plugin_gnsrecord_gns.c File Reference

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. More...

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_gnsrecord_plugin.h"
#include <inttypes.h>

Include dependency graph for plugin_gnsrecord_gns.c:

Go to the source code of this file.

Functions
static char *	gns_value_to_string (void *cls, uint32_t type, const void *data, size_t data_size)
	Convert the 'value' of a record to a string.
static int	gns_string_to_value (void *cls, uint32_t type, const char *s, void **data, size_t *data_size)
	Convert human-readable version of a 'value' of a record to the binary representation.
static uint32_t	gns_typename_to_number (void *cls, const char *gns_typename)
	Convert a type name (e.g.
static const char *	gns_number_to_typename (void *cls, uint32_t type)
	Convert a type number to the corresponding type string (e.g.
static enum GNUNET_GenericReturnValue	gns_is_critical (void *cls, uint32_t type)
void *	libgnunet_plugin_gnsrecord_gns_init (void *cls)
	Entry point for the plugin.
void *	libgnunet_plugin_gnsrecord_gns_done (void *cls)
	Exit point from the plugin.

Variables
struct {
const char *   name
uint32_t   number
}	gns_name_map []
	Mapping of record type numbers to human-readable record type names.

Detailed Description

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

Definition in file plugin_gnsrecord_gns.c.

Function Documentation

gns_value_to_string()

static char * gns_value_to_string ( void *  cls, uint32_t  type, const void *  data, size_t  data_size  )

static

Convert the 'value' of a record to a string.

Parameters

cls	closure, unused
type	type of the record
data	value in binary encoding
data_size	number of bytes in data

Returns

NULL on error, otherwise human-readable representation of the value

Definition at line 46 of file plugin_gnsrecord_gns.c.

{
  const char *cdata;
  struct GNUNET_CRYPTO_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_CRYPTO_public_key_to_string (&pk);
 
  case GNUNET_GNSRECORD_TYPE_NICK:
  case GNUNET_GNSRECORD_TYPE_REDIRECT:
  case GNUNET_GNSRECORD_TYPE_LEHO:
    return GNUNET_strndup (data, data_size);
 
  // See https://www.rfc-editor.org/rfc/rfc9498.html#name-gns2dns
  case GNUNET_GNSRECORD_TYPE_GNS2DNS: {
      const char *name;
      const char *dns_server_name;
      char *nstr;
 
      name = (const char *) data;
      /* DNS server IP/name must be UTF-8 */
      dns_server_name = name + strlen (name) + 1;
      GNUNET_asprintf (&nstr, "%s@%s", name, dns_server_name);
      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;
    }
  case GNUNET_GNSRECORD_TYPE_SBOX: {
      struct GNUNET_GNSRECORD_SBoxRecord box;
      uint32_t rt;
      char *box_str;
      char *ival;
      char *prefix;
 
      cdata = data;
      if (data_size < sizeof(struct GNUNET_GNSRECORD_SBoxRecord))
        return NULL; /* malformed */
      GNUNET_memcpy (&box, data, sizeof(box));
      rt = ntohl (box.record_type);
 
      prefix = GNUNET_strdup (&cdata[sizeof(box)]);
      ival = GNUNET_GNSRECORD_value_to_string (rt, &cdata[sizeof(box)
                                                          + strlen (prefix)
                                                          + 1],
                                               data_size - sizeof(box)
                                               - strlen (prefix) - 1);
      if (NULL == ival)
        return NULL; /* malformed */
      GNUNET_asprintf (&box_str,
                       "%s %u %s",
                       prefix,
                       (unsigned int) rt,
                       ival);
      GNUNET_free (prefix);
      GNUNET_free (ival);
      return box_str;
    }
  case GNUNET_GNSRECORD_TYPE_TOMBSTONE: {
      return GNUNET_strdup (_ (
                              "This is a memento of an older block for internal maintenance."));
    }
  default:
    return NULL;
  }
}

References _, data, data_size, GNUNET_asprintf(), GNUNET_CRYPTO_public_key_to_string(), GNUNET_free, GNUNET_GNSRECORD_identity_from_data(), GNUNET_GNSRECORD_TYPE_BOX, GNUNET_GNSRECORD_TYPE_EDKEY, GNUNET_GNSRECORD_TYPE_GNS2DNS, GNUNET_GNSRECORD_TYPE_LEHO, GNUNET_GNSRECORD_TYPE_NICK, GNUNET_GNSRECORD_TYPE_PKEY, GNUNET_GNSRECORD_TYPE_REDIRECT, GNUNET_GNSRECORD_TYPE_SBOX, GNUNET_GNSRECORD_TYPE_TOMBSTONE, GNUNET_GNSRECORD_TYPE_VPN, GNUNET_GNSRECORD_value_to_string(), GNUNET_i2s_full(), GNUNET_memcpy, GNUNET_OK, GNUNET_strdup, GNUNET_strndup, name, GNUNET_TUN_GnsVpnRecord::peer, pk, prefix, GNUNET_TUN_GnsVpnRecord::proto, GNUNET_GNSRECORD_BoxRecord::protocol, GNUNET_GNSRECORD_BoxRecord::record_type, GNUNET_GNSRECORD_SBoxRecord::record_type, GNUNET_GNSRECORD_BoxRecord::service, and type.

Referenced by libgnunet_plugin_gnsrecord_gns_init().

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gns_string_to_value()

static int gns_string_to_value ( void *  cls, uint32_t  type, const char *  s, void **  data, size_t *  data_size  )

static

Convert human-readable version of a 'value' of a record to the binary representation.

Parameters

cls	closure, unused
type	type of the record
s	human-readable string
data	set to value in binary encoding (will be allocated)
data_size	set to number of bytes in data

Returns

GNUNET_OK on success

Definition at line 178 of file plugin_gnsrecord_gns.c.

{
  struct GNUNET_CRYPTO_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_CRYPTO_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_CRYPTO_public_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:
  case GNUNET_GNSRECORD_TYPE_REDIRECT:
  case GNUNET_GNSRECORD_TYPE_LEHO:
    *data = GNUNET_strdup (s);
    *data_size = strlen (s);
    return GNUNET_OK;
 
  // See https://www.rfc-editor.org/rfc/rfc9498.html#name-gns2dns
  case GNUNET_GNSRECORD_TYPE_GNS2DNS: {
      char *cpy;
      char *at;
 
      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++;
 
      /* The DNS server location/name is in UTF-8 */
      *data_size = strlen (s) + 1;
      *data = cpy;
      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 rrtype;
      void *bval;
      size_t bval_size;
 
      if (3 != sscanf (s, "%u %u %u ", &protocol, &service, &rrtype))
      {
        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, rrtype);
      if (GNUNET_OK != GNUNET_GNSRECORD_string_to_value (rrtype,
                                                         &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 (rrtype);
      GNUNET_memcpy (&box[1], bval, bval_size);
      GNUNET_free (bval);
      return GNUNET_OK;
    }
  case GNUNET_GNSRECORD_TYPE_SBOX: {
      struct GNUNET_GNSRECORD_SBoxRecord *box;
      size_t rest;
      char *prefix;
      char *p;
      char *underscore_prefix;
      unsigned int rrtype;
      void *bval;
      size_t bval_size;
      size_t prefix_size;
 
      prefix = GNUNET_malloc (strlen (s) + 1);
      if (2 != sscanf (s, "%s %u ", prefix, &rrtype))
      {
        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                    _ ("Unable to parse SBOX record string `%s'\n"),
                    s);
        GNUNET_free (prefix);
        return GNUNET_SYSERR;
      }
      underscore_prefix = strrchr (prefix, '.');
      if (underscore_prefix == NULL)
      {
        underscore_prefix = prefix;
      }
      else
      {
        underscore_prefix++;
      }
      if ('_' != underscore_prefix[0])
      {
        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                    _ (
                      "Unable to parse SBOX record string `%s', the rightmost label `%s' does not start with an underscore\n"),
                    prefix, underscore_prefix);
        GNUNET_free (prefix);
        return GNUNET_SYSERR;
      }
      rest = snprintf (NULL, 0, "%s %u ", prefix, rrtype);
      if (GNUNET_OK != GNUNET_GNSRECORD_string_to_value (rrtype,
                                                         &s[rest],
                                                         &bval,
                                                         &bval_size))
      {
        GNUNET_free (prefix);
        return GNUNET_SYSERR;
      }
      prefix_size = strlen (prefix) + 1;
      *data_size = sizeof(struct GNUNET_GNSRECORD_SBoxRecord) + prefix_size
                   + bval_size;
      *data = GNUNET_malloc (*data_size);
      p = *data;
      box = *data;
      box->record_type = htonl (rrtype);
      p += sizeof(struct GNUNET_GNSRECORD_SBoxRecord);
      GNUNET_memcpy (p, prefix, prefix_size);
      p += prefix_size;
      GNUNET_memcpy (p, bval, bval_size);
      GNUNET_free (bval);
      GNUNET_free (prefix);
      return GNUNET_OK;
    }
  case GNUNET_GNSRECORD_TYPE_TOMBSTONE: {
      *data_size = 0;
      *data = NULL;
      return GNUNET_OK;
    }
 
  default:
    return GNUNET_SYSERR;
  }
}

References _, data, data_size, GNUNET_CRYPTO_eddsa_public_key_from_string(), GNUNET_CRYPTO_public_key_from_string(), GNUNET_CRYPTO_public_key_get_length(), GNUNET_ERROR_TYPE_ERROR, GNUNET_free, GNUNET_GNSRECORD_data_from_identity(), GNUNET_GNSRECORD_string_to_value(), GNUNET_GNSRECORD_TYPE_BOX, GNUNET_GNSRECORD_TYPE_EDKEY, GNUNET_GNSRECORD_TYPE_GNS2DNS, GNUNET_GNSRECORD_TYPE_LEHO, GNUNET_GNSRECORD_TYPE_NICK, GNUNET_GNSRECORD_TYPE_PKEY, GNUNET_GNSRECORD_TYPE_REDIRECT, GNUNET_GNSRECORD_TYPE_SBOX, GNUNET_GNSRECORD_TYPE_TOMBSTONE, GNUNET_GNSRECORD_TYPE_VPN, GNUNET_log, GNUNET_malloc, GNUNET_memcpy, GNUNET_OK, GNUNET_strdup, GNUNET_SYSERR, p, GNUNET_TUN_GnsVpnRecord::peer, pk, prefix, proto, GNUNET_TUN_GnsVpnRecord::proto, GNUNET_GNSRECORD_BoxRecord::protocol, GNUNET_PeerIdentity::public_key, GNUNET_GNSRECORD_BoxRecord::record_type, GNUNET_GNSRECORD_SBoxRecord::record_type, GNUNET_GNSRECORD_BoxRecord::service, service, and type.

Referenced by libgnunet_plugin_gnsrecord_gns_init().

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gns_typename_to_number()

static uint32_t gns_typename_to_number ( void *  cls, const char *  gns_typename  )

static

Convert a type name (e.g.

"AAAA") to the corresponding number.

Parameters

cls	closure, unused
gns_typename	name to convert

Returns

corresponding number, UINT32_MAX on error

Definition at line 414 of file plugin_gnsrecord_gns.c.

{
  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;
}

References gns_name_map, and name.

Referenced by libgnunet_plugin_gnsrecord_gns_init().

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gns_number_to_typename()

static const char * gns_number_to_typename ( void *  cls, uint32_t  type  )

static

Convert a type number to the corresponding type string (e.g.

1 to "A")

Parameters

cls	closure, unused
type	number of a type to convert

Returns

corresponding typestring, NULL on error

Definition at line 435 of file plugin_gnsrecord_gns.c.

{
  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;
}

References gns_name_map, name, number, and type.

Referenced by libgnunet_plugin_gnsrecord_gns_init().

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gns_is_critical()

static enum GNUNET_GenericReturnValue gns_is_critical ( void *  cls, uint32_t  type  )

static

Definition at line 449 of file plugin_gnsrecord_gns.c.

{
  return ((type == GNUNET_GNSRECORD_TYPE_PKEY) ||
          (type == GNUNET_GNSRECORD_TYPE_EDKEY) ||
          (type == GNUNET_GNSRECORD_TYPE_GNS2DNS) ||
          (type == GNUNET_GNSRECORD_TYPE_REDIRECT) ?
          GNUNET_YES : GNUNET_NO);
}

References GNUNET_GNSRECORD_TYPE_EDKEY, GNUNET_GNSRECORD_TYPE_GNS2DNS, GNUNET_GNSRECORD_TYPE_PKEY, GNUNET_GNSRECORD_TYPE_REDIRECT, GNUNET_NO, GNUNET_YES, and type.

Referenced by libgnunet_plugin_gnsrecord_gns_init().

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libgnunet_plugin_gnsrecord_gns_init()

void * libgnunet_plugin_gnsrecord_gns_init

(

void *

cls

)

Entry point for the plugin.

Parameters

cls

NULL

Returns

the exported block API

Definition at line 469 of file plugin_gnsrecord_gns.c.

{
  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;
  api->is_critical = &gns_is_critical;
  return api;
}

References gns_is_critical(), gns_number_to_typename(), gns_string_to_value(), gns_typename_to_number(), gns_value_to_string(), GNUNET_new, GNUNET_GNSRECORD_PluginFunctions::is_critical, GNUNET_GNSRECORD_PluginFunctions::number_to_typename, GNUNET_GNSRECORD_PluginFunctions::string_to_value, GNUNET_GNSRECORD_PluginFunctions::typename_to_number, and GNUNET_GNSRECORD_PluginFunctions::value_to_string.

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libgnunet_plugin_gnsrecord_gns_done()

void * libgnunet_plugin_gnsrecord_gns_done

(

void *

cls

)

Exit point from the plugin.

Parameters

cls	the return value from libgnunet_plugin_block_test_init()

Returns

NULL

Definition at line 493 of file plugin_gnsrecord_gns.c.

{
  struct GNUNET_GNSRECORD_PluginFunctions *api = cls;
 
  GNUNET_free (api);
  return NULL;
}

References GNUNET_GNSRECORD_PluginFunctions::cls, and GNUNET_free.

Variable Documentation

name

const char* name

Definition at line 387 of file plugin_gnsrecord_gns.c.

Referenced by gns_number_to_typename(), gns_typename_to_number(), and gns_value_to_string().

number

uint32_t number

Definition at line 388 of file plugin_gnsrecord_gns.c.

Referenced by gns_number_to_typename().

[struct]

struct { ... } gns_name_map[]

Initial value:

= {
  { "PKEY", GNUNET_GNSRECORD_TYPE_PKEY },
  { "EDKEY", GNUNET_GNSRECORD_TYPE_EDKEY },
  { "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 },
  { "SBOX", GNUNET_GNSRECORD_TYPE_SBOX },
  { "REDIRECT", GNUNET_GNSRECORD_TYPE_REDIRECT },
  
  { "\u271E", GNUNET_GNSRECORD_TYPE_TOMBSTONE },
  { NULL, UINT32_MAX }
}

Mapping of record type numbers to human-readable record type names.

Referenced by gns_number_to_typename(), and gns_typename_to_number().