convert namecache to new MQ API

1 files changed, 183 insertions, 335 deletions

diff --git a/src/namecache/namecache_api.c b/src/namecache/namecache_api.c
index 15a750448..51cbacf12 100644
--- a/src/namecache/namecache_api.c
+++ b/src/namecache/namecache_api.c
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     Copyright (C) 2010-2013 GNUnet e.V.
+     Copyright (C) 2010-2013, 2016 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
@@ -91,31 +91,6 @@ struct GNUNET_NAMECACHE_QueueEntry
 
 
 /**
- * Message in linked list we should send to the service.  The
- * actual binary message follows this struct.
- */
-struct PendingMessage
-{
-
-  /**
-   * Kept in a DLL.
-   */
-  struct PendingMessage *next;
-
-  /**
-   * Kept in a DLL.
-   */
-  struct PendingMessage *prev;
-
-  /**
-   * Size of the message.
-   */
-  size_t size;
-
-};
-
-
-/**
  * Connection to the NAMECACHE service.
  */
 struct GNUNET_NAMECACHE_Handle
@@ -127,9 +102,9 @@ struct GNUNET_NAMECACHE_Handle
   const struct GNUNET_CONFIGURATION_Handle *cfg;
 
   /**
-   * Socket (if available).
+   * Message queue to service.
    */
-  struct GNUNET_CLIENT_Connection *client;
+  struct GNUNET_MQ_Handle *mq;
 
   /**
    * Currently pending transmission request (or NULL).
@@ -137,16 +112,6 @@ struct GNUNET_NAMECACHE_Handle
   struct GNUNET_CLIENT_TransmitHandle *th;
 
   /**
-   * Head of linked list of pending messages to send to the service
-   */
-  struct PendingMessage *pending_head;
-
-  /**
-   * Tail of linked list of pending messages to send to the service
-   */
-  struct PendingMessage *pending_tail;
-
-  /**
    * Head of pending namecache queue entries
    */
   struct GNUNET_NAMECACHE_QueueEntry *op_head;
@@ -159,7 +124,7 @@ struct GNUNET_NAMECACHE_Handle
   /**
    * Reconnect task
    */
-  struct GNUNET_SCHEDULER_Task * reconnect_task;
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
 
   /**
    * Delay introduced before we reconnect.
@@ -172,11 +137,6 @@ struct GNUNET_NAMECACHE_Handle
   int reconnect;
 
   /**
-   * Did we start to receive yet?
-   */
-  int is_receiving;
-
-  /**
    * The last operation id used for a NAMECACHE operation
    */
   uint32_t last_op_id_used;
@@ -194,285 +154,165 @@ force_reconnect (struct GNUNET_NAMECACHE_Handle *h);
 
 
 /**
- * Handle an incoming message of type
- * #GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE.
+ * Find queue entry for the given @a rid.
  *
- * @param qe the respective entry in the message queue
- * @param msg the message we received
- * @param size the message size
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on error and we did NOT notify the client
+ * @param h handle to search
+ * @param rid request ID to look for
+ * @return NULL if not found, otherwise the queue entry (removed from the queue)
  */
-static int
-handle_lookup_block_response (struct GNUNET_NAMECACHE_QueueEntry *qe,
-                              const struct LookupBlockResponseMessage *msg,
-                              size_t size)
+static struct GNUNET_NAMECACHE_QueueEntry *
+find_qe (struct GNUNET_NAMECACHE_Handle *h,
+         uint32_t rid)
 {
-  struct GNUNET_GNSRECORD_Block *block;
-  char buf[size + sizeof (struct GNUNET_GNSRECORD_Block)
-           - sizeof (struct LookupBlockResponseMessage)];
-
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Received `%s'\n",
-       "LOOKUP_BLOCK_RESPONSE");
-  if (0 == GNUNET_TIME_absolute_ntoh (msg->expire).abs_value_us)
-  {
-    /* no match found */
-    if (NULL != qe->block_proc)
-      qe->block_proc (qe->block_proc_cls, NULL);
-    return GNUNET_OK;
-  }
+  struct GNUNET_NAMECACHE_QueueEntry *qe;
 
-  block = (struct GNUNET_GNSRECORD_Block *) buf;
-  block->signature = msg->signature;
-  block->derived_key = msg->derived_key;
-  block->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN);
-  block->purpose.size = htonl (size - sizeof (struct LookupBlockResponseMessage) +
-                               sizeof (struct GNUNET_TIME_AbsoluteNBO) +
-                               sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose));
-  block->expiration_time = msg->expire;
-  memcpy (&block[1],
-          &msg[1],
-          size - sizeof (struct LookupBlockResponseMessage));
-  if (GNUNET_OK !=
-      GNUNET_GNSRECORD_block_verify (block))
+  for (qe = h->op_head; qe != NULL; qe = qe->next)
   {
-    GNUNET_break (0);
-    return GNUNET_SYSERR;
+    if (qe->op_id == rid)
+    {
+      GNUNET_CONTAINER_DLL_remove (h->op_head,
+                                   h->op_tail,
+                                   qe);
+      return qe;
+    }
   }
-  if (NULL != qe->block_proc)
-    qe->block_proc (qe->block_proc_cls, block);
-  else
-    GNUNET_break (0);
-  return GNUNET_OK;
+  return NULL;
 }
 
 
 /**
  * Handle an incoming message of type
- * #GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE
+ * #GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE.
  *
- * @param qe the respective entry in the message queue
+ * @param cls the `struct GNUNET_NAMECACHE_Handle`
  * @param msg the message we received
- * @param size the message size
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on error and we did NOT notify the client
  */
 static int
-handle_block_cache_response (struct GNUNET_NAMECACHE_QueueEntry *qe,
-                            const struct BlockCacheResponseMessage *msg,
-                            size_t size)
+check_lookup_block_response (void *cls,
+                             const struct LookupBlockResponseMessage *msg)
 {
-  int res;
-
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Received `%s'\n",
-       "BLOCK_CACHE_RESPONSE");
-  res = ntohl (msg->op_result);
-  /* TODO: add actual error message from namecache to response... */
-  if (NULL != qe->cont)
-    qe->cont (qe->cont_cls,
-              res,
-              (GNUNET_OK == res)
-              ? NULL
-              : _("Namecache failed to cache block"));
+  /* any length will do, format validation is in handler */
   return GNUNET_OK;
 }
 
 
 /**
- * Handle incoming messages for record operations
+ * Handle an incoming message of type
+ * #GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE.
  *
- * @param qe the respective zone iteration handle
+ * @param cls the `struct GNUNET_NAMECACHE_Handle`
  * @param msg the message we received
- * @param type the message type in host byte order
- * @param size the message size
- * @return #GNUNET_OK on success, #GNUNET_NO if we notified the client about
- *         the error, #GNUNET_SYSERR on error and we did NOT notify the client
- */
-static int
-manage_record_operations (struct GNUNET_NAMECACHE_QueueEntry *qe,
-                          const struct GNUNET_MessageHeader *msg,
-                          uint16_t type,
-                          size_t size)
-{
-  /* handle different message type */
-  switch (type)
-  {
-  case GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE:
-    if (size < sizeof (struct LookupBlockResponseMessage))
-    {
-      GNUNET_break (0);
-      return GNUNET_SYSERR;
-    }
-    return handle_lookup_block_response (qe, (const struct LookupBlockResponseMessage *) msg, size);
-  case GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE:
-    if (size != sizeof (struct BlockCacheResponseMessage))
-    {
-      GNUNET_break (0);
-      return GNUNET_SYSERR;
-    }
-    return handle_block_cache_response (qe, (const struct BlockCacheResponseMessage *) msg, size);
-  default:
-    GNUNET_break (0);
-    return GNUNET_SYSERR;
-  }
-}
-
-
-/**
- * Type of a function to call when we receive a message
- * from the service.
- *
- * @param cls the `struct GNUNET_NAMECACHE_SchedulingHandle`
- * @param msg message received, NULL on timeout or fatal error
  */
 static void
-process_namecache_message (void *cls,
-                           const struct GNUNET_MessageHeader *msg)
+handle_lookup_block_response (void *cls,
+                              const struct LookupBlockResponseMessage *msg)
 {
   struct GNUNET_NAMECACHE_Handle *h = cls;
-  const struct GNUNET_NAMECACHE_Header *gm;
+  size_t size;
   struct GNUNET_NAMECACHE_QueueEntry *qe;
-  uint16_t size;
-  uint16_t type;
-  uint32_t r_id;
-  int ret;
 
-  if (NULL == msg)
-  {
-    force_reconnect (h);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Received LOOKUP_BLOCK_RESPONSE\n");
+  qe = find_qe (h,
+                ntohl (msg->gns_header.r_id));
+  if (NULL == qe)
     return;
-  }
-  size = ntohs (msg->size);
-  type = ntohs (msg->type);
-  if (size < sizeof (struct GNUNET_NAMECACHE_Header))
+  if (0 == GNUNET_TIME_absolute_ntoh (msg->expire).abs_value_us)
   {
-    GNUNET_break_op (0);
-    GNUNET_CLIENT_receive (h->client,
-                           &process_namecache_message, h,
-                           GNUNET_TIME_UNIT_FOREVER_REL);
+    /* no match found */
+    if (NULL != qe->block_proc)
+      qe->block_proc (qe->block_proc_cls,
+                      NULL);
+    GNUNET_free (qe);
     return;
   }
-  gm = (const struct GNUNET_NAMECACHE_Header *) msg;
-  r_id = ntohl (gm->r_id);
-
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Received message type %u size %u op %u\n",
-       (unsigned int) type,
-       (unsigned int) size,
-       (unsigned int) r_id);
-
-  /* Is it a record related operation ? */
-  for (qe = h->op_head; qe != NULL; qe = qe->next)
-    if (qe->op_id == r_id)
-      break;
-  if (NULL != qe)
+  size = ntohs (msg->gns_header.header.size)
+    - sizeof (struct LookupBlockResponseMessage);
   {
-    ret = manage_record_operations (qe, msg, type, size);
-    if (GNUNET_SYSERR == ret)
+    char buf[size + sizeof (struct GNUNET_GNSRECORD_Block)] GNUNET_ALIGN;
+    struct GNUNET_GNSRECORD_Block *block;
+
+    block = (struct GNUNET_GNSRECORD_Block *) buf;
+    block->signature = msg->signature;
+    block->derived_key = msg->derived_key;
+    block->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_GNS_RECORD_SIGN);
+    block->purpose.size = htonl (size +
+                                 sizeof (struct GNUNET_TIME_AbsoluteNBO) +
+                                 sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose));
+    block->expiration_time = msg->expire;
+    memcpy (&block[1],
+            &msg[1],
+            size);
+    if (GNUNET_OK !=
+        GNUNET_GNSRECORD_block_verify (block))
     {
-      /* protocol error, need to reconnect */
-      h->reconnect = GNUNET_YES;
+      GNUNET_break (0);
+      if (NULL != qe->block_proc)
+        qe->block_proc (qe->block_proc_cls,
+                        NULL);
+      force_reconnect (h);
     }
     else
     {
-      /* client was notified about success or failure, clean up 'qe' */
-      GNUNET_CONTAINER_DLL_remove (h->op_head,
-                                   h->op_tail,
-                                   qe);
-      GNUNET_free (qe);
+      if (NULL != qe->block_proc)
+        qe->block_proc (qe->block_proc_cls,
+                        block);
     }
   }
-  if (GNUNET_YES == h->reconnect)
-  {
-    force_reconnect (h);
-    return;
-  }
-  GNUNET_CLIENT_receive (h->client, &process_namecache_message, h,
-                         GNUNET_TIME_UNIT_FOREVER_REL);
+  GNUNET_free (qe);
 }
 
 
 /**
- * Transmit messages from the message queue to the service
- * (if there are any, and if we are not already trying).
- *
- * @param h handle to use
- */
-static void
-do_transmit (struct GNUNET_NAMECACHE_Handle *h);
-
-
-/**
- * We can now transmit a message to NAMECACHE. Do it.
+ * Handle an incoming message of type
+ * #GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE
  *
  * @param cls the `struct GNUNET_NAMECACHE_Handle`
- * @param size number of bytes we can transmit
- * @param buf where to copy the messages
- * @return number of bytes copied into @a buf
+ * @param msg the message we received
+ * @param size the message size
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error and we did NOT notify the client
  */
-static size_t
-transmit_message_to_namecache (void *cls,
-                               size_t size,
-                               void *buf)
+static void
+handle_block_cache_response (void *cls,
+                             const struct BlockCacheResponseMessage *msg)
 {
   struct GNUNET_NAMECACHE_Handle *h = cls;
-  struct PendingMessage *p;
-  size_t ret;
-  char *cbuf;
+  struct GNUNET_NAMECACHE_QueueEntry *qe;
+  int res;
 
-  h->th = NULL;
-  if ((0 == size) || (NULL == buf))
-  {
-    force_reconnect (h);
-    return 0;
-  }
-  ret = 0;
-  cbuf = buf;
-  while ( (NULL != (p = h->pending_head)) &&
-          (p->size <= size) )
-  {
-    memcpy (&cbuf[ret], &p[1], p->size);
-    ret += p->size;
-    size -= p->size;
-    GNUNET_CONTAINER_DLL_remove (h->pending_head,
-                                 h->pending_tail,
-                                 p);
-    if (GNUNET_NO == h->is_receiving)
-    {
-      h->is_receiving = GNUNET_YES;
-      GNUNET_CLIENT_receive (h->client,
-                             &process_namecache_message, h,
-                             GNUNET_TIME_UNIT_FOREVER_REL);
-    }
-    GNUNET_free (p);
-  }
-  do_transmit (h);
-  return ret;
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Received BLOCK_CACHE_RESPONSE\n");
+  qe = find_qe (h,
+                ntohl (msg->gns_header.r_id));
+  if (NULL == qe)
+    return;
+  res = ntohl (msg->op_result);
+  /* TODO: add actual error message from namecache to response... */
+  if (NULL != qe->cont)
+    qe->cont (qe->cont_cls,
+              res,
+              (GNUNET_OK == res)
+              ? NULL
+              : _("Namecache failed to cache block"));
+  GNUNET_free (qe);
 }
 
 
 /**
- * Transmit messages from the message queue to the service
- * (if there are any, and if we are not already trying).
+ * Generic error handler, called with the appropriate error code and
+ * the same closure specified at the creation of the message queue.
+ * Not every message queue implementation supports an error handler.
  *
- * @param h handle to use
+ * @param cls closure with the `struct GNUNET_NAMECACHE_Handle *`
+ * @param error error code
  */
 static void
-do_transmit (struct GNUNET_NAMECACHE_Handle *h)
+mq_error_handler (void *cls,
+                  enum GNUNET_MQ_Error error)
 {
-  struct PendingMessage *p;
-
-  if (NULL != h->th)
-    return; /* transmission request already pending */
-  if (NULL == (p = h->pending_head))
-    return; /* transmission queue empty */
-  if (NULL == h->client)
-    return;                     /* currently reconnecting */
-  h->th = GNUNET_CLIENT_notify_transmit_ready (h->client, p->size,
-                                               GNUNET_TIME_UNIT_FOREVER_REL,
-                                               GNUNET_NO, &transmit_message_to_namecache,
-                                               h);
-  GNUNET_break (NULL != h->th);
+  struct GNUNET_NAMECACHE_Handle *h = cls;
+
+  force_reconnect (h);
 }
 
 
@@ -484,10 +324,23 @@ do_transmit (struct GNUNET_NAMECACHE_Handle *h)
 static void
 reconnect (struct GNUNET_NAMECACHE_Handle *h)
 {
-  GNUNET_assert (NULL == h->client);
-  h->client = GNUNET_CLIENT_connect ("namecache", h->cfg);
-  GNUNET_assert (NULL != h->client);
-  do_transmit (h);
+  GNUNET_MQ_hd_var_size (lookup_block_response,
+                         GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK_RESPONSE,
+                         struct LookupBlockResponseMessage);
+  GNUNET_MQ_hd_fixed_size (block_cache_response,
+                           GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE_RESPONSE,
+                           struct BlockCacheResponseMessage);
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    make_lookup_block_response_handler (h),
+    make_block_cache_response_handler (h),
+    GNUNET_MQ_handler_end ()
+  };
+  GNUNET_assert (NULL == h->mq);
+  h->mq = GNUNET_CLIENT_connecT (h->cfg,
+                                 "namecache",
+                                 handlers,
+                                 &mq_error_handler,
+                                 h);
 }
 
 
@@ -514,17 +367,24 @@ reconnect_task (void *cls)
 static void
 force_reconnect (struct GNUNET_NAMECACHE_Handle *h)
 {
-  if (NULL != h->th)
+  struct GNUNET_NAMECACHE_QueueEntry *qe;
+
+  h->reconnect = GNUNET_NO;
+  GNUNET_MQ_destroy (h->mq);
+  h->mq = NULL;
+  while (NULL != (qe = h->op_head))
   {
-    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
-    h->th = NULL;
+    GNUNET_CONTAINER_DLL_remove (h->op_head,
+                                 h->op_tail,
+                                 qe);
+    if (NULL != qe->cont)
+      qe->cont (qe->cont_cls,
+                GNUNET_SYSERR,
+                _("Error communicating with namecache service"));
+    GNUNET_free (qe);
   }
-  h->reconnect = GNUNET_NO;
-  GNUNET_CLIENT_disconnect (h->client);
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Reconnecting to namecache\n");
-  h->is_receiving = GNUNET_NO;
-  h->client = NULL;
   h->reconnect_delay = GNUNET_TIME_STD_BACKOFF (h->reconnect_delay);
   h->reconnect_task = GNUNET_SCHEDULER_add_delayed (h->reconnect_delay,
                                                     &reconnect_task,
@@ -558,8 +418,12 @@ GNUNET_NAMECACHE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
 
   h = GNUNET_new (struct GNUNET_NAMECACHE_Handle);
   h->cfg = cfg;
-  h->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect_task, h);
-  h->last_op_id_used = 0;
+  reconnect (h);
+  if (NULL == h->mq)
+  {
+    GNUNET_free (h);
+    return NULL;
+  }
   return h;
 }
 
@@ -573,31 +437,20 @@ GNUNET_NAMECACHE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
 void
 GNUNET_NAMECACHE_disconnect (struct GNUNET_NAMECACHE_Handle *h)
 {
-  struct PendingMessage *p;
   struct GNUNET_NAMECACHE_QueueEntry *q;
 
-  LOG (GNUNET_ERROR_TYPE_DEBUG, "Cleaning up\n");
-  GNUNET_assert (NULL != h);
-  if (NULL != h->th)
-  {
-    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
-    h->th = NULL;
-  }
-  while (NULL != (p = h->pending_head))
-  {
-    GNUNET_CONTAINER_DLL_remove (h->pending_head, h->pending_tail, p);
-    GNUNET_free (p);
-  }
   GNUNET_break (NULL == h->op_head);
   while (NULL != (q = h->op_head))
   {
-    GNUNET_CONTAINER_DLL_remove (h->op_head, h->op_tail, q);
+    GNUNET_CONTAINER_DLL_remove (h->op_head,
+                                 h->op_tail,
+                                 q);
     GNUNET_free (q);
   }
-  if (NULL != h->client)
+  if (NULL != h->mq)
   {
-    GNUNET_CLIENT_disconnect (h->client);
-    h->client = NULL;
+    GNUNET_MQ_destroy (h->mq);
+    h->mq = NULL;
   }
   if (NULL != h->reconnect_task)
   {
@@ -615,8 +468,8 @@ GNUNET_NAMECACHE_disconnect (struct GNUNET_NAMECACHE_Handle *h)
  * @param h handle to the namecache
  * @param block block to store
  * @param cont continuation to call when done
- * @param cont_cls closure for cont
- * @return handle to abort the request
+ * @param cont_cls closure for @a cont
+ * @return handle to abort the request, NULL on error
  */
 struct GNUNET_NAMECACHE_QueueEntry *
 GNUNET_NAMECACHE_block_cache (struct GNUNET_NAMECACHE_Handle *h,
@@ -625,13 +478,13 @@ GNUNET_NAMECACHE_block_cache (struct GNUNET_NAMECACHE_Handle *h,
                               void *cont_cls)
 {
   struct GNUNET_NAMECACHE_QueueEntry *qe;
-  struct PendingMessage *pe;
   struct BlockCacheMessage *msg;
+  struct GNUNET_MQ_Envelope *env;
   uint32_t rid;
   size_t blen;
-  size_t msg_size;
 
-  GNUNET_assert (NULL != h);
+  if (NULL == h->mq)
+    return NULL;
   blen = ntohl (block->purpose.size)
     - sizeof (struct GNUNET_TIME_AbsoluteNBO)
     - sizeof (struct GNUNET_CRYPTO_EccSignaturePurpose);
@@ -641,27 +494,22 @@ GNUNET_NAMECACHE_block_cache (struct GNUNET_NAMECACHE_Handle *h,
   qe->cont = cont;
   qe->cont_cls = cont_cls;
   qe->op_id = rid;
-  GNUNET_CONTAINER_DLL_insert_tail (h->op_head, h->op_tail, qe);
-
-  /* setup msg */
-  msg_size = sizeof (struct BlockCacheMessage) + blen;
-  pe = GNUNET_malloc (sizeof (struct PendingMessage) + msg_size);
-  pe->size = msg_size;
-  msg = (struct BlockCacheMessage *) &pe[1];
-  msg->gns_header.header.type = htons (GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE);
-  msg->gns_header.header.size = htons (msg_size);
+  GNUNET_CONTAINER_DLL_insert_tail (h->op_head,
+                                    h->op_tail,
+                                    qe);
+  /* send msg */
+  env = GNUNET_MQ_msg_extra (msg,
+                             blen,
+                             GNUNET_MESSAGE_TYPE_NAMECACHE_BLOCK_CACHE);
   msg->gns_header.r_id = htonl (rid);
   msg->expire = block->expiration_time;
   msg->signature = block->signature;
   msg->derived_key = block->derived_key;
-  memcpy (&msg[1], &block[1], blen);
-  LOG (GNUNET_ERROR_TYPE_DEBUG,
-       "Sending `%s' message with size %u and expiration %s\n",
-       "NAMECACHE_BLOCK_CACHE",
-       (unsigned int) msg_size,
-       GNUNET_STRINGS_absolute_time_to_string (GNUNET_TIME_absolute_ntoh (msg->expire)));
-  GNUNET_CONTAINER_DLL_insert_tail (h->pending_head, h->pending_tail, pe);
-  do_transmit (h);
+  memcpy (&msg[1],
+          &block[1],
+          blen);
+  GNUNET_MQ_send (h->mq,
+                  env);
   return qe;
 }
 
@@ -674,41 +522,40 @@ GNUNET_NAMECACHE_block_cache (struct GNUNET_NAMECACHE_Handle *h,
  * @param derived_hash hash of zone key combined with name to lookup
  * @param proc function to call on the matching block, or with
  *        NULL if there is no matching block
- * @param proc_cls closure for proc
- * @return a handle that can be used to cancel
+ * @param proc_cls closure for @a proc
+ * @return a handle that can be used to cancel, NULL on error
  */
 struct GNUNET_NAMECACHE_QueueEntry *
 GNUNET_NAMECACHE_lookup_block (struct GNUNET_NAMECACHE_Handle *h,
                                const struct GNUNET_HashCode *derived_hash,
-                               GNUNET_NAMECACHE_BlockProcessor proc, void *proc_cls)
+                               GNUNET_NAMECACHE_BlockProcessor proc,
+                               void *proc_cls)
 {
   struct GNUNET_NAMECACHE_QueueEntry *qe;
-  struct PendingMessage *pe;
   struct LookupBlockMessage *msg;
-  size_t msg_size;
+  struct GNUNET_MQ_Envelope *env;
   uint32_t rid;
 
+  if (NULL == h->mq)
+    return NULL;
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        "Looking for block under %s\n",
        GNUNET_h2s (derived_hash));
-  rid = get_op_id(h);
+  rid = get_op_id (h);
   qe = GNUNET_new (struct GNUNET_NAMECACHE_QueueEntry);
   qe->nsh = h;
   qe->block_proc = proc;
   qe->block_proc_cls = proc_cls;
   qe->op_id = rid;
-  GNUNET_CONTAINER_DLL_insert_tail (h->op_head, h->op_tail, qe);
-
-  msg_size = sizeof (struct LookupBlockMessage);
-  pe = GNUNET_malloc (sizeof (struct PendingMessage) + msg_size);
-  pe->size = msg_size;
-  msg = (struct LookupBlockMessage *) &pe[1];
-  msg->gns_header.header.type = htons (GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK);
-  msg->gns_header.header.size = htons (msg_size);
+  GNUNET_CONTAINER_DLL_insert_tail (h->op_head,
+                                    h->op_tail,
+                                    qe);
+  env = GNUNET_MQ_msg (msg,
+                       GNUNET_MESSAGE_TYPE_NAMECACHE_LOOKUP_BLOCK);
   msg->gns_header.r_id = htonl (rid);
   msg->query = *derived_hash;
-  GNUNET_CONTAINER_DLL_insert_tail (h->pending_head, h->pending_tail, pe);
-  do_transmit (h);
+  GNUNET_MQ_send (h->mq,
+                  env);
   return qe;
 }
 
@@ -724,8 +571,9 @@ GNUNET_NAMECACHE_cancel (struct GNUNET_NAMECACHE_QueueEntry *qe)
 {
   struct GNUNET_NAMECACHE_Handle *h = qe->nsh;
 
-  GNUNET_assert (NULL != qe);
-  GNUNET_CONTAINER_DLL_remove (h->op_head, h->op_tail, qe);
+  GNUNET_CONTAINER_DLL_remove (h->op_head,
+                               h->op_tail,
+                               qe);
   GNUNET_free(qe);
 }