GNUnet  0.11.x
gnunet-service-gns.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2011-2018 GNUnet e.V.
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
10  GNUnet is distributed in the hope that it will be useful, but
11  WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19  */
26 #include "platform.h"
27 #include "gnunet_util_lib.h"
28 #include "gnunet_dns_service.h"
29 #include "gnunet_dnsparser_lib.h"
30 #include "gnunet_dht_service.h"
32 #include "gnunet_gnsrecord_lib.h"
33 #include "gnunet_gns_service.h"
35 #include "gns.h"
38 #include "gnunet_protocols.h"
39 
40 
44 struct GnsClient;
45 
50 {
55 
60 
64  struct GnsClient *gc;
65 
70 
74  uint32_t request_id;
75 };
76 
77 
81 struct GnsClient
82 {
87 
92 
97 
102 };
103 
104 
110 {
116 
122 
127 
131  char *tld;
132 };
133 
134 
139 
144 
148 static int v6_enabled;
149 
153 static int v4_enabled;
154 
159 
164 
169 
170 
178 int
179 GNS_find_tld (const char *tld_str,
181 {
182  if ('\0' == *tld_str)
183  return GNUNET_NO;
184  for (struct GNS_TopLevelDomain *tld = tld_head;
185  NULL != tld;
186  tld = tld->next)
187  {
188  if (0 == strcasecmp (tld_str,
189  tld->tld))
190  {
191  *pkey = tld->pkey;
192  return GNUNET_YES;
193  }
194  }
195  if (GNUNET_OK ==
196  GNUNET_GNSRECORD_zkey_to_pkey (tld_str + 1,
197  pkey))
198  return GNUNET_YES; /* TLD string *was* the public key */
199  return GNUNET_NO;
200 }
201 
202 
210 const char *
211 GNS_get_tld (const char *name)
212 {
213  const char *tld;
214 
215  tld = strrchr (name,
216  (unsigned char) '.');
217  if (NULL == tld)
218  tld = name;
219  else
220  tld++; /* skip the '.' */
221  return tld;
222 }
223 
224 
230 static void
231 shutdown_task (void *cls)
232 {
233  struct GNS_TopLevelDomain *tld;
234 
235  (void) cls;
237  "Shutting down!\n");
240  if (NULL != statistics)
241  {
242  GNUNET_STATISTICS_destroy (statistics,
243  GNUNET_NO);
244  statistics = NULL;
245  }
246  if (NULL != namecache_handle)
247  {
248  GNUNET_NAMECACHE_disconnect (namecache_handle);
249  namecache_handle = NULL;
250  }
251  if (NULL != dht_handle)
252  {
253  GNUNET_DHT_disconnect (dht_handle);
254  dht_handle = NULL;
255  }
256  while (NULL != (tld = tld_head))
257  {
258  GNUNET_CONTAINER_DLL_remove (tld_head,
259  tld_tail,
260  tld);
261  GNUNET_free (tld->tld);
262  GNUNET_free (tld);
263  }
264 }
265 
266 
274 static void
276  struct GNUNET_SERVICE_Client *client,
277  void *app_ctx)
278 {
279  struct ClientLookupHandle *clh;
280  struct GnsClient *gc = app_ctx;
281 
282  (void) cls;
284  "Client %p disconnected\n",
285  client);
286  while (NULL != (clh = gc->clh_head))
287  {
288  if (NULL != clh->lookup)
291  gc->clh_tail,
292  clh);
293  GNUNET_free (clh);
294  }
295  GNUNET_free (gc);
296 }
297 
298 
307 static void *
308 client_connect_cb (void *cls,
310  struct GNUNET_MQ_Handle *mq)
311 {
312  struct GnsClient *gc;
313 
314  (void) cls;
316  "Client %p connected\n",
317  client);
318  gc = GNUNET_new (struct GnsClient);
319  gc->client = client;
320  gc->mq = mq;
321  return gc;
322 }
323 
324 
332 static void
334  uint32_t rd_count,
335  const struct GNUNET_GNSRECORD_Data *rd)
336 {
337  struct ClientLookupHandle *clh = cls;
338  struct GnsClient *gc = clh->gc;
339  struct GNUNET_MQ_Envelope *env;
340  struct LookupResultMessage *rmsg;
341  ssize_t len;
342 
344  "Sending LOOKUP_RESULT message with %u results\n",
345  (unsigned int) rd_count);
346  len = GNUNET_GNSRECORD_records_get_size (rd_count,
347  rd);
348  if (len < 0)
349  {
350  GNUNET_break (0);
352  return;
353  }
354  if (len > UINT16_MAX - sizeof(*rmsg))
355  {
356  GNUNET_break (0);
358  return;
359  }
360  env = GNUNET_MQ_msg_extra (rmsg,
361  len,
363  rmsg->id = clh->request_id;
364  rmsg->rd_count = htonl (rd_count);
365  GNUNET_assert (len ==
367  rd,
368  len,
369  (char *) &rmsg[1]));
371  env);
373  gc->clh_tail,
374  clh);
375  GNUNET_free (clh);
376  GNUNET_STATISTICS_update (statistics,
377  "Completed lookups", 1,
378  GNUNET_NO);
379  GNUNET_STATISTICS_update (statistics,
380  "Records resolved",
381  rd_count,
382  GNUNET_NO);
383 }
384 
385 
393 static int
394 check_lookup (void *cls,
395  const struct LookupMessage *l_msg)
396 {
397  size_t nlen;
398 
399  (void) cls;
401  nlen = ntohs (l_msg->header.size) - sizeof(struct LookupMessage);
403  {
404  GNUNET_break (0);
405  return GNUNET_SYSERR;
406  }
407  return GNUNET_OK;
408 }
409 
410 
418 static void
419 handle_lookup (void *cls,
420  const struct LookupMessage *sh_msg)
421 {
422  struct GnsClient *gc = cls;
424  struct ClientLookupHandle *clh;
425  char *nameptr = name;
426  const char *utf_in;
427 
429  utf_in = (const char *) &sh_msg[1];
431  nameptr);
433  "Received LOOKUP `%s' message\n",
434  name);
435  clh = GNUNET_new (struct ClientLookupHandle);
437  gc->clh_tail,
438  clh);
439  clh->gc = gc;
440  clh->request_id = sh_msg->id;
441  if ((GNUNET_DNSPARSER_TYPE_A == ntohl (sh_msg->type)) &&
442  (GNUNET_OK != v4_enabled))
443  {
445  "LOOKUP: Query for A record but AF_INET not supported!");
447  0,
448  NULL);
449  return;
450  }
451  if ((GNUNET_DNSPARSER_TYPE_AAAA == ntohl (sh_msg->type)) &&
452  (GNUNET_OK != v6_enabled))
453  {
455  "LOOKUP: Query for AAAA record but AF_INET6 not supported!");
457  0,
458  NULL);
459  return;
460  }
461  clh->lookup = GNS_resolver_lookup (&sh_msg->zone,
462  ntohl (sh_msg->type),
463  name,
464  (enum GNUNET_GNS_LocalOptions) ntohs (
465  sh_msg->options),
466  ntohs (sh_msg->recursion_depth_limit),
467  &send_lookup_response, clh);
468  GNUNET_STATISTICS_update (statistics,
469  "Lookup attempts",
470  1, GNUNET_NO);
471 }
472 
473 
482 static void
483 read_service_conf (void *cls,
484  const char *section,
485  const char *option,
486  const char *value)
487 {
488  struct GNUNET_IDENTITY_PublicKey pk;
489  struct GNS_TopLevelDomain *tld;
490 
491  (void) cls;
492  (void) section;
493  if (option[0] != '.')
494  return;
495  if (GNUNET_OK !=
497  strlen (value),
498  &pk,
499  sizeof(pk)))
500  {
502  section,
503  option,
504  _ (
505  "Properly base32-encoded public key required"));
506  return;
507  }
508  tld = GNUNET_new (struct GNS_TopLevelDomain);
509  tld->tld = GNUNET_strdup (&option[1]);
510  tld->pkey = pk;
511  GNUNET_CONTAINER_DLL_insert (tld_head,
512  tld_tail,
513  tld);
514 }
515 
516 
524 static void
525 run (void *cls,
526  const struct GNUNET_CONFIGURATION_Handle *c,
528 {
529  unsigned long long max_parallel_bg_queries = 16;
530 
532  "gns",
534  NULL);
535  v6_enabled = GNUNET_NETWORK_test_pf (PF_INET6);
537  namecache_handle = GNUNET_NAMECACHE_connect (c);
538  if (NULL == namecache_handle)
539  {
541  _ ("Failed to connect to the namecache!\n"));
543  return;
544  }
545  if (GNUNET_OK ==
547  "gns",
548  "MAX_PARALLEL_BACKGROUND_QUERIES",
549  &max_parallel_bg_queries))
550  {
552  "Number of allowed parallel background queries: %llu\n",
553  max_parallel_bg_queries);
554  }
555  dht_handle = GNUNET_DHT_connect (c,
556  (unsigned int) max_parallel_bg_queries);
557  if (NULL == dht_handle)
558  {
560  _ ("Could not connect to DHT!\n"));
562  NULL);
563  return;
564  }
565  GNS_resolver_init (namecache_handle,
566  dht_handle,
567  c,
568  max_parallel_bg_queries);
569  if ((GNUNET_YES ==
571  "gns",
572  "INTERCEPT_DNS")) &&
573  (GNUNET_SYSERR ==
575  {
576  GNUNET_break (0);
578  NULL);
579  return;
580  }
581  statistics = GNUNET_STATISTICS_create ("gns",
582  c);
584  NULL);
585 }
586 
587 
592  ("gns",
594  &run,
597  NULL,
600  struct LookupMessage,
601  NULL),
603 
604 
605 /* end of gnunet-service-gns.c */
#define GNUNET_CONTAINER_DLL_remove(head, tail, element)
Remove an element from a DLL.
static void run(void *cls, const struct GNUNET_CONFIGURATION_Handle *c, struct GNUNET_SERVICE_Handle *service)
Process GNS requests.
Message from client to GNS service to lookup records.
Definition: gns.h:36
struct GNUNET_NAMECACHE_Handle * GNUNET_NAMECACHE_connect(const struct GNUNET_CONFIGURATION_Handle *cfg)
Connect to the namecache service.
Message from GNS service to client: new results.
Definition: gns.h:78
uint32_t id
Unique identifier for this request (for key collisions).
Definition: gns.h:46
static struct GNUNET_SERVICE_Handle * service
Handle to our service instance.
GNUNET_NETWORK_STRUCT_END ssize_t GNUNET_GNSRECORD_records_get_size(unsigned int rd_count, const struct GNUNET_GNSRECORD_Data *rd)
Calculate how many bytes we will need to serialize the given records.
struct GNS_TopLevelDomain * next
Kept in a DLL, as there are unlikely enough of these to warrant a hash map.
void GNS_resolver_lookup_cancel(struct GNS_ResolverHandle *rh)
Cancel active resolution (i.e.
struct ClientLookupHandle * prev
We keep these in a DLL.
int GNUNET_CONFIGURATION_get_value_number(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option, unsigned long long *number)
Get a configuration value that should be a number.
static struct GNS_TopLevelDomain * tld_head
Head of DLL of TLDs we map to GNS zones.
static char * pkey
Public key of the zone to look in, in ASCII.
uint32_t rd_count
The number of records contained in response.
Definition: gns.h:95
void GNUNET_CONFIGURATION_iterate_section_values(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, GNUNET_CONFIGURATION_Iterator iter, void *iter_cls)
Iterate over values of a section in the configuration.
#define GNUNET_CONTAINER_DLL_insert(head, tail, element)
Insert an element at the head of a DLL.
struct GNS_TopLevelDomain * prev
Kept in a DLL, as there are unlikely enough of these to warrant a hash map.
Handle to a service.
Definition: service.c:116
struct GNUNET_MQ_Handle * GNUNET_SERVICE_client_get_mq(struct GNUNET_SERVICE_Client *c)
Obtain the message queue of c.
Definition: service.c:2438
int GNUNET_GNSRECORD_zkey_to_pkey(const char *zkey, struct GNUNET_IDENTITY_PublicKey *pkey)
Convert an absolute domain name to the respective public key.
struct GNUNET_SCHEDULER_Task * GNUNET_SCHEDULER_add_shutdown(GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
Schedule a new task to be run on shutdown, that is when a CTRL-C signal is received, or when GNUNET_SCHEDULER_shutdown() is being invoked.
Definition: scheduler.c:1331
ssize_t GNUNET_GNSRECORD_records_serialize(unsigned int rd_count, const struct GNUNET_GNSRECORD_Data *rd, size_t dest_size, char *dest)
Serialize the given records to the given destination buffer.
const char * GNS_get_tld(const char *name)
Obtain the TLD of the given name.
#define GNUNET_MESSAGE_TYPE_GNS_LOOKUP
Client would like to resolve a name.
struct GNUNET_STATISTICS_Handle * GNUNET_STATISTICS_create(const char *subsystem, const struct GNUNET_CONFIGURATION_Handle *cfg)
Get handle for the statistics service.
static void client_disconnect_cb(void *cls, struct GNUNET_SERVICE_Client *client, void *app_ctx)
Called whenever a client is disconnected.
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
#define GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT
Service response to name resolution request from client.
GNUNET_GNS_LocalOptions
Options for the GNS lookup.
struct ClientLookupHandle * next
We keep these in a DLL.
int32_t type
the type of record to look up
Definition: gns.h:69
#define GNUNET_new(type)
Allocate a struct or union of the given type.
void GNUNET_log_config_invalid(enum GNUNET_ErrorType kind, const char *section, const char *option, const char *required)
Log error message about invalid configuration option value.
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format...
void GNUNET_STATISTICS_destroy(struct GNUNET_STATISTICS_Handle *h, int sync_first)
Destroy a handle (free all state associated with it).
void GNUNET_STATISTICS_update(struct GNUNET_STATISTICS_Handle *handle, const char *name, int64_t delta, int make_persistent)
Set statistic value for the peer.
void GNUNET_SCHEDULER_shutdown(void)
Request the shutdown of a scheduler.
Definition: scheduler.c:531
Handle for the service.
static int v6_enabled
GNUNET_YES if ipv6 is supported
#define GNUNET_strdup(a)
Wrapper around GNUNET_xstrdup_.
IPC messages between GNS API and GNS service.
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
int GNS_interceptor_init(const struct GNUNET_CONFIGURATION_Handle *c)
Initialized the interceptor.
Handle to a currently pending resolution.
Connection to the DHT service.
Definition: dht_api.c:201
struct GNUNET_MQ_Handle * mq
The MQ.
#define _(String)
GNU gettext support macro.
Definition: platform.h:184
static char * section
Name of the section.
Definition: gnunet-config.c:33
static struct GNUNET_STATISTICS_Handle * statistics
Handle to the statistics service.
Handle to a client that is connected to a service.
Definition: service.c:250
static int check_lookup(void *cls, const struct LookupMessage *l_msg)
Checks a GNUNET_MESSAGE_TYPE_GNS_LOOKUP message.
uint16_t recursion_depth_limit
Recursion depth limit, i.e.
Definition: gns.h:64
struct GNUNET_SERVICE_Client * client
The client.
uint32_t request_id
request id
struct GNUNET_MessageHeader header
Header of type GNUNET_MESSAGE_TYPE_GNS_LOOKUP.
Definition: gns.h:41
#define GNUNET_MQ_msg_extra(mvar, esize, type)
Allocate an envelope, with extra space allocated after the space needed by the message struct...
Definition: gnunet_mq_lib.h:52
#define GNUNET_DNSPARSER_MAX_NAME_LENGTH
Maximum length of a name in DNS.
#define GNUNET_MQ_check_zero_termination(m)
Insert code for a "check_" function that verifies that a given variable-length message received over ...
static void shutdown_task(void *cls)
Task run during shutdown.
static char * value
Value of the record to add/remove.
uint32_t id
Unique identifier for this request (for key collisions).
Definition: gns.h:88
static struct GNUNET_DHT_Handle * dht_handle
Our handle to the DHT.
#define GNUNET_MQ_hd_var_size(name, code, str, ctx)
static void handle_lookup(void *cls, const struct LookupMessage *sh_msg)
Handle lookup requests from client.
struct GNUNET_SCHEDULER_Task * GNUNET_SCHEDULER_add_now(GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
Schedule a new task to be run as soon as possible.
Definition: scheduler.c:1296
static struct GNUNET_NAMECACHE_Handle * namecache_handle
Our handle to the namecache service.
static struct GNS_TopLevelDomain * tld_tail
Tail of DLL of TLDs we map to GNS zones.
static char * option
Name of the option.
Definition: gnunet-config.c:38
static void * client_connect_cb(void *cls, struct GNUNET_SERVICE_Client *client, struct GNUNET_MQ_Handle *mq)
Add a client to our list of active clients.
void GNS_interceptor_done()
Disconnect from interceptor.
struct GnsClient * gc
Client handle.
void GNS_resolver_done()
Shutdown resolver.
static int v4_enabled
GNUNET_YES if ipv4 is supported
struct GNS_ResolverHandle * lookup
Active handle for the lookup.
void GNUNET_SERVICE_client_drop(struct GNUNET_SERVICE_Client *c)
Ask the server to disconnect from the given client.
Definition: service.c:2325
Handle to a lookup operation from client via API.
int16_t options
Local options for where to look for results (an enum GNUNET_GNS_LocalOptions in NBO).
Definition: gns.h:57
GNUnet GNS service.
struct GNUNET_DHT_Handle * GNUNET_DHT_connect(const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned int ht_len)
Initialize the connection with the DHT service.
Definition: dht_api.c:890
void GNUNET_DHT_disconnect(struct GNUNET_DHT_Handle *handle)
Shutdown connection with the DHT service.
Definition: dht_api.c:918
struct GNUNET_MQ_Envelope * env
Definition: 005.c:1
void GNS_resolver_init(struct GNUNET_NAMECACHE_Handle *nc, struct GNUNET_DHT_Handle *dht, const struct GNUNET_CONFIGURATION_Handle *c, unsigned long long max_bg_queries)
Initialize the resolver.
static void read_service_conf(void *cls, const char *section, const char *option, const char *value)
Reads the configuration and populates TLDs.
Handle to a message queue.
Definition: mq.c:85
An identity key as per LSD0001.
int GNS_find_tld(const char *tld_str, struct GNUNET_IDENTITY_PublicKey *pkey)
Find GNS zone belonging to TLD tld.
Information we track per connected client.
#define GNUNET_DNSPARSER_TYPE_AAAA
configuration data
Definition: configuration.c:84
struct GNUNET_IDENTITY_PrivateKey pk
Private key from command line option, or NULL.
Representation of a TLD, mapping the respective TLD string (i.e.
const char * name
struct ClientLookupHandle * clh_head
Head of the DLL.
Connection to the NAMECACHE service.
Definition: namecache_api.c:94
struct GNUNET_MQ_Handle * mq
Definition: 003.c:5
struct GNUNET_IDENTITY_PublicKey pkey
Public key associated with the tld.
#define GNUNET_log(kind,...)
static void send_lookup_response(void *cls, uint32_t rd_count, const struct GNUNET_GNSRECORD_Data *rd)
Reply to client with the result from our lookup.
char * tld
Top-level domain as a string, including leading ".".
void GNUNET_NAMECACHE_disconnect(struct GNUNET_NAMECACHE_Handle *h)
Disconnect from the namecache service (and free associated resources).
void GNUNET_MQ_send(struct GNUNET_MQ_Handle *mq, struct GNUNET_MQ_Envelope *ev)
Send a message with the given message queue.
Definition: mq.c:355
GNUNET_SERVICE_MAIN("gns", GNUNET_SERVICE_OPTION_NONE, &run, &client_connect_cb, &client_disconnect_cb, NULL, GNUNET_MQ_hd_var_size(lookup, GNUNET_MESSAGE_TYPE_GNS_LOOKUP, struct LookupMessage, NULL), GNUNET_MQ_handler_end())
Define "main" method using service macro.
int GNUNET_CONFIGURATION_get_value_yesno(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option)
Get a configuration value that should be in a set of "YES" or "NO".
struct GNUNET_IDENTITY_PublicKey zone
Zone that is to be used for lookup.
Definition: gns.h:51
#define GNUNET_DNSPARSER_TYPE_A
struct GNS_ResolverHandle * GNS_resolver_lookup(const struct GNUNET_IDENTITY_PublicKey *zone, uint32_t record_type, const char *name, enum GNUNET_GNS_LocalOptions options, uint16_t recursion_depth_limit, GNS_ResultProcessor proc, void *proc_cls)
Lookup of a record in a specific zone calls lookup result processor on result.
void GNUNET_SERVICE_client_continue(struct GNUNET_SERVICE_Client *c)
Continue receiving further messages from the given client.
Definition: service.c:2244
#define GNUNET_MQ_handler_end()
End-marker for the handlers array.
int GNUNET_STRINGS_string_to_data(const char *enc, size_t enclen, void *out, size_t out_size)
Convert CrockfordBase32 encoding back to data.
Definition: strings.c:972
int GNUNET_NETWORK_test_pf(int pf)
Test if the given protocol family is supported by this system.
Definition: network.c:85
struct ClientLookupHandle * clh_tail
Tail of the DLL.
#define GNUNET_free(ptr)
Wrapper around free.
void GNUNET_STRINGS_utf8_tolower(const char *input, char *output)
Convert the utf-8 input string to lower case.
Definition: strings.c:568
uint16_t len
length of data (which is always a uint32_t, but presumably this can be used to specify that fewer byt...