GNUnet  0.11.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 {
53 
58 
63 
68 
72  void *cont_cls;
73 
78 
83 
87  uint32_t op_id;
88 };
89 
90 
95 {
100 
105 
109  struct GNUNET_CLIENT_TransmitHandle *th;
110 
115 
120 
125 
129  struct GNUNET_TIME_Relative reconnect_delay;
130 
135 
139  uint32_t last_op_id_used;
140 };
141 
142 
148 static void
150 
151 
159 static struct GNUNET_NAMECACHE_QueueEntry *
161  uint32_t rid)
162 {
164 
165  for (qe = h->op_head; qe != NULL; qe = qe->next)
166  {
167  if (qe->op_id == rid)
168  {
170  h->op_tail,
171  qe);
172  return qe;
173  }
174  }
175  return NULL;
176 }
177 
178 
186 static int
188  const struct LookupBlockResponseMessage *msg)
189 {
190  /* any length will do, format validation is in handler */
191  return GNUNET_OK;
192 }
193 
194 
202 static void
204  const struct LookupBlockResponseMessage *msg)
205 {
206  struct GNUNET_NAMECACHE_Handle *h = cls;
207  size_t size;
209 
211  "Received LOOKUP_BLOCK_RESPONSE\n");
212  qe = find_qe (h,
213  ntohl (msg->gns_header.r_id));
214  if (NULL == qe)
215  return;
217  {
218  /* no match found */
219  if (NULL != qe->block_proc)
220  qe->block_proc (qe->block_proc_cls,
221  NULL);
222  GNUNET_free (qe);
223  return;
224  }
225  size = ntohs (msg->gns_header.header.size)
226  - sizeof(struct LookupBlockResponseMessage);
227  {
228  char buf[size + sizeof(struct GNUNET_GNSRECORD_Block)] GNUNET_ALIGN;
229  struct GNUNET_GNSRECORD_Block *block;
230 
231  block = (struct GNUNET_GNSRECORD_Block *) buf;
232  block->signature = msg->signature;
233  block->derived_key = msg->derived_key;
235  block->purpose.size = htonl (size
236  + sizeof(struct GNUNET_TIME_AbsoluteNBO)
237  + sizeof(struct
239  block->expiration_time = msg->expire;
240  GNUNET_memcpy (&block[1],
241  &msg[1],
242  size);
243  if (GNUNET_OK !=
245  {
246  GNUNET_break (0);
247  if (NULL != qe->block_proc)
248  qe->block_proc (qe->block_proc_cls,
249  NULL);
250  force_reconnect (h);
251  }
252  else
253  {
254  if (NULL != qe->block_proc)
255  qe->block_proc (qe->block_proc_cls,
256  block);
257  }
258  }
259  GNUNET_free (qe);
260 }
261 
262 
272 static void
274  const struct BlockCacheResponseMessage *msg)
275 {
276  struct GNUNET_NAMECACHE_Handle *h = cls;
278  int res;
279 
281  "Received BLOCK_CACHE_RESPONSE\n");
282  qe = find_qe (h,
283  ntohl (msg->gns_header.r_id));
284  if (NULL == qe)
285  return;
286  res = ntohl (msg->op_result);
287  /* TODO: add actual error message from namecache to response... */
288  if (NULL != qe->cont)
289  qe->cont (qe->cont_cls,
290  res,
291  (GNUNET_OK == res)
292  ? NULL
293  : _ ("Namecache failed to cache block"));
294  GNUNET_free (qe);
295 }
296 
297 
306 static void
307 mq_error_handler (void *cls,
308  enum GNUNET_MQ_Error error)
309 {
310  struct GNUNET_NAMECACHE_Handle *h = cls;
311 
312  force_reconnect (h);
313 }
314 
315 
321 static void
323 {
324  struct GNUNET_MQ_MessageHandler handlers[] = {
325  GNUNET_MQ_hd_var_size (lookup_block_response,
328  h),
329  GNUNET_MQ_hd_fixed_size (block_cache_response,
332  h),
334  };
335 
336  GNUNET_assert (NULL == h->mq);
337  h->mq = GNUNET_CLIENT_connect (h->cfg,
338  "namecache",
339  handlers,
341  h);
342 }
343 
344 
350 static void
352 {
353  struct GNUNET_NAMECACHE_Handle *h = cls;
354 
355  h->reconnect_task = NULL;
356  reconnect (h);
357 }
358 
359 
365 static void
367 {
369 
370  h->reconnect = GNUNET_NO;
371  GNUNET_MQ_destroy (h->mq);
372  h->mq = NULL;
373  while (NULL != (qe = h->op_head))
374  {
376  h->op_tail,
377  qe);
378  if (NULL != qe->cont)
379  qe->cont (qe->cont_cls,
381  _ ("Error communicating with namecache service"));
382  GNUNET_free (qe);
383  }
385  "Reconnecting to namecache\n");
389  h);
390 }
391 
392 
399 static uint32_t
401 {
402  return h->last_op_id_used++;
403 }
404 
405 
414 {
415  struct GNUNET_NAMECACHE_Handle *h;
416 
417  h = GNUNET_new (struct GNUNET_NAMECACHE_Handle);
418  h->cfg = cfg;
419  reconnect (h);
420  if (NULL == h->mq)
421  {
422  GNUNET_free (h);
423  return NULL;
424  }
425  return h;
426 }
427 
428 
435 void
437 {
439 
440  GNUNET_break (NULL == h->op_head);
441  while (NULL != (q = h->op_head))
442  {
444  h->op_tail,
445  q);
446  GNUNET_free (q);
447  }
448  if (NULL != h->mq)
449  {
450  GNUNET_MQ_destroy (h->mq);
451  h->mq = NULL;
452  }
453  if (NULL != h->reconnect_task)
454  {
456  h->reconnect_task = NULL;
457  }
458  GNUNET_free (h);
459 }
460 
461 
474  const struct GNUNET_GNSRECORD_Block *block,
476  void *cont_cls)
477 {
479  struct BlockCacheMessage *msg;
480  struct GNUNET_MQ_Envelope *env;
481  uint32_t rid;
482  size_t blen;
483 
484  if (NULL == h->mq)
485  return NULL;
486  blen = ntohl (block->purpose.size);
487  GNUNET_assert (blen > (sizeof(struct GNUNET_TIME_AbsoluteNBO)
488  + sizeof(struct GNUNET_CRYPTO_EccSignaturePurpose)));
489  blen -= (sizeof(struct GNUNET_TIME_AbsoluteNBO)
490  + sizeof(struct GNUNET_CRYPTO_EccSignaturePurpose));
491  rid = get_op_id (h);
493  qe->nsh = h;
494  qe->cont = cont;
495  qe->cont_cls = cont_cls;
496  qe->op_id = rid;
498  h->op_tail,
499  qe);
500  /* send msg */
501  env = GNUNET_MQ_msg_extra (msg,
502  blen,
504  msg->gns_header.r_id = htonl (rid);
505  msg->expire = block->expiration_time;
506  msg->signature = block->signature;
507  msg->derived_key = block->derived_key;
508  GNUNET_memcpy (&msg[1],
509  &block[1],
510  blen);
511  GNUNET_MQ_send (h->mq,
512  env);
513  return qe;
514 }
515 
516 
530  const struct GNUNET_HashCode *derived_hash,
532  void *proc_cls)
533 {
535  struct LookupBlockMessage *msg;
536  struct GNUNET_MQ_Envelope *env;
537  uint32_t rid;
538 
539  if (NULL == h->mq)
540  return NULL;
542  "Looking for block under %s\n",
543  GNUNET_h2s (derived_hash));
544  rid = get_op_id (h);
546  qe->nsh = h;
547  qe->block_proc = proc;
548  qe->block_proc_cls = proc_cls;
549  qe->op_id = rid;
551  h->op_tail,
552  qe);
553  env = GNUNET_MQ_msg (msg,
555  msg->gns_header.r_id = htonl (rid);
556  msg->query = *derived_hash;
557  GNUNET_MQ_send (h->mq,
558  env);
559  return qe;
560 }
561 
562 
569 void
571 {
572  struct GNUNET_NAMECACHE_Handle *h = qe->nsh;
573 
575  h->op_tail,
576  qe);
577  GNUNET_free (qe);
578 }
579 
580 
581 /* 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:90
Lookup response.
Definition: namecache.h:75
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_ntoh(struct GNUNET_TIME_AbsoluteNBO a)
Convert absolute time from network byte order.
Definition: time.c:673
void(* GNUNET_NAMECACHE_BlockProcessor)(void *cls, const struct GNUNET_GNSRECORD_Block *block)
Process a record that was stored in the namecache.
static const struct GNUNET_CONFIGURATION_Handle * cfg
Configuration we are using.
Definition: gnunet-abd.c:36
struct GNUNET_CRYPTO_EcdsaPublicKey derived_key
Derived public key.
Definition: namecache.h:124
uint32_t op_id
The operation id this zone iteration operation has.
Definition: namecache_api.c:87
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:1057
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:133
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:52
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_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#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:78
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:75
#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:99
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:181
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:1253
struct GNUNET_NAMECACHE_Handle * nsh
Main handle to access the namecache.
Definition: namecache_api.c:62
void * cls
Closure for mv and cb.
Cache a record in the namecache.
Definition: namecache.h:104
void * cont_cls
Closure for cont.
Definition: namecache_api.c:72
#define GNUNET_MQ_hd_var_size(name, code, str, ctx)
const struct GNUNET_CONFIGURATION_Handle * cfg
Configuration to use.
Definition: namecache_api.c:99
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:82
GNUNET_NAMECACHE_BlockProcessor block_proc
Function to call with the blocks we get back; or NULL.
Definition: namecache_api.c:77
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:138
static struct GNUNET_REVOCATION_Query * q
Handle for revocation query.
struct GNUNET_NAMECACHE_Header gns_header
Type will be GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE.
Definition: namecache.h:80
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:76
static unsigned int size
Size of the "table".
Definition: peer.c:67
struct GNUNET_TIME_AbsoluteNBO expire
Expiration time.
Definition: namecache.h:114
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:57
struct GNUNET_CRYPTO_EcdsaPublicKey derived_key
Derived public key.
Definition: namecache.h:95
uint32_t r_id
Request ID in NBO.
Definition: namecache.h:51
Connection to the NAMECACHE service.
Definition: namecache_api.c:94
#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:85
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:119
int32_t op_result
GNUNET_OK on success, GNUNET_SYSERR error
Definition: namecache.h:143
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:109
GNUNET_NAMECACHE_ContinuationWithStatus cont
Continuation to call.
Definition: namecache_api.c:67
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:966