);
GNUNET_break (0 == close (fd));
GNUNET_free (fn);
return;
}
if (SIZE_MAX < ((unsigned long long) st.st_size))
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"fstat-size",
fn);
GNUNET_break (0 == close (fd));
GNUNET_free (fn);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Loading legal information from file `%s'\n",
fn);
{
void *buf;
size_t bsize;
bsize = (size_t) st.st_size;
buf = mmap (NULL,
bsize,
PROT_READ,
MAP_SHARED,
fd,
0);
if (MAP_FAILED == buf)
{
GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
"mmap",
fn);
GNUNET_break (0 == close (fd));
GNUNET_free (fn);
return;
}
GNUNET_break (0 == close (fd));
GNUNET_free (fn);
/* insert into global list of terms of service */
{
struct Terms *t;
t = GNUNET_new (struct Terms);
t->mime_type = mime;
t->terms = buf;
t->language = GNUNET_strdup (lang);
t->terms_size = bsize;
t->priority = priority;
buf = GNUNET_memdup (t->terms,
t->terms_size);
if (TALER_MHD_body_compress (&buf,
&bsize))
{
t->compressed_terms = buf;
t->compressed_terms_size = bsize;
}
else
{
GNUNET_free (buf);
}
{
struct Terms *prev = NULL;
for (struct Terms *pos = legal->terms_head;
NULL != pos;
pos = pos->next)
{
if (pos->priority < priority)
break;
prev = pos;
}
GNUNET_CONTAINER_DLL_insert_after (legal->terms_head,
legal->terms_tail,
prev,
t);
}
}
}
}
}
/**
* Load all the terms of service from @a path under language @a lang.
*
* @param[in,out] legal where to write the result
* @param path where the terms are found
* @param lang which language directory to crawl
*/
static void
load_language (struct TALER_MHD_Legal *legal,
const char *path,
const char *lang)
{
char *dname;
DIR *d;
GNUNET_asprintf (&dname,
"%s/%s",
path,
lang);
d = opendir (dname);
if (NULL == d)
{
GNUNET_free (dname);
return;
}
for (struct dirent *de = readdir (d);
NULL != de;
de = readdir (d))
{
const char *fn = de->d_name;
if (fn[0] == '.')
continue;
load_terms (legal, path, lang, fn);
}
GNUNET_break (0 == closedir (d));
GNUNET_free (dname);
}
struct TALER_MHD_Legal *
TALER_MHD_legal_load (const struct GNUNET_CONFIGURATION_Handle *cfg,
const char *section,
const char *diroption,
const char *tagoption)
{
struct TALER_MHD_Legal *legal;
char *path;
DIR *d;
legal = GNUNET_new (struct TALER_MHD_Legal);
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_string (cfg,
section,
tagoption,
&legal->terms_etag))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_WARNING,
section,
tagoption);
GNUNET_free (legal);
return NULL;
}
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_filename (cfg,
section,
diroption,
&path))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_WARNING,
section,
diroption);
GNUNET_free (legal->terms_etag);
GNUNET_free (legal);
return NULL;
}
d = opendir (path);
if (NULL == d)
{
GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
section,
diroption,
"Could not open directory");
GNUNET_free (legal->terms_etag);
GNUNET_free (legal);
GNUNET_free (path);
return NULL;
}
for (struct dirent *de = readdir (d);
NULL != de;
de = readdir (d))
{
const char *lang = de->d_name;
if (lang[0] == '.')
continue;
load_language (legal, path, lang);
}
GNUNET_break (0 == closedir (d));
GNUNET_free (path);
return legal;
}
void
TALER_MHD_legal_free (struct TALER_MHD_Legal *legal)
{
struct Terms *t;
if (NULL == legal)
return;
while (NULL != (t = legal->terms_head))
{
GNUNET_free (t->language);
GNUNET_free (t->compressed_terms);
if (0 != munmap (t->terms, t->terms_size))
GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
"munmap");
GNUNET_CONTAINER_DLL_remove (legal->terms_head,
legal->terms_tail,
t);
GNUNET_free (t);
}
GNUNET_free (legal->terms_etag);
GNUNET_free (legal);
}
|