1 files changed, 589 insertions, 0 deletions

diff --git a/src/plugin/namecache/plugin_namecache_sqlite.c b/src/plugin/namecache/plugin_namecache_sqlite.c
new file mode 100644
index 000000000..d8b485381
--- /dev/null
+++ b/src/plugin/namecache/plugin_namecache_sqlite.c
@@ -0,0 +1,589 @@
+/*
+ * This file is part of GNUnet
+ * Copyright (C) 2009-2013 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
+ */
+
+/**
+ * @file namecache/plugin_namecache_sqlite.c
+ * @brief sqlite-based namecache backend
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_sq_lib.h"
+#include "gnunet_namecache_plugin.h"
+#include "gnunet_namecache_service.h"
+#include "gnunet_gnsrecord_lib.h"
+#include <sqlite3.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_SQLITE(db, level, cmd) do { GNUNET_log_from (level, \
+                                                         "namecache-sqlite", _ ( \
+                                                           "`%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, "namecache-sqlite", __VA_ARGS__)
+
+
+/**
+ * Context for all functions in this plugin.
+ */
+struct Plugin
+{
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Database filename.
+   */
+  char *fn;
+
+  /**
+   * Native SQLite database handle.
+   */
+  sqlite3 *dbh;
+
+  /**
+   * Precompiled SQL for caching a block
+   */
+  sqlite3_stmt *cache_block;
+
+  /**
+   * Precompiled SQL for deleting an older block
+   */
+  sqlite3_stmt *delete_block;
+
+  /**
+   * Precompiled SQL for looking up a block
+   */
+  sqlite3_stmt *lookup_block;
+
+  /**
+   * Precompiled SQL for removing expired blocks
+   */
+  sqlite3_stmt *expire_blocks;
+};
+
+
+/**
+ * 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)
+{
+  struct GNUNET_SQ_ExecuteStatement es[] = {
+    GNUNET_SQ_make_try_execute ("PRAGMA temp_store=MEMORY"),
+    GNUNET_SQ_make_try_execute ("PRAGMA synchronous=NORMAL"),
+    GNUNET_SQ_make_try_execute ("PRAGMA legacy_file_format=OFF"),
+    GNUNET_SQ_make_try_execute ("PRAGMA auto_vacuum=INCREMENTAL"),
+    GNUNET_SQ_make_try_execute ("PRAGMA encoding=\"UTF-8\""),
+    GNUNET_SQ_make_try_execute ("PRAGMA locking_mode=EXCLUSIVE"),
+    GNUNET_SQ_make_try_execute ("PRAGMA page_size=4092"),
+    GNUNET_SQ_make_try_execute ("PRAGMA journal_mode=WAL"),
+    GNUNET_SQ_make_execute ("CREATE TABLE IF NOT EXISTS ns096blocks ("
+                            " query BLOB NOT NULL,"
+                            " block BLOB NOT NULL,"
+                            " expiration_time INT8 NOT NULL"
+                            ")"),
+    GNUNET_SQ_make_execute ("CREATE INDEX IF NOT EXISTS ir_query_hash "
+                            "ON ns096blocks (query,expiration_time)"),
+    GNUNET_SQ_make_execute ("CREATE INDEX IF NOT EXISTS ir_block_expiration "
+                            "ON ns096blocks (expiration_time)"),
+    GNUNET_SQ_EXECUTE_STATEMENT_END
+  };
+  struct GNUNET_SQ_PrepareStatement ps[] = {
+    GNUNET_SQ_make_prepare (
+      "INSERT INTO ns096blocks (query,block,expiration_time) VALUES (?, ?, ?)",
+      &plugin->cache_block),
+    GNUNET_SQ_make_prepare ("DELETE FROM ns096blocks WHERE expiration_time<?",
+                            &plugin->expire_blocks),
+    GNUNET_SQ_make_prepare (
+      "DELETE FROM ns096blocks WHERE query=? AND expiration_time<=?",
+      &plugin->delete_block),
+    GNUNET_SQ_make_prepare ("SELECT block FROM ns096blocks WHERE query=? "
+                            "ORDER BY expiration_time DESC LIMIT 1",
+                            &plugin->lookup_block),
+    GNUNET_SQ_PREPARE_END
+  };
+  char *afsdir;
+
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_filename (plugin->cfg,
+                                               "namecache-sqlite",
+                                               "FILENAME",
+                                               &afsdir))
+  {
+    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
+                               "namecache-sqlite",
+                               "FILENAME");
+    return GNUNET_SYSERR;
+  }
+  if (GNUNET_OK !=
+      GNUNET_DISK_file_test (afsdir))
+  {
+    if (GNUNET_OK !=
+        GNUNET_DISK_directory_create_for_file (afsdir))
+    {
+      GNUNET_break (0);
+      GNUNET_free (afsdir);
+      return GNUNET_SYSERR;
+    }
+  }
+  /* afsdir should be UTF-8-encoded. If it isn't, it's a bug */
+  plugin->fn = afsdir;
+
+  /* Open database and precompile statements */
+  if (SQLITE_OK !=
+      sqlite3_open (plugin->fn, &plugin->dbh))
+  {
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _ ("Unable to initialize SQLite: %s.\n"),
+         sqlite3_errmsg (plugin->dbh));
+    return GNUNET_SYSERR;
+  }
+  if (GNUNET_OK !=
+      GNUNET_SQ_exec_statements (plugin->dbh,
+                                 es))
+  {
+    GNUNET_break (0);
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _ ("Failed to setup database at `%s'\n"),
+         plugin->fn);
+    return GNUNET_SYSERR;
+  }
+  GNUNET_break (SQLITE_OK ==
+                sqlite3_busy_timeout (plugin->dbh,
+                                      BUSY_TIMEOUT_MS));
+
+  if (GNUNET_OK !=
+      GNUNET_SQ_prepare (plugin->dbh,
+                         ps))
+  {
+    GNUNET_break (0);
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _ ("Failed to setup database at `%s'\n"),
+         plugin->fn);
+    return GNUNET_SYSERR;
+  }
+
+  return GNUNET_OK;
+}
+
+
+/**
+ * Shutdown database connection and associate data
+ * structures.
+ * @param plugin the plugin context (state for this module)
+ */
+static void
+database_shutdown (struct Plugin *plugin)
+{
+  int result;
+  sqlite3_stmt *stmt;
+
+  if (NULL != plugin->cache_block)
+    sqlite3_finalize (plugin->cache_block);
+  if (NULL != plugin->lookup_block)
+    sqlite3_finalize (plugin->lookup_block);
+  if (NULL != plugin->expire_blocks)
+    sqlite3_finalize (plugin->expire_blocks);
+  if (NULL != plugin->delete_block)
+    sqlite3_finalize (plugin->delete_block);
+  result = sqlite3_close (plugin->dbh);
+  if (result == SQLITE_BUSY)
+  {
+    LOG (GNUNET_ERROR_TYPE_WARNING,
+         _ (
+           "Tried to close sqlite without finalizing all prepared statements.\n"));
+    stmt = sqlite3_next_stmt (plugin->dbh,
+                              NULL);
+    while (stmt != NULL)
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+                       "sqlite",
+                       "Closing statement %p\n",
+                       stmt);
+      result = sqlite3_finalize (stmt);
+      if (result != SQLITE_OK)
+        GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
+                         "sqlite",
+                         "Failed to close statement %p: %d\n",
+                         stmt,
+                         result);
+      stmt = sqlite3_next_stmt (plugin->dbh,
+                                NULL);
+    }
+    result = sqlite3_close (plugin->dbh);
+  }
+  if (SQLITE_OK != result)
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR,
+                "sqlite3_close");
+
+  GNUNET_free (plugin->fn);
+}
+
+
+/**
+ * Removes any expired block.
+ *
+ * @param plugin the plugin
+ */
+static void
+namecache_sqlite_expire_blocks (struct Plugin *plugin)
+{
+  struct GNUNET_TIME_Absolute now;
+  now = GNUNET_TIME_absolute_get ();
+  struct GNUNET_SQ_QueryParam params[] = {
+    GNUNET_SQ_query_param_absolute_time (&now),
+    GNUNET_SQ_query_param_end
+  };
+  int n;
+
+  if (GNUNET_OK !=
+      GNUNET_SQ_bind (plugin->expire_blocks,
+                      params))
+  {
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    GNUNET_SQ_reset (plugin->dbh,
+                     plugin->expire_blocks);
+    return;
+  }
+  n = sqlite3_step (plugin->expire_blocks);
+  GNUNET_SQ_reset (plugin->dbh,
+                   plugin->expire_blocks);
+  switch (n)
+  {
+  case SQLITE_DONE:
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+                     "sqlite",
+                     "Records expired\n");
+    return;
+
+  case SQLITE_BUSY:
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return;
+
+  default:
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return;
+  }
+}
+
+
+/**
+ * Cache a block in the datastore.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param block block to cache
+ * @return #GNUNET_OK on success, else #GNUNET_SYSERR
+ */
+static int
+namecache_sqlite_cache_block (void *cls,
+                              const struct GNUNET_GNSRECORD_Block *block)
+{
+  static struct GNUNET_TIME_Absolute last_expire;
+  struct Plugin *plugin = cls;
+  struct GNUNET_HashCode query;
+  struct GNUNET_TIME_Absolute expiration;
+  size_t block_size = GNUNET_GNSRECORD_block_get_size (block);
+  struct GNUNET_SQ_QueryParam del_params[] = {
+    GNUNET_SQ_query_param_auto_from_type (&query),
+    GNUNET_SQ_query_param_absolute_time (&expiration),
+    GNUNET_SQ_query_param_end
+  };
+  struct GNUNET_SQ_QueryParam ins_params[] = {
+    GNUNET_SQ_query_param_auto_from_type (&query),
+    GNUNET_SQ_query_param_fixed_size (block,
+                                      block_size),
+    GNUNET_SQ_query_param_absolute_time (&expiration),
+    GNUNET_SQ_query_param_end
+  };
+  int n;
+
+  /* run expiration of old cache entries once per hour */
+  if (GNUNET_TIME_absolute_get_duration (last_expire).rel_value_us >
+      GNUNET_TIME_UNIT_HOURS.rel_value_us)
+  {
+    last_expire = GNUNET_TIME_absolute_get ();
+    namecache_sqlite_expire_blocks (plugin);
+  }
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_GNSRECORD_query_from_block (block, &query));
+  expiration = GNUNET_GNSRECORD_block_get_expiration (block);
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Caching new version of block %s (expires %s)\n",
+              GNUNET_h2s (&query),
+              GNUNET_STRINGS_absolute_time_to_string (expiration));
+  if (block_size > 64 * 65536)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+
+  /* delete old version of the block */
+  if (GNUNET_OK !=
+      GNUNET_SQ_bind (plugin->delete_block,
+                      del_params))
+  {
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    GNUNET_SQ_reset (plugin->dbh,
+                     plugin->delete_block);
+    return GNUNET_SYSERR;
+  }
+  n = sqlite3_step (plugin->delete_block);
+  switch (n)
+  {
+  case SQLITE_DONE:
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+                     "sqlite",
+                     "Old block deleted\n");
+    break;
+
+  case SQLITE_BUSY:
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    break;
+
+  default:
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    break;
+  }
+  GNUNET_SQ_reset (plugin->dbh,
+                   plugin->delete_block);
+
+  /* insert new version of the block */
+  if (GNUNET_OK !=
+      GNUNET_SQ_bind (plugin->cache_block,
+                      ins_params))
+  {
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    GNUNET_SQ_reset (plugin->dbh,
+                     plugin->cache_block);
+    return GNUNET_SYSERR;
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Caching block under derived key `%s'\n",
+              GNUNET_h2s_full (&query));
+  n = sqlite3_step (plugin->cache_block);
+  GNUNET_SQ_reset (plugin->dbh,
+                   plugin->cache_block);
+  switch (n)
+  {
+  case SQLITE_DONE:
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Record stored\n");
+    return GNUNET_OK;
+
+  case SQLITE_BUSY:
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return GNUNET_NO;
+
+  default:
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return GNUNET_SYSERR;
+  }
+}
+
+
+/**
+ * Get the block for a particular zone and label in the
+ * datastore.  Will return at most one result to the iterator.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param query hash of public key derived from the zone and the label
+ * @param iter function to call with the result
+ * @param iter_cls closure for @a iter
+ * @return #GNUNET_OK on success, #GNUNET_NO if there were no results, #GNUNET_SYSERR on error
+ */
+static int
+namecache_sqlite_lookup_block (void *cls,
+                               const struct GNUNET_HashCode *query,
+                               GNUNET_NAMECACHE_BlockCallback iter,
+                               void *iter_cls)
+{
+  struct Plugin *plugin = cls;
+  int ret;
+  int sret;
+  size_t block_size;
+  const struct GNUNET_GNSRECORD_Block *block;
+  struct GNUNET_SQ_QueryParam params[] = {
+    GNUNET_SQ_query_param_auto_from_type (query),
+    GNUNET_SQ_query_param_end
+  };
+  struct GNUNET_SQ_ResultSpec rs[] = {
+    GNUNET_SQ_result_spec_variable_size ((void **) &block,
+                                         &block_size),
+    GNUNET_SQ_result_spec_end
+  };
+
+  if (GNUNET_OK !=
+      GNUNET_SQ_bind (plugin->lookup_block,
+                      params))
+  {
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    GNUNET_SQ_reset (plugin->dbh,
+                     plugin->lookup_block);
+    return GNUNET_SYSERR;
+  }
+  ret = GNUNET_NO;
+  if (SQLITE_ROW ==
+      (sret = sqlite3_step (plugin->lookup_block)))
+  {
+    if (GNUNET_OK !=
+        GNUNET_SQ_extract_result (plugin->lookup_block,
+                                  rs))
+    {
+      GNUNET_break (0);
+      ret = GNUNET_SYSERR;
+    }
+    else if ((block_size < sizeof(struct GNUNET_GNSRECORD_Block)))
+    {
+      GNUNET_break (0);
+      GNUNET_SQ_cleanup_result (rs);
+      ret = GNUNET_SYSERR;
+    }
+    else
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Found block under derived key `%s'\n",
+                  GNUNET_h2s_full (query));
+      iter (iter_cls,
+            block);
+      GNUNET_SQ_cleanup_result (rs);
+      ret = GNUNET_YES;
+    }
+  }
+  else
+  {
+    if (SQLITE_DONE != sret)
+    {
+      LOG_SQLITE (plugin,
+                  GNUNET_ERROR_TYPE_ERROR,
+                  "sqlite_step");
+      ret = GNUNET_SYSERR;
+    }
+    else
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "No block found under derived key `%s'\n",
+                  GNUNET_h2s_full (query));
+    }
+  }
+  GNUNET_SQ_reset (plugin->dbh,
+                   plugin->lookup_block);
+  return ret;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls the "struct GNUNET_NAMECACHE_PluginEnvironment*"
+ * @return NULL on error, otherwise the plugin context
+ */
+void *
+libgnunet_plugin_namecache_sqlite_init (void *cls)
+{
+  static struct Plugin plugin;
+  const struct GNUNET_CONFIGURATION_Handle *cfg = cls;
+  struct GNUNET_NAMECACHE_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_new (struct GNUNET_NAMECACHE_PluginFunctions);
+  api->cls = &plugin;
+  api->cache_block = &namecache_sqlite_cache_block;
+  api->lookup_block = &namecache_sqlite_lookup_block;
+  LOG (GNUNET_ERROR_TYPE_INFO,
+       _ ("Sqlite 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_namecache_sqlite_done (void *cls)
+{
+  struct GNUNET_NAMECACHE_PluginFunctions *api = cls;
+  struct Plugin *plugin = api->cls;
+
+  database_shutdown (plugin);
+  plugin->cfg = NULL;
+  GNUNET_free (api);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "sqlite plugin is finished\n");
+  return NULL;
+}
+
+
+/* end of plugin_namecache_sqlite.c */