GNUnet  0.10.x
namecache_api.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2010-2013, 2016 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 */
20 
29 #include "platform.h"
30 #include "gnunet_util_lib.h"
31 #include "gnunet_crypto_lib.h"
32 #include "gnunet_constants.h"
33 #include "gnunet_dnsparser_lib.h"
34 #include "gnunet_gnsrecord_lib.h"
35 #include "gnunet_signatures.h"
37 #include "namecache.h"
38 
39 
40 #define LOG(kind,...) GNUNET_log_from (kind, "namecache-api",__VA_ARGS__)
41 
42 
48 {
49 
54 
59 
64 
69 
73  void *cont_cls;
74 
79 
84 
88  uint32_t op_id;
89 
90 };
91 
92 
97 {
98 
103 
108 
112  struct GNUNET_CLIENT_TransmitHandle *th;
113 
118 
123 
128 
132  struct GNUNET_TIME_Relative reconnect_delay;
133 
138 
142  uint32_t last_op_id_used;
143 
144 };
145 
146 
152 static void
154 
155 
163 static struct GNUNET_NAMECACHE_QueueEntry *
165  uint32_t rid)
166 {
168 
169  for (qe = h->op_head; qe != NULL; qe = qe->next)
170  {
171  if (qe->op_id == rid)
172  {
174  h->op_tail,
175  qe);
176  return qe;
177  }
178  }
179  return NULL;
180 }
181 
182 
190 static int
192  const struct LookupBlockResponseMessage *msg)
193 {
194  /* any length will do, format validation is in handler */
195  return GNUNET_OK;
196 }
197 
198 
206 static void
208  const struct LookupBlockResponseMessage *msg)
209 {
210  struct GNUNET_NAMECACHE_Handle *h = cls;
211  size_t size;
213 
215  "Received LOOKUP_BLOCK_RESPONSE\n");
216  qe = find_qe (h,
217  ntohl (msg->gns_header.r_id));
218  if (NULL == qe)
219  return;
221  {
222  /* no match found */
223  if (NULL != qe->block_proc)
224  qe->block_proc (qe->block_proc_cls,
225  NULL);
226  GNUNET_free (qe);
227  return;
228  }
229  size = ntohs (msg->gns_header.header.size)
230  - sizeof (struct LookupBlockResponseMessage);
231  {
232  char buf[size + sizeof (struct GNUNET_GNSRECORD_Block)] GNUNET_ALIGN;
233  struct GNUNET_GNSRECORD_Block *block;
234 
235  block = (struct GNUNET_GNSRECORD_Block *) buf;
236  block->signature = msg->signature;
237  block->derived_key = msg->derived_key;
239  block->purpose.size = htonl (size +
240  sizeof (struct GNUNET_TIME_AbsoluteNBO) +
241  sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose));
242  block->expiration_time = msg->expire;
243  GNUNET_memcpy (&block[1],
244  &msg[1],
245  size);
246  if (GNUNET_OK !=
248  {
249  GNUNET_break (0);
250  if (NULL != qe->block_proc)
251  qe->block_proc (qe->block_proc_cls,
252  NULL);
253  force_reconnect (h);
254  }
255  else
256  {
257  if (NULL != qe->block_proc)
258  qe->block_proc (qe->block_proc_cls,
259  block);
260  }
261  }
262  GNUNET_free (qe);
263 }
264 
265 
275 static void
277  const struct BlockCacheResponseMessage *msg)
278 {
279  struct GNUNET_NAMECACHE_Handle *h = cls;
281  int res;
282 
284  "Received BLOCK_CACHE_RESPONSE\n");
285  qe = find_qe (h,
286  ntohl (msg->gns_header.r_id));
287  if (NULL == qe)
288  return;
289  res = ntohl (msg->op_result);
290  /* TODO: add actual error message from namecache to response... */
291  if (NULL != qe->cont)
292  qe->cont (qe->cont_cls,
293  res,
294  (GNUNET_OK == res)
295  ? NULL
296  : _("Namecache failed to cache block"));
297  GNUNET_free (qe);
298 }
299 
300 
309 static void
310 mq_error_handler (void *cls,
311  enum GNUNET_MQ_Error error)
312 {
313  struct GNUNET_NAMECACHE_Handle *h = cls;
314 
315  force_reconnect (h);
316 }
317 
318 
324 static void
326 {
327  struct GNUNET_MQ_MessageHandler handlers[] = {
328  GNUNET_MQ_hd_var_size (lookup_block_response,
331  h),
332  GNUNET_MQ_hd_fixed_size (block_cache_response,
335  h),
337  };
338  GNUNET_assert (NULL == h->mq);
339  h->mq = GNUNET_CLIENT_connect (h->cfg,
340  "namecache",
341  handlers,
343  h);
344 }
345 
346 
352 static void
354 {
355  struct GNUNET_NAMECACHE_Handle *h = cls;
356 
357  h->reconnect_task = NULL;
358  reconnect (h);
359 }
360 
361 
367 static void
369 {
371 
372  h->reconnect = GNUNET_NO;
373  GNUNET_MQ_destroy (h->mq);
374  h->mq = NULL;
375  while (NULL != (qe = h->op_head))
376  {
378  h->op_tail,
379  qe);
380  if (NULL != qe->cont)
381  qe->cont (qe->cont_cls,
383  _("Error communicating with namecache service"));
384  GNUNET_free (qe);
385  }
387  "Reconnecting to namecache\n");
391  h);
392 }
393 
394 
401 static uint32_t
403 {
404  return h->last_op_id_used++;
405 }
406 
407 
416 {
417  struct GNUNET_NAMECACHE_Handle *h;
418 
419  h = GNUNET_new (struct GNUNET_NAMECACHE_Handle);
420  h->cfg = cfg;
421  reconnect (h);
422  if (NULL == h->mq)
423  {
424  GNUNET_free (h);
425  return NULL;
426  }
427  return h;
428 }
429 
430 
437 void
439 {
441 
442  GNUNET_break (NULL == h->op_head);
443  while (NULL != (q = h->op_head))
444  {
446  h->op_tail,
447  q);
448  GNUNET_free (q);
449  }
450  if (NULL != h->mq)
451  {
452  GNUNET_MQ_destroy (h->mq);
453  h->mq = NULL;
454  }
455  if (NULL != h->reconnect_task)
456  {
458  h->reconnect_task = NULL;
459  }
460  GNUNET_free (h);
461 }
462 
463 
476  const struct GNUNET_GNSRECORD_Block *block,
478  void *cont_cls)
479 {
481  struct BlockCacheMessage *msg;
482  struct GNUNET_MQ_Envelope *env;
483  uint32_t rid;
484  size_t blen;
485 
486  if (NULL == h->mq)
487  return NULL;
488  blen = ntohl (block->purpose.size);
489  GNUNET_assert (blen > (sizeof (struct GNUNET_TIME_AbsoluteNBO) +
490  sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose)));
491  blen -= (sizeof (struct GNUNET_TIME_AbsoluteNBO) +
492  sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose));
493  rid = get_op_id (h);
495  qe->nsh = h;
496  qe->cont = cont;
497  qe->cont_cls = cont_cls;
498  qe->op_id = rid;
500  h->op_tail,
501  qe);
502  /* send msg */
503  env = GNUNET_MQ_msg_extra (msg,
504  blen,
506  msg->gns_header.r_id = htonl (rid);
507  msg->expire = block->expiration_time;
508  msg->signature = block->signature;
509  msg->derived_key = block->derived_key;
510  GNUNET_memcpy (&msg[1],
511  &block[1],
512  blen);
513  GNUNET_MQ_send (h->mq,
514  env);
515  return qe;
516 }
517 
518 
532  const struct GNUNET_HashCode *derived_hash,
534  void *proc_cls)
535 {
537  struct LookupBlockMessage *msg;
538  struct GNUNET_MQ_Envelope *env;
539  uint32_t rid;
540 
541  if (NULL == h->mq)
542  return NULL;
544  "Looking for block under %s\n",
545  GNUNET_h2s (derived_hash));
546  rid = get_op_id (h);
548  qe->nsh = h;
549  qe->block_proc = proc;
550  qe->block_proc_cls = proc_cls;
551  qe->op_id = rid;
553  h->op_tail,
554  qe);
555  env = GNUNET_MQ_msg (msg,
557  msg->gns_header.r_id = htonl (rid);
558  msg->query = *derived_hash;
559  GNUNET_MQ_send (h->mq,
560  env);
561  return qe;
562 }
563 
564 
571 void
573 {
574  struct GNUNET_NAMECACHE_Handle *h = qe->nsh;
575 
577  h->op_tail,
578  qe);
579  GNUNET_free(qe);
580 }
581 
582 
583 /* end of namecache_api.c */
#define GNUNET_CONTAINER_DLL_remove(head, tail, element)
Remove an element from a DLL.
#define GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE
Service to client: result of block lookup.
#define GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE
Service to client: result of block cache request.
struct GNUNET_TIME_Relative reconnect_delay
Delay introduced before we reconnect.
Lookup a block in the namecache.
Definition: namecache.h:58
struct GNUNET_NAMECACHE_Handle * GNUNET_NAMECACHE_connect(const struct GNUNET_CONFIGURATION_Handle *cfg)
Initialize the connection with the NAMECACHE service.
struct GNUNET_TIME_AbsoluteNBO expiration_time
Expiration time of the block.
static struct GNUNET_DATASTORE_QueueEntry * qe
Current operation.
#define GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE
Client to service: cache a block.
struct GNUNET_MessageHeader * msg
Definition: 005.c:2
struct GNUNET_CRYPTO_EcdsaSignature signature
Signature.
Definition: namecache.h:91
Lookup response.
Definition: namecache.h:76
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_ntoh(struct GNUNET_TIME_AbsoluteNBO a)
Convert absolute time from network byte order.
Definition: time.c:670
void(* GNUNET_NAMECACHE_BlockProcessor)(void *cls, const struct GNUNET_GNSRECORD_Block *block)
Process a record that was stored in the namecache.
struct GNUNET_CRYPTO_EcdsaPublicKey derived_key
Derived public key.
Definition: namecache.h:125
uint32_t op_id
The operation id this zone iteration operation has.
Definition: namecache_api.c:88
struct GNUNET_MQ_Handle * GNUNET_CLIENT_connect(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *service_name, const struct GNUNET_MQ_MessageHandler *handlers, GNUNET_MQ_ErrorHandler error_handler, void *error_handler_cls)
Create a message queue to connect to a GNUnet service.
Definition: client.c:901
uint32_t purpose
What does this signature vouch for? This must contain a GNUNET_SIGNATURE_PURPOSE_XXX constant (from g...
GNUNET_MQ_Error
Error codes for the queue.
Response to a request to cache a block.
Definition: namecache.h:134
struct GNUNET_MessageHeader header
header.type will be GNUNET_MESSAGE_TYPE_NAMECACHE_* header.size will be message size ...
Definition: namecache.h:46
struct GNUNET_NAMECACHE_Header gns_header
Type will be GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK.
Definition: namecache.h:63
struct GNUNET_NAMECACHE_QueueEntry * next
Kept in a DLL.
Definition: namecache_api.c:53
struct GNUNET_NAMECACHE_QueueEntry * op_tail
Tail of pending namecache queue entries.
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
struct GNUNET_SCHEDULER_Task * reconnect_task
Reconnect task.
#define GNUNET_MQ_hd_fixed_size(name, code, str, ctx)
#define GNUNET_MQ_msg(mvar, type)
Allocate a GNUNET_MQ_Envelope.
Definition: gnunet_mq_lib.h:67
#define GNUNET_NO
Definition: gnunet_common.h:81
const char * GNUNET_h2s(const struct GNUNET_HashCode *hc)
Convert a hash value to a string (for printing debug messages).
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:78
#define GNUNET_new(type)
Allocate a struct or union of the given type.
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format...
Information we have in an encrypted block with record data (i.e.
static struct GNUNET_NAMECACHE_QueueEntry * find_qe(struct GNUNET_NAMECACHE_Handle *h, uint32_t rid)
Find queue entry for the given rid.
Time for absolute time used by GNUnet, in microseconds and in network byte order. ...
static int check_lookup_block_response(void *cls, const struct LookupBlockResponseMessage *msg)
Handle an incoming message of type GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE.
uint64_t abs_value_us
The actual value.
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
#define GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK
Client to service: lookup block.
static struct GNUNET_ARM_Handle * h
Connection with ARM.
Definition: gnunet-arm.c:94
static void mq_error_handler(void *cls, enum GNUNET_MQ_Error error)
Generic error handler, called with the appropriate error code and the same closure specified at the c...
static void handle_block_cache_response(void *cls, const struct BlockCacheResponseMessage *msg)
Handle an incoming message of type GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE.
#define _(String)
GNU gettext support macro.
Definition: platform.h:208
header of what an ECC signature signs this must be followed by "size - 8" bytes of the actual signed ...
cryptographic primitives for GNUnet
#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
struct GNUNET_SCHEDULER_Task * GNUNET_SCHEDULER_add_delayed(struct GNUNET_TIME_Relative delay, GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
Schedule a new task to be run with a specified delay.
Definition: scheduler.c:1246
struct GNUNET_NAMECACHE_Handle * nsh
Main handle to access the namecache.
Definition: namecache_api.c:63
#define GNUNET_memcpy(dst, src, n)
void * cls
Closure for mv and cb.
Cache a record in the namecache.
Definition: namecache.h:105
void * cont_cls
Closure for cont.
Definition: namecache_api.c:73
#define GNUNET_MQ_hd_var_size(name, code, str, ctx)
const struct GNUNET_CONFIGURATION_Handle * cfg
Configuration to use.
static char buf[2048]
void GNUNET_NAMECACHE_cancel(struct GNUNET_NAMECACHE_QueueEntry *qe)
Cancel a namecache operation.
void * block_proc_cls
Closure for block_proc.
Definition: namecache_api.c:83
GNUNET_NAMECACHE_BlockProcessor block_proc
Function to call with the blocks we get back; or NULL.
Definition: namecache_api.c:78
static void reconnect(struct GNUNET_NAMECACHE_Handle *h)
Reconnect to namecache service.
uint32_t size
How many bytes does this signature sign? (including this purpose header); in network byte order (!)...
struct GNUNET_NAMECACHE_QueueEntry * GNUNET_NAMECACHE_block_cache(struct GNUNET_NAMECACHE_Handle *h, const struct GNUNET_GNSRECORD_Block *block, GNUNET_NAMECACHE_ContinuationWithStatus cont, void *cont_cls)
Store an item in the namecache.
A 512-bit hashcode.
static uint32_t get_op_id(struct GNUNET_NAMECACHE_Handle *h)
Get a fresh operation id to distinguish between namecache requests.
Message handler for a specific message type.
static int res
struct GNUNET_NAMECACHE_Header gns_header
Type will be GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE.
Definition: namecache.h:139
static struct GNUNET_REVOCATION_Query * q
Handle for revocation query.
static struct GNUNET_CONFIGURATION_Handle * cfg
Our configuration.
Definition: gnunet-arm.c:104
struct GNUNET_NAMECACHE_Header gns_header
Type will be GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE.
Definition: namecache.h:81
int GNUNET_GNSRECORD_block_verify(const struct GNUNET_GNSRECORD_Block *block)
Check if a signature is valid.
struct GNUNET_MQ_Handle * mq
Message queue to service.
static void handle_lookup_block_response(void *cls, const struct LookupBlockResponseMessage *msg)
Handle an incoming message of type GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE.
#define GNUNET_SYSERR
Definition: gnunet_common.h:79
static unsigned int size
Size of the "table".
Definition: peer.c:67
struct GNUNET_TIME_AbsoluteNBO expire
Expiration time.
Definition: namecache.h:115
int reconnect
Should we reconnect to service due to some serious error?
void(* GNUNET_NAMECACHE_ContinuationWithStatus)(void *cls, int32_t success, const char *emsg)
Continuation called to notify client about result of the operation.
struct GNUNET_MQ_Envelope * env
Definition: 005.c:1
#define GNUNET_CONTAINER_DLL_insert_tail(head, tail, element)
Insert an element at the tail of a DLL.
#define GNUNET_TIME_STD_BACKOFF(r)
Perform our standard exponential back-off calculation, starting at 1 ms and then going by a factor of...
struct GNUNET_NAMECACHE_QueueEntry * GNUNET_NAMECACHE_lookup_block(struct GNUNET_NAMECACHE_Handle *h, const struct GNUNET_HashCode *derived_hash, GNUNET_NAMECACHE_BlockProcessor proc, void *proc_cls)
Get a result for a particular key from the namecache.
Handle to a message queue.
Definition: mq.c:85
struct GNUNET_CRYPTO_EcdsaSignature signature
Signature of the block.
struct GNUNET_HashCode query
The query.
Definition: namecache.h:68
struct GNUNET_NAMECACHE_QueueEntry * op_head
Head of pending namecache queue entries.
configuration data
Definition: configuration.c:85
struct GNUNET_NAMECACHE_QueueEntry * prev
Kept in a DLL.
Definition: namecache_api.c:58
struct GNUNET_CRYPTO_EcdsaPublicKey derived_key
Derived public key.
Definition: namecache.h:96
uint32_t r_id
Request ID in NBO.
Definition: namecache.h:51
Connection to the NAMECACHE service.
Definition: namecache_api.c:96
#define GNUNET_log(kind,...)
Entry in list of pending tasks.
Definition: scheduler.c:134
#define GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN
Signature of a gnunet naming system record block.
void GNUNET_NAMECACHE_disconnect(struct GNUNET_NAMECACHE_Handle *h)
Disconnect from the namecache service (and free associated resources).
#define LOG(kind,...)
Definition: namecache_api.c:40
void GNUNET_MQ_destroy(struct GNUNET_MQ_Handle *mq)
Destroy the message queue.
Definition: mq.c:824
struct GNUNET_TIME_AbsoluteNBO expire
Expiration time.
Definition: namecache.h:86
uint32_t last_op_id_used
The last operation id used for a NAMECACHE operation.
An QueueEntry used to store information for a pending NAMECACHE record operation. ...
Definition: namecache_api.c:47
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:353
struct GNUNET_CRYPTO_EcdsaSignature signature
Signature.
Definition: namecache.h:120
int32_t op_result
GNUNET_OK on success, GNUNET_SYSERR error
Definition: namecache.h:144
static void force_reconnect(struct GNUNET_NAMECACHE_Handle *h)
Disconnect from service and then reconnect.
struct GNUNET_CRYPTO_EccSignaturePurpose purpose
Number of bytes signed; also specifies the number of bytes of encrypted data that follow...
common internal definitions for namecache service
struct GNUNET_CRYPTO_EcdsaPublicKey derived_key
Derived key used for signing; hash of this is the query.
struct GNUNET_CLIENT_TransmitHandle * th
Currently pending transmission request (or NULL).
#define GNUNET_MQ_handler_end()
End-marker for the handlers array.
#define GNUNET_free(ptr)
Wrapper around free.
Time for relative time used by GNUnet, in microseconds.
struct GNUNET_NAMECACHE_Header gns_header
Type will be GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE.
Definition: namecache.h:110
GNUNET_NAMECACHE_ContinuationWithStatus cont
Continuation to call.
Definition: namecache_api.c:68
static void reconnect_task(void *cls)
Re-establish the connection to the service.
void * GNUNET_SCHEDULER_cancel(struct GNUNET_SCHEDULER_Task *task)
Cancel the task with the specified identifier.
Definition: scheduler.c:965