/*
This file is part of GNUnet
Copyright (C) 2013, 2014, 2016 GNUnet e.V.
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 .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file gns/plugin_gnsrecord_gns.c
* @brief gnsrecord plugin to provide the API for fundamental GNS records
* This includes the VPN record because GNS resolution
* is expected to understand VPN records and (if needed)
* map the result to A/AAAA.
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_dnsparser_lib.h"
#include "gnunet_gnsrecord_plugin.h"
#include
/**
* Convert the 'value' of a record to a string.
*
* @param cls closure, unused
* @param type type of the record
* @param data value in binary encoding
* @param data_size number of bytes in @a data
* @return NULL on error, otherwise human-readable representation of the value
*/
static char *
gns_value_to_string (void *cls,
uint32_t type,
const void *data,
size_t data_size)
{
const char *cdata;
switch (type)
{
case GNUNET_GNSRECORD_TYPE_PKEY:
if (data_size != sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey))
return NULL;
return GNUNET_CRYPTO_ecdsa_public_key_to_string (data);
case GNUNET_GNSRECORD_TYPE_NICK:
return GNUNET_strndup (data, data_size);
case GNUNET_GNSRECORD_TYPE_LEHO:
return GNUNET_strndup (data, data_size);
case GNUNET_GNSRECORD_TYPE_GNS2DNS:
{
char *ns;
char *ip;
size_t off;
char *nstr;
off = 0;
ns = GNUNET_DNSPARSER_parse_name (data,
data_size,
&off);
ip = GNUNET_DNSPARSER_parse_name (data,
data_size,
&off);
if ( (NULL == ns) ||
(NULL == ip) ||
(off != data_size) )
{
GNUNET_break_op (0);
GNUNET_free_non_null (ns);
GNUNET_free_non_null (ip);
return NULL;
}
GNUNET_asprintf (&nstr,
"%s@%s",
ns,
ip);
GNUNET_free_non_null (ns);
GNUNET_free_non_null (ip);
return nstr;
}
case GNUNET_GNSRECORD_TYPE_VPN:
{
struct GNUNET_TUN_GnsVpnRecord vpn;
char* vpn_str;
cdata = data;
if ( (data_size <= sizeof (vpn)) ||
('\0' != cdata[data_size - 1]) )
return NULL; /* malformed */
/* need to memcpy for alignment */
GNUNET_memcpy (&vpn,
data,
sizeof (vpn));
GNUNET_asprintf (&vpn_str,
"%u %s %s",
(unsigned int) ntohs (vpn.proto),
(const char*) GNUNET_i2s_full (&vpn.peer),
(const char*) &cdata[sizeof (vpn)]);
return vpn_str;
}
case GNUNET_GNSRECORD_TYPE_BOX:
{
struct GNUNET_GNSRECORD_BoxRecord box;
uint32_t rt;
char *box_str;
char *ival;
cdata = data;
if (data_size < sizeof (struct GNUNET_GNSRECORD_BoxRecord))
return NULL; /* malformed */
GNUNET_memcpy (&box,
data,
sizeof (box));
rt = ntohl (box.record_type);
ival = GNUNET_GNSRECORD_value_to_string (rt,
&cdata[sizeof (box)],
data_size - sizeof (box));
if (NULL == ival)
return NULL; /* malformed */
GNUNET_asprintf (&box_str,
"%u %u %u %s",
(unsigned int) ntohs (box.protocol),
(unsigned int) ntohs (box.service),
(unsigned int) rt,
ival);
GNUNET_free (ival);
return box_str;
}
default:
return NULL;
}
}
/**
* Convert human-readable version of a 'value' of a record to the binary
* representation.
*
* @param cls closure, unused
* @param type type of the record
* @param s human-readable string
* @param data set to value in binary encoding (will be allocated)
* @param data_size set to number of bytes in @a data
* @return #GNUNET_OK on success
*/
static int
gns_string_to_value (void *cls,
uint32_t type,
const char *s,
void **data,
size_t *data_size)
{
struct GNUNET_CRYPTO_EcdsaPublicKey pkey;
if (NULL == s)
return GNUNET_SYSERR;
switch (type)
{
case GNUNET_GNSRECORD_TYPE_PKEY:
if (GNUNET_OK !=
GNUNET_CRYPTO_ecdsa_public_key_from_string (s,
strlen (s),
&pkey))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Unable to parse PKEY record `%s'\n"),
s);
return GNUNET_SYSERR;
}
*data = GNUNET_new (struct GNUNET_CRYPTO_EcdsaPublicKey);
GNUNET_memcpy (*data,
&pkey,
sizeof (pkey));
*data_size = sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey);
return GNUNET_OK;
case GNUNET_GNSRECORD_TYPE_NICK:
*data = GNUNET_strdup (s);
*data_size = strlen (s);
return GNUNET_OK;
case GNUNET_GNSRECORD_TYPE_LEHO:
*data = GNUNET_strdup (s);
*data_size = strlen (s);
return GNUNET_OK;
case GNUNET_GNSRECORD_TYPE_GNS2DNS:
{
char nsbuf[514];
char *cpy;
char *at;
size_t off;
cpy = GNUNET_strdup (s);
at = strchr (cpy, '@');
if (NULL == at)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Unable to parse GNS2DNS record `%s'\n"),
s);
GNUNET_free (cpy);
return GNUNET_SYSERR;
}
*at = '\0';
at++;
off = 0;
if ( (GNUNET_OK !=
GNUNET_DNSPARSER_builder_add_name (nsbuf,
sizeof (nsbuf),
&off,
cpy)) ||
(GNUNET_OK !=
GNUNET_DNSPARSER_builder_add_name (nsbuf,
sizeof (nsbuf),
&off,
at)) )
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Failed to serialize GNS2DNS record with value `%s'\n"),
s);
GNUNET_free (cpy);
return GNUNET_SYSERR;
}
GNUNET_free (cpy);
*data_size = off;
*data = GNUNET_malloc (off);
GNUNET_memcpy (*data,
nsbuf,
off);
return GNUNET_OK;
}
case GNUNET_GNSRECORD_TYPE_VPN:
{
struct GNUNET_TUN_GnsVpnRecord *vpn;
char s_peer[103 + 1];
char s_serv[253 + 1];
unsigned int proto;
if (3 != SSCANF (s,
"%u %103s %253s",
&proto, s_peer, s_serv))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Unable to parse VPN record string `%s'\n"),
s);
return GNUNET_SYSERR;
}
*data_size = sizeof (struct GNUNET_TUN_GnsVpnRecord) + strlen (s_serv) + 1;
*data = vpn = GNUNET_malloc (*data_size);
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_public_key_from_string ((char*) s_peer,
strlen (s_peer),
&vpn->peer.public_key))
{
GNUNET_free (vpn);
*data_size = 0;
return GNUNET_SYSERR;
}
vpn->proto = htons ((uint16_t) proto);
strcpy ((char*)&vpn[1], s_serv);
return GNUNET_OK;
}
case GNUNET_GNSRECORD_TYPE_BOX:
{
struct GNUNET_GNSRECORD_BoxRecord *box;
size_t rest;
unsigned int protocol;
unsigned int service;
unsigned int record_type;
void *bval;
size_t bval_size;
if (3 != SSCANF (s,
"%u %u %u ",
&protocol,
&service,
&record_type))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Unable to parse BOX record string `%s'\n"),
s);
return GNUNET_SYSERR;
}
rest = snprintf (NULL, 0,
"%u %u %u ",
protocol,
service,
record_type);
if (GNUNET_OK !=
GNUNET_GNSRECORD_string_to_value (record_type,
&s[rest],
&bval,
&bval_size))
return GNUNET_SYSERR;
*data_size = sizeof (struct GNUNET_GNSRECORD_BoxRecord) + bval_size;
*data = box = GNUNET_malloc (*data_size);
box->protocol = htons (protocol);
box->service = htons (service);
box->record_type = htonl (record_type);
GNUNET_memcpy (&box[1],
bval,
bval_size);
GNUNET_free (bval);
return GNUNET_OK;
}
default:
return GNUNET_SYSERR;
}
}
/**
* Mapping of record type numbers to human-readable
* record type names.
*/
static struct {
const char *name;
uint32_t number;
} gns_name_map[] = {
{ "PKEY", GNUNET_GNSRECORD_TYPE_PKEY },
{ "NICK", GNUNET_GNSRECORD_TYPE_NICK },
{ "LEHO", GNUNET_GNSRECORD_TYPE_LEHO },
{ "VPN", GNUNET_GNSRECORD_TYPE_VPN },
{ "GNS2DNS", GNUNET_GNSRECORD_TYPE_GNS2DNS },
{ "BOX", GNUNET_GNSRECORD_TYPE_BOX },
{ NULL, UINT32_MAX }
};
/**
* Convert a type name (i.e. "AAAA") to the corresponding number.
*
* @param cls closure, unused
* @param gns_typename name to convert
* @return corresponding number, UINT32_MAX on error
*/
static uint32_t
gns_typename_to_number (void *cls,
const char *gns_typename)
{
unsigned int i;
i=0;
while ( (NULL != gns_name_map[i].name) &&
(0 != strcasecmp (gns_typename,
gns_name_map[i].name)) )
i++;
return gns_name_map[i].number;
}
/**
* Convert a type number (i.e. 1) to the corresponding type string (i.e. "A")
*
* @param cls closure, unused
* @param type number of a type to convert
* @return corresponding typestring, NULL on error
*/
static const char *
gns_number_to_typename (void *cls,
uint32_t type)
{
unsigned int i;
i=0;
while ( (NULL != gns_name_map[i].name) &&
(type != gns_name_map[i].number) )
i++;
return gns_name_map[i].name;
}
/**
* Entry point for the plugin.
*
* @param cls NULL
* @return the exported block API
*/
void *
libgnunet_plugin_gnsrecord_gns_init (void *cls)
{
struct GNUNET_GNSRECORD_PluginFunctions *api;
api = GNUNET_new (struct GNUNET_GNSRECORD_PluginFunctions);
api->value_to_string = &gns_value_to_string;
api->string_to_value = &gns_string_to_value;
api->typename_to_number = &gns_typename_to_number;
api->number_to_typename = &gns_number_to_typename;
return api;
}
/**
* Exit point from the plugin.
*
* @param cls the return value from #libgnunet_plugin_block_test_init()
* @return NULL
*/
void *
libgnunet_plugin_gnsrecord_gns_done (void *cls)
{
struct GNUNET_GNSRECORD_PluginFunctions *api = cls;
GNUNET_free (api);
return NULL;
}
/* end of plugin_gnsrecord_gns.c */