start to fix psycstore mysql
[oweals/gnunet.git] / src / psycstore / gnunet-service-psycstore.c
index 977f77e060b651abf099b1878734338c053fd283..33e894b5ec292191c9179fe9bf571671c23bafb2 100644 (file)
@@ -1,21 +1,21 @@
-/*
-  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.
+/**
+ * This file is part of GNUnet
+ * Copyright (C) 2013 GNUnet e.V.
+ *
* 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., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
  */
 
 /**
  * @brief PSYCstore service
  * @author Gabor X Toth
  * @author Christian Grothoff
- *
- * The purpose of this service is to manage private keys that
- * represent the various egos/pseudonyms/identities of a GNUnet user.
- *
  */
+
+#include <inttypes.h>
+
 #include "platform.h"
 #include "gnunet_util_lib.h"
 #include "gnunet_constants.h"
 #include "gnunet_protocols.h"
 #include "gnunet_statistics_service.h"
+#include "gnunet_psyc_util_lib.h"
 #include "gnunet_psycstore_service.h"
+#include "gnunet_psycstore_plugin.h"
 #include "psycstore.h"
 
 
@@ -53,19 +54,23 @@ static struct GNUNET_STATISTICS_Handle *stats;
 static struct GNUNET_SERVER_NotificationContext *nc;
 
 /**
- * Database file.
+ * Database handle
  */
-static char *db_file;
+static struct GNUNET_PSYCSTORE_PluginFunctions *db;
+
+/**
+ * Name of the database plugin
+ */
+static char *db_lib_name;
 
 
 /**
  * Task run during shutdown.
  *
  * @param cls unused
- * @param tc unused
  */
 static void
-shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+shutdown_task (void *cls)
 {
   if (NULL != nc)
   {
@@ -77,80 +82,902 @@ shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
     GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
     stats = NULL;
   }
-  GNUNET_free (db_file);
-  db_file = NULL;
+  GNUNET_break (NULL == GNUNET_PLUGIN_unload (db_lib_name, db));
+  GNUNET_free (db_lib_name);
+  db_lib_name = NULL;
 }
 
 
 /**
  * Send a result code back to the client.
  *
- * @param client client that should receive the result code
- * @param result_code code to transmit
- * @param emsg error message to include (or NULL for none)
+ * @param client
+ *        Client that should receive the result code.
+ * @param result_code
+ *        Code to transmit.
+ * @param op_id
+ *        Operation ID in network byte order.
+ * @param err_msg
+ *        Error message to include (or NULL for none).
  */
 static void
-send_result_code (struct GNUNET_SERVER_Client *client,
-                 uint32_t result_code,
-                 const char *emsg)
+send_result_code (struct GNUNET_SERVER_Client *client, uint64_t op_id,
+                  int64_t result_code, const char *err_msg)
+{
+  struct OperationResult *res;
+  size_t err_size = 0;
+
+  if (NULL != err_msg)
+    err_size = strnlen (err_msg,
+                        GNUNET_SERVER_MAX_MESSAGE_SIZE - sizeof (*res) - 1) + 1;
+  res = GNUNET_malloc (sizeof (struct OperationResult) + err_size);
+  res->header.type = htons (GNUNET_MESSAGE_TYPE_PSYCSTORE_RESULT_CODE);
+  res->header.size = htons (sizeof (struct OperationResult) + err_size);
+  res->result_code = GNUNET_htonll (result_code - INT64_MIN);
+  res->op_id = op_id;
+  if (0 < err_size)
+  {
+    GNUNET_memcpy (&res[1], err_msg, err_size);
+    ((char *) &res[1])[err_size - 1] = '\0';
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Sending result to client: %" PRId64 " (%s)\n",
+             result_code, err_msg);
+  GNUNET_SERVER_notification_context_add (nc, client);
+  GNUNET_SERVER_notification_context_unicast (nc, client, &res->header,
+                                              GNUNET_NO);
+  GNUNET_free (res);
+}
+
+
+enum
+{
+  MEMBERSHIP_TEST_NOT_NEEDED = 0,
+  MEMBERSHIP_TEST_NEEDED = 1,
+  MEMBERSHIP_TEST_DONE = 2,
+} MessageMembershipTest;
+
+
+struct SendClosure
+{
+  struct GNUNET_SERVER_Client *client;
+
+  /**
+   * Channel's public key.
+   */
+  struct GNUNET_CRYPTO_EddsaPublicKey channel_key;
+
+  /**
+   * Slave's public key.
+   */
+  struct GNUNET_CRYPTO_EcdsaPublicKey slave_key;
+
+  /**
+   * Operation ID.
+   */
+  uint64_t op_id;
+
+  /**
+   * Membership test result.
+   */
+  int membership_test_result;
+
+  /**
+   * Do membership test with @a slave_key before returning fragment?
+   * @see enum MessageMembershipTest
+   */
+  uint8_t membership_test;
+};
+
+
+static int
+send_fragment (void *cls, struct GNUNET_MULTICAST_MessageHeader *msg,
+               enum GNUNET_PSYCSTORE_MessageFlags flags)
 {
-  struct GNUNET_PSYCSTORE_ResultCodeMessage *rcm;
-  size_t elen;
+  struct SendClosure *sc = cls;
+  struct FragmentResult *res;
+
+  if (MEMBERSHIP_TEST_NEEDED == sc->membership_test)
+  {
+    sc->membership_test = MEMBERSHIP_TEST_DONE;
+    sc->membership_test_result
+      = db->membership_test (db->cls, &sc->channel_key, &sc->slave_key,
+                             GNUNET_ntohll (msg->message_id));
+    switch (sc->membership_test_result)
+    {
+    case GNUNET_YES:
+      break;
+
+    case GNUNET_NO:
+    case GNUNET_SYSERR:
+      return GNUNET_NO;
+    }
+  }
+
+  size_t msg_size = ntohs (msg->header.size);
+
+  res = GNUNET_malloc (sizeof (struct FragmentResult) + msg_size);
+  res->header.type = htons (GNUNET_MESSAGE_TYPE_PSYCSTORE_RESULT_FRAGMENT);
+  res->header.size = htons (sizeof (struct FragmentResult) + msg_size);
+  res->op_id = sc->op_id;
+  res->psycstore_flags = htonl (flags);
+  GNUNET_memcpy (&res[1], msg, msg_size);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Sending fragment %ld to client\n",
+             GNUNET_ntohll (msg->fragment_id));
+  GNUNET_free (msg);
+  GNUNET_SERVER_notification_context_add (nc, sc->client);
+  GNUNET_SERVER_notification_context_unicast (nc, sc->client, &res->header,
+                                              GNUNET_NO);
+  GNUNET_free (res);
+  return GNUNET_YES;
+}
+
+
+static int
+send_state_var (void *cls, const char *name,
+                const void *value, uint32_t value_size)
+{
+  struct SendClosure *sc = cls;
+  struct StateResult *res;
+  size_t name_size = strlen (name) + 1;
+
+  /** @todo FIXME: split up value into 64k chunks */
+
+  res = GNUNET_malloc (sizeof (struct StateResult) + name_size + value_size);
+  res->header.type = htons (GNUNET_MESSAGE_TYPE_PSYCSTORE_RESULT_STATE);
+  res->header.size = htons (sizeof (struct StateResult) + name_size + value_size);
+  res->op_id = sc->op_id;
+  res->name_size = htons (name_size);
+  GNUNET_memcpy (&res[1], name, name_size);
+  GNUNET_memcpy ((char *) &res[1] + name_size, value, value_size);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Sending state variable %s to client\n", name);
+  GNUNET_SERVER_notification_context_add (nc, sc->client);
+  GNUNET_SERVER_notification_context_unicast (nc, sc->client, &res->header,
+                                              GNUNET_NO);
+  GNUNET_free (res);
+  return GNUNET_OK;
+}
+
+
+static void
+handle_membership_store (void *cls,
+                         struct GNUNET_SERVER_Client *client,
+                         const struct GNUNET_MessageHeader *msg)
+{
+  const struct MembershipStoreRequest *req =
+    (const struct MembershipStoreRequest *) msg;
+
+  int ret = db->membership_store (db->cls, &req->channel_key, &req->slave_key,
+                                  req->did_join,
+                                  GNUNET_ntohll (req->announced_at),
+                                  GNUNET_ntohll (req->effective_since),
+                                  GNUNET_ntohll (req->group_generation));
+
+  if (ret != GNUNET_OK)
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to store membership information!\n"));
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_membership_test (void *cls,
+                        struct GNUNET_SERVER_Client *client,
+                        const struct GNUNET_MessageHeader *msg)
+{
+  const struct MembershipTestRequest *req =
+    (const struct MembershipTestRequest *) msg;
+
+  int ret = db->membership_test (db->cls, &req->channel_key, &req->slave_key,
+                                 GNUNET_ntohll (req->message_id));
+  switch (ret)
+  {
+  case GNUNET_YES:
+  case GNUNET_NO:
+    break;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to test membership!\n"));
+  }
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
 
-  if (NULL == emsg)
-    elen = 0;
+static void
+handle_fragment_store (void *cls,
+                       struct GNUNET_SERVER_Client *client,
+                       const struct GNUNET_MessageHeader *msg)
+{
+  const struct FragmentStoreRequest *req =
+    (const struct FragmentStoreRequest *) msg;
+
+  int ret = db->fragment_store (db->cls, &req->channel_key,
+                                (const struct GNUNET_MULTICAST_MessageHeader *)
+                                &req[1], ntohl (req->psycstore_flags));
+
+  if (ret != GNUNET_OK)
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to store fragment!\n"));
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_fragment_get (void *cls,
+                     struct GNUNET_SERVER_Client *client,
+                     const struct GNUNET_MessageHeader *msg)
+{
+  const struct FragmentGetRequest *
+    req = (const struct FragmentGetRequest *) msg;
+  struct SendClosure
+    sc = { .op_id = req->op_id,
+           .client = client,
+           .channel_key = req->channel_key,
+           .slave_key = req->slave_key,
+           .membership_test = req->do_membership_test };
+
+  int64_t ret;
+  uint64_t ret_frags = 0;
+  uint64_t first_fragment_id = GNUNET_ntohll (req->first_fragment_id);
+  uint64_t last_fragment_id = GNUNET_ntohll (req->last_fragment_id);
+  uint64_t limit = GNUNET_ntohll (req->fragment_limit);
+
+  if (0 == limit)
+    ret = db->fragment_get (db->cls, &req->channel_key,
+                            first_fragment_id, last_fragment_id,
+                            &ret_frags, send_fragment, &sc);
   else
-    elen = strlen (emsg) + 1;
-  rcm = GNUNET_malloc (sizeof (struct GNUNET_PSYCSTORE_ResultCodeMessage) + elen);
-  rcm->header.type = htons (GNUNET_MESSAGE_TYPE_PSYCSTORE_RESULT_CODE);
-  rcm->header.size = htons (sizeof (struct GNUNET_PSYCSTORE_ResultCodeMessage) + elen);
-  rcm->result_code = htonl (result_code);
-  memcpy (&rcm[1], emsg, elen);
+    ret = db->fragment_get_latest (db->cls, &req->channel_key, limit,
+                                   &ret_frags, send_fragment, &sc);
+
+  switch (ret)
+  {
+  case GNUNET_YES:
+  case GNUNET_NO:
+    if (MEMBERSHIP_TEST_DONE == sc.membership_test)
+    {
+      switch (sc.membership_test_result)
+      {
+      case GNUNET_YES:
+        break;
+
+      case GNUNET_NO:
+        ret = GNUNET_PSYCSTORE_MEMBERSHIP_TEST_FAILED;
+        break;
+
+      case GNUNET_SYSERR:
+        ret = GNUNET_SYSERR;
+        break;
+      }
+    }
+    break;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to get fragment!\n"));
+  }
+  send_result_code (client, req->op_id, (ret < 0) ? ret : ret_frags, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_message_get (void *cls,
+                    struct GNUNET_SERVER_Client *client,
+                    const struct GNUNET_MessageHeader *msg)
+{
+  const struct MessageGetRequest *
+    req = (const struct MessageGetRequest *) msg;
+  uint16_t size = ntohs (msg->size);
+  const char *method_prefix = (const char *) &req[1];
+
+  if (size < sizeof (*req) + 1
+      || '\0' != method_prefix[size - sizeof (*req) - 1])
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Message get: invalid method prefix. size: %u < %u?\n",
+                size,
+                (unsigned int) (sizeof (*req) + 1));
+    GNUNET_break (0);
+    GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
+    return;
+  }
+
+  struct SendClosure
+    sc = { .op_id = req->op_id,
+           .client = client,
+           .channel_key = req->channel_key,
+           .slave_key = req->slave_key,
+           .membership_test = req->do_membership_test };
+
+  int64_t ret;
+  uint64_t ret_frags = 0;
+  uint64_t first_message_id = GNUNET_ntohll (req->first_message_id);
+  uint64_t last_message_id = GNUNET_ntohll (req->last_message_id);
+  uint64_t msg_limit = GNUNET_ntohll (req->message_limit);
+  uint64_t frag_limit = GNUNET_ntohll (req->fragment_limit);
+
+  /** @todo method_prefix */
+  if (0 == msg_limit)
+    ret = db->message_get (db->cls, &req->channel_key,
+                           first_message_id, last_message_id, frag_limit,
+                           &ret_frags, send_fragment, &sc);
+  else
+    ret = db->message_get_latest (db->cls, &req->channel_key, msg_limit,
+                                  &ret_frags, send_fragment, &sc);
+
+  switch (ret)
+  {
+  case GNUNET_YES:
+  case GNUNET_NO:
+    break;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to get message!\n"));
+  }
+
+  send_result_code (client, req->op_id, (ret < 0) ? ret : ret_frags, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_message_get_fragment (void *cls,
+                             struct GNUNET_SERVER_Client *client,
+                             const struct GNUNET_MessageHeader *msg)
+{
+  const struct MessageGetFragmentRequest *
+    req = (const struct MessageGetFragmentRequest *) msg;
+  struct SendClosure
+    sc = { .op_id = req->op_id, .client = client,
+           .channel_key = req->channel_key, .slave_key = req->slave_key,
+           .membership_test = req->do_membership_test };
+
+  int ret = db->message_get_fragment (db->cls, &req->channel_key,
+                                      GNUNET_ntohll (req->message_id),
+                                      GNUNET_ntohll (req->fragment_offset),
+                                      &send_fragment, &sc);
+  switch (ret)
+  {
+  case GNUNET_YES:
+  case GNUNET_NO:
+    break;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to get message fragment!\n"));
+  }
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_counters_get (void *cls,
+                     struct GNUNET_SERVER_Client *client,
+                     const struct GNUNET_MessageHeader *msg)
+{
+  const struct OperationRequest *req = (const struct OperationRequest *) msg;
+  struct CountersResult res = { {0} };
+
+  int ret = db->counters_message_get (db->cls, &req->channel_key,
+                                      &res.max_fragment_id, &res.max_message_id,
+                                      &res.max_group_generation);
+  switch (ret)
+  {
+  case GNUNET_OK:
+    ret = db->counters_state_get (db->cls, &req->channel_key,
+                                  &res.max_state_message_id);
+  case GNUNET_NO:
+    break;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to get master counters!\n"));
+  }
+
+  res.header.type = htons (GNUNET_MESSAGE_TYPE_PSYCSTORE_RESULT_COUNTERS);
+  res.header.size = htons (sizeof (res));
+  res.result_code = htonl (ret);
+  res.op_id = req->op_id;
+  res.max_fragment_id = GNUNET_htonll (res.max_fragment_id);
+  res.max_message_id = GNUNET_htonll (res.max_message_id);
+  res.max_group_generation = GNUNET_htonll (res.max_group_generation);
+  res.max_state_message_id = GNUNET_htonll (res.max_state_message_id);
+
+  GNUNET_SERVER_notification_context_add (nc, client);
+  GNUNET_SERVER_notification_context_unicast (nc, client, &res.header,
+                                              GNUNET_NO);
+
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+struct StateModifyClosure
+{
+  const struct GNUNET_CRYPTO_EddsaPublicKey channel_key;
+  struct GNUNET_PSYC_ReceiveHandle *recv;
+  enum GNUNET_PSYC_MessageState msg_state;
+  char mod_oper;
+  char *mod_name;
+  char *mod_value;
+  uint32_t mod_value_size;
+  uint32_t mod_value_remaining;
+};
+
+
+static void
+recv_state_message_part (void *cls,
+                         const struct GNUNET_PSYC_MessageHeader *msg,
+                         const struct GNUNET_MessageHeader *pmsg)
+{
+  struct StateModifyClosure *scls = cls;
+  uint16_t psize;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "recv_state_message_part()  message_id: %" PRIu64
+              ", fragment_offset: %" PRIu64 ", flags: %u\n",
+              GNUNET_ntohll (msg->message_id),
+              GNUNET_ntohll (msg->fragment_offset),
+              ntohl (msg->flags));
+
+  if (NULL == pmsg)
+  {
+    scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_ERROR;
+    return;
+  }
+
+  switch (ntohs (pmsg->type))
+  {
+  case GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_METHOD:
+  {
+    scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_METHOD;
+    break;
+  }
+
+  case GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MODIFIER:
+  {
+    struct GNUNET_PSYC_MessageModifier *
+      pmod = (struct GNUNET_PSYC_MessageModifier *) pmsg;
+    psize = ntohs (pmod->header.size);
+    uint16_t name_size = ntohs (pmod->name_size);
+    uint32_t value_size = ntohl (pmod->value_size);
+
+    const char *name = (const char *) &pmod[1];
+    const void *value = name + name_size;
+
+    if (GNUNET_PSYC_OP_SET != pmod->oper)
+    { // Apply non-transient operation.
+      if (psize == sizeof (*pmod) + name_size + value_size)
+      {
+        db->state_modify_op (db->cls, &scls->channel_key,
+                             pmod->oper, name, value, value_size);
+      }
+      else
+      {
+        scls->mod_oper = pmod->oper;
+        scls->mod_name = GNUNET_malloc (name_size);
+        GNUNET_memcpy (scls->mod_name, name, name_size);
+
+        scls->mod_value_size = value_size;
+        scls->mod_value = GNUNET_malloc (scls->mod_value_size);
+        scls->mod_value_remaining
+          = scls->mod_value_size - (psize - sizeof (*pmod) - name_size);
+        GNUNET_memcpy (scls->mod_value, value, value_size - scls->mod_value_remaining);
+      }
+    }
+    scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_MODIFIER;
+    break;
+  }
+
+  case GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_MOD_CONT:
+    if (GNUNET_PSYC_OP_SET != scls->mod_oper)
+    {
+      if (scls->mod_value_remaining == 0)
+      {
+        GNUNET_break_op (0);
+        scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_ERROR;
+      }
+      psize = ntohs (pmsg->size);
+      GNUNET_memcpy (scls->mod_value + (scls->mod_value_size - scls->mod_value_remaining),
+              &pmsg[1], psize - sizeof (*pmsg));
+      scls->mod_value_remaining -= psize - sizeof (*pmsg);
+      if (0 == scls->mod_value_remaining)
+      {
+        db->state_modify_op (db->cls, &scls->channel_key,
+                             scls->mod_oper, scls->mod_name,
+                             scls->mod_value, scls->mod_value_size);
+        GNUNET_free (scls->mod_name);
+        GNUNET_free (scls->mod_value);
+        scls->mod_oper = 0;
+        scls->mod_name = NULL;
+        scls->mod_value = NULL;
+        scls->mod_value_size = 0;
+      }
+    }
+    scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_MOD_CONT;
+    break;
+
+  case GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_DATA:
+    scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_DATA;
+    break;
+
+  case GNUNET_MESSAGE_TYPE_PSYC_MESSAGE_END:
+    scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_END;
+    break;
+
+  default:
+    scls->msg_state = GNUNET_PSYC_MESSAGE_STATE_ERROR;
+  }
+}
+
+
+static int
+recv_state_fragment (void *cls, struct GNUNET_MULTICAST_MessageHeader *msg,
+                     enum GNUNET_PSYCSTORE_MessageFlags flags)
+{
+  struct StateModifyClosure *scls = cls;
+
+  if (NULL == scls->recv)
+  {
+    scls->recv = GNUNET_PSYC_receive_create (NULL, recv_state_message_part,
+                                             scls);
+  }
+
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Sending result %d (%s) to client\n",
-             (int) result_code,
-             emsg);
-  GNUNET_SERVER_notification_context_unicast (nc, client, &rcm->header, GNUNET_NO);
-  GNUNET_free (rcm);
+              "recv_state_fragment: %" PRIu64 "\n", GNUNET_ntohll (msg->fragment_id));
+
+  struct GNUNET_PSYC_MessageHeader *
+    pmsg = GNUNET_PSYC_message_header_create (msg, flags);
+  GNUNET_PSYC_receive_message (scls->recv, pmsg);
+  GNUNET_free (pmsg);
+
+  return GNUNET_YES;
+}
+
+
+static void
+handle_state_modify (void *cls,
+                     struct GNUNET_SERVER_Client *client,
+                     const struct GNUNET_MessageHeader *msg)
+{
+  const struct StateModifyRequest *req
+    = (const struct StateModifyRequest *) msg;
+
+  uint64_t message_id = GNUNET_ntohll (req->message_id);
+  uint64_t state_delta = GNUNET_ntohll (req->state_delta);
+  uint64_t ret_frags = 0;
+  struct StateModifyClosure
+    scls = { .channel_key = req->channel_key };
+
+  int ret = db->state_modify_begin (db->cls, &req->channel_key,
+                                    message_id, state_delta);
+
+  if (GNUNET_OK != ret)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                _("Failed to begin modifying state: %d\n"), ret);
+  }
+  else
+  {
+    ret = db->message_get (db->cls, &req->channel_key,
+                           message_id, message_id, 0,
+                           &ret_frags, recv_state_fragment, &scls);
+    if (GNUNET_OK != ret)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Failed to modify state: %d\n"), ret);
+      GNUNET_break (0);
+    }
+    else
+    {
+      if (GNUNET_OK != db->state_modify_end (db->cls, &req->channel_key, message_id))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                    _("Failed to end modifying state!\n"));
+        GNUNET_break (0);
+      }
+    }
+    if (NULL != scls.recv)
+    {
+      GNUNET_PSYC_receive_destroy (scls.recv);
+    }
+  }
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+/** @todo FIXME: stop processing further state sync messages after an error */
+static void
+handle_state_sync (void *cls,
+                   struct GNUNET_SERVER_Client *client,
+                   const struct GNUNET_MessageHeader *msg)
+{
+  const struct StateSyncRequest *req
+    = (const struct StateSyncRequest *) msg;
+
+  int ret = GNUNET_SYSERR;
+  const char *name = (const char *) &req[1];
+  uint16_t name_size = ntohs (req->name_size);
+
+  if (name_size <= 2 || '\0' != name[name_size - 1])
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Tried to set invalid state variable name!\n"));
+    GNUNET_break_op (0);
+  }
+  else
+  {
+    ret = GNUNET_OK;
+
+    if (req->flags & STATE_OP_FIRST)
+    {
+      ret = db->state_sync_begin (db->cls, &req->channel_key);
+    }
+    if (ret != GNUNET_OK)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  _("Failed to begin synchronizing state!\n"));
+    }
+    else
+    {
+      ret = db->state_sync_assign (db->cls, &req->channel_key, name,
+                                   name + ntohs (req->name_size),
+                                   ntohs (req->header.size) - sizeof (*req)
+                                   - ntohs (req->name_size));
+    }
+
+    if (GNUNET_OK == ret && req->flags & STATE_OP_LAST)
+    {
+      ret = db->state_sync_end (db->cls, &req->channel_key,
+                                GNUNET_ntohll (req->max_state_message_id),
+                                GNUNET_ntohll (req->state_hash_message_id));
+      if (ret != GNUNET_OK)
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                    _("Failed to end synchronizing state!\n"));
+    }
+  }
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_state_reset (void *cls,
+                    struct GNUNET_SERVER_Client *client,
+                    const struct GNUNET_MessageHeader *msg)
+{
+  const struct OperationRequest *req =
+    (const struct OperationRequest *) msg;
+
+  int ret = db->state_reset (db->cls, &req->channel_key);
+
+  if (ret != GNUNET_OK)
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to reset state!\n"));
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_state_hash_update (void *cls,
+                          struct GNUNET_SERVER_Client *client,
+                          const struct GNUNET_MessageHeader *msg)
+{
+  const struct OperationRequest *req =
+    (const struct OperationRequest *) msg;
+
+  int ret = db->state_reset (db->cls, &req->channel_key);
+
+  if (ret != GNUNET_OK)
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to reset state!\n"));
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_state_get (void *cls,
+                  struct GNUNET_SERVER_Client *client,
+                  const struct GNUNET_MessageHeader *msg)
+{
+  const struct OperationRequest *req =
+    (const struct OperationRequest *) msg;
+
+  struct SendClosure sc = { .op_id = req->op_id, .client = client };
+  int64_t ret = GNUNET_SYSERR;
+  const char *name = (const char *) &req[1];
+  uint16_t name_size = ntohs (req->header.size) - sizeof (*req);
+
+  if (name_size <= 2 || '\0' != name[name_size - 1])
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Tried to get invalid state variable name!\n"));
+    GNUNET_break (0);
+  }
+  else
+  {
+    ret = db->state_get (db->cls, &req->channel_key, name,
+                         &send_state_var, &sc);
+    if (GNUNET_NO == ret && name_size >= 5) /* min: _a_b\0 */
+    {
+      char *p, *n = GNUNET_malloc (name_size);
+      GNUNET_memcpy (n, name, name_size);
+      while (&n[1] < (p = strrchr (n, '_')) && GNUNET_NO == ret)
+      {
+        *p = '\0';
+        ret = db->state_get (db->cls, &req->channel_key, n,
+                             &send_state_var, &sc);
+      }
+      GNUNET_free (n);
+    }
+  }
+  switch (ret)
+  {
+  case GNUNET_OK:
+  case GNUNET_NO:
+    break;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to get state variable!\n"));
+  }
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
+}
+
+
+static void
+handle_state_get_prefix (void *cls,
+                         struct GNUNET_SERVER_Client *client,
+                         const struct GNUNET_MessageHeader *msg)
+{
+  const struct OperationRequest *req =
+    (const struct OperationRequest *) msg;
+
+  struct SendClosure sc = { .op_id = req->op_id, .client = client };
+  int64_t ret = GNUNET_SYSERR;
+  const char *name = (const char *) &req[1];
+  uint16_t name_size = ntohs (req->header.size) - sizeof (*req);
+
+  if (name_size <= 1 || '\0' != name[name_size - 1])
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Tried to get invalid state variable name!\n"));
+    GNUNET_break (0);
+  }
+  else
+  {
+    ret = db->state_get_prefix (db->cls, &req->channel_key, name,
+                                &send_state_var, &sc);
+  }
+  switch (ret)
+  {
+  case GNUNET_OK:
+  case GNUNET_NO:
+    break;
+  default:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _("Failed to get state variable!\n"));
+  }
+
+  send_result_code (client, req->op_id, ret, NULL);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
 }
 
 
 /**
- * Handle PSYCstore clients.
+ * Initialize the PSYCstore service.
  *
- * @param cls closure
- * @param server the initialized server
- * @param c configuration to use
+ * @param cls Closure.
+ * @param server The initialized server.
+ * @param c Configuration to use.
  */
 static void
-run (void *cls, 
-     struct GNUNET_SERVER_Handle *server,
+run (void *cls, struct GNUNET_SERVER_Handle *server,
      const struct GNUNET_CONFIGURATION_Handle *c)
 {
   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
-    {NULL, NULL, 0, 0}
+    { &handle_membership_store, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_MEMBERSHIP_STORE,
+      sizeof (struct MembershipStoreRequest) },
+
+    { &handle_membership_test, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_MEMBERSHIP_TEST,
+      sizeof (struct MembershipTestRequest) },
+
+    { &handle_fragment_store, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_FRAGMENT_STORE, 0, },
+
+    { &handle_fragment_get, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_FRAGMENT_GET,
+      sizeof (struct FragmentGetRequest) },
+
+    { &handle_message_get, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_MESSAGE_GET, 0 },
+
+    { &handle_message_get_fragment, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_MESSAGE_GET_FRAGMENT,
+      sizeof (struct MessageGetFragmentRequest) },
+
+    { &handle_counters_get, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_COUNTERS_GET,
+      sizeof (struct OperationRequest) },
+
+    { &handle_state_modify, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_STATE_MODIFY, 0 },
+
+    { &handle_state_sync, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_STATE_SYNC, 0 },
+
+    { &handle_state_reset, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_STATE_RESET,
+      sizeof (struct OperationRequest) },
+
+    { &handle_state_hash_update, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_STATE_HASH_UPDATE,
+      sizeof (struct StateHashUpdateRequest) },
+
+    { &handle_state_get, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_STATE_GET, 0 },
+
+    { &handle_state_get_prefix, NULL,
+      GNUNET_MESSAGE_TYPE_PSYCSTORE_STATE_GET_PREFIX, 0 },
+
+    { NULL, NULL, 0, 0 }
   };
 
   cfg = c;
+
+  /* Loading database plugin */
+  char *database;
   if (GNUNET_OK !=
-      GNUNET_CONFIGURATION_get_value_filename (cfg, "psycstore",
-                                              "DB_FILE",
-                                              &db_file))
+      GNUNET_CONFIGURATION_get_value_string (cfg, "psycstore", "database",
+                                             &database))
+  {
+    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
+                              "psycstore",
+                              "database");
+  }
+  else
   {
-    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "psycstore", "DB_FILE");
-    GNUNET_SCHEDULER_shutdown ();
+    GNUNET_asprintf (&db_lib_name,
+                    "libgnunet_plugin_psycstore_%s",
+                    database);
+    db = GNUNET_PLUGIN_load (db_lib_name, (void *) cfg);
+    GNUNET_free (database);
+  }
+  if (NULL == db)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+               "Could not load database backend `%s'\n",
+               db_lib_name);
+    GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
     return;
   }
+
   stats = GNUNET_STATISTICS_create ("psycstore", cfg);
   GNUNET_SERVER_add_handlers (server, handlers);
   nc = GNUNET_SERVER_notification_context_create (server, 1);
-  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task,
-                                NULL);
+  GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
+                                NULL);
 }
 
 
 /**
- * The main function for the network size estimation service.
+ * The main function for the service.
  *
  * @param argc number of arguments from the command line
  * @param argv command line arguments
@@ -160,7 +987,7 @@ int
 main (int argc, char *const *argv)
 {
   return (GNUNET_OK ==
-          GNUNET_SERVICE_run (argc, argv, "psycstore", 
+          GNUNET_SERVICE_run (argc, argv, "psycstore",
                              GNUNET_SERVICE_OPTION_NONE,
                               &run, NULL)) ? 0 : 1;
 }