/*
This file is part of GNUnet.
Copyright (C)
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
*/
/**
* @file rps/gnunet-service-rps_sampler.c
* @brief sampler implementation
* @author Julius Bünger
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet-service-rps_sampler_elem.h"
#include
#include "rps-test_util.h"
#define LOG(kind, ...) GNUNET_log_from(kind,"rps-sampler_elem",__VA_ARGS__)
// TODO check for overflows
/***********************************************************************
* WARNING: This section needs to be reviewed regarding the use of
* functions providing (pseudo)randomness!
***********************************************************************/
// TODO care about invalid input of the caller (size 0 or less...)
/**
* Reinitialise a previously initialised sampler element.
*
* @param sampler pointer to the memory that keeps the value.
*/
void
RPS_sampler_elem_reinit (struct RPS_SamplerElement *sampler_el)
{
sampler_el->is_empty = EMPTY;
// I guess I don't need to call GNUNET_CRYPTO_hmac_derive_key()...
GNUNET_CRYPTO_random_block(GNUNET_CRYPTO_QUALITY_STRONG,
&(sampler_el->auth_key.key),
GNUNET_CRYPTO_HASH_LENGTH);
#ifdef TO_FILE
/* Create a file(-name) to store internals to */
char *name_buf;
name_buf = auth_key_to_string (sampler_el->auth_key);
sampler_el->file_name = create_file (name_buf);
GNUNET_free (name_buf);
#endif /* TO_FILE */
sampler_el->last_client_request = GNUNET_TIME_UNIT_FOREVER_ABS;
sampler_el->birth = GNUNET_TIME_absolute_get ();
sampler_el->num_peers = 0;
sampler_el->num_change = 0;
}
/**
* Create a sampler element and initialise it.
*
* In this implementation this means choosing an auth_key for later use in
* a hmac at random.
*
* @return a newly created RPS_SamplerElement which currently holds no id.
*/
struct RPS_SamplerElement *
RPS_sampler_elem_create (void)
{
struct RPS_SamplerElement *s;
s = GNUNET_new (struct RPS_SamplerElement);
RPS_sampler_elem_reinit (s);
return s;
}
/**
* Destroy a sampler element.
*
* @param sampler_elem the element to destroy
*/
void
RPS_sampler_elem_destroy (struct RPS_SamplerElement *sampler_elem)
{
#ifdef TO_FILE
if (NULL != sampler_elem->file_name)
{
GNUNET_free (sampler_elem->file_name);
}
#endif /* TO_FILE */
GNUNET_free (sampler_elem);
}
/**
* Input an PeerID into the given sampler element.
*
* @param sampler the sampler the @a s_elem belongs to.
* Needed to know the
*/
void
RPS_sampler_elem_next (struct RPS_SamplerElement *s_elem,
const struct GNUNET_PeerIdentity *other)
{
struct GNUNET_HashCode other_hash;
s_elem->num_peers++;
#ifdef TO_FILE
to_file (s_elem->file_name,
"Got id %s",
GNUNET_i2s_full (other));
#endif /* TO_FILE */
if (0 == GNUNET_CRYPTO_cmp_peer_identity (other, &(s_elem->peer_id)))
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Have already PeerID %s\n",
GNUNET_i2s (&(s_elem->peer_id)));
}
else
{
GNUNET_CRYPTO_hmac(&s_elem->auth_key,
other,
sizeof(struct GNUNET_PeerIdentity),
&other_hash);
if (EMPTY == s_elem->is_empty)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Got PeerID %s; Simply accepting (was empty previously).\n",
GNUNET_i2s(other));
s_elem->peer_id = *other;
s_elem->peer_id_hash = other_hash;
s_elem->num_change++;
}
else if (0 > GNUNET_CRYPTO_hash_cmp (&other_hash, &s_elem->peer_id_hash))
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Discarding old PeerID %s\n",
GNUNET_i2s (&s_elem->peer_id));
s_elem->peer_id = *other;
s_elem->peer_id_hash = other_hash;
s_elem->num_change++;
}
else
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Keeping old PeerID %s\n",
GNUNET_i2s (&s_elem->peer_id));
}
}
s_elem->is_empty = NOT_EMPTY;
#ifdef TO_FILE
to_file (s_elem->file_name,
"Now holding %s",
GNUNET_i2s_full (&s_elem->peer_id));
#endif /* TO_FILE */
}
/**
* Initialise the min-wise independent function of the given sampler element.
*
* @param s_elem the sampler element
* @param auth_key the key to use
*/
void
RPS_sampler_elem_set (struct RPS_SamplerElement *s_elem,
struct GNUNET_CRYPTO_AuthKey auth_key)
{
s_elem->auth_key = auth_key;
#ifdef TO_FILE
/* Create a file(-name) to store internals to */
char *name_buf;
name_buf = auth_key_to_string (s_elem->auth_key);
s_elem->file_name = create_file (name_buf);
GNUNET_free (name_buf);
#endif /* TO_FILE */
}
/* end of gnunet-service-rps.c */