-adding plugin for fundamental gns records

1 files changed, 303 insertions, 0 deletions

diff --git a/src/gns/plugin_gnsrecord_gns.c b/src/gns/plugin_gnsrecord_gns.c
new file mode 100644
index 000000000..56e35f05b
--- /dev/null
+++ b/src/gns/plugin_gnsrecord_gns.c
@@ -0,0 +1,303 @@
+/*
+     This file is part of GNUnet
+     (C) 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/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"
+
+
+/**
+ * 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_PSEU:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_GNSRECORD_TYPE_LEHO:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_GNSRECORD_TYPE_GNS2DNS:
+    {
+      char *ns;
+      size_t off;
+
+      off = 0;
+      ns = GNUNET_DNSPARSER_parse_name (data,
+                                        data_size,
+                                        &off);
+      if ( (NULL == ns) ||
+           (off != data_size) )
+      {
+        GNUNET_break_op (0);
+        GNUNET_free_non_null (ns);
+        return NULL;
+      }
+      return ns;
+    }
+  case GNUNET_GNSRECORD_TYPE_VPN:
+    {
+      const struct GNUNET_TUN_GnsVpnRecord *vpn;
+      char* vpn_str;
+
+      cdata = data;
+      if ( (data_size <= sizeof (struct GNUNET_TUN_GnsVpnRecord)) ||
+           ('\0' != cdata[data_size - 1]) )
+        return NULL; /* malformed */
+      vpn = data;
+      if (0 == GNUNET_asprintf (&vpn_str, "%u %s %s",
+                                (unsigned int) ntohs (vpn->proto),
+                                (const char*) GNUNET_i2s_full (&vpn->peer),
+                                (const char*) &vpn[1]))
+      {
+        GNUNET_free (vpn_str);
+        return NULL;
+      }
+      return vpn_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;
+  struct GNUNET_TUN_GnsVpnRecord *vpn;
+  char s_peer[103 + 1];
+  char s_serv[253 + 1];
+  unsigned int proto;
+
+  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);
+    memcpy (*data, &pkey, sizeof (pkey));
+    *data_size = sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey);
+    return GNUNET_OK;
+
+  case GNUNET_GNSRECORD_TYPE_PSEU:
+    *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[256];
+      size_t off;
+
+      off = 0;
+      if (GNUNET_OK !=
+          GNUNET_DNSPARSER_builder_add_name (nsbuf,
+                                             sizeof (nsbuf),
+                                             &off,
+                                             s))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+             _("Failed to serialize GNS2DNS record with value `%s'\n"),
+             s);
+        return GNUNET_SYSERR;
+      }
+      *data_size = off;
+      *data = GNUNET_malloc (off);
+      memcpy (*data, nsbuf, off);
+      return GNUNET_OK;
+    }
+  case GNUNET_GNSRECORD_TYPE_VPN:
+    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;
+  default:
+    return GNUNET_SYSERR;
+  }
+}
+
+
+/**
+ * Mapping of record type numbers to human-readable
+ * record type names.
+ */
+static struct {
+  const char *name;
+  uint32_t number;
+} name_map[] = {
+  { "PKEY",  GNUNET_GNSRECORD_TYPE_PKEY },
+  { "PSEU",  GNUNET_GNSRECORD_TYPE_PSEU },
+  { "LEHO",  GNUNET_GNSRECORD_TYPE_LEHO },
+  { "VPN", GNUNET_GNSRECORD_TYPE_VPN },
+  { "GNS2DNS", GNUNET_GNSRECORD_TYPE_GNS2DNS },
+  { 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 ( (name_map[i].name != NULL) &&
+          (0 != strcasecmp (gns_typename, name_map[i].name)) )
+    i++;
+  return 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 ( (name_map[i].name != NULL) &&
+          (type != name_map[i].number) )
+    i++;
+  return 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 */