-towards implementing improved namestore API

1 files changed, 755 insertions, 0 deletions

diff --git a/src/namestore/namestore_api_common.c b/src/namestore/namestore_api_common.c
new file mode 100644
index 000000000..ab2506611
--- /dev/null
+++ b/src/namestore/namestore_api_common.c
@@ -0,0 +1,755 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009, 2010, 2012 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 namestore/namestore_common.c
+ * @brief API to access the NAMESTORE service
+ * @author Martin Schanzenbach
+ * @author Matthias Wachs
+ */
+
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_signatures.h"
+#include "gnunet_arm_service.h"
+#include "gnunet_namestore_service.h"
+#include "gnunet_dnsparser_lib.h"
+#include "gns_protocol.h"
+#include "namestore.h"
+
+
+#define LOG(kind,...) GNUNET_log_from (kind, "gns-api",__VA_ARGS__)
+
+GNUNET_NETWORK_STRUCT_BEGIN
+
+/**
+ * Internal format of a record in the serialized form.
+ */
+struct NetworkRecord
+{
+
+  /**
+   * Expiration time for the DNS record; relative or absolute depends
+   * on 'flags', network byte order.
+   */
+  uint64_t expiration_time GNUNET_PACKED;
+
+  /**
+   * Number of bytes in 'data', network byte order.
+   */
+  uint32_t data_size GNUNET_PACKED;
+
+  /**
+   * Type of the GNS/DNS record, network byte order.
+   */
+  uint32_t record_type GNUNET_PACKED;
+
+  /**
+   * Flags for the record, network byte order.
+   */
+  uint32_t flags GNUNET_PACKED;
+  
+};
+
+GNUNET_NETWORK_STRUCT_END
+
+/**
+ * Convert a UTF-8 string to UTF-8 lowercase
+ * @param src source string
+ * @return converted result
+ */
+char *
+GNUNET_NAMESTORE_normalize_string (const char *src)
+{
+  GNUNET_assert (NULL != src);
+  char *res = strdup (src);
+  /* normalize */
+  GNUNET_STRINGS_utf8_tolower(src, &res);
+  return res;
+}
+
+
+/**
+ * Convert a short hash to a string (for printing debug messages).
+ * This is one of the very few calls in the entire API that is
+ * NOT reentrant!
+ *
+ * @param hc the short hash code
+ * @return string form; will be overwritten by next call to GNUNET_h2s.
+ */
+const char *
+GNUNET_NAMESTORE_short_h2s (const struct GNUNET_CRYPTO_ShortHashCode * hc)
+{
+  static struct GNUNET_CRYPTO_ShortHashAsciiEncoded ret;
+
+  GNUNET_CRYPTO_short_hash_to_enc (hc, &ret);
+  return (const char *) &ret;
+}
+
+
+/**
+ * Calculate how many bytes we will need to serialize the given
+ * records.
+ *
+ * @param rd_count number of records in the rd array
+ * @param rd array of GNUNET_NAMESTORE_RecordData with rd_count elements
+ *
+ * @return the required size to serialize
+ *
+ */
+size_t
+GNUNET_NAMESTORE_records_get_size (unsigned int rd_count,
+                                   const struct GNUNET_NAMESTORE_RecordData *rd)
+{
+  unsigned int i;
+  size_t ret;
+
+  ret = sizeof (struct NetworkRecord) * rd_count;
+  for (i=0;i<rd_count;i++)
+  {
+    GNUNET_assert ((ret + rd[i].data_size) >= ret);
+    ret += rd[i].data_size;
+  }
+  return ret;  
+}
+
+
+/**
+ * Serialize the given records to the given destination buffer.
+ *
+ * @param rd_count number of records in the rd array
+ * @param rd array of GNUNET_NAMESTORE_RecordData with rd_count elements
+ * @param dest_size size of the destination array
+ * @param dest where to write the result
+ *
+ * @return the size of serialized records, -1 if records do not fit
+ */
+ssize_t
+GNUNET_NAMESTORE_records_serialize (unsigned int rd_count,
+                                    const struct GNUNET_NAMESTORE_RecordData *rd,
+                                    size_t dest_size,
+                                    char *dest)
+{
+  struct NetworkRecord rec;
+  unsigned int i;
+  size_t off;
+  
+  off = 0;
+  for (i=0;i<rd_count;i++)
+  {
+    rec.expiration_time = GNUNET_htonll (rd[i].expiration_time);
+    rec.data_size = htonl ((uint32_t) rd[i].data_size);
+    rec.record_type = htonl (rd[i].record_type);
+    rec.flags = htonl (rd[i].flags);
+    if (off + sizeof (rec) > dest_size)
+      return -1;
+    memcpy (&dest[off], &rec, sizeof (rec));
+    off += sizeof (rec);
+    if (off + rd[i].data_size > dest_size)
+      return -1;
+    memcpy (&dest[off], rd[i].data, rd[i].data_size);
+    off += rd[i].data_size;
+  }
+  return off;
+}
+
+
+/**
+ * Compares if two records are equal (ignoring flags such
+ * as authority, private and pending, but not relative vs.
+ * absolute expiration time).
+ *
+ * @param a record
+ * @param b record
+ * @return GNUNET_YES if the records are equal or GNUNET_NO if they are not
+ */
+int
+GNUNET_NAMESTORE_records_cmp (const struct GNUNET_NAMESTORE_RecordData *a,
+                              const struct GNUNET_NAMESTORE_RecordData *b)
+{
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+      "Comparing records\n");
+  if (a->record_type != b->record_type)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+        "Record type %lu != %lu\n", a->record_type, b->record_type);
+    return GNUNET_NO;
+  }
+  if ((a->expiration_time != b->expiration_time) &&
+      ((a->expiration_time != 0) && (b->expiration_time != 0)))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+        "Expiration time %llu != %llu\n", a->expiration_time, b->expiration_time);
+    return GNUNET_NO;
+  }
+  if ((a->flags & GNUNET_NAMESTORE_RF_RCMP_FLAGS) 
+       != (b->flags & GNUNET_NAMESTORE_RF_RCMP_FLAGS))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+        "Flags %lu (%lu) != %lu (%lu)\n", a->flags,
+        a->flags & GNUNET_NAMESTORE_RF_RCMP_FLAGS, b->flags,
+        b->flags & GNUNET_NAMESTORE_RF_RCMP_FLAGS);
+    return GNUNET_NO;
+  }
+  if (a->data_size != b->data_size)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+        "Data size %lu != %lu\n", a->data_size, b->data_size);
+    return GNUNET_NO;
+  }
+  if (0 != memcmp (a->data, b->data, a->data_size))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+        "Data contents do not match\n");
+    return GNUNET_NO;
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+      "Records are equal\n");
+  return GNUNET_YES;
+}
+
+
+/**
+ * Deserialize the given records to the given destination.
+ *
+ * @param len size of the serialized record data
+ * @param src the serialized record data
+ * @param rd_count number of records in the rd array
+ * @param dest where to put the data
+ *
+ * @return GNUNET_OK on success, GNUNET_SYSERR on error
+ */
+int
+GNUNET_NAMESTORE_records_deserialize (size_t len,
+                                      const char *src,
+                                      unsigned int rd_count,
+                                      struct GNUNET_NAMESTORE_RecordData *dest)
+{
+  struct NetworkRecord rec;
+  unsigned int i;
+  size_t off;
+  
+  off = 0;
+  for (i=0;i<rd_count;i++)
+  {
+    if (off + sizeof (rec) > len)
+      return GNUNET_SYSERR;
+    memcpy (&rec, &src[off], sizeof (rec));
+    dest[i].expiration_time = GNUNET_ntohll (rec.expiration_time);
+    dest[i].data_size = ntohl ((uint32_t) rec.data_size);
+    dest[i].record_type = ntohl (rec.record_type);
+    dest[i].flags = ntohl (rec.flags);
+    off += sizeof (rec);
+
+    if (off + dest[i].data_size > len)
+      return GNUNET_SYSERR;
+    dest[i].data = &src[off];
+    off += dest[i].data_size;
+  }
+  return GNUNET_OK; 
+}
+
+
+/**
+ * Sign name and records
+ *
+ * @param key the private key
+ * @param expire block expiration
+ * @param name the name
+ * @param rd record data
+ * @param rd_count number of records
+ *
+ * @return the signature
+ */
+struct GNUNET_CRYPTO_EccSignature *
+GNUNET_NAMESTORE_create_signature (const struct GNUNET_CRYPTO_EccPrivateKey *key,
+                                   struct GNUNET_TIME_Absolute expire,
+                                   const char *name,
+                                   const struct GNUNET_NAMESTORE_RecordData *rd,
+                                   unsigned int rd_count)
+{
+  struct GNUNET_CRYPTO_EccSignature *sig;
+  struct GNUNET_CRYPTO_EccSignaturePurpose *sig_purpose;
+  struct GNUNET_TIME_AbsoluteNBO expire_nbo;
+  size_t rd_ser_len;
+  size_t name_len;
+  struct GNUNET_TIME_AbsoluteNBO *expire_tmp;
+  char * name_tmp;
+  char * rd_tmp;
+  int res;
+  uint32_t sig_len;
+
+  if (NULL == name)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  sig = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_EccSignature));
+  name_len = strlen (name) + 1;
+  expire_nbo = GNUNET_TIME_absolute_hton (expire);
+  rd_ser_len = GNUNET_NAMESTORE_records_get_size (rd_count, rd);
+  {
+    char rd_ser[rd_ser_len];
+
+    GNUNET_assert (rd_ser_len ==
+                   GNUNET_NAMESTORE_records_serialize (rd_count, rd, rd_ser_len, rd_ser));
+    sig_len = sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose) + sizeof (struct GNUNET_TIME_AbsoluteNBO) + rd_ser_len + name_len;
+    sig_purpose = GNUNET_malloc (sig_len);
+    sig_purpose->size = htonl (sig_len);
+    sig_purpose->purpose = htonl (GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN);
+    expire_tmp = (struct GNUNET_TIME_AbsoluteNBO *) &sig_purpose[1];
+    memcpy (expire_tmp, &expire_nbo, sizeof (struct GNUNET_TIME_AbsoluteNBO));
+    name_tmp = (char *) &expire_tmp[1];
+    memcpy (name_tmp, name, name_len);
+    rd_tmp = &name_tmp[name_len];
+    memcpy (rd_tmp, rd_ser, rd_ser_len);
+    res = GNUNET_CRYPTO_ecc_sign (key, sig_purpose, sig);
+    GNUNET_free (sig_purpose);
+  }
+  if (GNUNET_OK != res)
+  {
+    GNUNET_break (0);
+    GNUNET_free (sig);
+    return NULL;
+  }
+  return sig;
+}
+
+
+/**
+ * Convert the 'value' of a record to a string.
+ *
+ * @param type type of the record
+ * @param data value in binary encoding
+ * @param data_size number of bytes in data
+ * @return NULL on error, otherwise human-readable representation of the value
+ */
+char *
+GNUNET_NAMESTORE_value_to_string (uint32_t type,
+                                  const void *data,
+                                  size_t data_size)
+{
+  uint16_t mx_pref;
+  const struct soa_data *soa;
+  const struct vpn_data *vpn;
+  const struct srv_data *srv;
+  const struct tlsa_data *tlsa;
+  struct GNUNET_CRYPTO_ShortHashAsciiEncoded enc;
+  struct GNUNET_CRYPTO_HashAsciiEncoded s_peer;
+  const char *cdata;
+  char* vpn_str;
+  char* srv_str;
+  char* tlsa_str;
+  char* result;
+  const char* soa_rname;
+  const char* soa_mname;
+  char tmp[INET6_ADDRSTRLEN];
+
+  switch (type)
+  {
+  case 0:
+    return NULL;
+  case GNUNET_DNSPARSER_TYPE_A:
+    if (data_size != sizeof (struct in_addr))
+      return NULL;
+    if (NULL == inet_ntop (AF_INET, data, tmp, sizeof (tmp)))
+      return NULL;
+    return GNUNET_strdup (tmp);
+  case GNUNET_DNSPARSER_TYPE_NS:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_DNSPARSER_TYPE_CNAME:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_DNSPARSER_TYPE_SOA:
+    if (data_size <= sizeof (struct soa_data))
+      return NULL;
+    soa = data;
+    soa_rname = (const char*) &soa[1];
+    soa_mname = memchr (soa_rname, 0, data_size - sizeof (struct soa_data) - 1);
+    if (NULL == soa_mname)
+      return NULL;
+    soa_mname++;
+    if (NULL == memchr (soa_mname, 0, 
+                        data_size - (sizeof (struct soa_data) + strlen (soa_rname) + 1)))
+      return NULL;
+    GNUNET_asprintf (&result, 
+                     "rname=%s mname=%s %lu,%lu,%lu,%lu,%lu",
+                     soa_rname, soa_mname,
+                     ntohl (soa->serial), 
+                     ntohl (soa->refresh),
+                     ntohl (soa->retry), 
+                     ntohl (soa->expire),
+                     ntohl (soa->minimum));
+    return result;
+  case GNUNET_DNSPARSER_TYPE_PTR:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_DNSPARSER_TYPE_MX:
+    mx_pref = ntohs(*((uint16_t*)data));
+    if (GNUNET_asprintf(&result, "%hu,%s", mx_pref, data+sizeof(uint16_t))
+        != 0)
+      return result;
+    else
+    {
+      GNUNET_free (result);
+      return NULL;
+    }
+  case GNUNET_DNSPARSER_TYPE_TXT:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_DNSPARSER_TYPE_AAAA:
+    if (data_size != sizeof (struct in6_addr))
+      return NULL;
+    if (NULL == inet_ntop (AF_INET6, data, tmp, sizeof (tmp)))
+      return NULL;
+    return GNUNET_strdup (tmp);
+  case GNUNET_NAMESTORE_TYPE_PKEY:
+    if (data_size != sizeof (struct GNUNET_CRYPTO_ShortHashCode))
+      return NULL;
+    GNUNET_CRYPTO_short_hash_to_enc (data,
+                                     &enc);
+    return GNUNET_strdup ((const char*) enc.short_encoding);
+  case GNUNET_NAMESTORE_TYPE_PSEU:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_NAMESTORE_TYPE_LEHO:
+    return GNUNET_strndup (data, data_size);
+  case GNUNET_NAMESTORE_TYPE_VPN:
+    cdata = data;
+    if ( (data_size <= sizeof (struct vpn_data)) ||
+         ('\0' != cdata[data_size - 1]) )
+      return NULL; /* malformed */
+    vpn = data;
+    GNUNET_CRYPTO_hash_to_enc (&vpn->peer, &s_peer);
+    if (0 == GNUNET_asprintf (&vpn_str, "%u %s %s",
+                              (unsigned int) ntohs (vpn->proto),
+                              (const char*) &s_peer,
+                              (const char*) &vpn[1]))
+    {
+      GNUNET_free (vpn_str);
+      return NULL;
+    }
+    return vpn_str;
+  case GNUNET_DNSPARSER_TYPE_SRV:
+    cdata = data;
+    if ( (data_size <= sizeof (struct srv_data)) ||
+         ('\0' != cdata[data_size - 1]) )
+      return NULL; /* malformed */
+    srv = data;
+
+    if (0 == GNUNET_asprintf (&srv_str, 
+                              "%d %d %d %s",
+                              ntohs (srv->prio),
+                              ntohs (srv->weight),
+                              ntohs (srv->port),
+                              (const char *)&srv[1]))
+    {
+      GNUNET_free (srv_str);
+      return NULL;
+    }
+    return srv_str;
+  case GNUNET_DNSPARSER_TYPE_TLSA:
+    cdata = data;
+    if ( (data_size <= sizeof (struct tlsa_data)) ||
+         ('\0' != cdata[data_size - 1]) )
+      return NULL; /* malformed */
+    tlsa = data;
+    if (0 == GNUNET_asprintf (&tlsa_str, 
+                              "%c %c %c %s",
+                              tlsa->usage,
+                              tlsa->selector,
+                              tlsa->matching_type,
+                              (const char *) &tlsa[1]))
+    {
+      GNUNET_free (tlsa_str);
+      return NULL;
+    }
+    return tlsa_str;
+  default:
+    GNUNET_break (0);
+  }
+  GNUNET_break (0); // not implemented
+  return NULL;
+}
+
+
+/**
+ * Convert human-readable version of a 'value' of a record to the binary
+ * representation.
+ *
+ * @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 data
+ * @return GNUNET_OK on success
+ */
+int
+GNUNET_NAMESTORE_string_to_value (uint32_t type,
+                                  const char *s,
+                                  void **data,
+                                  size_t *data_size)
+{
+  struct in_addr value_a;
+  struct in6_addr value_aaaa;
+  struct GNUNET_CRYPTO_ShortHashCode pkey;
+  struct soa_data *soa;
+  struct vpn_data *vpn;
+  struct tlsa_data *tlsa;
+  char result[253 + 1];
+  char soa_rname[253 + 1];
+  char soa_mname[253 + 1];
+  char s_peer[103 + 1];
+  char s_serv[253 + 1];
+  unsigned int soa_serial;
+  unsigned int soa_refresh;
+  unsigned int soa_retry;
+  unsigned int soa_expire;
+  unsigned int soa_min;
+  uint16_t mx_pref;
+  uint16_t mx_pref_n;
+  unsigned int proto;
+  
+  if (NULL == s)
+    return GNUNET_SYSERR;
+  switch (type)
+  {
+  case 0:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Unsupported record type %d\n"),
+                (int) type);
+    return GNUNET_SYSERR;
+  case GNUNET_DNSPARSER_TYPE_A:
+    if (1 != inet_pton (AF_INET, s, &value_a))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse IPv4 address `%s'\n"),
+                  s);
+      return GNUNET_SYSERR;
+    }
+    *data = GNUNET_malloc (sizeof (struct in_addr));
+    memcpy (*data, &value_a, sizeof (value_a));
+    *data_size = sizeof (value_a);
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_NS:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s) + 1;
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_CNAME:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s) + 1;
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_SOA:
+    if (7 != SSCANF (s, 
+                     "rname=%253s mname=%253s %u,%u,%u,%u,%u",
+                     soa_rname, soa_mname,
+                     &soa_serial, &soa_refresh, &soa_retry, &soa_expire, &soa_min))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse SOA record `%s'\n"),
+                  s);
+      return GNUNET_SYSERR;
+    }
+    *data_size = sizeof (struct soa_data)+strlen(soa_rname)+strlen(soa_mname)+2;
+    *data = GNUNET_malloc (*data_size);
+    soa = (struct soa_data*)*data;
+    soa->serial = htonl(soa_serial);
+    soa->refresh = htonl(soa_refresh);
+    soa->retry = htonl(soa_retry);
+    soa->expire = htonl(soa_expire);
+    soa->minimum = htonl(soa_min);
+    strcpy((char*)&soa[1], soa_rname);
+    strcpy((char*)&soa[1]+strlen(*data)+1, soa_mname);
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_PTR:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s);
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_MX:
+    if (2 != SSCANF(s, "%hu,%253s", &mx_pref, result))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse MX record `%s'\n"),
+                  s);
+      return GNUNET_SYSERR;
+    }
+    *data_size = sizeof (uint16_t)+strlen(result)+1;
+    *data = GNUNET_malloc (*data_size);
+    mx_pref_n = htons(mx_pref);
+    memcpy(*data, &mx_pref_n, sizeof (uint16_t));
+    strcpy((*data)+sizeof (uint16_t), result);
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_TXT:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s);
+    return GNUNET_OK;
+  case GNUNET_DNSPARSER_TYPE_AAAA:
+    if (1 != inet_pton (AF_INET6, s, &value_aaaa))    
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse IPv6 address `%s'\n"),
+                  s);
+      return GNUNET_SYSERR;
+    }
+    *data = GNUNET_malloc (sizeof (struct in6_addr));
+    *data_size = sizeof (struct in6_addr);
+    memcpy (*data, &value_aaaa, sizeof (value_aaaa));
+    return GNUNET_OK;
+  case GNUNET_NAMESTORE_TYPE_PKEY:
+    if (GNUNET_OK !=
+        GNUNET_CRYPTO_short_hash_from_string (s, &pkey))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse PKEY record `%s'\n"),
+                  s);
+      return GNUNET_SYSERR;
+    }
+    *data = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_ShortHashCode));
+    memcpy (*data, &pkey, sizeof (pkey));
+    *data_size = sizeof (struct GNUNET_CRYPTO_ShortHashCode);
+    return GNUNET_OK;
+  case GNUNET_NAMESTORE_TYPE_PSEU:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s);
+    return GNUNET_OK;
+  case GNUNET_NAMESTORE_TYPE_LEHO:
+    *data = GNUNET_strdup (s);
+    *data_size = strlen (s);
+    return GNUNET_OK;
+  case GNUNET_NAMESTORE_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 vpn_data) + strlen (s_serv) + 1;
+    *data = vpn = GNUNET_malloc (*data_size);
+    if (GNUNET_OK != GNUNET_CRYPTO_hash_from_string ((char*)&s_peer,
+                                                     &vpn->peer))
+    {
+      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_DNSPARSER_TYPE_TLSA:
+    *data_size = sizeof (struct tlsa_data) + strlen (s) - 6;
+    *data = tlsa = GNUNET_malloc (*data_size);
+    if (4 != SSCANF (s, "%c %c %c %s",
+                     &tlsa->usage,
+                     &tlsa->selector,
+                     &tlsa->matching_type,
+                     (char*)&tlsa[1]))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Unable to parse TLSA record string `%s'\n"), 
+                  s);
+      *data_size = 0;
+      GNUNET_free (tlsa);
+      return GNUNET_SYSERR;
+    }
+    return GNUNET_OK;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Unsupported record type %d\n"),
+                (int) type);
+    return GNUNET_SYSERR;
+  }
+}
+
+
+static struct { 
+  const char *name; 
+  uint32_t number; 
+} name_map[] = {
+  { "A", GNUNET_DNSPARSER_TYPE_A },
+  { "NS", GNUNET_DNSPARSER_TYPE_NS },
+  { "CNAME", GNUNET_DNSPARSER_TYPE_CNAME },
+  { "SOA", GNUNET_DNSPARSER_TYPE_SOA },
+  { "PTR", GNUNET_DNSPARSER_TYPE_PTR },
+  { "MX", GNUNET_DNSPARSER_TYPE_MX },
+  { "TXT", GNUNET_DNSPARSER_TYPE_TXT },
+  { "AAAA", GNUNET_DNSPARSER_TYPE_AAAA },
+  { "PKEY",  GNUNET_NAMESTORE_TYPE_PKEY },
+  { "PSEU",  GNUNET_NAMESTORE_TYPE_PSEU },
+  { "LEHO",  GNUNET_NAMESTORE_TYPE_LEHO },
+  { "VPN", GNUNET_NAMESTORE_TYPE_VPN },
+  { "TLSA", GNUNET_DNSPARSER_TYPE_TLSA },
+  { NULL, UINT32_MAX }
+};
+
+
+/**
+ * Convert a type name (i.e. "AAAA") to the corresponding number.
+ *
+ * @param typename name to convert
+ * @return corresponding number, UINT32_MAX on error
+ */
+uint32_t
+GNUNET_NAMESTORE_typename_to_number (const char *typename)
+{
+  unsigned int i;
+
+  i=0;
+  while ( (name_map[i].name != NULL) &&
+          (0 != strcasecmp (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 type number of a type to convert
+ * @return corresponding typestring, NULL on error
+ */
+const char *
+GNUNET_NAMESTORE_number_to_typename (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;  
+}
+
+/**
+ * Test if a given record is expired.
+ * 
+ * @return GNUNET_YES if the record is expired,
+ *         GNUNET_NO if not
+ */
+int
+GNUNET_NAMESTORE_is_expired (const struct GNUNET_NAMESTORE_RecordData *rd)
+{
+  struct GNUNET_TIME_Absolute at;
+
+  if (0 != (rd->flags & GNUNET_NAMESTORE_RF_RELATIVE_EXPIRATION))
+    return GNUNET_NO;
+  at.abs_value = rd->expiration_time;
+  return (0 == GNUNET_TIME_absolute_get_remaining (at).rel_value) ? GNUNET_YES : GNUNET_NO;
+}
+
+
+/* end of namestore_common.c */