plugin_gnsrecord_gns.c

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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
 */

#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>


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;
    }
}


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;
    }
}


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 } };


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;
}


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;
}


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;
}


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 */