aboutsummaryrefslogtreecommitdiff
path: root/src/templating/templating_api.c
blob: 47ada208e1c6b60f61f6c7fed48ab6f4a3b8df57 (plain)
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
/*
  This file is part of TALER
  Copyright (C) 2020, 2022 Taler Systems SA

  TALER is free software; you can redistribute it and/or modify it under the
  terms of the GNU 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 General Public License for more details.

  You should have received a copy of the GNU General Public License along with
  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file templating_api.c
 * @brief logic to load and complete HTML templates
 * @author Christian Grothoff
 */
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include "taler_util.h"
#include "taler_mhd_lib.h"
#include "taler_templating_lib.h"
#include "mustach.h"
#include "mustach-jansson.h"
#include <gnunet/gnunet_mhd_compat.h>


/**
 * Entry in a key-value array we use to cache templates.
 */
struct TVE
{
  /**
   * A name, used as the key. NULL for the last entry.
   */
  char *name;

  /**
   * Language the template is in.
   */
  char *lang;

  /**
   * 0-terminated (!) file data to return for @e name and @e lang.
   */
  char *value;

};


/**
 * Array of templates loaded into RAM.
 */
static struct TVE *loaded;

/**
 * Length of the #loaded array.
 */
static unsigned int loaded_length;


/**
 * Load Mustach template into memory.  Note that we intentionally cache
 * failures, that is if we ever failed to load a template, we will never try
 * again.
 *
 * @param connection the connection we act upon
 * @param name name of the template file to load
 *        (MUST be a 'static' string in memory!)
 * @return NULL on error, otherwise the template
 */
static const char *
lookup_template (struct MHD_Connection *connection,
                 const char *name)
{
  struct TVE *best = NULL;
  const char *lang;

  lang = MHD_lookup_connection_value (connection,
                                      MHD_HEADER_KIND,
                                      MHD_HTTP_HEADER_ACCEPT_LANGUAGE);
  if (NULL == lang)
    lang = "en";
  /* find best match by language */
  for (unsigned int i = 0; i<loaded_length; i++)
  {
    if (0 != strcmp (loaded[i].name,
                     name))
      continue; /* does not match by name */
    if ( (NULL == best) ||
         (TALER_language_matches (lang,
                                  loaded[i].lang) >
          TALER_language_matches (lang,
                                  best->lang) ) )
      best = &loaded[i];
  }
  if (NULL == best)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "No templates found in `%s'\n",
                name);
    return NULL;
  }
  return best->value;
}


/**
 * Get the base URL for static resources.
 *
 * @param con the MHD connection
 * @param instance_id the instance ID
 * @returns the static files base URL, guaranteed
 *          to have a trailing slash.
 */
static char *
make_static_url (struct MHD_Connection *con,
                 const char *instance_id)
{
  const char *host;
  const char *forwarded_host;
  const char *uri_path;
  struct GNUNET_Buffer buf = { 0 };

  host = MHD_lookup_connection_value (con,
                                      MHD_HEADER_KIND,
                                      "Host");
  forwarded_host = MHD_lookup_connection_value (con,
                                                MHD_HEADER_KIND,
                                                "X-Forwarded-Host");

  uri_path = MHD_lookup_connection_value (con,
                                          MHD_HEADER_KIND,
                                          "X-Forwarded-Prefix");
  if (NULL != forwarded_host)
    host = forwarded_host;

  if (NULL == host)
  {
    GNUNET_break (0);
    return NULL;
  }

  GNUNET_assert (NULL != instance_id);

  if (GNUNET_NO == TALER_mhd_is_https (con))
    GNUNET_buffer_write_str (&buf,
                             "http://");
  else
    GNUNET_buffer_write_str (&buf,
                             "https://");
  GNUNET_buffer_write_str (&buf,
                           host);
  if (NULL != uri_path)
    GNUNET_buffer_write_path (&buf,
                              uri_path);
  if (0 != strcmp ("default",
                   instance_id))
  {
    GNUNET_buffer_write_path (&buf,
                              "instances");
    GNUNET_buffer_write_path (&buf,
                              instance_id);
  }
  GNUNET_buffer_write_path (&buf,
                            "static/");
  return GNUNET_buffer_reap_str (&buf);
}


enum GNUNET_GenericReturnValue
TALER_TEMPLATING_build (struct MHD_Connection *connection,
                        unsigned int *http_status,
                        const char *template,
                        const char *instance_id,
                        const char *taler_uri,
                        const json_t *root,
                        struct MHD_Response **reply)
{
  char *body;
  size_t body_size;

  {
    const char *tmpl;
    int eno;

    tmpl = lookup_template (connection,
                            template);
    if (NULL == tmpl)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                  "Failed to load template `%s'\n",
                  template);
      *http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
      *reply = TALER_MHD_make_error (TALER_EC_GENERIC_FAILED_TO_LOAD_TEMPLATE,
                                     template);
      return GNUNET_NO;
    }
    /* Add default values to the context */
    if (NULL != instance_id)
    {
      char *static_url = make_static_url (connection,
                                          instance_id);

      GNUNET_break (0 ==
                    json_object_set_new ((json_t *) root,
                                         "static_url",
                                         json_string (static_url)));
      GNUNET_free (static_url);
    }
    if (0 !=
        (eno = mustach_jansson (tmpl,
                                (json_t *) root,
                                &body,
                                &body_size)))
    {
      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                  "mustach failed on template `%s' with error %d\n",
                  template,
                  eno);
      *http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
      *reply = TALER_MHD_make_error (TALER_EC_GENERIC_FAILED_TO_EXPAND_TEMPLATE,
                                     template);
      return GNUNET_NO;
    }
  }

  /* try to compress reply if client allows it */
  {
    bool compressed = false;

    if (MHD_YES ==
        TALER_MHD_can_compress (connection))
    {
      compressed = TALER_MHD_body_compress ((void **) &body,
                                            &body_size);
    }
    *reply = MHD_create_response_from_buffer (body_size,
                                              body,
                                              MHD_RESPMEM_MUST_FREE);
    if (NULL == *reply)
    {
      GNUNET_break (0);
      return GNUNET_SYSERR;
    }
    if (compressed)
    {
      if (MHD_NO ==
          MHD_add_response_header (*reply,
                                   MHD_HTTP_HEADER_CONTENT_ENCODING,
                                   "deflate"))
      {
        GNUNET_break (0);
        MHD_destroy_response (*reply);
        *reply = NULL;
        return GNUNET_SYSERR;
      }
    }
  }

  /* Add standard headers */
  if (NULL != taler_uri)
    GNUNET_break (MHD_NO !=
                  MHD_add_response_header (*reply,
                                           "Taler",
                                           taler_uri));
  GNUNET_break (MHD_NO !=
                MHD_add_response_header (*reply,
                                         MHD_HTTP_HEADER_CONTENT_TYPE,
                                         "text/html"));
  return GNUNET_OK;
}


enum GNUNET_GenericReturnValue
TALER_TEMPLATING_reply (struct MHD_Connection *connection,
                        unsigned int http_status,
                        const char *template,
                        const char *instance_id,
                        const char *taler_uri,
                        const json_t *root)
{
  enum GNUNET_GenericReturnValue res;
  struct MHD_Response *reply;
  MHD_RESULT ret;

  res = TALER_TEMPLATING_build (connection,
                                &http_status,
                                template,
                                instance_id,
                                taler_uri,
                                root,
                                &reply);
  if (GNUNET_SYSERR == res)
    return res;
  ret = MHD_queue_response (connection,
                            http_status,
                            reply);
  MHD_destroy_response (reply);
  if (MHD_NO == ret)
    return GNUNET_SYSERR;
  return (res == GNUNET_OK)
    ? GNUNET_OK
    : GNUNET_NO;
}


/**
 * Function called with a template's filename.
 *
 * @param cls closure, NULL
 * @param filename complete filename (absolute path)
 * @return #GNUNET_OK to continue to iterate,
 *  #GNUNET_NO to stop iteration with no error,
 *  #GNUNET_SYSERR to abort iteration with error!
 */
static enum GNUNET_GenericReturnValue
load_template (void *cls,
               const char *filename)
{
  char *lang;
  char *end;
  int fd;
  struct stat sb;
  char *map;
  const char *name;

  (void) cls;
  if ('.' == filename[0])
    return GNUNET_OK;

  name = strrchr (filename,
                  '/');
  if (NULL == name)
    name = filename;
  else
    name++;
  lang = strchr (name,
                 '.');
  if (NULL == lang)
    return GNUNET_OK; /* name must include .$LANG */
  lang++;
  end = strchr (lang,
                '.');
  if ( (NULL == end) ||
       (0 != strcmp (end,
                     ".must")) )
    return GNUNET_OK; /* name must end with '.must' */

  /* finally open template */
  fd = open (filename,
             O_RDONLY);
  if (-1 == fd)
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
                              "open",
                              filename);

    return GNUNET_SYSERR;
  }
  if (0 !=
      fstat (fd,
             &sb))
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
                              "open",
                              filename);
    GNUNET_break (0 == close (fd));
    return GNUNET_OK;
  }
  map = GNUNET_malloc_large (sb.st_size + 1);
  if (NULL == map)
  {
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
                         "malloc");
    GNUNET_break (0 == close (fd));
    return GNUNET_SYSERR;
  }
  if (sb.st_size !=
      read (fd,
            map,
            sb.st_size))
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
                              "read",
                              filename);
    GNUNET_break (0 == close (fd));
    return GNUNET_OK;
  }
  GNUNET_break (0 == close (fd));
  GNUNET_array_grow (loaded,
                     loaded_length,
                     loaded_length + 1);
  loaded[loaded_length - 1].name = GNUNET_strndup (name,
                                                   (lang - 1) - name);
  loaded[loaded_length - 1].lang = GNUNET_strndup (lang,
                                                   end - lang);
  loaded[loaded_length - 1].value = map;
  return GNUNET_OK;
}


enum GNUNET_GenericReturnValue
TALER_TEMPLATING_init (const char *subsystem)
{
  char *dn;
  int ret;

  {
    char *path;

    path = GNUNET_OS_installation_get_path (GNUNET_OS_IPK_DATADIR);
    if (NULL == path)
    {
      GNUNET_break (0);
      return GNUNET_SYSERR;
    }
    GNUNET_asprintf (&dn,
                     "%s/%s/templates/",
                     path,
                     subsystem);
    GNUNET_free (path);
  }
  ret = GNUNET_DISK_directory_scan (dn,
                                    &load_template,
                                    NULL);
  GNUNET_free (dn);
  if (-1 == ret)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}


void
TALER_TEMPLATING_done (void)
{
  for (unsigned int i = 0; i<loaded_length; i++)
  {
    GNUNET_free (loaded[i].name);
    GNUNET_free (loaded[i].lang);
    GNUNET_free (loaded[i].value);
  }
  GNUNET_array_grow (loaded,
                     loaded_length,
                     0);
}


/* end of templating_api.c */