1 files changed, 594 insertions, 231 deletions

diff --git a/src/namestore/gnunet-service-namestore.c b/src/namestore/gnunet-service-namestore.c
index f47c8776b..2d6020552 100644
--- a/src/namestore/gnunet-service-namestore.c
+++ b/src/namestore/gnunet-service-namestore.c
@@ -1,21 +1,19 @@
 /*
      This file is part of GNUnet.
-     Copyright (C) 2012, 2013, 2014 GNUnet e.V.
+     Copyright (C) 2012, 2013, 2014, 2018 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 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
-     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.
+     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/>.
 */
 
 /**
@@ -23,6 +21,9 @@
  * @brief namestore for the GNUnet naming system
  * @author Matthias Wachs
  * @author Christian Grothoff
+ *
+ * TODO:
+ * - run testcases, make sure everything works!
  */
 #include "platform.h"
 #include "gnunet_util_lib.h"
@@ -37,6 +38,11 @@
 
 #define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename)
 
+/**
+ * If a monitor takes more than 1 minute to process an event, print a warning.
+ */
+#define MONITOR_STALL_WARN_DELAY GNUNET_TIME_UNIT_MINUTES
+
 
 /**
  * A namestore client
@@ -161,6 +167,16 @@ struct ZoneMonitor
   struct GNUNET_SCHEDULER_Task *task;
 
   /**
+   * Task to warn about slow monitors.
+   */
+  struct GNUNET_SCHEDULER_Task *sa_wait_warning;
+
+  /**
+   * Since when are we blocked on this monitor?
+   */
+  struct GNUNET_TIME_Absolute sa_waiting_start;
+
+  /**
    * Last sequence number in the zone iteration used to address next
    * result of the zone iteration in the store
    *
@@ -175,6 +191,27 @@ struct ZoneMonitor
    */
   uint64_t limit;
 
+  /**
+   * How many more requests may we receive from the iterator
+   * before it is at the limit we gave it?  Will be below or
+   * equal to @e limit.  The effective limit for monitor
+   * events is thus @e iteration_cnt - @e limit!
+   */
+  uint64_t iteration_cnt;
+
+  /**
+   * Are we (still) in the initial iteration pass?
+   */
+  int in_first_iteration;
+
+  /**
+   * Is there a store activity waiting for this monitor?  We only raise the
+   * flag when it happens and search the DLL for the store activity when we
+   * had a limit increase.  If we cannot find any waiting store activity at
+   * that time, we clear the flag again.
+   */
+  int sa_waiting;
+
 };
 
 
@@ -212,6 +249,46 @@ struct CacheOperation
 
 
 /**
+ * Information for an ongoing #handle_record_store() operation.
+ * Needed as we may wait for monitors to be ready for the notification.
+ */
+struct StoreActivity
+{
+  /**
+   * Kept in a DLL.
+   */
+  struct StoreActivity *next;
+
+  /**
+   * Kept in a DLL.
+   */
+  struct StoreActivity *prev;
+
+  /**
+   * Which client triggered the store activity?
+   */
+  struct NamestoreClient *nc;
+
+  /**
+   * Copy of the original store message (as data fields in @e rd will
+   * point into it!).
+   */
+  const struct RecordStoreMessage *rsm;
+
+  /**
+   * Next zone monitor that still needs to be notified about this PUT.
+   */
+  struct ZoneMonitor *zm_pos;
+
+  /**
+   * Label nicely canonicalized (lower case).
+   */
+  char *conv_name;
+
+};
+
+
+/**
  * Public key of all zeros.
  */
 static const struct GNUNET_CRYPTO_EcdsaPrivateKey zero;
@@ -262,6 +339,16 @@ static struct ZoneMonitor *monitor_head;
 static struct ZoneMonitor *monitor_tail;
 
 /**
+ * Head of DLL of monitor-blocked store activities.
+ */
+static struct StoreActivity *sa_head;
+
+/**
+ * Tail of DLL of monitor-blocked store activities.
+ */
+static struct StoreActivity *sa_tail;
+
+/**
  * Notification context shared by all monitors.
  */
 static struct GNUNET_NotificationContext *monitor_nc;
@@ -326,80 +413,18 @@ cleanup_task (void *cls)
 
 
 /**
- * Called whenever a client is disconnected.
- * Frees our resources associated with that client.
+ * Release memory used by @a sa.
  *
- * @param cls closure
- * @param client identification of the client
- * @param app_ctx the `struct NamestoreClient` of @a client
+ * @param sa activity to free
  */
 static void
-client_disconnect_cb (void *cls,
-                      struct GNUNET_SERVICE_Client *client,
-                      void *app_ctx)
-{
-  struct NamestoreClient *nc = app_ctx;
-  struct ZoneIteration *no;
-  struct ZoneMonitor *zm;
-  struct CacheOperation *cop;
-
-  (void) cls;
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Client %p disconnected\n",
-              client);
-  for (zm = monitor_head; NULL != zm; zm = zm->next)
-  {
-    if (nc == zm->nc)
-    {
-      GNUNET_CONTAINER_DLL_remove (monitor_head,
-                                   monitor_tail,
-                                   zm);
-      if (NULL != zm->task)
-      {
-        GNUNET_SCHEDULER_cancel (zm->task);
-        zm->task = NULL;
-      }
-      GNUNET_free (zm);
-      break;
-    }
-  }
-  while (NULL != (no = nc->op_head))
-  {
-    GNUNET_CONTAINER_DLL_remove (nc->op_head,
-                                 nc->op_tail,
-                                 no);
-    GNUNET_free (no);
-  }
-  for (cop = cop_head; NULL != cop; cop = cop->next)
-    if (nc == cop->nc)
-      cop->nc = NULL;
-  GNUNET_free (nc);
-}
-
-
-/**
- * Add a client to our list of active clients.
- *
- * @param cls NULL
- * @param client client to add
- * @param mq message queue for @a client
- * @return internal namestore client structure for this client
- */
-static void *
-client_connect_cb (void *cls,
-                   struct GNUNET_SERVICE_Client *client,
-                   struct GNUNET_MQ_Handle *mq)
+free_store_activity (struct StoreActivity *sa)
 {
-  struct NamestoreClient *nc;
-
-  (void) cls;
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Client %p connected\n",
-              client);
-  nc = GNUNET_new (struct NamestoreClient);
-  nc->client = client;
-  nc->mq = mq;
-  return nc;
+  GNUNET_CONTAINER_DLL_remove (sa_head,
+                               sa_tail,
+                               sa);
+  GNUNET_free (sa->conv_name);
+  GNUNET_free (sa);
 }
 
 
@@ -509,51 +534,63 @@ merge_with_nick_records (const struct GNUNET_GNSRECORD_Data *nick_rd,
   uint64_t latest_expiration;
   size_t req;
   char *data;
-  int record_offset;
   size_t data_offset;
+  struct GNUNET_GNSRECORD_Data *target;
 
   (*rdc_res) = 1 + rd2_length;
   if (0 == 1 + rd2_length)
   {
+    GNUNET_break (0);
     (*rd_res) = NULL;
     return;
   }
-  req = 0;
-  for (unsigned int c=0; c< 1; c++)
-    req += sizeof (struct GNUNET_GNSRECORD_Data) + nick_rd[c].data_size;
-  for (unsigned int c=0; c< rd2_length; c++)
-    req += sizeof (struct GNUNET_GNSRECORD_Data) + rd2[c].data_size;
-  (*rd_res) = GNUNET_malloc (req);
-  data = (char *) &(*rd_res)[1 + rd2_length];
+  req = sizeof (struct GNUNET_GNSRECORD_Data) + nick_rd->data_size;
+  for (unsigned int i=0; i<rd2_length; i++)
+  {
+    const struct GNUNET_GNSRECORD_Data *orig = &rd2[i];
+
+    if (req + sizeof (struct GNUNET_GNSRECORD_Data) + orig->data_size < req)
+    {
+      GNUNET_break (0);
+      (*rd_res) = NULL;
+      return;
+    }
+    req += sizeof (struct GNUNET_GNSRECORD_Data) + orig->data_size;
+  }
+  target = GNUNET_malloc (req);
+  (*rd_res) = target;
+  data = (char *) &target[1 + rd2_length];
   data_offset = 0;
   latest_expiration = 0;
-  for (unsigned int c=0; c< rd2_length; c++)
+  for (unsigned int i=0;i<rd2_length;i++)
   {
-    if (0 != (rd2[c].flags & GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION))
+    const struct GNUNET_GNSRECORD_Data *orig = &rd2[i];
+
+    if (0 != (orig->flags & GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION))
     {
-      if ((GNUNET_TIME_absolute_get().abs_value_us + rd2[c].expiration_time) >
-        latest_expiration)
-          latest_expiration = rd2[c].expiration_time;
+      if ((GNUNET_TIME_absolute_get().abs_value_us + orig->expiration_time) >
+          latest_expiration)
+        latest_expiration = orig->expiration_time;
     }
-    else if (rd2[c].expiration_time > latest_expiration)
-      latest_expiration = rd2[c].expiration_time;
-    (*rd_res)[c] = rd2[c];
-    (*rd_res)[c].data = (void *) &data[data_offset];
-    GNUNET_memcpy ((void *) (*rd_res)[c].data,
-                   rd2[c].data,
-                   rd2[c].data_size);
-    data_offset += (*rd_res)[c].data_size;
+    else if (orig->expiration_time > latest_expiration)
+      latest_expiration = orig->expiration_time;
+    target[i] = *orig;
+    target[i].data = (void *) &data[data_offset];
+    GNUNET_memcpy (&data[data_offset],
+                   orig->data,
+                   orig->data_size);
+    data_offset += orig->data_size;
   }
   /* append nick */
-  record_offset = rd2_length;
-  (*rd_res)[record_offset] = *nick_rd;
-  (*rd_res)[record_offset].expiration_time = latest_expiration;
-  (*rd_res)[record_offset].data = (void *) &data[data_offset];
-  GNUNET_memcpy ((void *) (*rd_res)[record_offset].data,
+  target[rd2_length] = *nick_rd;
+  target[rd2_length].expiration_time = latest_expiration;
+  target[rd2_length].data = (void *) &data[data_offset];
+  GNUNET_memcpy (&data[data_offset],
                  nick_rd->data,
                  nick_rd->data_size);
-  data_offset += (*rd_res)[record_offset].data_size;
-  GNUNET_assert (req == (sizeof (struct GNUNET_GNSRECORD_Data)) * (*rdc_res) + data_offset);
+  data_offset += nick_rd->data_size;
+  GNUNET_assert (req ==
+                 (sizeof (struct GNUNET_GNSRECORD_Data)) * (*rdc_res) + data_offset);
 }
 
 
@@ -582,11 +619,16 @@ send_lookup_response (struct NamestoreClient *nc,
   struct GNUNET_GNSRECORD_Data *res;
   unsigned int res_count;
   size_t name_len;
-  size_t rd_ser_len;
+  ssize_t rd_ser_len;
   char *name_tmp;
   char *rd_ser;
 
   nick = get_nick_record (zone_key);
+
+  GNUNET_assert (-1 !=
+                 GNUNET_GNSRECORD_records_get_size (rd_count,
+                                                    rd));
+
   if ( (NULL != nick) &&
        (0 != strcmp (name,
                      GNUNET_GNS_EMPTY_LABEL_AT)))
@@ -605,25 +647,44 @@ send_lookup_response (struct NamestoreClient *nc,
     res = (struct GNUNET_GNSRECORD_Data *) rd;
   }
 
+  GNUNET_assert (-1 !=
+                 GNUNET_GNSRECORD_records_get_size (res_count,
+                                                    res));
+
+
   name_len = strlen (name) + 1;
-  rd_ser_len = GNUNET_GNSRECORD_records_get_size (res_count, res);
+  rd_ser_len = GNUNET_GNSRECORD_records_get_size (res_count,
+                                                  res);
+  if (rd_ser_len < 0)
+  {
+    GNUNET_break (0);
+    GNUNET_SERVICE_client_drop (nc->client);
+    return;
+  }
+  if (rd_ser_len >= UINT16_MAX - name_len - sizeof (*zir_msg))
+  {
+    GNUNET_break (0);
+    GNUNET_SERVICE_client_drop (nc->client);
+    return;
+  }
   env = GNUNET_MQ_msg_extra (zir_msg,
                              name_len + rd_ser_len,
                              GNUNET_MESSAGE_TYPE_NAMESTORE_RECORD_RESULT);
   zir_msg->gns_header.r_id = htonl (request_id);
   zir_msg->name_len = htons (name_len);
   zir_msg->rd_count = htons (res_count);
-  zir_msg->rd_len = htons (rd_ser_len);
+  zir_msg->rd_len = htons ((uint16_t) rd_ser_len);
   zir_msg->private_key = *zone_key;
   name_tmp = (char *) &zir_msg[1];
   GNUNET_memcpy (name_tmp,
                  name,
                  name_len);
   rd_ser = &name_tmp[name_len];
-  GNUNET_GNSRECORD_records_serialize (res_count,
-                                      res,
-                                      rd_ser_len,
-                                      rd_ser);
+  GNUNET_assert (rd_ser_len ==
+                 GNUNET_GNSRECORD_records_serialize (res_count,
+                                                     res,
+                                                     rd_ser_len,
+                                                     rd_ser));
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Sending RECORD_RESULT message with %u records\n",
               res_count);
@@ -655,6 +716,10 @@ send_store_response (struct NamestoreClient *nc,
 
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Sending RECORD_STORE_RESPONSE message\n");
+  GNUNET_STATISTICS_update (statistics,
+                            "Store requests completed",
+                            1,
+                            GNUNET_NO);
   env = GNUNET_MQ_msg (rcr_msg,
                        GNUNET_MESSAGE_TYPE_NAMESTORE_RECORD_STORE_RESPONSE);
   rcr_msg->gns_header.r_id = htonl (rid);
@@ -795,6 +860,206 @@ refresh_block (struct NamestoreClient *nc,
 
 
 /**
+ * Print a warning that one of our monitors is no longer reacting.
+ *
+ * @param cls a `struct ZoneMonitor` to warn about
+ */
+static void
+warn_monitor_slow (void *cls)
+{
+  struct ZoneMonitor *zm = cls;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+              "No response from monitor since %s\n",
+              GNUNET_STRINGS_absolute_time_to_string (zm->sa_waiting_start));
+  zm->sa_wait_warning = GNUNET_SCHEDULER_add_delayed (MONITOR_STALL_WARN_DELAY,
+                                                      &warn_monitor_slow,
+                                                      zm);
+}
+
+
+/**
+ * Continue processing the @a sa.
+ *
+ * @param sa store activity to process
+ */
+static void
+continue_store_activity (struct StoreActivity *sa)
+{
+  const struct RecordStoreMessage *rp_msg = sa->rsm;
+  unsigned int rd_count;
+  size_t name_len;
+  size_t rd_ser_len;
+  uint32_t rid;
+  const char *name_tmp;
+  const char *rd_ser;
+
+  rid = ntohl (rp_msg->gns_header.r_id);
+  name_len = ntohs (rp_msg->name_len);
+  rd_count = ntohs (rp_msg->rd_count);
+  rd_ser_len = ntohs (rp_msg->rd_len);
+  name_tmp = (const char *) &rp_msg[1];
+  rd_ser = &name_tmp[name_len];
+  {
+    struct GNUNET_GNSRECORD_Data rd[GNUNET_NZL(rd_count)];
+
+    /* We did this before, must succeed again */
+    GNUNET_assert (GNUNET_OK ==
+                   GNUNET_GNSRECORD_records_deserialize (rd_ser_len,
+                                                         rd_ser,
+                                                         rd_count,
+                                                         rd));
+
+    for (struct ZoneMonitor *zm = sa->zm_pos;
+         NULL != zm;
+         zm = sa->zm_pos)
+    {
+      if ( (0 != memcmp (&rp_msg->private_key,
+                         &zm->zone,
+                         sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey))) &&
+           (0 != memcmp (&zm->zone,
+                         &zero,
+                         sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey))) )
+        sa->zm_pos = zm->next; /* not interesting to this monitor */
+      if (zm->limit == zm->iteration_cnt)
+      {
+        zm->sa_waiting = GNUNET_YES;
+        zm->sa_waiting_start = GNUNET_TIME_absolute_get ();
+        if (NULL != zm->sa_wait_warning)
+          GNUNET_SCHEDULER_cancel (zm->sa_wait_warning);
+        zm->sa_wait_warning = GNUNET_SCHEDULER_add_delayed (MONITOR_STALL_WARN_DELAY,
+                                                            &warn_monitor_slow,
+                                                            zm);
+        return; /* blocked on zone monitor */
+      }
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Notifying monitor about changes under label `%s'\n",
+                  sa->conv_name);
+      zm->limit--;
+      send_lookup_response (zm->nc,
+                            0,
+                            &rp_msg->private_key,
+                            sa->conv_name,
+                            rd_count,
+                            rd);
+      sa->zm_pos = zm->next;
+    }
+    /* great, done with the monitors, unpack (again) for refresh_block operation */
+    refresh_block (sa->nc,
+                   rid,
+                   &rp_msg->private_key,
+                   sa->conv_name,
+                   rd_count,
+                   rd);
+  }
+  GNUNET_SERVICE_client_continue (sa->nc->client);
+  free_store_activity (sa);
+}
+
+
+/**
+ * Called whenever a client is disconnected.
+ * Frees our resources associated with that client.
+ *
+ * @param cls closure
+ * @param client identification of the client
+ * @param app_ctx the `struct NamestoreClient` of @a client
+ */
+static void
+client_disconnect_cb (void *cls,
+                      struct GNUNET_SERVICE_Client *client,
+                      void *app_ctx)
+{
+  struct NamestoreClient *nc = app_ctx;
+  struct ZoneIteration *no;
+  struct CacheOperation *cop;
+
+  (void) cls;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Client %p disconnected\n",
+              client);
+  for (struct ZoneMonitor *zm = monitor_head; NULL != zm; zm = zm->next)
+  {
+    struct StoreActivity *san;
+
+    if (nc != zm->nc)
+      continue;
+    GNUNET_CONTAINER_DLL_remove (monitor_head,
+                                 monitor_tail,
+                                 zm);
+    if (NULL != zm->task)
+    {
+      GNUNET_SCHEDULER_cancel (zm->task);
+      zm->task = NULL;
+    }
+    if (NULL != zm->sa_wait_warning)
+    {
+      GNUNET_SCHEDULER_cancel (zm->sa_wait_warning);
+      zm->sa_wait_warning = NULL;
+    }
+    for (struct StoreActivity *sa = sa_head; NULL != sa; sa = san)
+    {
+      san = sa->next;
+      if (zm == sa->zm_pos)
+      {
+        sa->zm_pos = zm->next;
+        /* this may free sa */
+        continue_store_activity (sa);
+      }
+    }
+    GNUNET_free (zm);
+    break;
+  }
+  for (struct StoreActivity *sa = sa_head; NULL != sa; sa = sa->next)
+  {
+    if (sa->nc == nc)
+    {
+      /* this may free sa */
+      free_store_activity (sa);
+      break; /* there can only be one per nc */
+    }
+  }
+  while (NULL != (no = nc->op_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (nc->op_head,
+                                 nc->op_tail,
+                                 no);
+    GNUNET_free (no);
+  }
+  for (cop = cop_head; NULL != cop; cop = cop->next)
+    if (nc == cop->nc)
+      cop->nc = NULL;
+  GNUNET_free (nc);
+}
+
+
+/**
+ * Add a client to our list of active clients.
+ *
+ * @param cls NULL
+ * @param client client to add
+ * @param mq message queue for @a client
+ * @return internal namestore client structure for this client
+ */
+static void *
+client_connect_cb (void *cls,
+                   struct GNUNET_SERVICE_Client *client,
+                   struct GNUNET_MQ_Handle *mq)
+{
+  struct NamestoreClient *nc;
+
+  (void) cls;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Client %p connected\n",
+              client);
+  nc = GNUNET_new (struct NamestoreClient);
+  nc->client = client;
+  nc->mq = mq;
+  return nc;
+}
+
+
+/**
  * Closure for #lookup_it().
  */
 struct RecordLookupContext
@@ -828,12 +1093,13 @@ struct RecordLookupContext
   /**
    * FIXME.
    */
-  size_t rd_ser_len;
+  ssize_t rd_ser_len;
 };
 
 
 /**
  * FIXME.
+ *
  * @param seq sequence number of the record
  */
 static void
@@ -845,60 +1111,93 @@ lookup_it (void *cls,
            const struct GNUNET_GNSRECORD_Data *rd)
 {
   struct RecordLookupContext *rlc = cls;
-  struct GNUNET_GNSRECORD_Data *rd_res;
-  unsigned int rdc_res;
 
   (void) private_key;
   (void) seq;
-  if (0 == strcmp (label,
+  if (0 != strcmp (label,
                    rlc->label))
+    return;
+  rlc->found = GNUNET_YES;
+  if (0 == rd_count)
   {
-    rlc->found = GNUNET_YES;
-    if (0 != rd_count)
+    rlc->rd_ser_len = 0;
+    rlc->res_rd_count = 0;
+    rlc->res_rd = NULL;
+    return;
+  }
+  if ( (NULL != rlc->nick) &&
+       (0 != strcmp (label,
+                     GNUNET_GNS_EMPTY_LABEL_AT)) )
+  {
+    /* Merge */
+    struct GNUNET_GNSRECORD_Data *rd_res;
+    unsigned int rdc_res;
+
+    rd_res = NULL;
+    rdc_res = 0;
+    rlc->nick->flags = (rlc->nick->flags | GNUNET_GNSRECORD_RF_PRIVATE) ^ GNUNET_GNSRECORD_RF_PRIVATE;
+    merge_with_nick_records (rlc->nick,
+                             rd_count,
+                             rd,
+                             &rdc_res,
+                             &rd_res);
+    rlc->rd_ser_len = GNUNET_GNSRECORD_records_get_size (rdc_res,
+                                                         rd_res);
+    if (rlc->rd_ser_len < 0)
     {
-      if ( (NULL != rlc->nick) &&
-           (0 != strcmp (label,
-                         GNUNET_GNS_EMPTY_LABEL_AT)) )
-      {
-        /* Merge */
-        rd_res = NULL;
-        rdc_res = 0;
-        rlc->nick->flags = (rlc->nick->flags | GNUNET_GNSRECORD_RF_PRIVATE) ^ GNUNET_GNSRECORD_RF_PRIVATE;
-        merge_with_nick_records (rlc->nick,
-                                 rd_count,
-                                 rd,
-                                 &rdc_res,
-                                 &rd_res);
-        rlc->rd_ser_len = GNUNET_GNSRECORD_records_get_size (rdc_res,
-                                                             rd_res);
-        rlc->res_rd_count = rdc_res;
-        rlc->res_rd = GNUNET_malloc (rlc->rd_ser_len);
+      GNUNET_break (0);
+      GNUNET_free  (rd_res);
+      rlc->found = GNUNET_NO;
+      rlc->rd_ser_len = 0;
+      return;
+    }
+    rlc->res_rd_count = rdc_res;
+    rlc->res_rd = GNUNET_malloc (rlc->rd_ser_len);
+    if (rlc->rd_ser_len !=
         GNUNET_GNSRECORD_records_serialize (rdc_res,
                                             rd_res,
                                             rlc->rd_ser_len,
-                                            rlc->res_rd);
-
-        GNUNET_free  (rd_res);
-        GNUNET_free  (rlc->nick);
-        rlc->nick = NULL;
-      }
-      else
-      {
-        rlc->rd_ser_len = GNUNET_GNSRECORD_records_get_size (rd_count,
-                                                             rd);
-        rlc->res_rd_count = rd_count;
-        rlc->res_rd = GNUNET_malloc (rlc->rd_ser_len);
+                                            rlc->res_rd))
+    {
+      GNUNET_break (0);
+      GNUNET_free  (rlc->res_rd);
+      rlc->res_rd = NULL;
+      rlc->res_rd_count = 0;
+      rlc->rd_ser_len = 0;
+      GNUNET_free  (rd_res);
+      rlc->found = GNUNET_NO;
+      return;
+    }
+    GNUNET_free (rd_res);
+    GNUNET_free (rlc->nick);
+    rlc->nick = NULL;
+  }
+  else
+  {
+    rlc->rd_ser_len = GNUNET_GNSRECORD_records_get_size (rd_count,
+                                                         rd);
+    if (rlc->rd_ser_len < 0)
+    {
+      GNUNET_break (0);
+      rlc->found = GNUNET_NO;
+      rlc->rd_ser_len = 0;
+      return;
+    }
+    rlc->res_rd_count = rd_count;
+    rlc->res_rd = GNUNET_malloc (rlc->rd_ser_len);
+    if (rlc->rd_ser_len !=
         GNUNET_GNSRECORD_records_serialize (rd_count,
                                             rd,
                                             rlc->rd_ser_len,
-                                            rlc->res_rd);
-      }
-    }
-    else
+                                            rlc->res_rd))
     {
-      rlc->rd_ser_len = 0;
-      rlc->res_rd_count = 0;
+      GNUNET_break (0);
+      GNUNET_free  (rlc->res_rd);
       rlc->res_rd = NULL;
+      rlc->res_rd_count = 0;
+      rlc->rd_ser_len = 0;
+      rlc->found = GNUNET_NO;
+      return;
     }
   }
 }
@@ -1073,7 +1372,7 @@ handle_record_store (void *cls,
   const char *rd_ser;
   unsigned int rd_count;
   int res;
-  struct ZoneMonitor *zm;
+  struct StoreActivity *sa;
 
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Received NAMESTORE_RECORD_STORE message\n");
@@ -1085,7 +1384,7 @@ handle_record_store (void *cls,
   name_tmp = (const char *) &rp_msg[1];
   rd_ser = &name_tmp[name_len];
   {
-    struct GNUNET_GNSRECORD_Data rd[rd_count];
+    struct GNUNET_GNSRECORD_Data rd[GNUNET_NZL(rd_count)];
 
     if (GNUNET_OK !=
         GNUNET_GNSRECORD_records_deserialize (rd_ser_len,
@@ -1108,6 +1407,10 @@ handle_record_store (void *cls,
       GNUNET_SERVICE_client_drop (nc->client);
       return;
     }
+    GNUNET_STATISTICS_update (statistics,
+                              "Well-formed store requests received",
+                              1,
+                              GNUNET_NO);
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                 "Creating %u records for name `%s'\n",
                 (unsigned int) rd_count,
@@ -1128,11 +1431,11 @@ handle_record_store (void *cls,
     }
     else
     {
-      struct GNUNET_GNSRECORD_Data rd_clean[rd_count];
-      unsigned int rd_clean_off;
-
       /* remove "NICK" records, unless this is for the
          #GNUNET_GNS_EMPTY_LABEL_AT label */
+      struct GNUNET_GNSRECORD_Data rd_clean[GNUNET_NZL(rd_count)];
+      unsigned int rd_clean_off;
+
       rd_clean_off = 0;
       for (unsigned int i=0;i<rd_count;i++)
       {
@@ -1147,59 +1450,33 @@ handle_record_store (void *cls,
                                          conv_name,
                                          rd_clean_off,
                                          rd_clean);
-      if (GNUNET_OK == res)
-      {
-        for (zm = monitor_head; NULL != zm; zm = zm->next)
-        {
-          if ( (0 == memcmp (&rp_msg->private_key,
-                             &zm->zone,
-                             sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey))) ||
-               (0 == memcmp (&zm->zone,
-                             &zero,
-                             sizeof (struct GNUNET_CRYPTO_EcdsaPrivateKey))) )
-          {
-            GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                        "Notifying monitor about changes under label `%s'\n",
-                        conv_name);
-            send_lookup_response (zm->nc,
-                                  0,
-                                  &rp_msg->private_key,
-                                  conv_name,
-                                  rd_count, rd);
-          }
-          else
-            GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                        "Monitor is for another zone\n");
-        }
-        if (NULL == monitor_head)
-          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                      "No monitors active\n");
-      }
-      else
-      {
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    "Error storing record: %d\n",
-                    res);
-      }
     }
-    if (GNUNET_OK == res)
+
+    if (GNUNET_OK != res)
     {
-      refresh_block (nc,
-                     rid,
-                     &rp_msg->private_key,
-                     conv_name,
-                     rd_count,
-                     rd);
+      /* store not successful, not need to tell monitors */
+      send_store_response (nc,
+                           res,
+                           rid);
       GNUNET_SERVICE_client_continue (nc->client);
       GNUNET_free (conv_name);
       return;
     }
-    GNUNET_free (conv_name);
+
+    sa = GNUNET_malloc (sizeof (struct StoreActivity) +
+                        ntohs (rp_msg->gns_header.header.size));
+    GNUNET_CONTAINER_DLL_insert (sa_head,
+                                 sa_tail,
+                                 sa);
+    sa->nc = nc;
+    sa->rsm = (const struct RecordStoreMessage *) &sa[1];
+    GNUNET_memcpy (&sa[1],
+                   rp_msg,
+                   ntohs (rp_msg->gns_header.header.size));
+    sa->zm_pos = monitor_head;
+    sa->conv_name = conv_name;
+    continue_store_activity (sa);
   }
-  send_store_response (nc,
-                       res,
-                       rid);
-  GNUNET_SERVICE_client_continue (nc->client);
 }
 
 
@@ -1251,7 +1528,7 @@ handle_zone_to_name_it (void *cls,
   struct ZoneToNameResponseMessage *ztnr_msg;
   int16_t res;
   size_t name_len;
-  size_t rd_ser_len;
+  ssize_t rd_ser_len;
   size_t msg_size;
   char *name_tmp;
   char *rd_tmp;
@@ -1262,7 +1539,14 @@ handle_zone_to_name_it (void *cls,
               name);
   res = GNUNET_YES;
   name_len = (NULL == name) ? 0 : strlen (name) + 1;
-  rd_ser_len = GNUNET_GNSRECORD_records_get_size (rd_count, rd);
+  rd_ser_len = GNUNET_GNSRECORD_records_get_size (rd_count,
+                                                  rd);
+  if (rd_ser_len < 0)
+  {
+    GNUNET_break (0);
+    ztn_ctx->success = GNUNET_SYSERR;
+    return;
+  }
   msg_size = sizeof (struct ZoneToNameResponseMessage) + name_len + rd_ser_len;
   if (msg_size >= GNUNET_MAX_MESSAGE_SIZE)
   {
@@ -1285,10 +1569,11 @@ handle_zone_to_name_it (void *cls,
                  name,
                  name_len);
   rd_tmp = &name_tmp[name_len];
-  GNUNET_GNSRECORD_records_serialize (rd_count,
-                                      rd,
-                                      rd_ser_len,
-                                      rd_tmp);
+  GNUNET_assert (rd_ser_len ==
+                 GNUNET_GNSRECORD_records_serialize (rd_count,
+                                                     rd,
+                                                     rd_ser_len,
+                                                     rd_tmp));
   ztn_ctx->success = GNUNET_OK;
   GNUNET_MQ_send (ztn_ctx->nc->mq,
                   env);
@@ -1311,8 +1596,7 @@ handle_zone_to_name (void *cls,
   struct ZoneToNameResponseMessage *ztnr_msg;
 
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Received `%s' message\n",
-              "ZONE_TO_NAME");
+              "Received ZONE_TO_NAME message\n");
   ztn_ctx.rid = ntohl (ztn_msg->gns_header.r_id);
   ztn_ctx.nc = nc;
   ztn_ctx.success = GNUNET_NO;
@@ -1601,6 +1885,46 @@ handle_iteration_next (void *cls,
 
 
 /**
+ * Function called when the monitor is ready for more data, and we
+ * should thus unblock PUT operations that were blocked on the
+ * monitor not being ready.
+ */
+static void
+monitor_unblock (struct ZoneMonitor *zm)
+{
+  struct StoreActivity *sa = sa_head;
+
+  while ( (NULL != sa) &&
+          (zm->limit > zm->iteration_cnt) )
+  {
+    struct StoreActivity *sn = sa->next;
+
+    if (sa->zm_pos == zm)
+      continue_store_activity (sa);
+    sa = sn;
+  }
+  if (zm->limit > zm->iteration_cnt)
+  {
+    zm->sa_waiting = GNUNET_NO;
+    if (NULL != zm->sa_wait_warning)
+    {
+      GNUNET_SCHEDULER_cancel (zm->sa_wait_warning);
+      zm->sa_wait_warning = NULL;
+    }
+  }
+  else if (GNUNET_YES == zm->sa_waiting)
+  {
+    zm->sa_waiting_start = GNUNET_TIME_absolute_get ();
+    if (NULL != zm->sa_wait_warning)
+      GNUNET_SCHEDULER_cancel (zm->sa_wait_warning);
+    zm->sa_wait_warning = GNUNET_SCHEDULER_add_delayed (MONITOR_STALL_WARN_DELAY,
+                                                        &warn_monitor_slow,
+                                                        zm);
+  }
+}
+
+
+/**
  * Send 'sync' message to zone monitor, we're now in sync.
  *
  * @param zm monitor that is now in sync
@@ -1615,16 +1939,22 @@ monitor_sync (struct ZoneMonitor *zm)
                        GNUNET_MESSAGE_TYPE_NAMESTORE_MONITOR_SYNC);
   GNUNET_MQ_send (zm->nc->mq,
                   env);
+  /* mark iteration done */
+  zm->in_first_iteration = GNUNET_NO;
+  zm->iteration_cnt = 0;
+  if ( (zm->limit > 0) &&
+       (zm->sa_waiting) )
+    monitor_unblock (zm);
 }
 
 
 /**
- * Obtain the next datum during the zone monitor's zone intiial iteration.
+ * Obtain the next datum during the zone monitor's zone initial iteration.
  *
  * @param cls zone monitor that does its initial iteration
  */
 static void
-monitor_next (void *cls);
+monitor_iteration_next (void *cls);
 
 
 /**
@@ -1658,14 +1988,23 @@ monitor_iterate_cb (void *cls,
                             "Monitor notifications sent",
                             1,
                             GNUNET_NO);
+  zm->limit--;
+  zm->iteration_cnt--;
   send_lookup_response (zm->nc,
                         0,
                         zone_key,
                         name,
                         rd_count,
                         rd);
-  zm->task = GNUNET_SCHEDULER_add_now (&monitor_next,
-                                       zm);
+  if ( (0 == zm->iteration_cnt) &&
+       (0 != zm->limit) )
+  {
+    /* We are done with the current iteration batch, AND the
+       client would right now accept more, so go again! */
+    GNUNET_assert (NULL == zm->task);
+    zm->task = GNUNET_SCHEDULER_add_now (&monitor_iteration_next,
+                                         zm);
+  }
 }
 
 
@@ -1687,6 +2026,8 @@ handle_monitor_start (void *cls,
   zm = GNUNET_new (struct ZoneMonitor);
   zm->nc = nc;
   zm->zone = zis_msg->zone;
+  zm->limit = 1;
+  zm->in_first_iteration = (GNUNET_YES == ntohl (zis_msg->iterate_first));
   GNUNET_CONTAINER_DLL_insert (monitor_head,
                                monitor_tail,
                                zm);
@@ -1694,8 +2035,8 @@ handle_monitor_start (void *cls,
   GNUNET_SERVICE_client_continue (nc->client);
   GNUNET_notification_context_add (monitor_nc,
                                    nc->mq);
-  if (GNUNET_YES == ntohl (zis_msg->iterate_first))
-    zm->task = GNUNET_SCHEDULER_add_now (&monitor_next,
+  if (zm->in_first_iteration)
+    zm->task = GNUNET_SCHEDULER_add_now (&monitor_iteration_next,
                                          zm);
   else
     monitor_sync (zm);
@@ -1708,12 +2049,17 @@ handle_monitor_start (void *cls,
  * @param cls zone monitor that does its initial iteration
  */
 static void
-monitor_next (void *cls)
+monitor_iteration_next (void *cls)
 {
   struct ZoneMonitor *zm = cls;
   int ret;
 
   zm->task = NULL;
+  GNUNET_assert (0 == zm->iteration_cnt);
+  if (zm->limit > 16)
+    zm->iteration_cnt = zm->limit / 2; /* leave half for monitor events */
+  else
+    zm->iteration_cnt = zm->limit; /* use it all */
   ret = GSN_database->iterate_records (GSN_database->cls,
                                        (0 == memcmp (&zm->zone,
                                                      &zero,
@@ -1721,7 +2067,7 @@ monitor_next (void *cls)
                                        ? NULL
                                        : &zm->zone,
                                        zm->seq,
-                                       1,
+                                       zm->iteration_cnt,
                                        &monitor_iterate_cb,
                                        zm);
   if (GNUNET_SYSERR == ret)
@@ -1773,13 +2119,30 @@ handle_monitor_next (void *cls,
     return;
   }
   zm->limit += inc;
-#if 0
-  if (GNUNET_YES == ntohl (zis_msg->iterate_first))
-    zm->task = GNUNET_SCHEDULER_add_now (&monitor_next,
-                                         zm);
-  else
-    monitor_sync (zm);
-#endif
+  if ( (zm->in_first_iteration) &&
+       (zm->limit == inc) )
+  {
+    /* We are still iterating, and the previous iteration must
+       have stopped due to the client's limit, so continue it! */
+    GNUNET_assert (NULL == zm->task);
+    zm->task = GNUNET_SCHEDULER_add_now (&monitor_iteration_next,
+                                         zm);
+  }
+  GNUNET_assert (zm->iteration_cnt <= zm->limit);
+  if ( (zm->limit > zm->iteration_cnt) &&
+       (zm->sa_waiting) )
+  {
+    monitor_unblock (zm);
+  }
+  else if (GNUNET_YES == zm->sa_waiting)
+  {
+    if (NULL != zm->sa_wait_warning)
+      GNUNET_SCHEDULER_cancel (zm->sa_wait_warning);
+    zm->sa_waiting_start = GNUNET_TIME_absolute_get ();
+    zm->sa_wait_warning = GNUNET_SCHEDULER_add_delayed (MONITOR_STALL_WARN_DELAY,
+                                                        &warn_monitor_slow,
+                                                        zm);
+  }
 }