gnunet-service-dht_neighbours.h File Reference

GNUnet DHT routing code. More...

#include "gnunet_util_lib.h"
#include "gnunet_block_lib.h"
#include "gnunet_dht_service.h"
#include "gnunet_dhtu_plugin.h"
#include "gnunet-service-dht_datacache.h"

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Functions
struct PeerInfo *	GDS_NEIGHBOURS_lookup_peer (const struct GNUNET_PeerIdentity *target)
	Lookup peer by peer's identity. More...
enum GNUNET_GenericReturnValue	GDS_NEIGHBOURS_handle_put (const struct GNUNET_DATACACHE_Block *bd, uint16_t desired_replication_level, uint16_t hop_count, struct GNUNET_CONTAINER_BloomFilter *bf)
	Perform a PUT operation. More...
enum GNUNET_GenericReturnValue	GDS_NEIGHBOURS_handle_get (enum GNUNET_BLOCK_Type type, enum GNUNET_DHT_RouteOption options, uint16_t desired_replication_level, uint16_t hop_count, const struct GNUNET_HashCode *key, const void *xquery, size_t xquery_size, struct GNUNET_BLOCK_Group *bg, struct GNUNET_CONTAINER_BloomFilter *peer_bf)
	Perform a GET operation. More...
bool	GDS_NEIGHBOURS_handle_reply (struct PeerInfo *pi, const struct GNUNET_DATACACHE_Block *bd, const struct GNUNET_HashCode *query_hash, unsigned int get_path_length, const struct GNUNET_DHT_PathElement *get_path)
	Handle a reply (route to origin). More...
enum GNUNET_GenericReturnValue	GDS_am_closest_peer (const struct GNUNET_HashCode *key, const struct GNUNET_CONTAINER_BloomFilter *bloom)
	Check whether my identity is closer than any known peers. More...
void	GDS_try_connect (void *cls, const char *uri)
	Callback function used to extract URIs from a builder. More...
void	GDS_u_connect (void *cls, struct GNUNET_DHTU_Target *target, const struct GNUNET_PeerIdentity *pid, void **ctx)
	Function to call when we connect to a peer and can henceforth transmit to that peer. More...
void	GDS_u_disconnect (void *ctx)
	Function to call when we disconnected from a peer and can henceforth cannot transmit to that peer anymore. More...
void	GDS_u_receive (void *cls, void **tctx, void **sctx, const void *message, size_t message_size)
	Function to call when we receive a message. More...
void	GDS_NEIGHBOURS_broadcast (const struct GNUNET_MessageHeader *msg)
	Send msg to all peers in our buckets. More...
enum GNUNET_GenericReturnValue	GDS_NEIGHBOURS_init (void)
	Initialize neighbours subsystem. More...
void	GDS_NEIGHBOURS_done (void)
	Shutdown neighbours subsystem. More...
struct GNUNET_PeerIdentity *	GDS_NEIGHBOURS_get_id (void)
	Get the ID of the local node. More...

Detailed Description

GNUnet DHT routing code.

Author

Christian Grothoff

Nathan Evans

Definition in file gnunet-service-dht_neighbours.h.

Function Documentation

GDS_NEIGHBOURS_lookup_peer()

struct PeerInfo* GDS_NEIGHBOURS_lookup_peer

(

const struct GNUNET_PeerIdentity *

target

)

Lookup peer by peer's identity.

Parameters

target

peer to look up

Returns

NULL if we are not connected to target

Definition at line 1665 of file gnunet-service-dht_neighbours.c.

{
  return GNUNET_CONTAINER_multipeermap_get (all_connected_peers,
                                            target);
}

References all_connected_peers, and GNUNET_CONTAINER_multipeermap_get().

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GDS_NEIGHBOURS_handle_put()

enum GNUNET_GenericReturnValue GDS_NEIGHBOURS_handle_put	(	const struct GNUNET_DATACACHE_Block *	bd,
		uint16_t	desired_replication_level,
		uint16_t	hop_count,
		struct GNUNET_CONTAINER_BloomFilter *	bf
	)

Perform a PUT operation.

Forwards the given request to other peers. Does not store the data locally. Does not give the data to local clients. May do nothing if this is the only peer in the network (or if we are the closest peer in the network).

Parameters

bd	data about the block
desired_replication_level	desired replication level
hop_count	how many hops has this message traversed so far
bf	Bloom filter of peers this PUT has already traversed

Returns

GNUNET_OK if the request was forwarded, GNUNET_NO if not

Definition at line 1302 of file gnunet-service-dht_neighbours.c.

{
  unsigned int target_count;
  struct PeerInfo **targets;
  size_t msize;
  unsigned int skip_count;
  enum GNUNET_DHT_RouteOption ro = bd->ro;
  unsigned int put_path_length = bd->put_path_length;
  const struct GNUNET_DHT_PathElement *put_path = bd->put_path;
  bool truncated = (0 != (ro & GNUNET_DHT_RO_TRUNCATED));
  bool tracking = (0 != (ro & GNUNET_DHT_RO_RECORD_ROUTE));
  const struct GNUNET_PeerIdentity *trunc_peer
    = truncated
    ? &bd->trunc_peer
    : NULL;
 
#if SANITY_CHECKS > 1
  unsigned int failure_offset;
 
  failure_offset
    = GNUNET_DHT_verify_path (bd->data,
                              bd->data_size,
                              bd->expiration_time,
                              trunc_peer,
                              put_path,
                              put_path_length,
                              NULL, 0,    /* get_path */
                              &GDS_my_identity);
  if (0 != failure_offset)
  {
    GNUNET_break_op (0);
    truncated = true;
    trunc_peer = &put_path[failure_offset - 1].pred;
    put_path = &put_path[failure_offset];
    put_path_length = put_path_length - failure_offset;
    ro |= GNUNET_DHT_RO_TRUNCATED;
  }
#endif
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Adding myself (%s) to PUT bloomfilter for %s with RO(%s/%s)\n",
              GNUNET_i2s (&GDS_my_identity),
              GNUNET_h2s (&bd->key),
              (bd->ro & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE) ? "x" : "-",
              (bd->ro & GNUNET_DHT_RO_RECORD_ROUTE) ? "R" : "-");
 
  /* if we got a HELLO, consider it for our own routing table */
  hello_check (bd);
  GNUNET_assert (NULL != bf);
  GNUNET_CONTAINER_bloomfilter_add (bf,
                                    &GDS_my_identity_hash);
  GNUNET_STATISTICS_update (GDS_stats,
                            "# PUT requests routed",
                            1,
                            GNUNET_NO);
  if (bd->data_size
      > GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE
      - sizeof(struct PeerPutMessage))
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  msize = bd->data_size + sizeof(struct PeerPutMessage);
  if (tracking)
  {
    if (msize + sizeof (struct GNUNET_CRYPTO_EddsaSignature)
        > GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "Discarding message that is too large due to tracking\n");
      return GNUNET_NO;
    }
    msize += sizeof (struct GNUNET_CRYPTO_EddsaSignature);
  }
  else
  {
    /* If tracking is disabled, also discard any path we might have
       gotten from some broken peer */
    GNUNET_break_op (0 == put_path_length);
    put_path_length = 0;
  }
  if (truncated)
    msize += sizeof (struct GNUNET_PeerIdentity);
  if (msize + put_path_length * sizeof(struct GNUNET_DHT_PathElement)
      > GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE)
  {
    unsigned int mlen;
    unsigned int ppl;
 
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                "Truncating path that is too large due\n");
    mlen = GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE - msize;
    if (! truncated)
    {
      /* We need extra space for the truncation, consider that,
         too! */
      truncated = true;
      mlen -= sizeof (struct GNUNET_PeerIdentity);
      msize += sizeof (struct GNUNET_PeerIdentity);
    }
    /* compute maximum length of path we can keep */
    ppl = mlen / sizeof (struct GNUNET_DHT_PathElement);
    GNUNET_assert (put_path_length - ppl > 0);
    trunc_peer = &put_path[put_path_length - ppl - 1].pred;
    put_path = &put_path[put_path_length - ppl];
    put_path_length = ppl;
    ro |= GNUNET_DHT_RO_TRUNCATED;
  }
  else
  {
    msize += bd->put_path_length * sizeof(struct GNUNET_DHT_PathElement);
  }
  target_count
    = get_target_peers (&bd->key,
                        bf,
                        hop_count,
                        desired_replication_level,
                        &targets);
  if (0 == target_count)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Routing PUT for %s terminates after %u hops at %s\n",
                GNUNET_h2s (&bd->key),
                (unsigned int) hop_count,
                GNUNET_i2s (&GDS_my_identity));
    return GNUNET_NO;
  }
  skip_count = 0;
  for (unsigned int i = 0; i < target_count; i++)
  {
    struct PeerInfo *target = targets[i];
    struct PeerPutMessage *ppm;
    char buf[msize] GNUNET_ALIGN;
    struct GNUNET_DHT_PathElement *pp;
    void *data;
 
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Routing PUT for %s after %u hops to %s\n",
                GNUNET_h2s (&bd->key),
                (unsigned int) hop_count,
                GNUNET_i2s (&target->id));
    ppm = (struct PeerPutMessage *) buf;
    ppm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_PUT);
    ppm->header.size = htons (sizeof (buf));
    ppm->type = htonl (bd->type);
    ppm->options = htons (ro);
    ppm->hop_count = htons (hop_count + 1);
    ppm->desired_replication_level = htons (desired_replication_level);
    ppm->put_path_length = htons (put_path_length);
    ppm->expiration_time = GNUNET_TIME_absolute_hton (bd->expiration_time);
    GNUNET_break (GNUNET_YES ==
                  GNUNET_CONTAINER_bloomfilter_test (bf,
                                                     &target->phash));
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_CONTAINER_bloomfilter_get_raw_data (bf,
                                                              ppm->bloomfilter,
                                                              DHT_BLOOM_SIZE));
    ppm->key = bd->key;
    if (truncated)
    {
      void *tgt = &ppm[1];
 
      GNUNET_memcpy (tgt,
                     trunc_peer,
                     sizeof (struct GNUNET_PeerIdentity));
      pp = (struct GNUNET_DHT_PathElement *)
           (tgt + sizeof (struct GNUNET_PeerIdentity));
    }
    else
    {
      pp = (struct GNUNET_DHT_PathElement *) &ppm[1];
    }
    GNUNET_memcpy (pp,
                   put_path,
                   sizeof (struct GNUNET_DHT_PathElement) * put_path_length);
    if (tracking)
    {
      void *tgt = &pp[put_path_length];
      struct GNUNET_CRYPTO_EddsaSignature last_sig;
 
      if (0 == put_path_length)
      {
        /* Note that the signature in 'put_path' was not initialized before,
           so this is crucial to avoid sending garbage. */
        sign_path (bd->data,
                   bd->data_size,
                   bd->expiration_time,
                   trunc_peer,
                   &target->id,
                   &last_sig);
      }
      else
      {
        sign_path (bd->data,
                   bd->data_size,
                   bd->expiration_time,
                   &pp[put_path_length - 1].pred,
                   &target->id,
                   &last_sig);
      }
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Signing PUT PATH %u => %s\n",
                  put_path_length,
                  GNUNET_B2S (&last_sig));
      memcpy (tgt,
              &last_sig,
              sizeof (last_sig));
      data = tgt + sizeof (last_sig);
    }
    else /* ! tracking */
    {
      data = &ppm[1];
    }
    GNUNET_memcpy (data,
                   bd->data,
                   bd->data_size);
    do_send (target,
             &ppm->header);
  }
  GNUNET_free (targets);
  GNUNET_STATISTICS_update (GDS_stats,
                            "# PUT messages queued for transmission",
                            target_count - skip_count,
                            GNUNET_NO);
  return (skip_count < target_count) ? GNUNET_OK : GNUNET_NO;
}

Referenced by handle_dht_local_put(), and handle_dht_p2p_put().

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GDS_NEIGHBOURS_handle_get()

enum GNUNET_GenericReturnValue GDS_NEIGHBOURS_handle_get	(	enum GNUNET_BLOCK_Type	type,
		enum GNUNET_DHT_RouteOption	options,
		uint16_t	desired_replication_level,
		uint16_t	hop_count,
		const struct GNUNET_HashCode *	key,
		const void *	xquery,
		size_t	xquery_size,
		struct GNUNET_BLOCK_Group *	bg,
		struct GNUNET_CONTAINER_BloomFilter *	peer_bf
	)

Perform a GET operation.

Forwards the given request to other peers. Does not lookup the key locally. May do nothing if this is the only peer in the network (or if we are the closest peer in the network).

Parameters

type	type of the block
options	routing options
desired_replication_level	desired replication count
hop_count	how many hops did this request traverse so far?
key	key for the content
xquery	extended query
xquery_size	number of bytes in xquery
bg	block group to filter replies
peer_bf	filter for peers not to select (again, updated)

Returns

GNUNET_OK if the request was forwarded, GNUNET_NO if not

Definition at line 1302 of file gnunet-service-dht_neighbours.c.

{
  unsigned int target_count;
  struct PeerInfo **targets;
  size_t msize;
  size_t result_filter_size;
  void *result_filter;
  unsigned int skip_count;
 
  GNUNET_assert (NULL != peer_bf);
  GNUNET_STATISTICS_update (GDS_stats,
                            "# GET requests routed",
                            1,
                            GNUNET_NO);
  target_count = get_target_peers (key,
                                   peer_bf,
                                   hop_count,
                                   desired_replication_level,
                                   &targets);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Adding myself (%s) to GET bloomfilter for %s with RO(%s/%s)\n",
              GNUNET_i2s (&GDS_my_identity),
              GNUNET_h2s (key),
              (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE) ? "x" : "-",
              (options & GNUNET_DHT_RO_RECORD_ROUTE) ? "R" : "-");
 
  GNUNET_CONTAINER_bloomfilter_add (peer_bf,
                                    &GDS_my_identity_hash);
  if (0 == target_count)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Routing GET for %s terminates after %u hops at %s\n",
                GNUNET_h2s (key),
                (unsigned int) hop_count,
                GNUNET_i2s (&GDS_my_identity));
    return GNUNET_NO;
  }
  if (GNUNET_OK !=
      GNUNET_BLOCK_group_serialize (bg,
                                    &result_filter,
                                    &result_filter_size))
  {
    result_filter = NULL;
    result_filter_size = 0;
  }
  msize = xquery_size + result_filter_size;
  if (msize + sizeof(struct PeerGetMessage) >= GNUNET_MAX_MESSAGE_SIZE)
  {
    GNUNET_break (0);
    GNUNET_free (result_filter);
    GNUNET_free (targets);
    return GNUNET_NO;
  }
  /* forward request */
  skip_count = 0;
  for (unsigned int i = 0; i < target_count; i++)
  {
    struct PeerInfo *target = targets[i];
    struct PeerGetMessage *pgm;
    char buf[sizeof (*pgm) + msize] GNUNET_ALIGN;
    char *rf;
 
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Routing GET for %s after %u hops to %s\n",
                GNUNET_h2s (key),
                (unsigned int) hop_count,
                GNUNET_i2s (&target->id));
    pgm = (struct PeerGetMessage *) buf;
    pgm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_GET);
    pgm->header.size = htons (sizeof (buf));
    pgm->type = htonl (type);
    pgm->options = htons (options);
    pgm->hop_count = htons (hop_count + 1);
    pgm->desired_replication_level = htons (desired_replication_level);
    pgm->result_filter_size = htons ((uint16_t) result_filter_size);
    GNUNET_break (GNUNET_YES ==
                  GNUNET_CONTAINER_bloomfilter_test (peer_bf,
                                                     &target->phash));
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_CONTAINER_bloomfilter_get_raw_data (peer_bf,
                                                              pgm->bloomfilter,
                                                              DHT_BLOOM_SIZE));
    pgm->key = *key;
    rf = (char *) &pgm[1];
    GNUNET_memcpy (rf,
                   result_filter,
                   result_filter_size);
    GNUNET_memcpy (&rf[result_filter_size],
                   xquery,
                   xquery_size);
    do_send (target,
             &pgm->header);
  }
  GNUNET_STATISTICS_update (GDS_stats,
                            "# GET messages queued for transmission",
                            target_count - skip_count,
                            GNUNET_NO);
  GNUNET_free (targets);
  GNUNET_free (result_filter);
  return (skip_count < target_count) ? GNUNET_OK : GNUNET_NO;
}

References GNUNET_DATACACHE_Block::data, GNUNET_DATACACHE_Block::data_size, disable_try_connect, GDS_try_connect(), GNUNET_BLOCK_TYPE_DHT_URL_HELLO, GNUNET_HELLO_builder_free(), GNUNET_HELLO_builder_from_block(), GNUNET_HELLO_builder_iterate(), GNUNET_YES, pid, and GNUNET_DATACACHE_Block::type.

Referenced by handle_dht_p2p_get(), send_find_peer_message(), and transmit_request().

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GDS_NEIGHBOURS_handle_reply()

bool GDS_NEIGHBOURS_handle_reply	(	struct PeerInfo *	pi,
		const struct GNUNET_DATACACHE_Block *	bd,
		const struct GNUNET_HashCode *	query_hash,
		unsigned int	get_path_length,
		const struct GNUNET_DHT_PathElement *	get_path
	)

Handle a reply (route to origin).

Only forwards the reply back to other peers waiting for it. Does not do local caching or forwarding to local clients.

Parameters

pi	neighbour that should receive the block
type	type of the block
bd	details about the reply
query_hash	query that was used for the request
get_path_length	number of entries in put_path
get_path	peers this reply has traversed so far (if tracked)

Returns

true on success

Definition at line 1673 of file gnunet-service-dht_neighbours.c.

{
  struct GNUNET_DHT_PathElement *paths;
  size_t msize;
  unsigned int ppl = bd->put_path_length;
  const struct GNUNET_DHT_PathElement *put_path = bd->put_path;
  enum GNUNET_DHT_RouteOption ro = bd->ro;
  bool truncated = (0 != (ro & GNUNET_DHT_RO_TRUNCATED));
  const struct GNUNET_PeerIdentity *trunc_peer
    = truncated
    ? &bd->trunc_peer
    : NULL;
  bool tracking = (0 != (ro & GNUNET_DHT_RO_RECORD_ROUTE));
#if SANITY_CHECKS > 1
  unsigned int failure_offset;
 
  failure_offset
    = GNUNET_DHT_verify_path (bd->data,
                              bd->data_size,
                              bd->expiration_time,
                              trunc_peer,
                              put_path,
                              ppl,
                              get_path,
                              get_path_length,
                              &GDS_my_identity);
  if (0 != failure_offset)
  {
    GNUNET_assert (failure_offset <= ppl + get_path_length);
    GNUNET_break_op (0);
    if (failure_offset < ppl)
    {
      trunc_peer = &put_path[failure_offset - 1].pred;
      put_path += failure_offset;
      ppl -= failure_offset;
      truncated = true;
      ro |= GNUNET_DHT_RO_TRUNCATED;
    }
    else
    {
      failure_offset -= ppl;
      if (0 == failure_offset)
        trunc_peer = &put_path[ppl - 1].pred;
      else
        trunc_peer = &get_path[failure_offset - 1].pred;
      ppl = 0;
      put_path = NULL;
      truncated = true;
      ro |= GNUNET_DHT_RO_TRUNCATED;
      get_path += failure_offset;
      get_path_length -= failure_offset;
    }
  }
#endif
  msize = bd->data_size + sizeof (struct PeerResultMessage);
  if (msize > GNUNET_MAX_MESSAGE_SIZE)
  {
    GNUNET_break_op (0);
    return false;
  }
  if (truncated)
    msize += sizeof (struct GNUNET_PeerIdentity);
  if (tracking)
    msize += sizeof (struct GNUNET_CRYPTO_EddsaSignature);
  if (msize < bd->data_size)
  {
    GNUNET_break_op (0);
    return false;
  }
  if ( (GNUNET_MAX_MESSAGE_SIZE - msize)
       / sizeof(struct GNUNET_DHT_PathElement)
       < (get_path_length + ppl) )
  {
    get_path_length = 0;
    ppl = 0;
  }
  if ( (get_path_length > UINT16_MAX) ||
       (ppl > UINT16_MAX) )
  {
    GNUNET_break (0);
    get_path_length = 0;
    ppl = 0;
  }
  msize += (get_path_length + ppl)
           * sizeof(struct GNUNET_DHT_PathElement);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Forwarding reply for key %s to peer %s\n",
              GNUNET_h2s (query_hash),
              GNUNET_i2s (&pi->id));
  GNUNET_STATISTICS_update (GDS_stats,
                            "# RESULT messages queued for transmission",
                            1,
                            GNUNET_NO);
  {
    struct PeerResultMessage *prm;
    char buf[msize] GNUNET_ALIGN;
    void *data;
 
    prm = (struct PeerResultMessage *) buf;
    prm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT);
    prm->header.size = htons (sizeof (buf));
    prm->type = htonl ((uint32_t) bd->type);
    prm->reserved = htons (0);
    prm->options = htons ((uint16_t) ro);
    prm->put_path_length = htons ((uint16_t) ppl);
    prm->get_path_length = htons ((uint16_t) get_path_length);
    prm->expiration_time = GNUNET_TIME_absolute_hton (bd->expiration_time);
    prm->key = *query_hash;
    if (truncated)
    {
      void *tgt = &prm[1];
 
      GNUNET_memcpy (tgt,
                     trunc_peer,
                     sizeof (struct GNUNET_PeerIdentity));
      paths = (struct GNUNET_DHT_PathElement *)
              (tgt + sizeof (struct GNUNET_PeerIdentity));
    }
    else
    {
      paths = (struct GNUNET_DHT_PathElement *) &prm[1];
    }
    if (NULL != put_path)
    {
      GNUNET_memcpy (paths,
                     put_path,
                     ppl * sizeof(struct GNUNET_DHT_PathElement));
    }
    else
    {
      GNUNET_assert (0 == ppl);
    }
    if (NULL != get_path)
    {
      GNUNET_memcpy (&paths[ppl],
                     get_path,
                     get_path_length * sizeof(struct GNUNET_DHT_PathElement));
    }
    else
    {
      GNUNET_assert (0 == get_path_length);
    }
    if (tracking)
    {
      struct GNUNET_CRYPTO_EddsaSignature sig;
      void *tgt = &paths[get_path_length + ppl];
      const struct GNUNET_PeerIdentity *pred;
 
      if (ppl + get_path_length > 0)
        pred = &paths[ppl + get_path_length - 1].pred;
      else if (truncated)
        pred = trunc_peer;
      else
        pred = NULL; /* we are first! */
      /* Note that the last signature in 'paths' was not initialized before,
         so this is crucial to avoid sending garbage. */
      sign_path (bd->data,
                 bd->data_size,
                 bd->expiration_time,
                 pred,
                 &pi->id,
                 &sig);
      memcpy (tgt,
              &sig,
              sizeof (sig));
      data = tgt + sizeof (sig);
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Signing GET PATH %u/%u of %s => %s\n",
                  ppl,
                  get_path_length,
                  GNUNET_h2s (query_hash),
                  GNUNET_B2S (&sig));
#if SANITY_CHECKS > 1
      {
        struct GNUNET_DHT_PathElement xpaths[get_path_length + 1];
 
        memcpy (xpaths,
                &paths[ppl],
                get_path_length * sizeof (struct GNUNET_DHT_PathElement));
        xpaths[get_path_length].sig = sig;
        xpaths[get_path_length].pred = GDS_my_identity;
        if (0 !=
            GNUNET_DHT_verify_path (bd->data,
                                    bd->data_size,
                                    bd->expiration_time,
                                    trunc_peer,
                                    paths,
                                    ppl,
                                    xpaths,
                                    get_path_length + 1,
                                    &pi->id))
        {
          GNUNET_break (0);
          return false;
        }
      }
#endif
    }
    else
    {
      data = &prm[1];
    }
    GNUNET_memcpy (data,
                   bd->data,
                   bd->data_size);
    do_send (pi,
             &prm->header);
  }
  return true;
}

Referenced by check_dht_p2p_get(), handle_find_local_hello(), and handle_find_my_hello().

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GDS_am_closest_peer()

enum GNUNET_GenericReturnValue GDS_am_closest_peer	(	const struct GNUNET_HashCode *	key,
		const struct GNUNET_CONTAINER_BloomFilter *	bloom
	)

Check whether my identity is closer than any known peers.

If a non-null bloomfilter is given, check if this is the closest peer that hasn't already been routed to.

Parameters

key	hash code to check closeness to
bloom	bloomfilter, exclude these entries from the decision

Returns

GNUNET_YES if node location is closest, GNUNET_NO otherwise.

Definition at line 895 of file gnunet-service-dht_neighbours.c.

{
  if (0 == GNUNET_memcmp (&GDS_my_identity_hash,
                          key))
    return GNUNET_YES;
  for (int bucket_num = find_bucket (key);
       bucket_num < closest_bucket;
       bucket_num++)
  {
    unsigned int count = 0;
 
    GNUNET_assert (bucket_num >= 0);
    for (struct PeerInfo *pos = k_buckets[bucket_num].head;
         NULL != pos;
         pos = pos->next)
    {
      if (count >= bucket_size)
        break; /* we only consider first #bucket_size entries per bucket */
      count++;
      if ( (NULL != bloom) &&
           (GNUNET_YES ==
            GNUNET_CONTAINER_bloomfilter_test (bloom,
                                               &pos->phash)) )
        continue;               /* Ignore filtered peers */
      /* All peers in this bucket must be closer than us, as
         they mismatch with our PID on the pivotal bit. So
         because an unfiltered peer exists, we are not the
         closest. */
      int delta = GNUNET_CRYPTO_hash_xorcmp (&pos->phash,
                                             &GDS_my_identity_hash,
                                             key);
      switch (delta)
      {
      case -1: /* pos closer */
        return GNUNET_NO;
      case 0: /* identical, impossible! */
        GNUNET_assert (0);
        break;
      case 1: /* I am closer */
        break;
      }
    }
  }
  /* No closer (unfiltered) peers found; we must be the closest! */
  return GNUNET_YES;
}

References GDS_NSE_get(), GDS_stats, GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CRYPTO_random_u32(), GNUNET_DHT_MAXIMUM_REPLICATION_LEVEL, GNUNET_MIN, GNUNET_NO, and GNUNET_STATISTICS_update().

Referenced by handle_dht_local_put(), handle_dht_p2p_get(), and handle_dht_p2p_put().

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GDS_try_connect()

void GDS_try_connect	(	void *	cls,
		const char *	uri
	)

Callback function used to extract URIs from a builder.

Called when we should consider connecting to a peer.

Parameters

cls	closure pointing to a struct GNUNET_PeerIdentity *
uri	one of the URIs

Definition at line 2847 of file gnunet-service-dht_neighbours.c.

{
  const struct GNUNET_PeerIdentity *pid = cls;
  struct GNUNET_HashCode phash;
  int peer_bucket;
  struct PeerBucket *bucket;
 
  if (0 == GNUNET_memcmp (&GDS_my_identity,
                          pid))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Got a HELLO for my own PID, ignoring it\n");
    return; /* that's us! */
  }
  GNUNET_CRYPTO_hash (pid,
                      sizeof(*pid),
                      &phash);
  peer_bucket = find_bucket (&phash);
  GNUNET_assert ( (peer_bucket >= 0) &&
                  ((unsigned int) peer_bucket < MAX_BUCKETS));
  bucket = &k_buckets[peer_bucket];
  if (bucket->peers_size >= bucket_size)
    return; /* do not care */
  for (struct PeerInfo *pi = bucket->head;
       NULL != pi;
       pi = pi->next)
    if (0 ==
        GNUNET_memcmp (&pi->id,
                       pid))
    {
      /* already connected */
      /* TODO: maybe consider 'uri' anyway as an additional
         alternative address??? */
      return;
    }
  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
              "Discovered peer %s at %s suitable for bucket %d (%u/%u), trying to connect\n",
              GNUNET_i2s (pid),
              uri,
              peer_bucket,
              bucket->peers_size,
              bucket_size);
  /* new peer that we like! */
  GDS_u_try_connect (pid,
                     uri);
}

References bucket_size, find_bucket(), GDS_my_identity, GDS_u_try_connect(), GNUNET_assert, GNUNET_CRYPTO_hash(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_INFO, GNUNET_i2s(), GNUNET_log, GNUNET_memcmp, PeerBucket::head, k_buckets, MAX_BUCKETS, PeerBucket::peers_size, pi, pid, and uri.

Referenced by GDS_NEIGHBOURS_handle_get(), and handle_dht_local_hello_offer().

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GDS_u_connect()

void GDS_u_connect	(	void *	cls,
		struct GNUNET_DHTU_Target *	target,
		const struct GNUNET_PeerIdentity *	pid,
		void **	ctx
	)

Function to call when we connect to a peer and can henceforth transmit to that peer.

Parameters

	cls	the closure, must be a struct GDS_Underlay
	target	handle to the target, pointer will remain valid until disconnect_cb is called @para pid peer identity, pointer will remain valid until disconnect_cb is called
[out]	ctx	storage space for DHT to use in association with this target

Definition at line 741 of file gnunet-service-dht_neighbours.c.

{
  struct GDS_Underlay *u = cls;
  struct PeerInfo *pi;
  struct PeerBucket *bucket;
  bool do_hold = false;
 
  /* Check for connect to self message */
  if (0 == GNUNET_memcmp (&GDS_my_identity,
                          pid))
    return;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Connected to peer %s\n",
              GNUNET_i2s (pid));
  pi = GNUNET_CONTAINER_multipeermap_get (all_connected_peers,
                                          pid);
  if (NULL == pi)
  {
    GNUNET_STATISTICS_update (GDS_stats,
                              "# peers connected",
                              1,
                              GNUNET_NO);
    pi = GNUNET_new (struct PeerInfo);
    pi->id = *pid;
    GNUNET_CRYPTO_hash (pid,
                        sizeof(*pid),
                        &pi->phash);
    pi->peer_bucket = find_bucket (&pi->phash);
    GNUNET_assert ( (pi->peer_bucket >= 0) &&
                    ((unsigned int) pi->peer_bucket < MAX_BUCKETS));
    bucket = &k_buckets[pi->peer_bucket];
    GNUNET_CONTAINER_DLL_insert_tail (bucket->head,
                                      bucket->tail,
                                      pi);
    bucket->peers_size++;
    closest_bucket = GNUNET_MAX (closest_bucket,
                                 (unsigned int) pi->peer_bucket + 1);
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_CONTAINER_multipeermap_put (all_connected_peers,
                                                      &pi->id,
                                                      pi,
                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
    if (bucket->peers_size <= bucket_size)
    {
      newly_found_peers++;
      do_hold = true;
    }
    if ( (1 == GNUNET_CONTAINER_multipeermap_size (all_connected_peers)) &&
         (GNUNET_YES != disable_try_connect) )
    {
      /* got a first connection, good time to start with FIND PEER requests... */
      GNUNET_assert (NULL == find_peer_task);
      find_peer_task = GNUNET_SCHEDULER_add_now (&send_find_peer_message,
                                                 NULL);
    }
  }
  {
    struct Target *t;
 
    t = GNUNET_new (struct Target);
    t->u = u;
    t->utarget = target;
    t->pi = pi;
    GNUNET_CONTAINER_DLL_insert (pi->t_head,
                                 pi->t_tail,
                                 t);
    *ctx = t;
 
  }
  if (do_hold)
    update_hold (bucket);
}

References all_connected_peers, bucket_size, closest_bucket, ctx, disable_try_connect, find_bucket(), find_peer_task, GDS_my_identity, GDS_stats, GNUNET_assert, GNUNET_CONTAINER_DLL_insert, GNUNET_CONTAINER_DLL_insert_tail, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY, GNUNET_CONTAINER_multipeermap_get(), GNUNET_CONTAINER_multipeermap_put(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_CRYPTO_hash(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s(), GNUNET_log, GNUNET_MAX, GNUNET_memcmp, GNUNET_new, GNUNET_NO, GNUNET_OK, GNUNET_SCHEDULER_add_now(), GNUNET_STATISTICS_update(), GNUNET_YES, PeerBucket::head, k_buckets, MAX_BUCKETS, newly_found_peers, PeerBucket::peers_size, pi, pid, send_find_peer_message(), t, PeerBucket::tail, Target::u, and update_hold().

Referenced by load_underlay().

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GDS_u_disconnect()

void GDS_u_disconnect

(

void *

ctx

)

Function to call when we disconnected from a peer and can henceforth cannot transmit to that peer anymore.

Parameters

[in]

ctx

storage space used by the DHT in association with this target

Definition at line 819 of file gnunet-service-dht_neighbours.c.

{
  struct Target *t = ctx;
  struct PeerInfo *pi;
  struct PeerBucket *bucket;
  bool was_held = false;
 
  /* Check for disconnect from self message (on shutdown) */
  if (NULL == t)
    return;
  pi = t->pi;
  GNUNET_CONTAINER_DLL_remove (pi->t_head,
                               pi->t_tail,
                               t);
  if (NULL != t->ph)
  {
    GDS_u_drop (t->u,
                t->ph);
    t->ph = NULL;
    was_held = true;
  }
  if (t->load > 0)
  {
    t->dropped = true;
    t->pi = NULL;
  }
  else
  {
    GNUNET_free (t);
  }
  if (NULL != pi->t_head)
    return; /* got other connections still */
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Disconnected from peer %s\n",
              GNUNET_i2s (&pi->id));
  GNUNET_STATISTICS_update (GDS_stats,
                            "# peers connected",
                            -1,
                            GNUNET_NO);
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multipeermap_remove (all_connected_peers,
                                                       &pi->id,
                                                       pi));
  if ( (0 == GNUNET_CONTAINER_multipeermap_size (all_connected_peers)) &&
       (GNUNET_YES != disable_try_connect))
  {
    GNUNET_SCHEDULER_cancel (find_peer_task);
    find_peer_task = NULL;
  }
  GNUNET_assert (pi->peer_bucket >= 0);
  bucket = &k_buckets[pi->peer_bucket];
  GNUNET_CONTAINER_DLL_remove (bucket->head,
                               bucket->tail,
                               pi);
  GNUNET_assert (bucket->peers_size > 0);
  bucket->peers_size--;
  if ( (was_held) &&
       (bucket->peers_size >= bucket_size - 1) )
    update_hold (bucket);
  while ( (closest_bucket > 0) &&
          (0 == k_buckets[closest_bucket - 1].peers_size))
    closest_bucket--;
  GNUNET_free (pi->hello);
  GNUNET_free (pi);
}

References all_connected_peers, bucket_size, closest_bucket, ctx, disable_try_connect, find_peer_task, GDS_stats, GDS_u_drop(), GNUNET_assert, GNUNET_CONTAINER_DLL_remove, GNUNET_CONTAINER_multipeermap_remove(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_i2s(), GNUNET_log, GNUNET_NO, GNUNET_SCHEDULER_cancel(), GNUNET_STATISTICS_update(), GNUNET_YES, PeerBucket::head, k_buckets, PeerBucket::peers_size, pi, t, PeerBucket::tail, and update_hold().

Referenced by load_underlay().

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GDS_u_receive()

void GDS_u_receive	(	void *	cls,
		void **	tctx,
		void **	sctx,
		const void *	message,
		size_t	message_size
	)

Function to call when we receive a message.

Parameters

	cls	the closure
	origin	where the message originated from
[in,out]	tctx	ctx of target address where we received the message from
[in,out]	sctx	ctx of our own source address at which we received the message
	message	the message we received
	message_size	number of bytes in message

Definition at line 2778 of file gnunet-service-dht_neighbours.c.

{
  struct Target *t = *tctx;
  struct GNUNET_MQ_MessageHandler core_handlers[] = {
    GNUNET_MQ_hd_var_size (dht_p2p_get,
                           GNUNET_MESSAGE_TYPE_DHT_P2P_GET,
                           struct PeerGetMessage,
                           t),
    GNUNET_MQ_hd_var_size (dht_p2p_put,
                           GNUNET_MESSAGE_TYPE_DHT_P2P_PUT,
                           struct PeerPutMessage,
                           t),
    GNUNET_MQ_hd_var_size (dht_p2p_result,
                           GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT,
                           struct PeerResultMessage,
                           t),
    GNUNET_MQ_hd_var_size (dht_p2p_hello,
                           GNUNET_MESSAGE_TYPE_DHT_P2P_HELLO,
                           struct GNUNET_MessageHeader,
                           t),
    GNUNET_MQ_handler_end ()
  };
  const struct GNUNET_MessageHeader *mh = message;
 
  (void) cls; /* the 'struct GDS_Underlay' */
  (void) sctx; /* our receiver address */
  if (NULL == t)
  {
    /* Received message claiming to originate from myself?
       Ignore! */
    GNUNET_break_op (0);
    return;
  }
  if (message_size < sizeof (*mh))
  {
    GNUNET_break_op (0);
    return;
  }
  if (message_size != ntohs (mh->size))
  {
    GNUNET_break_op (0);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Handling message of type %u from peer %s\n",
              ntohs (mh->type),
              GNUNET_i2s (&t->pi->id));
  if (GNUNET_OK !=
      GNUNET_MQ_handle_message (core_handlers,
                                mh))
  {
    GNUNET_break_op (0);
    return;
  }
}

References GNUNET_break_op, GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s(), GNUNET_log, GNUNET_MESSAGE_TYPE_DHT_P2P_GET, GNUNET_MESSAGE_TYPE_DHT_P2P_HELLO, GNUNET_MESSAGE_TYPE_DHT_P2P_PUT, GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT, GNUNET_MQ_handle_message(), GNUNET_MQ_handler_end, GNUNET_MQ_hd_var_size, GNUNET_OK, mh, and t.

Referenced by load_underlay().

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GDS_NEIGHBOURS_broadcast()

void GDS_NEIGHBOURS_broadcast

(

const struct GNUNET_MessageHeader *

msg

)

Send msg to all peers in our buckets.

Parameters

msg	message to broadcast

Definition at line 2902 of file gnunet-service-dht_neighbours.c.

{
  for (unsigned int bc = 0; bc<closest_bucket; bc++)
  {
    struct PeerBucket *bucket = &k_buckets[bc];
    unsigned int count = 0;
 
    for (struct PeerInfo *pos = bucket->head;
         NULL != pos;
         pos = pos->next)
    {
      if (count >= bucket_size)
        break;   /* we only consider first #bucket_size entries per bucket */
      count++;
      do_send (pos,
               msg);
    }
  }
}

References bucket_size, closest_bucket, do_send(), PeerBucket::head, k_buckets, msg, and PeerInfo::next.

Referenced by broadcast_hello().

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GDS_NEIGHBOURS_init()

enum GNUNET_GenericReturnValue GDS_NEIGHBOURS_init

(

void

)

Initialize neighbours subsystem.

Returns

GNUNET_OK on success, GNUNET_SYSERR on error

Definition at line 2902 of file gnunet-service-dht_neighbours.c.

{
 
  unsigned long long temp_config_num;
 
  disable_try_connect
    = GNUNET_CONFIGURATION_get_value_yesno (GDS_cfg,
                                            "DHT",
                                            "DISABLE_TRY_CONNECT");
  if (GNUNET_OK ==
      GNUNET_CONFIGURATION_get_value_number (GDS_cfg,
                                             "DHT",
                                             "bucket_size",
                                             &temp_config_num))
    bucket_size = (unsigned int) temp_config_num;
  cache_results
    = GNUNET_CONFIGURATION_get_value_yesno (GDS_cfg,
                                            "DHT",
                                            "CACHE_RESULTS");
  all_connected_peers = GNUNET_CONTAINER_multipeermap_create (256,
                                                              GNUNET_YES);
  return GNUNET_OK;
}

Referenced by run().

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GDS_NEIGHBOURS_done()

void GDS_NEIGHBOURS_done

(

void

)

Shutdown neighbours subsystem.

Definition at line 2950 of file gnunet-service-dht_neighbours.c.

{
  if (NULL == all_connected_peers)
    return;
  GNUNET_assert (0 ==
                 GNUNET_CONTAINER_multipeermap_size (all_connected_peers));
  GNUNET_CONTAINER_multipeermap_destroy (all_connected_peers);
  all_connected_peers = NULL;
  GNUNET_assert (NULL == find_peer_task);
}

References all_connected_peers, find_peer_task, GNUNET_assert, GNUNET_CONTAINER_multipeermap_destroy(), and GNUNET_CONTAINER_multipeermap_size().

Referenced by shutdown_task().

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GDS_NEIGHBOURS_get_id()

struct GNUNET_PeerIdentity* GDS_NEIGHBOURS_get_id

(

void

)

Get the ID of the local node.

Returns

identity of the local node

Definition at line 2963 of file gnunet-service-dht_neighbours.c.

{
  return &GDS_my_identity;
}