ack florian
[oweals/gnunet.git] / src / util / client.c
index f656cc20f667d6a1d24e43ae82261ba844cc2d7d..f40d5e6ebc907b5ee64fe98293ae3f9a8777cd6a 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2001-2013 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2001-2013 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
@@ -14,8 +14,8 @@
 
      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.
+     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
 */
 
 /**
@@ -29,6 +29,7 @@
 #include "platform.h"
 #include "gnunet_protocols.h"
 #include "gnunet_util_lib.h"
+#include "gnunet_socks.h"
 
 
 /**
@@ -56,7 +57,7 @@ struct GNUNET_CLIENT_TransmitHandle
   GNUNET_CONNECTION_TransmitReadyNotify notify;
 
   /**
-   * Closure for notify.
+   * Closure for @e notify.
    */
   void *notify_cls;
 
@@ -70,7 +71,7 @@ struct GNUNET_CLIENT_TransmitHandle
    * If we are re-trying and are delaying to do so,
    * handle to the scheduled task managing the delay.
    */
-  GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
 
   /**
    * Timeout for the operation overall.
@@ -99,39 +100,6 @@ struct GNUNET_CLIENT_TransmitHandle
 };
 
 
-/**
- * Context for processing
- * "GNUNET_CLIENT_transmit_and_get_response" requests.
- */
-struct TransmitGetResponseContext
-{
-  /**
-   * Client handle.
-   */
-  struct GNUNET_CLIENT_Connection *client;
-
-  /**
-   * Message to transmit; do not free, allocated
-   * right after this struct.
-   */
-  const struct GNUNET_MessageHeader *hdr;
-
-  /**
-   * Timeout to use.
-   */
-  struct GNUNET_TIME_Absolute timeout;
-
-  /**
-   * Function to call when done.
-   */
-  GNUNET_CLIENT_MessageHandler rn;
-
-  /**
-   * Closure for "rn".
-   */
-  void *rn_cls;
-};
-
 /**
  * Struct to refer to a GNUnet TCP connection.
  * This is more than just a socket because if the server
@@ -156,19 +124,13 @@ struct GNUNET_CLIENT_Connection
    */
   char *service_name;
 
-  /**
-   * Context of a transmit_and_get_response operation, NULL
-   * if no such operation is pending.
-   */
-  struct TransmitGetResponseContext *tag;
-
   /**
    * Handler for current receiver task.
    */
   GNUNET_CLIENT_MessageHandler receiver_handler;
 
   /**
-   * Closure for receiver_handler.
+   * Closure for @e receiver_handler.
    */
   void *receiver_handler_cls;
 
@@ -182,7 +144,7 @@ struct GNUNET_CLIENT_Connection
    * If we are re-trying and are delaying to do so,
    * handle to the scheduled task managing the delay.
    */
-  GNUNET_SCHEDULER_TaskIdentifier receive_task;
+  struct GNUNET_SCHEDULER_Task * receive_task;
 
   /**
    * Buffer for received message.
@@ -217,7 +179,9 @@ struct GNUNET_CLIENT_Connection
 
   /**
    * Are we currently busy doing receive-processing?
-   * GNUNET_YES if so, GNUNET_NO if not.
+   * #GNUNET_YES if so, #GNUNET_NO if not. #GNUNET_SYSERR
+   * if the connection has failed (but we may not have
+   * closed the handle itself yet).
    */
   int in_receive;
 
@@ -287,7 +251,7 @@ try_unixpath (const char *service_name,
  *
  * @param service_name name of service to connect to
  * @param cfg configuration to use
- * @return GNUNET_OK if the configuration is valid, GNUNET_SYSERR if not
+ * @return #GNUNET_OK if the configuration is valid, #GNUNET_SYSERR if not
  */
 static int
 test_service_configuration (const char *service_name,
@@ -330,12 +294,17 @@ test_service_configuration (const char *service_name,
  */
 static struct GNUNET_CONNECTION_Handle *
 do_connect (const char *service_name,
-            const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned int attempt)
+            const struct GNUNET_CONFIGURATION_Handle *cfg,
+           unsigned int attempt)
 {
   struct GNUNET_CONNECTION_Handle *connection;
   char *hostname;
   unsigned long long port;
 
+  /* Never use a local source if a proxy is configured */
+  if (GNUNET_YES == GNUNET_SOCKS_check_service (service_name,cfg))
+    return GNUNET_SOCKS_do_connect (service_name,cfg);
+
   connection = NULL;
   if (0 == (attempt % 2))
   {
@@ -395,6 +364,36 @@ do_connect (const char *service_name,
 }
 
 
+/**
+ * Create a message queue to connect to a GNUnet service.
+ * If handlers are specfied, receive messages from the connection.
+ *
+ * @param connection the client connection
+ * @param handlers handlers for receiving messages, can be NULL
+ * @param error_handler error handler
+ * @param error_handler_cls closure for the @a error_handler
+ * @return the message queue, NULL on error
+ */
+struct GNUNET_MQ_Handle *
+GNUNET_CLIENT_connecT (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                       const char *service_name,
+                       const struct GNUNET_MQ_MessageHandler *handlers,
+                       GNUNET_MQ_ErrorHandler error_handler,
+                       void *error_handler_cls)
+{
+  struct GNUNET_CLIENT_Connection *c;
+
+  c = GNUNET_CLIENT_connect (service_name,
+                             cfg);
+  if (NULL == c)
+    return NULL;
+  return GNUNET_MQ_queue_for_connection_client (c,
+                                                handlers,
+                                                error_handler,
+                                                error_handler_cls);
+}
+
+
 /**
  * Get a connection with a service.
  *
@@ -456,18 +455,15 @@ GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *client)
     GNUNET_CONNECTION_destroy (client->connection);
     client->connection = NULL;
   }
-  if (GNUNET_SCHEDULER_NO_TASK != client->receive_task)
+  if (NULL != client->receive_task)
   {
     GNUNET_SCHEDULER_cancel (client->receive_task);
-    client->receive_task = GNUNET_SCHEDULER_NO_TASK;
-  }
-  if (NULL != client->tag)
-  {
-    GNUNET_free (client->tag);
-    client->tag = NULL;
+    client->receive_task = NULL;
   }
   client->receiver_handler = NULL;
-  GNUNET_array_grow (client->received_buf, client->received_size, 0);
+  GNUNET_array_grow (client->received_buf,
+                     client->received_size,
+                     0);
   GNUNET_free (client->service_name);
   GNUNET_free (client);
 }
@@ -492,19 +488,23 @@ check_complete (struct GNUNET_CLIENT_Connection *client)
 
 /**
  * Callback function for data received from the network.  Note that
- * both "available" and "errCode" would be 0 if the read simply timed out.
+ * both @a available and @a errCode would be 0 if the read simply timed out.
  *
  * @param cls closure
  * @param buf pointer to received data
- * @param available number of bytes availabe in "buf",
+ * @param available number of bytes availabe in @a buf,
  *        possibly 0 (on errors)
  * @param addr address of the sender
- * @param addrlen size of addr
+ * @param addrlen size of @a addr
  * @param errCode value of errno (on errors receiving)
  */
 static void
-receive_helper (void *cls, const void *buf, size_t available,
-                const struct sockaddr *addr, socklen_t addrlen, int errCode)
+receive_helper (void *cls,
+                const void *buf,
+                size_t available,
+                const struct sockaddr *addr,
+                socklen_t addrlen,
+                int errCode)
 {
   struct GNUNET_CLIENT_Connection *client = cls;
   struct GNUNET_TIME_Relative remaining;
@@ -514,18 +514,24 @@ receive_helper (void *cls, const void *buf, size_t available,
   GNUNET_assert (GNUNET_NO == client->msg_complete);
   GNUNET_assert (GNUNET_YES == client->in_receive);
   client->in_receive = GNUNET_NO;
-  if ((0 == available) || (NULL == client->connection) || (0 != errCode))
+  if ( (0 == available) ||
+       (NULL == client->connection) ||
+       (0 != errCode) )
   {
     /* signal timeout! */
     LOG (GNUNET_ERROR_TYPE_DEBUG,
          "Timeout in receive_helper, available %u, client->connection %s, errCode `%s'\n",
-         (unsigned int) available, NULL == client->connection ? "NULL" : "non-NULL",
+         (unsigned int) available,
+         NULL == client->connection ? "NULL" : "non-NULL",
          STRERROR (errCode));
+    /* remember failure */
+    client->in_receive = GNUNET_SYSERR;
     if (NULL != (receive_handler = client->receiver_handler))
     {
       receive_handler_cls = client->receiver_handler_cls;
       client->receiver_handler = NULL;
-      receive_handler (receive_handler_cls, NULL);
+      receive_handler (receive_handler_cls,
+                       NULL);
     }
     return;
   }
@@ -536,7 +542,7 @@ receive_helper (void *cls, const void *buf, size_t available,
   if (client->received_size < client->received_pos + available)
     GNUNET_array_grow (client->received_buf, client->received_size,
                        client->received_pos + available);
-  memcpy (&client->received_buf[client->received_pos], buf, available);
+  GNUNET_memcpy (&client->received_buf[client->received_pos], buf, available);
   client->received_pos += available;
   check_complete (client);
   /* check for timeout */
@@ -544,8 +550,11 @@ receive_helper (void *cls, const void *buf, size_t available,
   if (0 == remaining.rel_value_us)
   {
     /* signal timeout! */
-    if (NULL != client->receiver_handler)
-      client->receiver_handler (client->receiver_handler_cls, NULL);
+    if (NULL != (receive_handler = client->receiver_handler))
+    {
+      client->receiver_handler = NULL;
+      receive_handler (client->receiver_handler_cls, NULL);
+    }
     return;
   }
   /* back to receive -- either for more data or to call callback! */
@@ -557,11 +566,10 @@ receive_helper (void *cls, const void *buf, size_t available,
 /**
  * Continuation to call the receive callback.
  *
- * @param cls  our handle to the client connection
- * @param tc scheduler context
+ * @param cls our handle to the client connection
  */
 static void
-receive_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+receive_task (void *cls)
 {
   struct GNUNET_CLIENT_Connection *client = cls;
   GNUNET_CLIENT_MessageHandler handler = client->receiver_handler;
@@ -569,16 +577,30 @@ receive_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
       (const struct GNUNET_MessageHeader *) client->received_buf;
   void *handler_cls = client->receiver_handler_cls;
   uint16_t msize = ntohs (cmsg->size);
-  char mbuf[msize];
+  char mbuf[msize] GNUNET_ALIGN;
   struct GNUNET_MessageHeader *msg = (struct GNUNET_MessageHeader *) mbuf;
 
-  LOG (GNUNET_ERROR_TYPE_DEBUG, "Received message of type %u and size %u\n",
-       ntohs (cmsg->type), msize);
-  client->receive_task = GNUNET_SCHEDULER_NO_TASK;
+  client->receive_task = NULL;
+  if ( (GNUNET_SYSERR == client->in_receive) &&
+       (GNUNET_YES != client->msg_complete) )
+  {
+    /* Connection failure, signal to caller! */
+    client->receiver_handler = NULL;
+    if (NULL != handler)
+      handler (handler_cls,
+               NULL);
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Received message of type %u and size %u from %s service.\n",
+       ntohs (cmsg->type),
+       msize,
+       client->service_name);
   GNUNET_assert (GNUNET_YES == client->msg_complete);
   GNUNET_assert (client->received_pos >= msize);
-  memcpy (msg, cmsg, msize);
-  memmove (client->received_buf, &client->received_buf[msize],
+  GNUNET_memcpy (msg, cmsg, msize);
+  memmove (client->received_buf,
+          &client->received_buf[msize],
            client->received_pos - msize);
   client->received_pos -= msize;
   client->msg_complete = GNUNET_NO;
@@ -594,38 +616,47 @@ receive_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
  *
  * @param client the service
  * @param handler function to call with the message
- * @param handler_cls closure for handler
+ * @param handler_cls closure for @a handler
  * @param timeout how long to wait until timing out
  */
 void
 GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *client,
-                       GNUNET_CLIENT_MessageHandler handler, void *handler_cls,
+                       GNUNET_CLIENT_MessageHandler handler,
+                      void *handler_cls,
                        struct GNUNET_TIME_Relative timeout)
 {
   if (NULL == client->connection)
   {
     /* already disconnected, fail instantly! */
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+               "Client API violation for service `%s'\n",
+               client->service_name);
     GNUNET_break (0);           /* this should not happen in well-written code! */
     if (NULL != handler)
-      handler (handler_cls, NULL);
+      handler (handler_cls,
+               NULL);
     return;
   }
   client->receiver_handler = handler;
   client->receiver_handler_cls = handler_cls;
   client->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout);
-  if (GNUNET_YES == client->msg_complete)
+  if ( (GNUNET_YES == client->msg_complete) ||
+       (GNUNET_SYSERR == client->in_receive) )
   {
-    GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == client->receive_task);
-    client->receive_task = GNUNET_SCHEDULER_add_now (&receive_task, client);
-  }
-  else
-  {
-    LOG (GNUNET_ERROR_TYPE_DEBUG, "calling GNUNET_CONNECTION_receive\n");
-    GNUNET_assert (GNUNET_NO == client->in_receive);
-    client->in_receive = GNUNET_YES;
-    GNUNET_CONNECTION_receive (client->connection, GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
-                               timeout, &receive_helper, client);
+    GNUNET_assert (NULL == client->receive_task);
+    client->receive_task = GNUNET_SCHEDULER_add_now (&receive_task,
+                                                    client);
+    return;
   }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "calling GNUNET_CONNECTION_receive\n");
+  GNUNET_assert (GNUNET_NO == client->in_receive);
+  client->in_receive = GNUNET_YES;
+  GNUNET_CONNECTION_receive (client->connection,
+                             GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
+                             timeout,
+                             &receive_helper,
+                             client);
 }
 
 
@@ -640,7 +671,7 @@ struct GNUNET_CLIENT_TestHandle
   GNUNET_CLIENT_TestResultCallback cb;
 
   /**
-   * Closure for 'cb'.
+   * Closure for @e cb.
    */
   void *cb_cls;
 
@@ -655,14 +686,14 @@ struct GNUNET_CLIENT_TestHandle
   struct GNUNET_CLIENT_TransmitHandle *th;
 
   /**
-   * Deadline for calling 'cb'.
+   * Deadline for calling @e cb.
    */
   struct GNUNET_TIME_Absolute test_deadline;
 
   /**
    * ID of task used for asynchronous operations.
    */
-  GNUNET_SCHEDULER_TaskIdentifier task;
+  struct GNUNET_SCHEDULER_Task *task;
 
   /**
    * Final result to report back (once known).
@@ -689,10 +720,10 @@ GNUNET_CLIENT_service_test_cancel (struct GNUNET_CLIENT_TestHandle *th)
     GNUNET_CLIENT_disconnect (th->client);
     th->client = NULL;
   }
-  if (GNUNET_SCHEDULER_NO_TASK != th->task)
+  if (NULL != th->task)
   {
     GNUNET_SCHEDULER_cancel (th->task);
-    th->task = GNUNET_SCHEDULER_NO_TASK;
+    th->task = NULL;
   }
   GNUNET_free (th);
 }
@@ -702,16 +733,14 @@ GNUNET_CLIENT_service_test_cancel (struct GNUNET_CLIENT_TestHandle *th)
  * Task that reports back the result by calling the callback
  * and then cleans up.
  *
- * @param cls the 'struct GNUNET_CLIENT_TestHandle'
- * @param tc scheduler context
+ * @param cls the `struct GNUNET_CLIENT_TestHandle`
  */
 static void
-report_result (void *cls,
-              const struct GNUNET_SCHEDULER_TaskContext *tc)
+report_result (void *cls)
 {
   struct GNUNET_CLIENT_TestHandle *th = cls;
 
-  th->task = GNUNET_SCHEDULER_NO_TASK;
+  th->task = NULL;
   th->cb (th->cb_cls, th->result);
   GNUNET_CLIENT_service_test_cancel (th);
 }
@@ -736,11 +765,12 @@ service_test_report (struct GNUNET_CLIENT_TestHandle *th,
 /**
  * Receive confirmation from test, service is up.
  *
- * @param cls closure with the 'struct GNUNET_CLIENT_TestHandle'
+ * @param cls closure with the `struct GNUNET_CLIENT_TestHandle`
  * @param msg message received, NULL on timeout or fatal error
  */
 static void
-confirm_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+confirm_handler (void *cls,
+                 const struct GNUNET_MessageHeader *msg)
 {
   struct GNUNET_CLIENT_TestHandle *th = cls;
 
@@ -764,10 +794,10 @@ confirm_handler (void *cls, const struct GNUNET_MessageHeader *msg)
  * Send the 'TEST' message to the service.  If successful, prepare to
  * receive the reply.
  *
- * @param cls the 'struct GNUNET_CLIENT_TestHandle' of the test
- * @param size number of bytes available in buf
+ * @param cls the `struct GNUNET_CLIENT_TestHandle` of the test
+ * @param size number of bytes available in @a buf
  * @param buf where to write the message
- * @return number of bytes written to buf
+ * @return number of bytes written to @a buf
  */
 static size_t
 write_test (void *cls, size_t size, void *buf)
@@ -807,14 +837,15 @@ write_test (void *cls, size_t size, void *buf)
  * @param cfg configuration to use
  * @param timeout how long to wait at most
  * @param cb function to call with the result
- * @param cb_cls closure for 'cb'
+ * @param cb_cls closure for @a cb
  * @return handle to cancel the test
  */
 struct GNUNET_CLIENT_TestHandle *
 GNUNET_CLIENT_service_test (const char *service,
                             const struct GNUNET_CONFIGURATION_Handle *cfg,
                             struct GNUNET_TIME_Relative timeout,
-                            GNUNET_CLIENT_TestResultCallback cb, void *cb_cls)
+                            GNUNET_CLIENT_TestResultCallback cb,
+                           void *cb_cls)
 {
   struct GNUNET_CLIENT_TestHandle *th;
   char *hostname;
@@ -833,22 +864,40 @@ GNUNET_CLIENT_service_test (const char *service,
     /* probe UNIX support */
     struct sockaddr_un s_un;
     char *unixpath;
+    int abstract;
 
     unixpath = NULL;
     if ((GNUNET_OK ==
-        GNUNET_CONFIGURATION_get_value_filename (cfg, service, "UNIXPATH", &unixpath)) &&
+        GNUNET_CONFIGURATION_get_value_filename (cfg,
+                                                 service,
+                                                 "UNIXPATH",
+                                                 &unixpath)) &&
        (0 < strlen (unixpath)))  /* We have a non-NULL unixpath, does that mean it's valid? */
     {
       if (strlen (unixpath) >= sizeof (s_un.sun_path))
       {
         LOG (GNUNET_ERROR_TYPE_WARNING,
-             _("UNIXPATH `%s' too long, maximum length is %llu\n"), unixpath,
+             _("UNIXPATH `%s' too long, maximum length is %llu\n"),
+            unixpath,
              (unsigned long long) sizeof (s_un.sun_path));
        unixpath = GNUNET_NETWORK_shorten_unixpath (unixpath);
         LOG (GNUNET_ERROR_TYPE_INFO,
              _("Using `%s' instead\n"), unixpath);
       }
     }
+#ifdef LINUX
+    abstract = GNUNET_CONFIGURATION_get_value_yesno (cfg,
+                                                     "TESTING",
+                                                     "USE_ABSTRACT_SOCKETS");
+#else
+    abstract = GNUNET_NO;
+#endif
+    if ((NULL != unixpath) && (GNUNET_YES != abstract))
+    {
+      if (GNUNET_SYSERR == GNUNET_DISK_directory_create_for_file (unixpath))
+        GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
+                                  "mkdir", unixpath);
+    }
     if (NULL != unixpath)
     {
       sock = GNUNET_NETWORK_socket_create (PF_UNIX, SOCK_STREAM, 0);
@@ -857,6 +906,8 @@ GNUNET_CLIENT_service_test (const char *service,
        memset (&s_un, 0, sizeof (s_un));
        s_un.sun_family = AF_UNIX;
         strncpy (s_un.sun_path, unixpath, sizeof (s_un.sun_path) - 1);
+        if (GNUNET_YES == abstract)
+          s_un.sun_path[0] = '\0';
 #if HAVE_SOCKADDR_IN_SIN_LEN
         s_un.sun_len = (u_char) sizeof (struct sockaddr_un);
 #endif
@@ -1001,10 +1052,10 @@ GNUNET_CLIENT_service_test (const char *service,
  * a transmission request.  Either pass it on to our
  * user or, if possible, retry.
  *
- * @param cls our "struct GNUNET_CLIENT_TransmissionHandle"
+ * @param cls our `struct GNUNET_CLIENT_TransmissionHandle`
  * @param size number of bytes available for transmission
  * @param buf where to write them
- * @return number of bytes written to buf
+ * @return number of bytes written to @a buf
  */
 static size_t
 client_notify (void *cls, size_t size, void *buf);
@@ -1014,49 +1065,43 @@ client_notify (void *cls, size_t size, void *buf);
  * This task is run if we should re-try connection to the
  * service after a while.
  *
- * @param cls our "struct GNUNET_CLIENT_TransmitHandle" of the request
- * @param tc unused
+ * @param cls our `struct GNUNET_CLIENT_TransmitHandle` of the request
  */
 static void
-client_delayed_retry (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+client_delayed_retry (void *cls)
 {
   struct GNUNET_CLIENT_TransmitHandle *th = cls;
   struct GNUNET_TIME_Relative delay;
 
-  th->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
-  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
-  {
-    /* give up, was shutdown */
-    th->client->th = NULL;
-    th->notify (th->notify_cls, 0, NULL);
-    GNUNET_free (th);
-    return;
-  }
+  th->reconnect_task = NULL;
   th->client->connection =
-      do_connect (th->client->service_name, th->client->cfg, th->client->attempts++);
+    do_connect (th->client->service_name,
+               th->client->cfg,
+               th->client->attempts++);
   th->client->first_message = GNUNET_YES;
   if (NULL == th->client->connection)
   {
     /* could happen if we're out of sockets */
-    delay =
-        GNUNET_TIME_relative_min (GNUNET_TIME_absolute_get_remaining
-                                  (th->timeout), th->client->back_off);
-    th->client->back_off =
-        GNUNET_TIME_relative_min (GNUNET_TIME_relative_multiply
-                                  (th->client->back_off, 2),
-                                  GNUNET_TIME_UNIT_SECONDS);
+    delay = GNUNET_TIME_relative_min (GNUNET_TIME_absolute_get_remaining (th->timeout),
+                                      th->client->back_off);
+    th->client->back_off = GNUNET_TIME_STD_BACKOFF (th->client->back_off);
     LOG (GNUNET_ERROR_TYPE_DEBUG,
          "Transmission failed %u times, trying again in %s.\n",
          MAX_ATTEMPTS - th->attempts_left,
          GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
+    GNUNET_assert (NULL == th->th);
+    GNUNET_assert (NULL == th->reconnect_task);
     th->reconnect_task =
-        GNUNET_SCHEDULER_add_delayed (delay, &client_delayed_retry, th);
+        GNUNET_SCHEDULER_add_delayed (delay,
+                                     &client_delayed_retry,
+                                     th);
     return;
   }
   th->th =
       GNUNET_CONNECTION_notify_transmit_ready (th->client->connection, th->size,
                                                GNUNET_TIME_absolute_get_remaining
-                                               (th->timeout), &client_notify,
+                                               (th->timeout),
+                                              &client_notify,
                                                th);
   if (NULL == th->th)
   {
@@ -1073,34 +1118,38 @@ client_delayed_retry (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
  * Connection notifies us about failure or success of a transmission
  * request.  Either pass it on to our user or, if possible, retry.
  *
- * @param cls our "struct GNUNET_CLIENT_TransmissionHandle"
+ * @param cls our `struct GNUNET_CLIENT_TransmissionHandle`
  * @param size number of bytes available for transmission
  * @param buf where to write them
- * @return number of bytes written to buf
+ * @return number of bytes written to @a buf
  */
 static size_t
-client_notify (void *cls, size_t size, void *buf)
+client_notify (void *cls,
+               size_t size,
+               void *buf)
 {
   struct GNUNET_CLIENT_TransmitHandle *th = cls;
   struct GNUNET_CLIENT_Connection *client = th->client;
   size_t ret;
   struct GNUNET_TIME_Relative delay;
 
-  LOG (GNUNET_ERROR_TYPE_DEBUG, "client_notify is running\n");
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "client_notify is running\n");
   th->th = NULL;
   client->th = NULL;
   if (NULL == buf)
   {
     delay = GNUNET_TIME_absolute_get_remaining (th->timeout);
     delay.rel_value_us /= 2;
-    if ((GNUNET_YES != th->auto_retry) || (0 == --th->attempts_left) ||
-        (delay.rel_value_us < 1)||
-       (0 != (GNUNET_SCHEDULER_get_reason() & GNUNET_SCHEDULER_REASON_SHUTDOWN)))
+    if ( (GNUNET_YES != th->auto_retry) ||
+         (0 == --th->attempts_left) ||
+         (delay.rel_value_us < 1) )
     {
       LOG (GNUNET_ERROR_TYPE_DEBUG,
            "Transmission failed %u times, giving up.\n",
            MAX_ATTEMPTS - th->attempts_left);
-      GNUNET_break (0 == th->notify (th->notify_cls, 0, NULL));
+      GNUNET_break (0 ==
+                    th->notify (th->notify_cls, 0, NULL));
       GNUNET_free (th);
       return 0;
     }
@@ -1125,21 +1174,33 @@ client_notify (void *cls, size_t size, void *buf)
          MAX_ATTEMPTS - th->attempts_left,
          GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
     client->th = th;
+    GNUNET_assert (NULL == th->reconnect_task);
+    GNUNET_assert (NULL == th->th);
     th->reconnect_task =
-        GNUNET_SCHEDULER_add_delayed (delay, &client_delayed_retry, th);
+        GNUNET_SCHEDULER_add_delayed (delay,
+                                     &client_delayed_retry,
+                                     th);
     return 0;
   }
   GNUNET_assert (size >= th->size);
   ret = th->notify (th->notify_cls, size, buf);
   GNUNET_free (th);
+  if (sizeof (struct GNUNET_MessageHeader) <= ret)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Transmitting message of type %u and size %u to %s service.\n",
+         ntohs (((struct GNUNET_MessageHeader *) buf)->type),
+         ntohs (((struct GNUNET_MessageHeader *) buf)->size),
+         client->service_name);
+  }
   return ret;
 }
 
 
 /**
  * Ask the client to call us once the specified number of bytes
- * are free in the transmission buffer.  May call the notify
- * method immediately if enough space is available.
+ * are free in the transmission buffer.  Will never call the @a notify
+ * callback in this task, but always first go into the scheduler.
  *
  * @param client connection to the service
  * @param size number of bytes to send
@@ -1151,7 +1212,7 @@ client_notify (void *cls, size_t size, void *buf)
  *        if the caller does not care about temporary connection errors,
  *        for example because the protocol is stateless
  * @param notify function to call
- * @param notify_cls closure for notify
+ * @param notify_cls closure for @a notify
  * @return NULL if our buffer will never hold size bytes,
  *         a handle if the notify callback was queued (can be used to cancel)
  */
@@ -1160,8 +1221,8 @@ GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
                                      size_t size,
                                      struct GNUNET_TIME_Relative timeout,
                                      int auto_retry,
-                                     GNUNET_CONNECTION_TransmitReadyNotify
-                                     notify, void *notify_cls)
+                                     GNUNET_CONNECTION_TransmitReadyNotify notify,
+                                    void *notify_cls)
 {
   struct GNUNET_CLIENT_TransmitHandle *th;
 
@@ -1169,10 +1230,10 @@ GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
   {
     /* If this breaks, you most likley called this function twice without waiting
      * for completion or canceling the request */
-    GNUNET_break (0);
+    GNUNET_assert (0);
     return NULL;
   }
-  th = GNUNET_malloc (sizeof (struct GNUNET_CLIENT_TransmitHandle));
+  th = GNUNET_new (struct GNUNET_CLIENT_TransmitHandle);
   th->client = client;
   th->size = size;
   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
@@ -1185,16 +1246,20 @@ GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
   client->th = th;
   if (NULL == client->connection)
   {
+    GNUNET_assert (NULL == th->th);
+    GNUNET_assert (NULL == th->reconnect_task);
     th->reconnect_task =
-        GNUNET_SCHEDULER_add_delayed (client->back_off, &client_delayed_retry,
+        GNUNET_SCHEDULER_add_delayed (client->back_off,
+                                      &client_delayed_retry,
                                       th);
-
   }
   else
   {
-    th->th =
-        GNUNET_CONNECTION_notify_transmit_ready (client->connection, size, timeout,
-                                                 &client_notify, th);
+    th->th = GNUNET_CONNECTION_notify_transmit_ready (client->connection,
+                                                      size,
+                                                      timeout,
+                                                      &client_notify,
+                                                      th);
     if (NULL == th->th)
     {
       GNUNET_break (0);
@@ -1213,14 +1278,13 @@ GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
  * @param th handle from the original request.
  */
 void
-GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle
-                                            *th)
+GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle *th)
 {
-  if (GNUNET_SCHEDULER_NO_TASK != th->reconnect_task)
+  if (NULL != th->reconnect_task)
   {
     GNUNET_assert (NULL == th->th);
     GNUNET_SCHEDULER_cancel (th->reconnect_task);
-    th->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+    th->reconnect_task = NULL;
   }
   else
   {
@@ -1232,97 +1296,4 @@ GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle
 }
 
 
-/**
- * Function called to notify a client about the socket
- * begin ready to queue the message.  "buf" will be
- * NULL and "size" zero if the socket was closed for
- * writing in the meantime.
- *
- * @param cls closure of type "struct TransmitGetResponseContext*"
- * @param size number of bytes available in buf
- * @param buf where the callee should write the message
- * @return number of bytes written to buf
- */
-static size_t
-transmit_for_response (void *cls, size_t size, void *buf)
-{
-  struct TransmitGetResponseContext *tc = cls;
-  uint16_t msize;
-
-  tc->client->tag = NULL;
-  msize = ntohs (tc->hdr->size);
-  if (NULL == buf)
-  {
-    LOG (GNUNET_ERROR_TYPE_DEBUG,
-         _("Could not submit request, not expecting to receive a response.\n"));
-    if (NULL != tc->rn)
-      tc->rn (tc->rn_cls, NULL);
-    GNUNET_free (tc);
-    return 0;
-  }
-  GNUNET_assert (size >= msize);
-  memcpy (buf, tc->hdr, msize);
-  GNUNET_CLIENT_receive (tc->client, tc->rn, tc->rn_cls,
-                         GNUNET_TIME_absolute_get_remaining (tc->timeout));
-  GNUNET_free (tc);
-  return msize;
-}
-
-
-/**
- * Convenience API that combines sending a request
- * to the service and waiting for a response.
- * If either operation times out, the callback
- * will be called with a "NULL" response (in which
- * case the connection should probably be destroyed).
- *
- * @param client connection to use
- * @param hdr message to transmit
- * @param timeout when to give up (for both transmission
- *         and for waiting for a response)
- * @param auto_retry if the connection to the service dies, should we
- *        automatically re-connect and retry (within the timeout period)
- *        or should we immediately fail in this case?  Pass GNUNET_YES
- *        if the caller does not care about temporary connection errors,
- *        for example because the protocol is stateless
- * @param rn function to call with the response
- * @param rn_cls closure for rn
- * @return GNUNET_OK on success, GNUNET_SYSERR if a request
- *         is already pending
- */
-int
-GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection *client,
-                                         const struct GNUNET_MessageHeader *hdr,
-                                         struct GNUNET_TIME_Relative timeout,
-                                         int auto_retry,
-                                         GNUNET_CLIENT_MessageHandler rn,
-                                         void *rn_cls)
-{
-  struct TransmitGetResponseContext *tc;
-  uint16_t msize;
-
-  if (NULL != client->th)
-    return GNUNET_SYSERR;
-  GNUNET_assert (NULL == client->tag);
-  msize = ntohs (hdr->size);
-  tc = GNUNET_malloc (sizeof (struct TransmitGetResponseContext) + msize);
-  tc->client = client;
-  tc->hdr = (const struct GNUNET_MessageHeader *) &tc[1];
-  memcpy (&tc[1], hdr, msize);
-  tc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
-  tc->rn = rn;
-  tc->rn_cls = rn_cls;
-  if (NULL ==
-      GNUNET_CLIENT_notify_transmit_ready (client, msize, timeout, auto_retry,
-                                           &transmit_for_response, tc))
-  {
-    GNUNET_break (0);
-    GNUNET_free (tc);
-    return GNUNET_SYSERR;
-  }
-  client->tag = tc;
-  return GNUNET_OK;
-}
-
-
 /*  end of client.c */