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- /*
- 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 <http://www.gnu.org/licenses/>.
- 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 <inttypes.h>
- /**
- * 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;
- struct GNUNET_IDENTITY_PublicKey pk;
- switch (type)
- {
- case GNUNET_GNSRECORD_TYPE_PKEY:
- case GNUNET_GNSRECORD_TYPE_EDKEY:
- if (GNUNET_OK != GNUNET_GNSRECORD_identity_from_data (data,
- data_size,
- type,
- &pk))
- return NULL;
- return GNUNET_IDENTITY_public_key_to_string (&pk);
- 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);
- if (NULL == ns)
- {
- GNUNET_break_op (0);
- GNUNET_free (ns);
- return NULL;
- }
- /* DNS server IP/name must be UTF-8 */
- ip = GNUNET_strdup (&((const char*) data)[off]);
- GNUNET_asprintf (&nstr, "%s@%s", ns, ip);
- GNUNET_free (ns);
- GNUNET_free (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_IDENTITY_PublicKey pk;
- uint32_t record_type;
- if (NULL == s)
- return GNUNET_SYSERR;
- switch (type)
- {
- case GNUNET_GNSRECORD_TYPE_PKEY:
- case GNUNET_GNSRECORD_TYPE_EDKEY:
- if (GNUNET_OK !=
- GNUNET_IDENTITY_public_key_from_string (s, &pk))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _ ("Unable to parse zone key record `%s'\n"),
- s);
- return GNUNET_SYSERR;
- }
- *data_size = GNUNET_IDENTITY_key_get_length (&pk);
- if (GNUNET_OK != GNUNET_GNSRECORD_data_from_identity (&pk,
- (char **) data,
- data_size,
- &record_type))
- return GNUNET_SYSERR;
- if (record_type != type)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Record type does not match parsed record type\n"));
- return GNUNET_SYSERR;
- }
- 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_log (GNUNET_ERROR_TYPE_ERROR,
- _ (
- "Failed to serialize GNS2DNS record with value `%s': Not a DNS name.\n"),
- s);
- GNUNET_free (cpy);
- return GNUNET_SYSERR;
- }
- /* The DNS server location/name is in UTF-8 */
- GNUNET_memcpy (&nsbuf[off], at, strlen (at) + 1);
- off += strlen (at) + 1;
- 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 },
- { "EDKEY", 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 (e.g. "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 to the corresponding type string (e.g. 1 to "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 */
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