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/*
This file is part of GNUnet.
(C) 2009-2013 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 3, 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
/**
* @file gnsrecord/gnsrecord_serialization.c
* @brief API to serialize and deserialize GNS records
* @author Martin Schanzenbach
* @author Matthias Wachs
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_constants.h"
#include "gnunet_signatures.h"
#include "gnunet_arm_service.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_dnsparser_lib.h"
#include "gnunet_tun_lib.h"
#define LOG(kind,...) GNUNET_log_from (kind, "gnsrecord",__VA_ARGS__)
GNUNET_NETWORK_STRUCT_BEGIN
/**
* Internal format of a record in the serialized form.
*/
struct NetworkRecord
{
/**
* Expiration time for the DNS record; relative or absolute depends
* on 'flags', network byte order.
*/
uint64_t expiration_time GNUNET_PACKED;
/**
* Number of bytes in 'data', network byte order.
*/
uint32_t data_size GNUNET_PACKED;
/**
* Type of the GNS/DNS record, network byte order.
*/
uint32_t record_type GNUNET_PACKED;
/**
* Flags for the record, network byte order.
*/
uint32_t flags GNUNET_PACKED;
};
GNUNET_NETWORK_STRUCT_END
/**
* Calculate how many bytes we will need to serialize the given
* records.
*
* @param rd_count number of records in the rd array
* @param rd array of #GNUNET_GNSRECORD_Data with @a rd_count elements
* @return the required size to serialize
*/
size_t
GNUNET_GNSRECORD_records_get_size (unsigned int rd_count,
const struct GNUNET_GNSRECORD_Data *rd)
{
unsigned int i;
size_t ret;
ret = sizeof (struct NetworkRecord) * rd_count;
for (i=0;i<rd_count;i++)
{
GNUNET_assert ((ret + rd[i].data_size) >= ret);
ret += rd[i].data_size;
}
return ret;
}
/**
* Serialize the given records to the given destination buffer.
*
* @param rd_count number of records in the rd array
* @param rd array of #GNUNET_GNSRECORD_Data with @a rd_count elements
* @param dest_size size of the destination array
* @param dest where to write the result
* @return the size of serialized records, -1 if records do not fit
*/
ssize_t
GNUNET_GNSRECORD_records_serialize (unsigned int rd_count,
const struct GNUNET_GNSRECORD_Data *rd,
size_t dest_size,
char *dest)
{
struct NetworkRecord rec;
unsigned int i;
size_t off;
off = 0;
for (i=0;i<rd_count;i++)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Serializing record %u with flags %d and expiration time %llu\n",
i,
rd[i].flags,
(unsigned long long) rd[i].expiration_time);
rec.expiration_time = GNUNET_htonll (rd[i].expiration_time);
rec.data_size = htonl ((uint32_t) rd[i].data_size);
rec.record_type = htonl (rd[i].record_type);
rec.flags = htonl (rd[i].flags);
if (off + sizeof (rec) > dest_size)
return -1;
memcpy (&dest[off], &rec, sizeof (rec));
off += sizeof (rec);
if (off + rd[i].data_size > dest_size)
return -1;
memcpy (&dest[off], rd[i].data, rd[i].data_size);
off += rd[i].data_size;
}
return off;
}
/**
* Deserialize the given records to the given destination.
*
* @param len size of the serialized record data
* @param src the serialized record data
* @param rd_count number of records in the rd array
* @param dest where to put the data
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
GNUNET_GNSRECORD_records_deserialize (size_t len,
const char *src,
unsigned int rd_count,
struct GNUNET_GNSRECORD_Data *dest)
{
struct NetworkRecord rec;
unsigned int i;
size_t off;
off = 0;
for (i=0;i<rd_count;i++)
{
if (off + sizeof (rec) > len)
return GNUNET_SYSERR;
memcpy (&rec, &src[off], sizeof (rec));
dest[i].expiration_time = GNUNET_ntohll (rec.expiration_time);
dest[i].data_size = ntohl ((uint32_t) rec.data_size);
dest[i].record_type = ntohl (rec.record_type);
dest[i].flags = ntohl (rec.flags);
off += sizeof (rec);
if (off + dest[i].data_size > len)
return GNUNET_SYSERR;
dest[i].data = &src[off];
off += dest[i].data_size;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Deserialized record %u with flags %d and expiration time %llu\n",
i,
dest[i].flags,
(unsigned long long) dest[i].expiration_time);
}
return GNUNET_OK;
}
/* end of gnsrecord_serialization.c */
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