aboutsummaryrefslogtreecommitdiff
path: root/src/gns/gns_tld_api.c
blob: 3ebf07db66bc1b4e6e1fcc50e500938c31a80fb2 (plain) (blame)
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
/*
     This file is part of GNUnet.
     Copyright (C) 2009-2013, 2016, 2018 GNUnet e.V.

     GNUnet 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 of the License,
     or (at your option) any later version.

     GNUnet 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 this program.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
 */
/**
 * @file gns/gns_tld_api.c
 * @brief library to access the GNS service, including TLD lookup
 * @author Martin Schanzenbach
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_constants.h"
#include "gnunet_arm_service.h"
#include "gnunet_identity_service.h"
#include "gnunet_hello_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_dht_service.h"
#include "gns.h"
#include "gns_api.h"


#define LOG(kind, ...) GNUNET_log_from (kind, "gns-tld-api", __VA_ARGS__)


/**
 * Handle to a lookup request
 */
struct GNUNET_GNS_LookupWithTldRequest
{
  /**
   * handle to gns
   */
  struct GNUNET_GNS_Handle *gns_handle;

  /**
   * processor to call on lookup result
   */
  GNUNET_GNS_LookupResultProcessor2 lookup_proc;

  /**
   * Domain name we are resolving.
   */
  char *name;

  /**
   * @e lookup_proc closure
   */
  void *lookup_proc_cls;

  /**
   * Underlying GNS lookup.
   */
  struct GNUNET_GNS_LookupRequest *lr;

  /**
   * Lookup an ego with the identity service.
   */
  struct GNUNET_IDENTITY_EgoSuffixLookup *id_co;

  /**
   * Name of the longest matching ego found so far.
   * Must be freed on termination.
   */
  char *longest_match;

  /**
   * Ego corresponding to @e longest_match.
   */
  struct GNUNET_IDENTITY_Ego *longest_match_ego;

  /**
   * Desired result record type.
   */
  uint32_t type;

  /**
   * Lookup options.
   */
  enum GNUNET_GNS_LocalOptions options;
};


/**
 * Obtain the TLD of the given @a name.
 *
 * @param name a name
 * @return the part of @a name after the last ".",
 *         or @a name if @a name does not contain a "."
 */
static const char *
get_tld (const char *name)
{
  const char *tld;

  tld = strrchr (name, (unsigned char) '.');
  if (NULL == tld)
    tld = name;
  else
    tld++; /* skip the '.' */
  return tld;
}


/**
 * Eat the "TLD" (last bit) of the given @a name.
 *
 * @param[in,out] name a name
 * @param tld what to eat (can be more than just the tld)
 */
static void
eat_tld (char *name, const char *tld)
{
  GNUNET_assert (0 < strlen (name));
  if ((NULL == tld) || (strlen (name) == strlen (tld)))
  {
    strcpy (name, GNUNET_GNS_EMPTY_LABEL_AT);
  }
  else
  {
    GNUNET_assert (strlen (tld) < strlen (name));
    name[strlen (name) - strlen (tld) - 1] = '\0';
  }
}


/**
 * Function called with the result of a GNS lookup.
 *
 * @param cls a `struct GNUNET_GNS_LookupWithTldRequest *`
 * @param rd_count number of records returned
 * @param rd array of @a rd_count records with the results
 */
static void
process_lookup_result (void *cls,
                       uint32_t rd_count,
                       const struct GNUNET_GNSRECORD_Data *rd)
{
  struct GNUNET_GNS_LookupWithTldRequest *ltr = cls;

  ltr->lr = NULL;
  ltr->lookup_proc (ltr->lookup_proc_cls, GNUNET_YES, rd_count, rd);
  GNUNET_GNS_lookup_with_tld_cancel (ltr);
}


/**
 * Perform the actual resolution, starting with the zone
 * identified by the given public key.
 *
 * @param pkey public key to use for the zone, can be NULL
 */
static void
lookup_with_public_key (struct GNUNET_GNS_LookupWithTldRequest *ltr,
                        const struct GNUNET_CRYPTO_EcdsaPublicKey *pkey)
{
  ltr->lr = GNUNET_GNS_lookup (ltr->gns_handle,
                               ltr->name,
                               pkey,
                               ltr->type,
                               ltr->options,
                               &process_lookup_result,
                               ltr);
}


/**
 * Method called to with the ego we are to use for the lookup,
 * when the ego is determined by a name.
 *
 * @param cls a `struct GNUNET_GNS_LookupWithTldRequest *`
 * @param ego ego handle, NULL at the end of the iteration
 * @param ctx context we could store data to associate with @e ego
 * @param name name of the ego
 */
static void
identity_zone_cb (void *cls,
                  const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv,
                  const char *ego_name)
{
  struct GNUNET_GNS_LookupWithTldRequest *ltr = cls;
  struct GNUNET_CRYPTO_EcdsaPublicKey pkey;

  ltr->id_co = NULL;
  if (NULL == priv)
  {
    /* no matching ego found */
    ltr->lookup_proc (ltr->lookup_proc_cls, GNUNET_NO, 0, NULL);
    return;
  }
  /* Final case: TLD matches one of our egos */
  if (0 == strcmp (ltr->name, ego_name))
  {
    /* name matches ego name perfectly, only "@" remains */
    strcpy (ltr->name, GNUNET_GNS_EMPTY_LABEL_AT);
  }
  else
  {
    GNUNET_assert (strlen (ego_name) < strlen (ltr->name));
    ltr->name[strlen (ltr->name) - strlen (ego_name) - 1] = '\0';
  }
  /* if the name is of the form 'label' (and not 'label.SUBDOMAIN'), never go to the DHT */
  if (NULL == strchr (ltr->name, (unsigned char) '.'))
    ltr->options = GNUNET_GNS_LO_NO_DHT;
  else
    ltr->options = GNUNET_GNS_LO_LOCAL_MASTER;
  GNUNET_CRYPTO_ecdsa_key_get_public (priv, &pkey);
  lookup_with_public_key (ltr, &pkey);
}


/**
 * Perform an asynchronous lookup operation on the GNS,
 * determining the zone using the TLD of the given name
 * and the current configuration to resolve TLDs to zones.
 *
 * @param handle handle to the GNS service
 * @param name the name to look up, including TLD (in UTF-8 encoding)
 * @param type the record type to look up
 * @param options local options for the lookup
 * @param proc processor to call on result
 * @param proc_cls closure for @a proc
 * @return handle to the get request, NULL on error (i.e. bad configuration)
 */
struct GNUNET_GNS_LookupWithTldRequest *
GNUNET_GNS_lookup_with_tld (struct GNUNET_GNS_Handle *handle,
                            const char *name,
                            uint32_t type,
                            enum GNUNET_GNS_LocalOptions options,
                            GNUNET_GNS_LookupResultProcessor2 proc,
                            void *proc_cls)
{
  struct GNUNET_GNS_LookupWithTldRequest *ltr;
  const char *tld;
  char *dot_tld;
  char *zonestr;
  struct GNUNET_CRYPTO_EcdsaPublicKey pkey;

  ltr = GNUNET_new (struct GNUNET_GNS_LookupWithTldRequest);
  ltr->gns_handle = handle;
  ltr->name = GNUNET_strdup (name);
  ltr->type = type;
  ltr->options = options;
  ltr->lookup_proc = proc;
  ltr->lookup_proc_cls = proc_cls;
  /* start with trivial case: TLD is zkey */
  tld = get_tld (ltr->name);
  if (GNUNET_OK ==
      GNUNET_CRYPTO_ecdsa_public_key_from_string (tld, strlen (tld), &pkey))
  {
    eat_tld (ltr->name, tld);
    lookup_with_public_key (ltr, &pkey);
    return ltr;
  }

  /* second case: domain is mapped in our configuration file */
  for (const char *domain = name; NULL != domain;
       domain = strchr (domain, (unsigned char) '.'))
  {
    if ('.' == domain[0])
      domain++;
    GNUNET_asprintf (&dot_tld, ".%s", domain);
    if (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (handle->cfg,
                                                            "gns",
                                                            dot_tld,
                                                            &zonestr))
    {
      if (GNUNET_OK !=
          GNUNET_CRYPTO_ecdsa_public_key_from_string (zonestr,
                                                      strlen (zonestr),
                                                      &pkey))
      {
        GNUNET_log_config_invalid (
          GNUNET_ERROR_TYPE_ERROR,
          "gns",
          dot_tld,
          _ ("Expected a base32-encoded public zone key\n"));
        GNUNET_free (zonestr);
        GNUNET_free (dot_tld);
        GNUNET_free (ltr->name);
        GNUNET_free (ltr);
        return NULL;
      }
      eat_tld (ltr->name, &dot_tld[1]);
      GNUNET_free (zonestr);
      GNUNET_free (dot_tld);
      lookup_with_public_key (ltr, &pkey);
      return ltr;
    }
    GNUNET_free (dot_tld);
  }
  ltr->id_co =
    GNUNET_IDENTITY_ego_lookup_by_suffix (ltr->gns_handle->cfg,
                                          ltr->name,
                                          &identity_zone_cb,
                                          ltr);
  if (NULL == ltr->id_co)
  {
    GNUNET_free (ltr->name);
    GNUNET_free (ltr);
    return NULL;
  }
  return ltr;
}


/**
 * Cancel pending lookup request
 *
 * @param ltr the lookup request to cancel
 * @return closure from the lookup result processor
 */
void *
GNUNET_GNS_lookup_with_tld_cancel (struct GNUNET_GNS_LookupWithTldRequest *ltr)
{
  void *ret = ltr->lookup_proc_cls;

  if (NULL != ltr->id_co)
  {
    GNUNET_IDENTITY_ego_lookup_by_suffix_cancel (ltr->id_co);
    ltr->id_co = NULL;
  }
  if (NULL != ltr->lr)
  {
    GNUNET_GNS_lookup_cancel (ltr->lr);
    ltr->lr = NULL;
  }
  GNUNET_free (ltr->longest_match);
  GNUNET_free (ltr->name);
  GNUNET_free (ltr);
  return ret;
}


/* end of gns_tld_api.c */