-first draft of postgres namestore plugin (#2157)

3 files changed, 689 insertions, 7 deletions

diff --git a/src/namestore/Makefile.am b/src/namestore/Makefile.am
index aea857d74..2106ccf76 100644
--- a/src/namestore/Makefile.am
+++ b/src/namestore/Makefile.am
@@ -18,13 +18,18 @@ if USE_COVERAGE
 endif
 
 if HAVE_SQLITE
-SQLITE_TESTS = \
- test_plugin_namestore_sqlite 
+SQLITE_PLUGIN = libgnunet_plugin_namestore_sqlite.la
+SQLITE_TESTS = test_plugin_namestore_sqlite 
+endif
+if HAVE_POSTGRES
+POSTGRES_TESTS = test_plugin_namestore_postgres
+POSTGRES_PLUGIN = libgnunet_plugin_namestore_postgres.la
 endif
 
 
 check_PROGRAMS = \
  $(SQLITE_TESTS) \
+ $(POSTGRES_TESTS) \
  test_namestore_record_serialization \
  test_namestore_api_sign_verify \
  test_namestore_api \
@@ -87,12 +92,10 @@ gnunet_service_namestore_DEPENDENCIES = \
   $(top_builddir)/src/util/libgnunetutil.la \
   libgnunetnamestore.la
 
-if HAVE_SQLITE
- SQLITE_PLUGIN = libgnunet_plugin_namestore_sqlite.la
-endif
 
 plugin_LTLIBRARIES = \
-  $(SQLITE_PLUGIN) 
+  $(SQLITE_PLUGIN) \
+  $(POSTGRES_PLUGIN)
 
 libgnunet_plugin_namestore_sqlite_la_SOURCES = \
   plugin_namestore_sqlite.c namestore_common.c
@@ -104,6 +107,25 @@ libgnunet_plugin_namestore_sqlite_la_LIBADD = \
 libgnunet_plugin_namestore_sqlite_la_LDFLAGS = \
  $(GN_PLUGIN_LDFLAGS)
 libgnunet_plugin_namestore_sqlite_la_DEPENDENCIES = \
+  $(top_builddir)/src/namestore/libgnunetnamestore.la  \
+  $(top_builddir)/src/statistics/libgnunetstatistics.la \
+  $(top_builddir)/src/util/libgnunetutil.la \
+  libgnunetnamestore.la
+
+
+libgnunet_plugin_namestore_postgres_la_SOURCES = \
+  plugin_namestore_postgres.c namestore_common.c
+libgnunet_plugin_namestore_postgres_la_LIBADD = \
+  $(top_builddir)/src/namestore/libgnunetnamestore.la  \
+  $(top_builddir)/src/postgres/libgnunetpostgres.la  \
+  $(top_builddir)/src/statistics/libgnunetstatistics.la \
+  $(top_builddir)/src/util/libgnunetutil.la $(XLIBS) -lpq \
+  $(LTLIBINTL)
+libgnunet_plugin_namestore_postgres_la_LDFLAGS = \
+ $(GN_PLUGIN_LDFLAGS)
+libgnunet_plugin_namestore_postgres_la_DEPENDENCIES = \
+  $(top_builddir)/src/namestore/libgnunetnamestore.la  \
+  $(top_builddir)/src/postgres/libgnunetpostgres.la  \
   $(top_builddir)/src/statistics/libgnunetstatistics.la \
   $(top_builddir)/src/util/libgnunetutil.la \
   libgnunetnamestore.la
diff --git a/src/namestore/plugin_namestore_postgres.c b/src/namestore/plugin_namestore_postgres.c
new file mode 100644
index 000000000..a60ed8c0a
--- /dev/null
+++ b/src/namestore/plugin_namestore_postgres.c
@@ -0,0 +1,654 @@
+ /*
+  * This file is part of GNUnet
+  * (C) 2009, 2011, 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/plugin_namestore_postgres.c
+ * @brief postgres-based namestore backend
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_namestore_plugin.h"
+#include "gnunet_namestore_service.h"
+#include "gnunet_postgres_lib.h"
+#include "namestore.h"
+
+
+/**
+ * After how many ms "busy" should a DB operation fail for good?
+ * A low value makes sure that we are more responsive to requests
+ * (especially PUTs).  A high value guarantees a higher success
+ * rate (SELECTs in iterate can take several seconds despite LIMIT=1).
+ *
+ * The default value of 1s should ensure that users do not experience
+ * huge latencies while at the same time allowing operations to succeed
+ * with reasonable probability.
+ */
+#define BUSY_TIMEOUT_MS 1000
+
+
+/**
+ * Log an error message at log-level 'level' that indicates
+ * a failure of the command 'cmd' on file 'filename'
+ * with the message given by strerror(errno).
+ */
+#define LOG_POSTGRES(db, level, cmd) do { GNUNET_log_from (level, "namestore-postgres", _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, sqlite3_errmsg(db->dbh)); } while(0)
+
+#define LOG(kind,...) GNUNET_log_from (kind, "namestore-postgres", __VA_ARGS__)
+
+
+/**
+ * Context for all functions in this plugin.
+ */
+struct Plugin
+{
+
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Native Postgres database handle.
+   */
+  PGconn *dbh;
+
+};
+
+
+/**
+ * Create our database indices.
+ *
+ * @param dbh handle to the database
+ */
+static void
+create_indices (PGconn * dbh)
+{
+  /* create indices */
+  if ( (GNUNET_OK !=
+        GNUNET_POSTGRES_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_zone_name_rv ON ns091records (zone_hash,record_name_hash,rvalue)")) ||
+       (GNUNET_OK !=
+        GNUNET_POSTGRES_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_zone_delegation ON ns091records (zone_hash,zone_delegation)")) ||
+       (GNUNET_OK !=
+        GNUNET_POSTGRES_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_zone_rv ON ns091records (zone_hash,rvalue)")) ||
+       (GNUNET_OK !=
+        GNUNET_POSTGRES_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_zone ON ns091records (zone_hash)")) ||
+       (GNUNET_OK !=
+        GNUNET_POSTGRES_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_name_rv ON ns091records (record_name_hash,rvalue)")) ||
+       (GNUNET_OK !=
+        GNUNET_POSTGRES_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_rv ON ns091records (rvalue)")) )
+    LOG (GNUNET_ERROR_TYPE_ERROR, 
+         _("Failed to create indices\n"));
+}
+
+
+/**
+ * Initialize the database connections and associated
+ * data structures (create tables and indices
+ * as needed as well).
+ *
+ * @param plugin the plugin context (state for this module)
+ * @return GNUNET_OK on success
+ */
+static int
+database_setup (struct Plugin *plugin)
+{
+  PGresult *res;
+
+  plugin->dbh = GNUNET_POSTGRES_connect (plugin->cfg,
+                                         "namestore-postgres");
+  if (NULL == plugin->dbh)
+    return GNUNET_SYSERR;
+  res =
+      PQexec (plugin->dbh,
+              "CREATE TABLE ns091records ("
+              " zone_key BLOB NOT NULL DEFAULT ''," 
+              " zone_delegation BLOB NOT NULL DEFAULT ''," 
+              " zone_hash BLOB NOT NULL DEFAULT ''," 
+              " record_count INT NOT NULL DEFAULT 0,"
+              " record_data BLOB NOT NULL DEFAULT '',"
+              " block_expiration_time INT8 NOT NULL DEFAULT 0," 
+              " signature BLOB NOT NULL DEFAULT '',"
+              " record_name TEXT NOT NULL DEFAULT ''," 
+              " record_name_hash BLOB NOT NULL DEFAULT ''," 
+              " rvalue INT8 NOT NULL DEFAULT ''"
+              ")" "WITH OIDS");
+  if ((NULL == res) || ((PQresultStatus (res) != PGRES_COMMAND_OK) && (0 != strcmp ("42P07",    /* duplicate table */
+                                                                                    PQresultErrorField
+                                                                                    (res,
+                                                                                     PG_DIAG_SQLSTATE)))))
+  {
+    (void) GNUNET_POSTGRES_check_result (plugin->dbh, res, PGRES_COMMAND_OK, "CREATE TABLE",
+                                         "ns091records");
+    PQfinish (plugin->dbh);
+    plugin->dbh = NULL;
+    return GNUNET_SYSERR;
+  }
+  if (PQresultStatus (res) == PGRES_COMMAND_OK)
+    create_indices (plugin->dbh);
+  PQclear (res);
+
+#define ALL "zone_key, record_name, record_count, record_data, block_expiration_time, signature"
+  if ((GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "put_records",
+                                "INSERT INTO ns091records (" ALL 
+                                ", zone_delegation, zone_hash, record_name_hash, rvalue) VALUES "
+                                "($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)", 10)) ||
+      (GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "remove_records",
+                                "DELETE FROM ns091records WHERE zone_hash=$1 AND record_name_hash=$2", 2)) ||
+      (GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "iterate_records",
+                                "SELECT " ALL
+                                " FROM ns091records WHERE zone_hash=$1 AND record_name_hash=$2 ORDER BY rvalue LIMIT 1 OFFSET $3", 3)) ||
+      (GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "iterate_by_zone",
+                                "SELECT " ALL
+                                " FROM ns091records WHERE zone_hash=$1 ORDER BY rvalue  LIMIT 1 OFFSET $2", 2)) ||
+      (GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "iterate_by_name",
+                                "SELECT " ALL 
+                                " FROM ns091records WHERE record_name_hash=$1 ORDER BY rvalue LIMIT 1 OFFSET $2", 2)) ||
+      (GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "iterate_all",
+                                "SELECT " ALL
+                                " FROM ns091records ORDER BY rvalue LIMIT 1 OFFSET $1", 1)) ||
+      (GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "zone_to_name",
+                                "SELECT " ALL
+                                " FROM ns091records WHERE zone_hash=$1 AND zone_delegation=$2", 2)) ||
+      (GNUNET_OK !=
+       GNUNET_POSTGRES_prepare (plugin->dbh,
+                                "delete_zone",
+                                "DELETE FROM ns091records WHERE zone_hash=$1", 1)))
+  {
+    PQfinish (plugin->dbh);
+    plugin->dbh = NULL;
+    return GNUNET_SYSERR;
+  }
+#undef ALL
+  return GNUNET_OK;
+}
+
+
+/**
+ * Removes any existing record in the given zone with the same name.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param zone hash of the public key of the zone
+ * @param name name to remove (at most 255 characters long)
+ * @return GNUNET_OK on success
+ */
+static int 
+namestore_postgres_remove_records (void *cls, 
+                                 const struct GNUNET_CRYPTO_ShortHashCode *zone,
+                                 const char *name)
+{
+  struct Plugin *plugin = cls;
+  PGresult *ret;
+  struct GNUNET_CRYPTO_ShortHashCode nh;
+  const char *paramValues[] = {
+    (const char *) zone,
+    (const char *) &nh
+  };
+  int paramLengths[] = {
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode)
+  };
+  const int paramFormats[] = { 1, 1 };
+  size_t name_len;
+
+  name_len = strlen (name);
+  GNUNET_CRYPTO_short_hash (name, name_len, &nh);
+  ret =
+      PQexecPrepared (plugin->dbh, "remove_records", 2, paramValues, paramLengths,
+                      paramFormats, 1);
+  if (GNUNET_OK !=
+      GNUNET_POSTGRES_check_result (plugin->dbh, ret, PGRES_COMMAND_OK, "PQexecPrepared", "put"))
+    return GNUNET_SYSERR;
+  PQclear (ret);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Store a record in the datastore.  Removes any existing record in the
+ * same zone with the same name.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param zone_key public key of the zone
+ * @param expire when does the corresponding block in the DHT expire (until
+ *               when should we never do a DHT lookup for the same name again)?
+ * @param name name that is being mapped (at most 255 characters long)
+ * @param rd_count number of entries in 'rd' array
+ * @param rd array of records with data to store
+ * @param signature signature of the record block, NULL if signature is unavailable (i.e. 
+ *        because the user queried for a particular record type only)
+ * @return GNUNET_OK on success, else GNUNET_SYSERR
+ */
+static int 
+namestore_postgres_put_records (void *cls, 
+                                const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *zone_key,
+                                struct GNUNET_TIME_Absolute expire,
+                                const char *name,
+                                unsigned int rd_count,
+                                const struct GNUNET_NAMESTORE_RecordData *rd,
+                                const struct GNUNET_CRYPTO_RsaSignature *signature)
+{
+  struct Plugin *plugin = cls;
+  PGresult *ret;
+  struct GNUNET_CRYPTO_ShortHashCode zone;
+  struct GNUNET_CRYPTO_ShortHashCode zone_delegation;
+  struct GNUNET_CRYPTO_ShortHashCode nh;
+  size_t name_len;
+  uint64_t rvalue;
+  size_t data_size;
+  unsigned int i;
+
+  GNUNET_CRYPTO_short_hash (zone_key, 
+                            sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
+                            &zone);
+  (void) namestore_postgres_remove_records (plugin, &zone, name);
+  name_len = strlen (name);
+  GNUNET_CRYPTO_short_hash (name, name_len, &nh);
+  memset (&zone_delegation, 0, sizeof (zone_delegation));
+  for (i=0;i<rd_count;i++)
+    if (rd[i].record_type == GNUNET_NAMESTORE_TYPE_PKEY)
+    {
+      GNUNET_assert (sizeof (struct GNUNET_CRYPTO_ShortHashCode) == rd[i].data_size);
+      memcpy (&zone_delegation,
+              rd[i].data,
+              sizeof (struct GNUNET_CRYPTO_ShortHashCode));
+      break;
+    }
+  rvalue = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, UINT64_MAX);
+  data_size = GNUNET_NAMESTORE_records_get_size (rd_count, rd);
+  if (data_size > 64 * 65536)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  {
+    char data[data_size];
+    uint64_t expire_be = GNUNET_htonll (expire.abs_value);
+    uint64_t rvalue_be = GNUNET_htonll (rvalue);
+    uint32_t rd_count_be = htonl ((uint32_t) rd_count);
+    const char *paramValues[] = {
+      (const char *) zone_key,
+      (const char *) name,
+      (const char *) &rd_count_be,
+      (const char *) data,
+      (const char *) &expire_be,
+      (const char *) signature,
+      (const char *) &zone_delegation,
+      (const char *) &zone,
+      (const char *) &nh,
+      (const char *) &rvalue_be
+    };
+    int paramLengths[] = {
+      sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
+      name_len + 1,
+      sizeof (uint32_t),
+      data_size,
+      sizeof (uint64_t),
+      sizeof (struct GNUNET_CRYPTO_RsaSignature), 
+      sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+      sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+      sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+      sizeof (uint64_t)
+    };
+    const int paramFormats[] = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
+
+    if (data_size != GNUNET_NAMESTORE_records_serialize (rd_count, rd,
+                                                         data_size, data))
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+    ret =
+      PQexecPrepared (plugin->dbh, "put", 10, paramValues, paramLengths,
+                      paramFormats, 1);
+    if (GNUNET_OK !=
+        GNUNET_POSTGRES_check_result (plugin->dbh, ret, PGRES_COMMAND_OK, "PQexecPrepared", "put"))
+      return GNUNET_SYSERR;
+    PQclear (ret);
+  }
+  return GNUNET_OK;  
+}
+
+
+/**
+ * The given 'postgres' result was obtained from the database.
+ * Parse the record and give it to the iterator.
+ *
+ * @param plugin plugin context
+ * @param stmt_name name of the prepared statement that was executed
+ * @param res result from postgres to interpret (and then clean up)
+ * @param iter iterator to call with the result
+ * @param iter_cls closure for 'iter'
+ * @return GNUNET_OK on success, GNUNET_NO if there were no results, GNUNET_SYSERR on error
+ */
+static int
+get_record_and_call_iterator (struct Plugin *plugin,
+                              const char *stmt_name,
+                              PGresult *res,
+                              GNUNET_NAMESTORE_RecordIterator iter, void *iter_cls)
+{
+  unsigned int record_count;
+  size_t data_size;
+  const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *zone_key;
+  const struct GNUNET_CRYPTO_RsaSignature *sig;
+  struct GNUNET_TIME_Absolute expiration;
+  const char *data;
+  const char *name;
+  unsigned int cnt;
+
+  if (GNUNET_OK !=
+      GNUNET_POSTGRES_check_result (plugin->dbh, res, PGRES_TUPLES_OK, "PQexecPrepared",
+                                    stmt_name))
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Ending iteration (postgres error)\n");
+    return GNUNET_SYSERR;
+  }
+
+  if (0 == (cnt = PQntuples (res)))
+  {
+    /* no result */
+    LOG (GNUNET_ERROR_TYPE_DEBUG, 
+         "Ending iteration (no more results)\n");
+    PQclear (res);
+    return GNUNET_NO;
+  }
+  GNUNET_assert (1 == cnt);
+  if ((6 != PQnfields (res)) || 
+      (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) != PQfsize (res, 0)) || 
+      (sizeof (uint32_t) != PQfsize (res, 2)) || 
+      (sizeof (uint64_t) != PQfsize (res, 4)) || 
+      (sizeof (struct GNUNET_CRYPTO_RsaSignature) != PQfsize (res, 5)))
+  {
+    GNUNET_break (0);
+    PQclear (res);
+    return GNUNET_SYSERR;
+  }
+  zone_key = (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *) PQgetvalue (res, 0, 0);
+  name = PQgetvalue (res, 0, 1);
+  if ('\0' != name[PQgetlength (res, 0, 1)-1])
+  {
+    GNUNET_break (0);
+    PQclear (res);
+    return GNUNET_SYSERR;
+  }
+  record_count = ntohl (*(uint32_t *) PQgetvalue (res, 0, 2));
+  data_size = PQgetlength (res, 0, 3);
+  data = PQgetvalue (res, 0, 3);
+  expiration.abs_value =
+    GNUNET_ntohll (*(uint64_t *) PQgetvalue (res, 0, 4));
+  sig = (const struct GNUNET_CRYPTO_RsaSignature*) PQgetvalue (res, 0, 5);
+  if (record_count > 64 * 1024)
+  {
+    /* sanity check, don't stack allocate far too much just
+       because database might contain a large value here */
+    GNUNET_break (0);
+    PQclear (res);
+    return GNUNET_SYSERR;
+  }
+  {
+    struct GNUNET_NAMESTORE_RecordData rd[record_count];
+    
+    if (GNUNET_OK !=
+        GNUNET_NAMESTORE_records_deserialize (data_size, data,
+                                              record_count, rd))
+    {
+      GNUNET_break (0);
+      PQclear (res);
+      return GNUNET_SYSERR;
+    }
+    iter (iter_cls, zone_key, expiration, name, 
+          record_count, rd, sig);
+  }
+  PQclear (res);
+  return GNUNET_OK;
+}
+  
+  
+/**
+ * Iterate over the results for a particular key and zone in the
+ * datastore.  Will return at most one result to the iterator.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param zone hash of public key of the zone, NULL to iterate over all zones
+ * @param name name as string, NULL to iterate over all records of the zone
+ * @param offset offset in the list of all matching records
+ * @param iter function to call with the result
+ * @param iter_cls closure for iter
+ * @return GNUNET_OK on success, GNUNET_NO if there were no results, GNUNET_SYSERR on error
+ */
+static int 
+namestore_postgres_iterate_records (void *cls, 
+                                  const struct GNUNET_CRYPTO_ShortHashCode *zone,
+                                  const char *name,
+                                  uint64_t offset,
+                                  GNUNET_NAMESTORE_RecordIterator iter, void *iter_cls)
+{
+  struct Plugin *plugin = cls;
+  const char *stmt_name;
+  struct GNUNET_CRYPTO_ShortHashCode name_hase;
+  uint64_t offset_be = GNUNET_htonll (offset);
+  const char *paramValues[] = {
+    (const char *) zone,
+    (const char *) &name_hase,
+    (const char *) &offset_be,
+    (const char *) zone,
+    (const char *) &offset_be,
+  };
+  int paramLengths[] = {
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+    sizeof (uint64_t),
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+    sizeof (uint64_t)
+  };
+  const int paramFormats[] = { 1, 1, 1, 1, 1 };
+  unsigned int num_params;
+  unsigned int first_param;
+  PGresult *res;
+
+  if (NULL == zone)
+    if (NULL == name)
+    {
+      stmt_name = "iterate_all";
+      num_params = 1;
+      first_param = 2;
+    }
+    else
+    {
+      GNUNET_CRYPTO_short_hash (name, strlen(name), &name_hase);
+      stmt_name = "iterate_by_name";
+      num_params = 2;
+      first_param = 1;
+    }
+  else
+    if (NULL == name)
+    {
+      stmt_name = "iterate_by_zone";
+      num_params = 2;
+      first_param = 3;
+    }
+    else
+    {
+      GNUNET_CRYPTO_short_hash (name, strlen(name), &name_hase);
+      stmt_name = "iterate_records";
+      num_params = 3;
+      first_param = 0;
+    }
+  res =
+      PQexecPrepared (plugin->dbh, stmt_name, num_params, 
+                      &paramValues[first_param],
+                      &paramLengths[first_param],
+                      &paramFormats[first_param], 1);
+  return get_record_and_call_iterator (plugin, stmt_name, res, iter, iter_cls);
+}
+
+
+/**
+ * Look for an existing PKEY delegation record for a given public key.
+ * Returns at most one result to the iterator.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param zone hash of public key of the zone to look up in, never NULL
+ * @param value_zone hash of the public key of the target zone (value), never NULL
+ * @param iter function to call with the result
+ * @param iter_cls closure for iter
+ * @return GNUNET_OK on success, GNUNET_NO if there were no results, GNUNET_SYSERR on error
+ */
+static int
+namestore_postgres_zone_to_name (void *cls, 
+                               const struct GNUNET_CRYPTO_ShortHashCode *zone,
+                               const struct GNUNET_CRYPTO_ShortHashCode *value_zone,
+                               GNUNET_NAMESTORE_RecordIterator iter, void *iter_cls)
+{
+  struct Plugin *plugin = cls;
+  const char *paramValues[] = {
+    (const char *) zone,
+    (const char *) value_zone
+  };
+  int paramLengths[] = {
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode),
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode)
+  };
+  const int paramFormats[] = { 1, 1 };
+  PGresult *res;
+
+  res =
+    PQexecPrepared (plugin->dbh, "zone_to_name", 2,
+                    paramValues, paramLengths, paramFormats, 1);
+  return get_record_and_call_iterator (plugin, "zone_to_name", res, iter, iter_cls);
+}
+
+
+/**
+ * Delete an entire zone (all records).  Not used in normal operation.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param zone zone to delete
+ */
+static void 
+namestore_postgres_delete_zone (void *cls,
+                              const struct GNUNET_CRYPTO_ShortHashCode *zone)
+{
+  struct Plugin *plugin = cls;
+  PGresult *ret;
+  const char *paramValues[] = {
+    (const char *) zone,
+  };
+  int paramLengths[] = {
+    sizeof (struct GNUNET_CRYPTO_ShortHashCode)
+  };
+  const int paramFormats[] = { 1 };
+
+  ret =
+      PQexecPrepared (plugin->dbh, "delete_zone", 1, paramValues, paramLengths,
+                      paramFormats, 1);
+  if (GNUNET_OK !=
+      GNUNET_POSTGRES_check_result (plugin->dbh, ret, PGRES_COMMAND_OK, "PQexecPrepared", "delete_zone"))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Deleting zone failed!\n");             
+    return;
+  }
+  PQclear (ret);
+}
+
+
+/**
+ * Shutdown database connection and associate data
+ * structures.
+ *
+ * @param plugin the plugin context (state for this module)
+ */
+static void
+database_shutdown (struct Plugin *plugin)
+{
+  PQfinish (plugin->dbh);
+  plugin->dbh = NULL;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls the "struct GNUNET_NAMESTORE_PluginEnvironment*"
+ * @return NULL on error, othrewise the plugin context
+ */
+void *
+libgnunet_plugin_namestore_postgres_init (void *cls)
+{
+  static struct Plugin plugin;
+  const struct GNUNET_CONFIGURATION_Handle *cfg = cls;
+  struct GNUNET_NAMESTORE_PluginFunctions *api;
+
+  if (NULL != plugin.cfg)
+    return NULL;                /* can only initialize once! */
+  memset (&plugin, 0, sizeof (struct Plugin));
+  plugin.cfg = cfg;  
+  if (GNUNET_OK != database_setup (&plugin))
+  {
+    database_shutdown (&plugin);
+    return NULL;
+  }
+  api = GNUNET_malloc (sizeof (struct GNUNET_NAMESTORE_PluginFunctions));
+  api->cls = &plugin;
+  api->put_records = &namestore_postgres_put_records;
+  api->remove_records = &namestore_postgres_remove_records;
+  api->iterate_records = &namestore_postgres_iterate_records;
+  api->zone_to_name = &namestore_postgres_zone_to_name;
+  api->delete_zone = &namestore_postgres_delete_zone;
+  LOG (GNUNET_ERROR_TYPE_INFO, 
+       _("Postgres database running\n"));
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ *
+ * @param cls the plugin context (as returned by "init")
+ * @return always NULL
+ */
+void *
+libgnunet_plugin_namestore_postgres_done (void *cls)
+{
+  struct GNUNET_NAMESTORE_PluginFunctions *api = cls;
+  struct Plugin *plugin = api->cls;
+
+  database_shutdown (plugin);
+  plugin->cfg = NULL;
+  GNUNET_free (api);
+  LOG (GNUNET_ERROR_TYPE_DEBUG, 
+       "postgres plugin is finished\n");
+  return NULL;
+}
+
+/* end of plugin_namestore_postgres.c */
diff --git a/src/namestore/plugin_namestore_sqlite.c b/src/namestore/plugin_namestore_sqlite.c
index f6858876e..b3f57033a 100644
--- a/src/namestore/plugin_namestore_sqlite.c
+++ b/src/namestore/plugin_namestore_sqlite.c
@@ -591,6 +591,13 @@ get_record_and_call_iterator (struct Plugin *plugin,
       GNUNET_break (0);
       ret = GNUNET_SYSERR;
     }
+    else if (record_count > 64 * 1024)
+    {
+      /* sanity check, don't stack allocate far too much just
+         because database might contain a large value here */
+      GNUNET_break (0);
+      ret = GNUNET_SYSERR;
+    } 
     else
     {
       struct GNUNET_NAMESTORE_RecordData rd[record_count];
@@ -601,7 +608,6 @@ get_record_and_call_iterator (struct Plugin *plugin,
       {
         GNUNET_break (0);
         ret = GNUNET_SYSERR;
-        record_count = 0;
       }
       else
       {