-removing 2nd argument from GNUNET_CLIENT_disconnect as it was virtually always GNUNE...
[oweals/gnunet.git] / src / util / connection.c
index 6c2aafb0e7780930cbaa87dbe1033d1dddc6b692..6908144b790ca7f7a5ec7b4db53974534b228663 100644 (file)
 #include "gnunet_container_lib.h"
 #include "gnunet_resolver_service.h"
 #include "gnunet_scheduler_lib.h"
+#include "gnunet_server_lib.h"
 
-#define DEBUG_CONNECTION GNUNET_NO
 
+#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+
+#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall)
 
 /**
  * Possible functions to call after connect failed or succeeded.
  */
 enum ConnectContinuations
-  {
+{
     /**
      * Call nothing.
      */
-    COCO_NONE = 0,
+  COCO_NONE = 0,
 
     /**
      * Call "receive_again".
      */
-    COCO_RECEIVE_AGAIN = 1,
+  COCO_RECEIVE_AGAIN = 1,
 
     /**
      * Call "transmit_ready".
      */
-    COCO_TRANSMIT_READY = 2,
+  COCO_TRANSMIT_READY = 2,
 
     /**
      * Call "destroy_continuation".
      */
-    COCO_DESTROY_CONTINUATION = 4
-  };
+  COCO_DESTROY_CONTINUATION = 4
+};
 
 
 /**
  * Transmission handle.  There can only be one for each connection.
- */ 
+ */
 struct GNUNET_CONNECTION_TransmitHandle
 {
 
@@ -111,7 +114,7 @@ struct GNUNET_CONNECTION_TransmitHandle
 
 /**
  * During connect, we try multiple possible IP addresses
- * to find out which one might work. 
+ * to find out which one might work.
  */
 struct AddressProbe
 {
@@ -159,24 +162,19 @@ struct AddressProbe
 struct GNUNET_CONNECTION_Handle
 {
 
-  /**
-   * Scheduler that was used for the connect task.
-   */
-  struct GNUNET_SCHEDULER_Handle *sched;
-
   /**
    * Configuration to use.
-   */ 
+   */
   const struct GNUNET_CONFIGURATION_Handle *cfg;
 
   /**
-   * Linked list of sockets we are currently trying out 
+   * Linked list of sockets we are currently trying out
    * (during connect).
    */
   struct AddressProbe *ap_head;
 
   /**
-   * Linked list of sockets we are currently trying out 
+   * Linked list of sockets we are currently trying out
    * (during connect).
    */
   struct AddressProbe *ap_tail;
@@ -213,7 +211,7 @@ struct GNUNET_CONNECTION_Handle
   char *write_buffer;
 
   /**
-   * Size of our write buffer.
+   * Current size of our write buffer.
    */
   size_t write_buffer_size;
 
@@ -225,7 +223,7 @@ struct GNUNET_CONNECTION_Handle
 
   /**
    * Current read-offset in write buffer (how many
-   * bytes have already been send).
+   * bytes have already been sent).
    */
   size_t write_buffer_pos;
 
@@ -244,6 +242,16 @@ struct GNUNET_CONNECTION_Handle
    */
   GNUNET_SCHEDULER_TaskIdentifier write_task;
 
+  /**
+   * Destroy task (if already scheduled).
+   */
+  GNUNET_SCHEDULER_TaskIdentifier destroy_task;
+
+  /**
+   * Handle to a pending DNS lookup request.
+   */
+  struct GNUNET_RESOLVER_RequestHandle *dns_active;
+
   /**
    * The handle we return for GNUNET_CONNECTION_notify_transmit_ready.
    */
@@ -253,55 +261,86 @@ struct GNUNET_CONNECTION_Handle
    * Timeout for receiving (in absolute time).
    */
   struct GNUNET_TIME_Absolute receive_timeout;
-  
+
   /**
    * Functions to call after connect failed or succeeded.
    */
   enum ConnectContinuations ccs;
+
   /**
    * Maximum number of bytes to read (for receiving).
    */
   size_t max;
 
   /**
-   * Are we still waiting for DNS replies (on connect)?
-   * GNUNET_YES if we are, GNUNET_NO if we are not waiting for DNS,
-   * GNUNET_SYSERR if destroying the handle was deferred due to 
-   * a pending DNS lookup.
+   * Ignore GNUNET_SCHEDULER_REASON_SHUTDOWN for this socket.
    */
-  int dns_active;
+  int ignore_shutdown;
 
   /**
    * Port to connect to.
    */
   uint16_t port;
 
+  /**
+   * When shutdown, do not ever actually close the socket, but
+   * free resources.  Only should ever be set if using program
+   * termination as a signal (because only then will the leaked
+   * socket be freed!)
+   */
+  int16_t persist;
+
 };
 
+/**
+ * Set the persist option on this connection handle.  Indicates
+ * that the underlying socket or fd should never really be closed.
+ * Used for indicating process death.
+ *
+ * @param sock the connection to set persistent
+ */
+void
+GNUNET_CONNECTION_persist_ (struct GNUNET_CONNECTION_Handle *sock)
+{
+  sock->persist = GNUNET_YES;
+}
+
+
+/**
+ * Disable the "CORK" feature for communication with the given socket,
+ * forcing the OS to immediately flush the buffer on transmission
+ * instead of potentially buffering multiple messages.  Essentially
+ * reduces the OS send buffers to zero.
+ * Used to make sure that the last messages sent through the connection
+ * reach the other side before the process is terminated.
+ *
+ * @param sock the connection to make flushing and blocking
+ * @return GNUNET_OK on success
+ */
+int
+GNUNET_CONNECTION_disable_corking (struct GNUNET_CONNECTION_Handle *sock)
+{
+  return GNUNET_NETWORK_socket_disable_corking (sock->sock);
+}
+
 
 /**
  * Create a socket handle by boxing an existing OS socket.  The OS
  * socket should henceforth be no longer used directly.
  * GNUNET_socket_destroy will close it.
  *
- * @param sched scheduler to use
  * @param osSocket existing socket to box
- * @param maxbuf maximum write buffer size for the socket (use
- *        0 for sockets that need no write buffers, such as listen sockets)
  * @return the boxed socket handle
  */
 struct GNUNET_CONNECTION_Handle *
-GNUNET_CONNECTION_create_from_existing (struct GNUNET_SCHEDULER_Handle
-                                            *sched, struct GNUNET_NETWORK_Handle *osSocket,
-                                            size_t maxbuf)
+GNUNET_CONNECTION_create_from_existing (struct GNUNET_NETWORK_Handle *osSocket)
 {
   struct GNUNET_CONNECTION_Handle *ret;
-  ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle) + maxbuf);
-  ret->write_buffer = (char *) &ret[1];
-  ret->write_buffer_size = maxbuf;
+
+  ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle));
+  ret->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
+  ret->write_buffer = GNUNET_malloc (ret->write_buffer_size);
   ret->sock = osSocket;
-  ret->sched = sched;
   return ret;
 }
 
@@ -310,23 +349,18 @@ GNUNET_CONNECTION_create_from_existing (struct GNUNET_SCHEDULER_Handle
  * Create a socket handle by accepting on a listen socket.  This
  * function may block if the listen socket has no connection ready.
  *
- * @param sched scheduler to use
  * @param access function to use to check if access is allowed
  * @param access_cls closure for access
  * @param lsock listen socket
- * @param maxbuf maximum write buffer size for the socket (use
- *        0 for sockets that need no write buffers, such as listen sockets)
  * @return the socket handle, NULL on error
  */
 struct GNUNET_CONNECTION_Handle *
-GNUNET_CONNECTION_create_from_accept (struct GNUNET_SCHEDULER_Handle
-                                          *sched,
-                                          GNUNET_CONNECTION_AccessCheck access,
-                                          void *access_cls, struct GNUNET_NETWORK_Handle *lsock,
-                                          size_t maxbuf)
+GNUNET_CONNECTION_create_from_accept (GNUNET_CONNECTION_AccessCheck access,
+                                      void *access_cls,
+                                      struct GNUNET_NETWORK_Handle *lsock)
 {
   struct GNUNET_CONNECTION_Handle *ret;
-  char addr[32];
+  char addr[128];
   socklen_t addrlen;
   struct GNUNET_NETWORK_Handle *sock;
   int aret;
@@ -334,71 +368,117 @@ GNUNET_CONNECTION_create_from_accept (struct GNUNET_SCHEDULER_Handle
   struct sockaddr_in6 *v6;
   struct sockaddr *sa;
   void *uaddr;
+  struct GNUNET_CONNECTION_Credentials *gcp;
+  struct GNUNET_CONNECTION_Credentials gc;
+
+#ifdef SO_PEERCRED
+  struct ucred uc;
+  socklen_t olen;
+#endif
 
   addrlen = sizeof (addr);
-  sock = GNUNET_NETWORK_socket_accept (lsock, (struct sockaddr *) &addr, &addrlen);
+  sock =
+      GNUNET_NETWORK_socket_accept (lsock, (struct sockaddr *) &addr, &addrlen);
   if (NULL == sock)
-    {
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "accept");
-      return NULL;
-    }
-  if (addrlen > sizeof (addr))
-    {
-      GNUNET_break (0);
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
-      return NULL;
-    }
+  {
+    LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "accept");
+    return NULL;
+  }
+  if ((addrlen > sizeof (addr)) || (addrlen < sizeof (sa_family_t)))
+  {
+    GNUNET_break (0);
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
+    return NULL;
+  }
 
   sa = (struct sockaddr *) addr;
   v6 = (struct sockaddr_in6 *) addr;
   if ((sa->sa_family == AF_INET6) && (IN6_IS_ADDR_V4MAPPED (&v6->sin6_addr)))
-    {
-      /* convert to V4 address */
-      v4 = GNUNET_malloc (sizeof (struct sockaddr_in));
-      memset (v4, 0, sizeof (struct sockaddr_in));
-      v4->sin_family = AF_INET;
-      memcpy (&v4->sin_addr,
-              &((char *) &v6->sin6_addr)[sizeof (struct in6_addr) -
-                                         sizeof (struct in_addr)],
-              sizeof (struct in_addr));
-      v4->sin_port = v6->sin6_port;
-      uaddr = v4;
-      addrlen = sizeof (struct sockaddr_in);
-    }
+  {
+    /* convert to V4 address */
+    v4 = GNUNET_malloc (sizeof (struct sockaddr_in));
+    memset (v4, 0, sizeof (struct sockaddr_in));
+    v4->sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+    v4->sin_len = (u_char) sizeof (struct sockaddr_in);
+#endif
+    memcpy (&v4->sin_addr,
+            &((char *) &v6->sin6_addr)[sizeof (struct in6_addr) -
+                                       sizeof (struct in_addr)],
+            sizeof (struct in_addr));
+    v4->sin_port = v6->sin6_port;
+    uaddr = v4;
+    addrlen = sizeof (struct sockaddr_in);
+  }
   else
+  {
+    uaddr = GNUNET_malloc (addrlen);
+    memcpy (uaddr, addr, addrlen);
+  }
+  gcp = NULL;
+  gc.uid = 0;
+  gc.gid = 0;
+  if (sa->sa_family == AF_UNIX)
+  {
+#if HAVE_GETPEEREID
+    /* most BSDs */
+    if (0 == getpeereid (GNUNET_NETWORK_get_fd (sock), &gc.uid, &gc.gid))
+      gcp = &gc;
+#else
+#ifdef SO_PEERCRED
+    /* largely traditional GNU/Linux */
+    olen = sizeof (uc);
+    if ((0 ==
+         getsockopt (GNUNET_NETWORK_get_fd (sock), SOL_SOCKET, SO_PEERCRED, &uc,
+                     &olen)) && (olen == sizeof (uc)))
     {
-      uaddr = GNUNET_malloc (addrlen);
-      memcpy (uaddr, addr, addrlen);
+      gc.uid = uc.uid;
+      gc.gid = uc.gid;
+      gcp = &gc;
     }
+#else
+#if HAVE_GETPEERUCRED
+    /* this is for Solaris 10 */
+    ucred_t *uc;
 
-  if ((access != NULL) &&
-      (GNUNET_YES != (aret = access (access_cls, uaddr, addrlen))))
+    uc = NULL;
+    if (0 == getpeerucred (GNUNET_NETWORK_get_fd (sock), &uc))
     {
-      if (aret == GNUNET_NO)
-       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                   _("Access denied to `%s'\n"),
-                   GNUNET_a2s(uaddr, addrlen));
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_shutdown (sock, SHUT_RDWR));
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
-      GNUNET_free (uaddr);
-      return NULL;
+      gc.uid = ucred_geteuid (uc);
+      gc.gid = ucred_getegid (uc);
+      gcp = &gc;
     }
-  ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle) + maxbuf);
-  ret->write_buffer = (char *) &ret[1];
-  ret->write_buffer_size = maxbuf;
+    ucred_free (uc);
+#endif
+#endif
+#endif
+  }
+
+  if ((access != NULL) &&
+      (GNUNET_YES != (aret = access (access_cls, gcp, uaddr, addrlen))))
+  {
+    if (aret == GNUNET_NO)
+      LOG (GNUNET_ERROR_TYPE_INFO, _("Access denied to `%s'\n"),
+           GNUNET_a2s (uaddr, addrlen));
+    GNUNET_break (GNUNET_OK ==
+                  GNUNET_NETWORK_socket_shutdown (sock, SHUT_RDWR));
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
+    GNUNET_free (uaddr);
+    return NULL;
+  }
+  ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle));
+  ret->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
+  ret->write_buffer = GNUNET_malloc (ret->write_buffer_size);
   ret->addr = uaddr;
   ret->addrlen = addrlen;
   ret->sock = sock;
-  ret->sched = sched;
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-             _("Accepting connection from `%s': %p\n"),
-             GNUNET_a2s(uaddr, addrlen),
-             ret);
-#endif
+  LOG (GNUNET_ERROR_TYPE_INFO, 
+       _("Accepting connection from `%s': %p\n"),
+       GNUNET_a2s (uaddr, addrlen), ret);
   return ret;
 }
 
+
 /**
  * Obtain the network address of the other party.
  *
@@ -409,7 +489,7 @@ GNUNET_CONNECTION_create_from_accept (struct GNUNET_SCHEDULER_Handle
  */
 int
 GNUNET_CONNECTION_get_address (struct GNUNET_CONNECTION_Handle *sock,
-                                   void **addr, size_t * addrlen)
+                               void **addr, size_t * addrlen)
 {
   if ((sock->addr == NULL) || (sock->addrlen == 0))
     return GNUNET_NO;
@@ -420,17 +500,6 @@ GNUNET_CONNECTION_get_address (struct GNUNET_CONNECTION_Handle *sock,
 }
 
 
-/**
- * It is time to re-try connecting.
- * 
- * @param cls the handle for the connection that should be re-tried
- * @param tc unused scheduler taks context
- */
-static void
-retry_connect_continuation (void *cls,
-                           const struct GNUNET_SCHEDULER_TaskContext *tc);
-
-
 /**
  * This function is called after establishing a connection either has
  * succeeded or timed out.  Note that it is possible that the attempt
@@ -453,85 +522,83 @@ receive_again (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
  * @param tc unused
  */
 static void
-destroy_continuation (void *cls,
-                      const struct GNUNET_SCHEDULER_TaskContext *tc)
+destroy_continuation (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct GNUNET_CONNECTION_Handle *sock = cls;
   GNUNET_CONNECTION_TransmitReadyNotify notify;
+  struct AddressProbe *pos;
 
-  if (sock->dns_active == GNUNET_YES)
-    {
-      sock->dns_active = GNUNET_SYSERR;
-      return;
-    }
+  sock->destroy_task = GNUNET_SCHEDULER_NO_TASK;
+  GNUNET_assert (sock->dns_active == NULL);
   if (0 != (sock->ccs & COCO_TRANSMIT_READY))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "Destroy waits for CCS-TR to be done (%p)\n",
-                 sock);
-#endif
-      sock->ccs |= COCO_DESTROY_CONTINUATION;
-      return;
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroy waits for CCS-TR to be done (%p)\n",
+         sock);
+    sock->ccs |= COCO_DESTROY_CONTINUATION;
+    return;
+  }
   if (sock->write_task != GNUNET_SCHEDULER_NO_TASK)
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "Destroy waits for write_task to be done (%p)\n",
-                 sock);
-#endif
-      GNUNET_SCHEDULER_add_after (sock->sched,
-                                  GNUNET_YES,
-                                  GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                  sock->write_task,
-                                  &destroy_continuation, sock);
-      return;
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Destroy waits for write_task to be done (%p)\n", sock);
+    GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == sock->destroy_task);
+    sock->destroy_task =
+        GNUNET_SCHEDULER_add_after (sock->write_task, &destroy_continuation,
+                                    sock);
+    return;
+  }
   if (0 != (sock->ccs & COCO_RECEIVE_AGAIN))
-    {
-      sock->ccs |= COCO_DESTROY_CONTINUATION;
-      return;
-    }
+  {
+    sock->ccs |= COCO_DESTROY_CONTINUATION;
+    return;
+  }
   if (sock->sock != NULL)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down socket (%p)\n", sock);
+    if (sock->persist != GNUNET_YES)
     {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "Shutting down socket (%p)\n",
-                 sock);
-#endif
-      GNUNET_NETWORK_socket_shutdown (sock->sock, SHUT_RDWR);
+      if ((GNUNET_YES != GNUNET_NETWORK_socket_shutdown (sock->sock, SHUT_RDWR))
+          && (errno != ENOTCONN) && (errno != ECONNRESET))
+        LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "shutdown");
     }
+  }
   if (sock->read_task != GNUNET_SCHEDULER_NO_TASK)
-    {
-      GNUNET_SCHEDULER_add_after (sock->sched,
-                                  GNUNET_YES,
-                                  GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                  sock->read_task,
-                                  &destroy_continuation, sock);
-      return;
-    }
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-             "Destroy actually runs (%p)!\n",
-             sock);
-#endif
+  {
+    GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == sock->destroy_task);
+    sock->destroy_task =
+        GNUNET_SCHEDULER_add_after (sock->read_task, &destroy_continuation,
+                                    sock);
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroy actually runs (%p)!\n", sock);
+  while (NULL != (pos = sock->ap_head))
+  {
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (pos->sock));
+    GNUNET_SCHEDULER_cancel (pos->task);
+    GNUNET_CONTAINER_DLL_remove (sock->ap_head, sock->ap_tail, pos);
+    GNUNET_free (pos);
+  }
   GNUNET_assert (sock->nth.timeout_task == GNUNET_SCHEDULER_NO_TASK);
   GNUNET_assert (sock->ccs == COCO_NONE);
   if (NULL != (notify = sock->nth.notify_ready))
-    {
-      sock->nth.notify_ready = NULL;
-      notify (sock->nth.notify_ready_cls, 0, NULL);
-    }
+  {
+    sock->nth.notify_ready = NULL;
+    notify (sock->nth.notify_ready_cls, 0, NULL);
+  }
+
   if (sock->sock != NULL)
-    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock->sock));
+  {
+    if (sock->persist != GNUNET_YES)
+      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock->sock));
+    else
+      GNUNET_free (sock->sock); /* at least no memory leak (we deliberately
+                                 * leak the socket in this special case) ... */
+  }
   GNUNET_free_non_null (sock->addr);
   GNUNET_free_non_null (sock->hostname);
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Freeing memory of connection %p.\n",
-             sock);
-#endif
+  GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == sock->destroy_task);
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Freeing memory of connection %p.\n", sock);
+  GNUNET_free (sock->write_buffer);
   GNUNET_free (sock);
 }
 
@@ -557,68 +624,44 @@ transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
 static void
 connect_fail_continuation (struct GNUNET_CONNECTION_Handle *h)
 {
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Failed to establish TCP connection to `%s:%u', no further addresses to try (%p).\n",
-             h->hostname,
-             h->port,
-             h);
-#endif
+  LOG (GNUNET_ERROR_TYPE_INFO,
+       _("Failed to establish TCP connection to `%s:%u', no further addresses to try.\n"),
+       h->hostname, h->port);
   /* connect failed / timed out */
   GNUNET_break (h->ap_head == NULL);
   GNUNET_break (h->ap_tail == NULL);
   GNUNET_break (h->dns_active == GNUNET_NO);
   GNUNET_break (h->sock == NULL);
 
-  /* FIXME: trigger delayed reconnect attempt... */
   /* trigger jobs that used to wait on "connect_task" */
   if (0 != (h->ccs & COCO_RECEIVE_AGAIN))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "connect_timeout_continuation triggers receive_again (%p)\n",
-                 h);
-#endif
-      h->ccs -= COCO_RECEIVE_AGAIN;
-      h->read_task = GNUNET_SCHEDULER_add_after (h->sched,
-                                                GNUNET_NO,
-                                                GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                                GNUNET_SCHEDULER_NO_TASK,
-                                                &receive_again,
-                                                h);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "connect_fail_continuation triggers receive_again (%p)\n", h);
+    h->ccs -= COCO_RECEIVE_AGAIN;
+    h->read_task = GNUNET_SCHEDULER_add_now (&receive_again, h);
+  }
   if (0 != (h->ccs & COCO_TRANSMIT_READY))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "connect_timeout_continuation cancels timeout_task, triggers transmit_ready (%p)\n",
-                 h);
-#endif
-      GNUNET_assert (h->nth.timeout_task != GNUNET_SCHEDULER_NO_TASK);    
-      GNUNET_SCHEDULER_cancel (h->sched, h->nth.timeout_task);
-      h->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
-      h->ccs -= COCO_TRANSMIT_READY;
-      h->write_task = GNUNET_SCHEDULER_add_after (h->sched,
-                                                 GNUNET_NO,
-                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                                 GNUNET_SCHEDULER_NO_TASK,
-                                                 &transmit_ready,
-                                                 h);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "connect_fail_continuation cancels timeout_task, triggers transmit_ready (%p)\n",
+         h);
+    GNUNET_assert (h->nth.timeout_task != GNUNET_SCHEDULER_NO_TASK);
+    GNUNET_SCHEDULER_cancel (h->nth.timeout_task);
+    h->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
+    h->ccs -= COCO_TRANSMIT_READY;
+    GNUNET_assert (h->nth.notify_ready != NULL);
+    GNUNET_assert (h->write_task == GNUNET_SCHEDULER_NO_TASK);
+    h->write_task = GNUNET_SCHEDULER_add_now (&transmit_ready, h);
+  }
   if (0 != (h->ccs & COCO_DESTROY_CONTINUATION))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "connect_timeout_continuation runs destroy_continuation (%p)\n",
-                 h);
-#endif
-      h->ccs -= COCO_DESTROY_CONTINUATION;
-      GNUNET_SCHEDULER_add_continuation (h->sched,
-                                        GNUNET_NO,
-                                        &destroy_continuation,
-                                        h,
-                                        GNUNET_SCHEDULER_REASON_TIMEOUT);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "connect_fail_continuation runs destroy_continuation (%p)\n", h);
+    h->ccs -= COCO_DESTROY_CONTINUATION;
+    GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == h->destroy_task);
+    h->destroy_task = GNUNET_SCHEDULER_add_now (&destroy_continuation, h);
+  }
 }
 
 
@@ -630,61 +673,40 @@ connect_fail_continuation (struct GNUNET_CONNECTION_Handle *h)
 static void
 connect_success_continuation (struct GNUNET_CONNECTION_Handle *h)
 {
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Connection to `%s' succeeded! (%p)\n",
-             GNUNET_a2s(h->addr, h->addrlen),
-             h);
-#endif
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection to `%s' succeeded! (%p)\n",
+       GNUNET_a2s (h->addr, h->addrlen), h);
   /* trigger jobs that waited for the connection */
   if (0 != (h->ccs & COCO_RECEIVE_AGAIN))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "connect_success_continuation runs receive_again (%p)\n",
-                 h);
-#endif
-      h->ccs -= COCO_RECEIVE_AGAIN;
-      h->read_task = GNUNET_SCHEDULER_add_after (h->sched,
-                                                GNUNET_NO,
-                                                GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                                GNUNET_SCHEDULER_NO_TASK,
-                                                &receive_again,
-                                                h);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "connect_success_continuation runs receive_again (%p)\n", h);
+    h->ccs -= COCO_RECEIVE_AGAIN;
+    h->read_task = GNUNET_SCHEDULER_add_now (&receive_again, h);
+  }
   if (0 != (h->ccs & COCO_TRANSMIT_READY))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "connect_success_continuation runs transmit_ready, cancels timeout_task (%p)\n",
-                 h);
-#endif
-      GNUNET_assert (h->nth.timeout_task != GNUNET_SCHEDULER_NO_TASK);    
-      GNUNET_SCHEDULER_cancel (h->sched, h->nth.timeout_task);
-      h->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
-      h->ccs -= COCO_TRANSMIT_READY;
-      h->write_task =
-       GNUNET_SCHEDULER_add_write_net (h->sched,
-                                       GNUNET_NO,
-                                       GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                       GNUNET_SCHEDULER_NO_TASK,
-                                       GNUNET_TIME_absolute_get_remaining (h->nth.transmit_timeout),
-                                       h->sock, &transmit_ready, h);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "connect_success_continuation runs transmit_ready, cancels timeout_task (%p)\n",
+         h);
+    GNUNET_assert (h->nth.timeout_task != GNUNET_SCHEDULER_NO_TASK);
+    GNUNET_SCHEDULER_cancel (h->nth.timeout_task);
+    h->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
+    h->ccs -= COCO_TRANSMIT_READY;
+    GNUNET_assert (h->write_task == GNUNET_SCHEDULER_NO_TASK);
+    GNUNET_assert (h->nth.notify_ready != NULL);
+    h->write_task =
+        GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_absolute_get_remaining
+                                        (h->nth.transmit_timeout), h->sock,
+                                        &transmit_ready, h);
+  }
   if (0 != (h->ccs & COCO_DESTROY_CONTINUATION))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "connect_success_continuation runs destroy_continuation (%p)\n",
-                 h);
-#endif
-      h->ccs -= COCO_DESTROY_CONTINUATION;
-      GNUNET_SCHEDULER_add_continuation (h->sched,
-                                        GNUNET_NO,
-                                        &destroy_continuation,
-                                        h,
-                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "connect_success_continuation runs destroy_continuation (%p)\n", h);
+    h->ccs -= COCO_DESTROY_CONTINUATION;
+    GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == h->destroy_task);
+    h->destroy_task = GNUNET_SCHEDULER_add_now (&destroy_continuation, h);
+  }
 }
 
 
@@ -697,29 +719,31 @@ connect_success_continuation (struct GNUNET_CONNECTION_Handle *h)
  */
 static void
 connect_probe_continuation (void *cls,
-                           const struct GNUNET_SCHEDULER_TaskContext *tc)
+                            const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct AddressProbe *ap = cls;
   struct GNUNET_CONNECTION_Handle *h = ap->h;
   struct AddressProbe *pos;
   int error;
-  unsigned int len;
+  socklen_t len;
 
+  GNUNET_assert (ap->sock != NULL);
   GNUNET_CONTAINER_DLL_remove (h->ap_head, h->ap_tail, ap);
   len = sizeof (error);
   errno = 0;
   error = 0;
-  if ( (0 == (tc->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) ||
-       (GNUNET_OK != GNUNET_NETWORK_socket_getsockopt (ap->sock, SOL_SOCKET, SO_ERROR, &error, &len)) ||
-       (error != 0) || (errno != 0) )
-    {
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ap->sock));
-      GNUNET_free (ap);
-      if ( (NULL == h->ap_head) &&
-          (h->dns_active == GNUNET_NO) )
-       connect_fail_continuation (h);
-      return;
-    }
+  if ((0 == (tc->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) ||
+      (GNUNET_OK !=
+       GNUNET_NETWORK_socket_getsockopt (ap->sock, SOL_SOCKET, SO_ERROR, &error,
+                                         &len)) || (error != 0))
+  {
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ap->sock));
+    GNUNET_free (ap);
+    if ((NULL == h->ap_head) && (h->dns_active == GNUNET_NO))
+      connect_fail_continuation (h);
+    return;
+  }
+  GNUNET_assert (h->sock == NULL);
   h->sock = ap->sock;
   GNUNET_assert (h->addr == NULL);
   h->addr = GNUNET_malloc (ap->addrlen);
@@ -728,12 +752,12 @@ connect_probe_continuation (void *cls,
   GNUNET_free (ap);
   /* cancel all other attempts */
   while (NULL != (pos = h->ap_head))
-    {
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (pos->sock));
-      GNUNET_SCHEDULER_cancel (h->sched, pos->task);
-      GNUNET_CONTAINER_DLL_remove (h->ap_head, h->ap_tail, pos);
-      GNUNET_free (pos);
-    }
+  {
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (pos->sock));
+    GNUNET_SCHEDULER_cancel (pos->task);
+    GNUNET_CONTAINER_DLL_remove (h->ap_head, h->ap_tail, pos);
+    GNUNET_free (pos);
+  }
   connect_success_continuation (h);
 }
 
@@ -747,134 +771,83 @@ connect_probe_continuation (void *cls,
  * @param addrlen length of addr
  */
 static void
-try_connect_using_address (void *cls,
-                          const struct sockaddr * addr,
-                          socklen_t addrlen)
+try_connect_using_address (void *cls, const struct sockaddr *addr,
+                           socklen_t addrlen)
 {
   struct GNUNET_CONNECTION_Handle *h = cls;
   struct AddressProbe *ap;
   struct GNUNET_TIME_Relative delay;
+
   if (addr == NULL)
-    {
-      if (h->dns_active == GNUNET_SYSERR)
-       {
-         h->dns_active = GNUNET_NO;
-         GNUNET_SCHEDULER_add_after (h->sched,
-                                     GNUNET_YES,
-                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                     h->read_task,
-                                     &destroy_continuation, 
-                                     h);
-         return;
-       }
-      h->dns_active = GNUNET_NO;
-      if (NULL == h->ap_head)
-       connect_fail_continuation (h);
-      return;
-    }
+  {
+    h->dns_active = NULL;
+    if ((NULL == h->ap_head) && (NULL == h->sock))
+      connect_fail_continuation (h);
+    return;
+  }
   if (h->sock != NULL)
-    return; /* already connected */
-  if (h->dns_active == GNUNET_SYSERR)
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                 "Connection %p has already been destroyed.\n",
-                 h);
-#endif
-      return; /* already destroyed */
-    }
+    return;                     /* already connected */
+  GNUNET_assert (h->addr == NULL);
   /* try to connect */
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Trying to connect using address `%s:%u/%s:%u'\n",
-             h->hostname,
-             h->port,
-             GNUNET_a2s (addr, addrlen),
-             h->port);
-#endif
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Trying to connect using address `%s:%u/%s:%u'\n", h->hostname, h->port,
+       GNUNET_a2s (addr, addrlen), h->port);
   ap = GNUNET_malloc (sizeof (struct AddressProbe) + addrlen);
-  ap->addr = (const struct sockaddr*) &ap[1];
+  ap->addr = (const struct sockaddr *) &ap[1];
   memcpy (&ap[1], addr, addrlen);
-  ap->addrlen = addrlen;  
+  ap->addrlen = addrlen;
   ap->h = h;
 
   switch (ap->addr->sa_family)
-    {
-    case AF_INET:
-      ((struct sockaddr_in *) ap->addr)->sin_port = htons (h->port);
-      break;
-    case AF_INET6:
-      ((struct sockaddr_in6 *) ap->addr)->sin6_port = htons (h->port);
-      break;
-    default:
-      GNUNET_break (0);
-      GNUNET_free (ap);
-      return; /* not supported by us */
-    }
+  {
+  case AF_INET:
+    ((struct sockaddr_in *) ap->addr)->sin_port = htons (h->port);
+    break;
+  case AF_INET6:
+    ((struct sockaddr_in6 *) ap->addr)->sin6_port = htons (h->port);
+    break;
+  default:
+    GNUNET_break (0);
+    GNUNET_free (ap);
+    return;                     /* not supported by us */
+  }
   ap->sock = GNUNET_NETWORK_socket_create (ap->addr->sa_family, SOCK_STREAM, 0);
   if (ap->sock == NULL)
-    {
-      GNUNET_free (ap);
-      return; /* not supported by OS */
-    }
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-             _("Trying to connect to `%s' (%p)\n"),
-             GNUNET_a2s(ap->addr,
-                        ap->addrlen),
-             h);
+  {
+    GNUNET_free (ap);
+    return;                     /* not supported by OS */
+  }
+  LOG (GNUNET_ERROR_TYPE_INFO, _("Trying to connect to `%s' (%p)\n"),
+       GNUNET_a2s (ap->addr, ap->addrlen), h);
+  if ((GNUNET_OK !=
+       GNUNET_NETWORK_socket_connect (ap->sock, ap->addr, ap->addrlen)) &&
+      (errno != EINPROGRESS))
+  {
+    /* maybe refused / unsupported address, try next */
+    LOG_STRERROR (GNUNET_ERROR_TYPE_INFO, "connect");
+#if 0
+    LOG (GNUNET_ERROR_TYPE_INFO, _("Failed to connect to `%s' (%p)\n"),
+         GNUNET_a2s (ap->addr, ap->addrlen), h);
 #endif
-  if ( (GNUNET_OK != GNUNET_NETWORK_socket_connect (ap->sock,
-                                                   ap->addr,
-                                                   ap->addrlen)) && 
-       (errno != EINPROGRESS))
-    {
-      /* maybe refused / unsupported address, try next */
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO, "connect");
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ap->sock));
-      GNUNET_free (ap);
-      return;
-    }
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ap->sock));
+    GNUNET_free (ap);
+    return;
+  }
   GNUNET_CONTAINER_DLL_insert (h->ap_head, h->ap_tail, ap);
   delay = GNUNET_CONNECTION_CONNECT_RETRY_TIMEOUT;
   if (h->nth.notify_ready != NULL)
-    delay = GNUNET_TIME_relative_min (delay,
-                                     GNUNET_TIME_absolute_get_remaining (h->nth.transmit_timeout));
+    delay =
+        GNUNET_TIME_relative_min (delay,
+                                  GNUNET_TIME_absolute_get_remaining (h->
+                                                                      nth.transmit_timeout));
   if (h->receiver != NULL)
-    delay = GNUNET_TIME_relative_min (delay,
-                                     GNUNET_TIME_absolute_get_remaining (h->receive_timeout));
-   ap->task = GNUNET_SCHEDULER_add_write_net (h->sched,
-                                            GNUNET_NO,
-                                            GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                            GNUNET_SCHEDULER_NO_TASK,
-                                            delay,
-                                            ap->sock,
-                                            &connect_probe_continuation,
-                                            ap);
-}
-
-
-/**
- * It is time to re-try connecting.
- * 
- * @param cls the handle for the connection that should be re-tried
- * @param tc unused scheduler taks context
- */
-static void
-retry_connect_continuation (void *cls,
-                           const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-  struct GNUNET_CONNECTION_Handle *sock = cls;
-
-  sock->dns_active = GNUNET_YES;
-  GNUNET_RESOLVER_ip_get (sock->sched,
-                         sock->cfg,
-                         sock->hostname,
-                         AF_UNSPEC,
-                         GNUNET_CONNECTION_CONNECT_RETRY_TIMEOUT,
-                         &try_connect_using_address,
-                         sock);
+    delay =
+        GNUNET_TIME_relative_min (delay,
+                                  GNUNET_TIME_absolute_get_remaining
+                                  (h->receive_timeout));
+  ap->task =
+      GNUNET_SCHEDULER_add_write_net (delay, ap->sock,
+                                      &connect_probe_continuation, ap);
 }
 
 
@@ -883,32 +856,96 @@ retry_connect_continuation (void *cls,
  * This function returns immediately, even if the connection has not
  * yet been established.  This function only creates TCP connections.
  *
- * @param sched scheduler to use
  * @param cfg configuration to use
  * @param hostname name of the host to connect to
  * @param port port to connect to
- * @param maxbuf maximum write buffer size for the socket (use
- *        0 for sockets that need no write buffers, such as listen sockets)
  * @return the socket handle
  */
 struct GNUNET_CONNECTION_Handle *
-GNUNET_CONNECTION_create_from_connect (struct GNUNET_SCHEDULER_Handle *sched, 
-                                      const struct GNUNET_CONFIGURATION_Handle *cfg,
-                                      const char *hostname,
-                                      uint16_t port, size_t maxbuf)
+GNUNET_CONNECTION_create_from_connect (const struct GNUNET_CONFIGURATION_Handle
+                                       *cfg, const char *hostname,
+                                       uint16_t port)
 {
   struct GNUNET_CONNECTION_Handle *ret;
 
-  GNUNET_assert (0 < strlen (hostname)); /* sanity check */
-  ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle) + maxbuf);
+  GNUNET_assert (0 < strlen (hostname));        /* sanity check */
+  ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle));
   ret->cfg = cfg;
-  ret->sched = sched;
-  ret->write_buffer = (char *) &ret[1];
-  ret->write_buffer_size = maxbuf;
+  ret->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
+  ret->write_buffer = GNUNET_malloc (ret->write_buffer_size);
   ret->port = port;
   ret->hostname = GNUNET_strdup (hostname);
-  retry_connect_continuation (ret, NULL);
+  ret->dns_active =
+      GNUNET_RESOLVER_ip_get (ret->hostname, AF_UNSPEC,
+                              GNUNET_CONNECTION_CONNECT_RETRY_TIMEOUT,
+                              &try_connect_using_address, ret);
+  return ret;
+}
+
+
+/**
+ * Create a socket handle by connecting to a UNIX domain service.
+ * This function returns immediately, even if the connection has not
+ * yet been established.  This function only creates UNIX connections.
+ *
+ * @param cfg configuration to use
+ * @param unixpath path to connect to
+ * @return the socket handle, NULL on systems without UNIX support
+ */
+struct GNUNET_CONNECTION_Handle *
+GNUNET_CONNECTION_create_from_connect_to_unixpath (const struct
+                                                   GNUNET_CONFIGURATION_Handle
+                                                   *cfg, const char *unixpath)
+{
+#ifdef AF_UNIX
+  struct GNUNET_CONNECTION_Handle *ret;
+  struct sockaddr_un *un;
+  size_t slen;
+
+  GNUNET_assert (0 < strlen (unixpath));        /* sanity check */
+  un = GNUNET_malloc (sizeof (struct sockaddr_un));
+  un->sun_family = AF_UNIX;
+  slen = strlen (unixpath);
+  if (slen >= sizeof (un->sun_path))
+    slen = sizeof (un->sun_path) - 1;
+  memcpy (un->sun_path, unixpath, slen);
+  un->sun_path[slen] = '\0';
+  slen = sizeof (struct sockaddr_un);
+#if HAVE_SOCKADDR_IN_SIN_LEN
+  un->sun_len = (u_char) slen;
+#endif
+#if LINUX
+  un->sun_path[0] = '\0';
+#endif
+  ret = GNUNET_malloc (sizeof (struct GNUNET_CONNECTION_Handle));
+  ret->cfg = cfg;
+  ret->write_buffer_size = GNUNET_SERVER_MIN_BUFFER_SIZE;
+  ret->write_buffer = GNUNET_malloc (ret->write_buffer_size);
+  ret->port = 0;
+  ret->hostname = NULL;
+  ret->addr = (struct sockaddr *) un;
+  ret->addrlen = slen;
+  ret->sock = GNUNET_NETWORK_socket_create (AF_UNIX, SOCK_STREAM, 0);
+  if (NULL == ret->sock)
+  {
+    GNUNET_free (ret->addr);
+    GNUNET_free (ret->write_buffer);
+    GNUNET_free (ret);
+    return NULL;
+  }
+  if (GNUNET_OK !=
+      GNUNET_NETWORK_socket_connect (ret->sock, ret->addr, ret->addrlen))
+  {
+    /* Just return; we expect everything to work eventually so don't fail HARD */
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (ret->sock));
+    ret->sock = NULL;
+    return ret;
+  }
+  connect_success_continuation (ret);
   return ret;
+#else
+  return NULL;
+#endif
 }
 
 
@@ -917,47 +954,42 @@ GNUNET_CONNECTION_create_from_connect (struct GNUNET_SCHEDULER_Handle *sched,
  * This function returns immediately, even if the connection has not
  * yet been established.  This function only creates TCP connections.
  *
- * @param sched scheduler to use
  * @param af_family address family to use
  * @param serv_addr server address
  * @param addrlen length of server address
- * @param maxbuf maximum write buffer size for the socket (use
- *        0 for sockets that need no write buffers, such as listen sockets)
  * @return the socket handle
  */
 struct GNUNET_CONNECTION_Handle *
-GNUNET_CONNECTION_create_from_sockaddr (struct GNUNET_SCHEDULER_Handle
-                                            *sched, int af_family,
-                                            const struct sockaddr *serv_addr,
-                                            socklen_t addrlen, size_t maxbuf)
+GNUNET_CONNECTION_create_from_sockaddr (int af_family,
+                                        const struct sockaddr *serv_addr,
+                                        socklen_t addrlen)
 {
   struct GNUNET_NETWORK_Handle *s;
   struct GNUNET_CONNECTION_Handle *ret;
 
+
   s = GNUNET_NETWORK_socket_create (af_family, SOCK_STREAM, 0);
   if (s == NULL)
-    {
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING |
-                           GNUNET_ERROR_TYPE_BULK, "socket");
-      return NULL;
-    }
-  if ((GNUNET_OK != GNUNET_NETWORK_socket_connect (s, serv_addr, addrlen)) && (errno != EINPROGRESS))
-    {
-      /* maybe refused / unsupported address, try next */
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO, "connect");
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (s));
-      return NULL;
-    }
-  ret = GNUNET_CONNECTION_create_from_existing (sched, s, maxbuf);
+  {
+    LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, "socket");
+    return NULL;
+  }
+  if ((GNUNET_OK != GNUNET_NETWORK_socket_connect (s, serv_addr, addrlen)) &&
+      (errno != EINPROGRESS))
+  {
+    /* maybe refused / unsupported address, try next */
+    LOG_STRERROR (GNUNET_ERROR_TYPE_INFO, "connect");
+    LOG (GNUNET_ERROR_TYPE_INFO, _("Attempt to connect to `%s' failed\n"),
+         GNUNET_a2s (serv_addr, addrlen));
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (s));
+    return NULL;
+  }
+  ret = GNUNET_CONNECTION_create_from_existing (s);
   ret->addr = GNUNET_malloc (addrlen);
   memcpy (ret->addr, serv_addr, addrlen);
   ret->addrlen = addrlen;
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-             _("Trying to connect to `%s' (%p)\n"),
-             GNUNET_a2s(serv_addr, addrlen),
-             ret);
-#endif
+  LOG (GNUNET_ERROR_TYPE_INFO, _("Trying to connect to `%s' (%p)\n"),
+       GNUNET_a2s (serv_addr, addrlen), ret);
   return ret;
 }
 
@@ -973,8 +1005,7 @@ GNUNET_CONNECTION_create_from_sockaddr (struct GNUNET_SCHEDULER_Handle
 int
 GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *sock)
 {
-  if ( (sock->ap_head != NULL) ||
-       (sock->dns_active == GNUNET_YES) )
+  if ((sock->ap_head != NULL) || (sock->dns_active != NULL))
     return GNUNET_YES;          /* still trying to connect */
   return (sock->sock == NULL) ? GNUNET_NO : GNUNET_YES;
 }
@@ -982,27 +1013,38 @@ GNUNET_CONNECTION_check (struct GNUNET_CONNECTION_Handle *sock)
 
 /**
  * Close the socket and free associated resources. Pending
- * transmissions are simply dropped.  A pending receive call will be
- * called with an error code of "EPIPE".
+ * transmissions may be completed or dropped depending on the
+ * arguments.   If a receive call is pending and should
+ * NOT be completed, 'GNUNET_CONNECTION_receive_cancel'
+ * should be called explicitly first.
  *
  * @param sock socket to destroy
+ * @param finish_pending_write should pending writes be completed or aborted?
+ *        (this applies to transmissions where the data has already been
+ *        read from the application; all other transmissions should be
+ *        aborted using 'GNUNET_CONNECTION_notify_transmit_ready_cancel').
  */
 void
-GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *sock)
+GNUNET_CONNECTION_destroy (struct GNUNET_CONNECTION_Handle *sock,
+                           int finish_pending_write)
 {
-  if ( (sock->write_buffer_off == 0) &&
-       (sock->dns_active == GNUNET_YES) )
+  if (GNUNET_NO == finish_pending_write)
+  {
+    if (sock->write_task != GNUNET_SCHEDULER_NO_TASK)
     {
-      sock->dns_active = GNUNET_SYSERR;        /* if we're still trying to connect and have
-                                                 no message pending, stop trying! */
-      return;
+      GNUNET_SCHEDULER_cancel (sock->write_task);
+      sock->write_task = GNUNET_SCHEDULER_NO_TASK;
+      sock->write_buffer_off = 0;
     }
-  GNUNET_assert (sock->sched != NULL);
-  GNUNET_SCHEDULER_add_after (sock->sched,
-                              GNUNET_YES,
-                              GNUNET_SCHEDULER_PRIORITY_KEEP,
-                              GNUNET_SCHEDULER_NO_TASK,
-                              &destroy_continuation, sock);
+    sock->nth.notify_ready = NULL;
+  }
+  if ((sock->write_buffer_off == 0) && (sock->dns_active != NULL))
+  {
+    GNUNET_RESOLVER_request_cancel (sock->dns_active);
+    sock->dns_active = NULL;
+  }
+  GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == sock->destroy_task);
+  sock->destroy_task = GNUNET_SCHEDULER_add_now (&destroy_continuation, sock);
 }
 
 
@@ -1014,11 +1056,8 @@ signal_timeout (struct GNUNET_CONNECTION_Handle *sh)
 {
   GNUNET_CONNECTION_Receiver receiver;
 
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Network signals time out to receiver (%p)!\n",
-             sh);
-#endif
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Network signals time out to receiver (%p)!\n",
+       sh);
   GNUNET_assert (NULL != (receiver = sh->receiver));
   sh->receiver = NULL;
   receiver (sh->receiver_cls, NULL, 0, NULL, 0, 0);
@@ -1032,6 +1071,7 @@ static void
 signal_error (struct GNUNET_CONNECTION_Handle *sh, int errcode)
 {
   GNUNET_CONNECTION_Receiver receiver;
+
   GNUNET_assert (NULL != (receiver = sh->receiver));
   sh->receiver = NULL;
   receiver (sh->receiver_cls, NULL, 0, sh->addr, sh->addrlen, errcode);
@@ -1052,56 +1092,54 @@ receive_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
   GNUNET_CONNECTION_Receiver receiver;
 
   sh->read_task = GNUNET_SCHEDULER_NO_TASK;
+  if ((GNUNET_YES == sh->ignore_shutdown) &&
+      (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)))
+  {
+    /* ignore shutdown request, go again immediately */
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Ignoring shutdown signal per configuration\n");
+    sh->read_task =
+        GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_absolute_get_remaining
+                                       (sh->receive_timeout), sh->sock,
+                                       &receive_ready, sh);
+    return;
+  }
   now = GNUNET_TIME_absolute_get ();
-  if ( (now.value > sh->receive_timeout.value) ||
-       (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT)) ||
-       (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) )
-    {
-#if DEBUG_CONNECTION
-      if (0 == (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
-       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                   "Receive from `%s' encounters error: time out by %llums... (%p)\n",
-                   GNUNET_a2s (sh->addr, sh->addrlen),
-                   GNUNET_TIME_absolute_get_duration (sh->receive_timeout).value,
-                   sh);
-#endif
-      signal_timeout (sh);
-      return;
-    }
+  if ((now.abs_value > sh->receive_timeout.abs_value) ||
+      (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT)) ||
+      (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)))
+  {
+    if (0 == (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "Receive from `%s' encounters error: time out by %llums... (%p)\n",
+           GNUNET_a2s (sh->addr, sh->addrlen),
+           GNUNET_TIME_absolute_get_duration (sh->receive_timeout).rel_value,
+           sh);
+    signal_timeout (sh);
+    return;
+  }
   if (sh->sock == NULL)
-    {
-      /* connect failed for good */
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Receive encounters error, socket closed... (%p)\n",
-                 sh);
-#endif
-      signal_error (sh, ECONNREFUSED);
-      return;
-    }
+  {
+    /* connect failed for good */
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Receive encounters error, socket closed... (%p)\n", sh);
+    signal_error (sh, ECONNREFUSED);
+    return;
+  }
   GNUNET_assert (GNUNET_NETWORK_fdset_isset (tc->read_ready, sh->sock));
 RETRY:
   ret = GNUNET_NETWORK_socket_recv (sh->sock, buffer, sh->max);
   if (ret == -1)
-    {
-      if (errno == EINTR)
-        goto RETRY;
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Error receiving: %s\n", 
-                 STRERROR (errno));
-#endif
-      signal_error (sh, errno);
-      return;
-    }
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "receive_ready read %u/%u bytes from `%s' (%p)!\n",
-             (unsigned int) ret,
-             sh->max,
-             GNUNET_a2s(sh->addr, sh->addrlen),
-             sh);
-#endif
+  {
+    if (errno == EINTR)
+      goto RETRY;
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "Error receiving: %s\n", STRERROR (errno));
+    signal_error (sh, errno);
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "receive_ready read %u/%u bytes from `%s' (%p)!\n", (unsigned int) ret,
+       sh->max, GNUNET_a2s (sh->addr, sh->addrlen), sh);
   GNUNET_assert (NULL != (receiver = sh->receiver));
   sh->receiver = NULL;
   receiver (sh->receiver_cls, buffer, ret, sh->addr, sh->addrlen, 0);
@@ -1125,40 +1163,29 @@ receive_again (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
   struct GNUNET_TIME_Absolute now;
 
   sh->read_task = GNUNET_SCHEDULER_NO_TASK;
-  if (sh->sock == NULL) 
-    {
-      /* not connected and no longer trying */
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Receive encounters error, socket closed (%p)...\n",
-                 sh);
-#endif
-      signal_error (sh, ECONNREFUSED);
-      return;
-    }
+  if (sh->sock == NULL)
+  {
+    /* not connected and no longer trying */
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Receive encounters error, socket closed (%p)...\n", sh);
+    signal_error (sh, ECONNREFUSED);
+    return;
+  }
   now = GNUNET_TIME_absolute_get ();
-  if ((now.value > sh->receive_timeout.value) ||
+  if ((now.abs_value > sh->receive_timeout.abs_value) ||
       (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Receive encounters error: time out (%p)...\n",
-                 sh);
-#endif
-      signal_timeout (sh);
-      return;
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Receive encounters error: time out (%p)...\n", sh);
+    signal_timeout (sh);
+    return;
+  }
   GNUNET_assert (sh->sock != NULL);
   /* connect succeeded, wait for data! */
-  sh->read_task = GNUNET_SCHEDULER_add_read_net (tc->sched,
-                                                GNUNET_YES,
-                                                GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                                GNUNET_SCHEDULER_NO_TASK,
-                                                GNUNET_TIME_absolute_get_remaining
-                                                (sh->receive_timeout),
-                                                sh->sock,
-                                                &receive_ready,
-                                                sh);
+  sh->read_task =
+      GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_absolute_get_remaining
+                                     (sh->receive_timeout), sh->sock,
+                                     &receive_ready, sh);
 }
 
 
@@ -1176,38 +1203,50 @@ receive_again (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
  * @param receiver_cls closure for receiver
  */
 void
-GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle *sock,
-                        size_t max,
-                        struct GNUNET_TIME_Relative timeout,
-                        GNUNET_CONNECTION_Receiver receiver, void *receiver_cls)
+GNUNET_CONNECTION_receive (struct GNUNET_CONNECTION_Handle *sock, size_t max,
+                           struct GNUNET_TIME_Relative timeout,
+                           GNUNET_CONNECTION_Receiver receiver,
+                           void *receiver_cls)
 {
   struct GNUNET_SCHEDULER_TaskContext tc;
 
   GNUNET_assert ((sock->read_task == GNUNET_SCHEDULER_NO_TASK) &&
-                (0 == (sock->ccs & COCO_RECEIVE_AGAIN)) &&
+                 (0 == (sock->ccs & COCO_RECEIVE_AGAIN)) &&
                  (sock->receiver == NULL));
   sock->receiver = receiver;
   sock->receiver_cls = receiver_cls;
   sock->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout);
   sock->max = max;
   if (sock->sock != NULL)
-    {
-      memset (&tc, 0, sizeof (tc));
-      tc.sched = sock->sched;
-      tc.reason = GNUNET_SCHEDULER_REASON_PREREQ_DONE;
-      receive_again (sock, &tc);
-      return;
-    }
-  if ( (sock->dns_active != GNUNET_YES) &&
-       (sock->ap_head == NULL) )
-    {
-      receiver (receiver_cls, NULL, 0, NULL, 0, ETIMEDOUT);
-      return;
-    }
+  {
+    memset (&tc, 0, sizeof (tc));
+    tc.reason = GNUNET_SCHEDULER_REASON_PREREQ_DONE;
+    receive_again (sock, &tc);
+    return;
+  }
+  if ((sock->dns_active == NULL) && (sock->ap_head == NULL))
+  {
+    receiver (receiver_cls, NULL, 0, NULL, 0, ETIMEDOUT);
+    return;
+  }
   sock->ccs += COCO_RECEIVE_AGAIN;
 }
 
 
+/**
+ * Configure this connection to ignore shutdown signals.
+ *
+ * @param sock socket handle
+ * @param do_ignore GNUNET_YES to ignore, GNUNET_NO to restore default
+ */
+void
+GNUNET_CONNECTION_ignore_shutdown (struct GNUNET_CONNECTION_Handle *sock,
+                                   int do_ignore)
+{
+  sock->ignore_shutdown = do_ignore;
+}
+
+
 /**
  * Cancel receive job on the given socket.  Note that the
  * receiver callback must not have been called yet in order
@@ -1220,16 +1259,15 @@ void *
 GNUNET_CONNECTION_receive_cancel (struct GNUNET_CONNECTION_Handle *sock)
 {
   if (sock->read_task != GNUNET_SCHEDULER_NO_TASK)
-    {
-      GNUNET_assert (sock == GNUNET_SCHEDULER_cancel (sock->sched, 
-                                                     sock->read_task));
-      sock->read_task = GNUNET_SCHEDULER_NO_TASK;
-    }
+  {
+    GNUNET_assert (sock == GNUNET_SCHEDULER_cancel (sock->read_task));
+    sock->read_task = GNUNET_SCHEDULER_NO_TASK;
+  }
   else
-    {                                         
-      GNUNET_assert (0 != (sock->ccs & COCO_RECEIVE_AGAIN));
-      sock->ccs -= COCO_RECEIVE_AGAIN;
-    }
+  {
+    GNUNET_assert (0 != (sock->ccs & COCO_RECEIVE_AGAIN));
+    sock->ccs -= COCO_RECEIVE_AGAIN;
+  }
   sock->receiver = NULL;
   return sock->receiver_cls;
 }
@@ -1256,21 +1294,23 @@ process_notify (struct GNUNET_CONNECTION_Handle *sock)
   used = sock->write_buffer_off - sock->write_buffer_pos;
   avail = sock->write_buffer_size - used;
   size = sock->nth.notify_size;
-  if (sock->nth.notify_size > avail)
+  if (size > avail)
     return GNUNET_NO;
   sock->nth.notify_ready = NULL;
   if (sock->write_buffer_size - sock->write_buffer_off < size)
-    {
-      /* need to compact */
-      memmove (sock->write_buffer,
-               &sock->write_buffer[sock->write_buffer_pos], used);
-      sock->write_buffer_off -= sock->write_buffer_pos;
-      sock->write_buffer_pos = 0;
-    }
-  GNUNET_assert (sock->write_buffer_size - sock->write_buffer_off >= size);
-  size = notify (sock->nth.notify_ready_cls,
-                 sock->write_buffer_size - sock->write_buffer_off,
-                 &sock->write_buffer[sock->write_buffer_off]);
+  {
+    /* need to compact */
+    memmove (sock->write_buffer, &sock->write_buffer[sock->write_buffer_pos],
+             used);
+    sock->write_buffer_off -= sock->write_buffer_pos;
+    sock->write_buffer_pos = 0;
+  }
+  avail = sock->write_buffer_size - sock->write_buffer_off;
+  GNUNET_assert (avail >= size);
+  size =
+      notify (sock->nth.notify_ready_cls, avail,
+              &sock->write_buffer[sock->write_buffer_off]);
+  GNUNET_assert (size <= avail);
   sock->write_buffer_off += size;
   return GNUNET_YES;
 }
@@ -1283,30 +1323,23 @@ process_notify (struct GNUNET_CONNECTION_Handle *sock)
  * expired).
  *
  * This task notifies the client about the timeout.
+ *
+ * @param cls the 'struct GNUNET_CONNECTION_Handle'
+ * @param tc scheduler context
  */
 static void
-transmit_timeout (void *cls,
-                 const struct GNUNET_SCHEDULER_TaskContext *tc)
+transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct GNUNET_CONNECTION_Handle *sock = cls;
   GNUNET_CONNECTION_TransmitReadyNotify notify;
 
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-             "transmit_timeout running (%p)\n",
-             sock);
-#endif
   sock->nth.timeout_task = GNUNET_SCHEDULER_NO_TASK;
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-             "Transmit to `%s:%u/%s' fails, time out reached (%p).\n",
-             sock->hostname,
-             sock->port,
-             GNUNET_a2s (sock->addr, sock->addrlen),
-             sock);
-#endif
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Transmit to `%s:%u/%s' fails, time out reached (%p).\n",
+       sock->hostname,
+       sock->port, GNUNET_a2s (sock->addr, sock->addrlen), sock);
   GNUNET_assert (0 != (sock->ccs & COCO_TRANSMIT_READY));
-  sock->ccs -= COCO_TRANSMIT_READY; /* remove request */
+  sock->ccs -= COCO_TRANSMIT_READY;     /* remove request */
   notify = sock->nth.notify_ready;
   sock->nth.notify_ready = NULL;
   notify (sock->nth.notify_ready_cls, 0, NULL);
@@ -1318,20 +1351,19 @@ transmit_timeout (void *cls,
  * at the time of being asked to transmit.
  *
  * This task notifies the client about the error.
+ *
+ * @param cls the 'struct GNUNET_CONNECTION_Handle'
+ * @param tc scheduler context
  */
 static void
-connect_error (void *cls,
-              const struct GNUNET_SCHEDULER_TaskContext *tc)
+connect_error (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct GNUNET_CONNECTION_Handle *sock = cls;
   GNUNET_CONNECTION_TransmitReadyNotify notify;
 
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Transmission request of size %u fails, connection failed (%p).\n",
-             sock->nth.notify_size,
-             sock);
-#endif
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Transmission request of size %u fails (%s/%u), connection failed (%p).\n",
+       sock->nth.notify_size, sock->hostname, sock->port, sock);
   sock->write_task = GNUNET_SCHEDULER_NO_TASK;
   notify = sock->nth.notify_ready;
   sock->nth.notify_ready = NULL;
@@ -1339,11 +1371,30 @@ connect_error (void *cls,
 }
 
 
+/**
+ * FIXME
+ *
+ * @param sock FIXME
+ */
 static void
 transmit_error (struct GNUNET_CONNECTION_Handle *sock)
 {
   GNUNET_CONNECTION_TransmitReadyNotify notify;
 
+  if (NULL != sock->sock)
+  {
+    GNUNET_NETWORK_socket_shutdown (sock->sock, SHUT_RDWR);
+    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock->sock));
+    sock->sock = NULL;
+    GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == sock->write_task);
+  }
+  if (sock->read_task != GNUNET_SCHEDULER_NO_TASK)
+  {
+    GNUNET_SCHEDULER_cancel (sock->read_task);
+    sock->read_task = GNUNET_SCHEDULER_NO_TASK;
+    signal_timeout (sock);
+    return;
+  }
   if (sock->nth.notify_ready == NULL)
     return;                     /* nobody to tell about it */
   notify = sock->nth.notify_ready;
@@ -1368,111 +1419,115 @@ transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
   ssize_t ret;
   size_t have;
 
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-             "transmit_ready running (%p).\n",
-             sock);
-#endif
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "transmit_ready running (%p).\n", sock);
   GNUNET_assert (sock->write_task != GNUNET_SCHEDULER_NO_TASK);
   sock->write_task = GNUNET_SCHEDULER_NO_TASK;
   GNUNET_assert (sock->nth.timeout_task == GNUNET_SCHEDULER_NO_TASK);
-  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT))
+  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+  {
+    if ((sock->ignore_shutdown == GNUNET_YES) && (NULL != sock->sock))
+      goto SCHEDULE_WRITE;      /* ignore shutdown, go again immediately */
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Transmit to `%s' fails, shutdown happened (%p).\n",
+         GNUNET_a2s (sock->addr, sock->addrlen), sock);
+    notify = sock->nth.notify_ready;
+    if (NULL != notify)
     {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "Transmit to `%s' fails, time out reached (%p).\n",
-                 GNUNET_a2s (sock->addr, sock->addrlen),
-                 sock);
-#endif
-      notify = sock->nth.notify_ready;
       sock->nth.notify_ready = NULL;
       notify (sock->nth.notify_ready_cls, 0, NULL);
-      return;
     }
+    return;
+  }
+  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_TIMEOUT))
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Transmit to `%s' fails, time out reached (%p).\n",
+         GNUNET_a2s (sock->addr, sock->addrlen), sock);
+    notify = sock->nth.notify_ready;
+    GNUNET_assert (NULL != notify);
+    sock->nth.notify_ready = NULL;
+    notify (sock->nth.notify_ready_cls, 0, NULL);
+    return;
+  }
   GNUNET_assert (NULL != sock->sock);
   if (tc->write_ready == NULL)
-    {
-      /* special circumstances (in particular,
-        PREREQ_DONE after connect): not yet ready to write,
-        but no "fatal" error either.  Hence retry.  */
-      goto SCHEDULE_WRITE;
-    }
-  if (! GNUNET_NETWORK_fdset_isset (tc->write_ready, 
-                                   sock->sock))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                  _("Could not satisfy pending transmission request, socket closed or connect failed (%p).\n"),
-                 sock);
-#endif
-      if (NULL != sock->sock)
-       {
-         GNUNET_NETWORK_socket_shutdown (sock->sock, SHUT_RDWR);
-         GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock->sock));
-         sock->sock = NULL;
-       }
-      transmit_error (sock);
-      return;                   /* connect failed for good, we're finished */
-    }
+  {
+    /* special circumstances (in particular,
+     * PREREQ_DONE after connect): not yet ready to write,
+     * but no "fatal" error either.  Hence retry.  */
+    goto SCHEDULE_WRITE;
+  }
+  if (!GNUNET_NETWORK_fdset_isset (tc->write_ready, sock->sock))
+  {
+    LOG (GNUNET_ERROR_TYPE_INFO,
+         _
+         ("Could not satisfy pending transmission request, socket closed or connect failed (%p).\n"),
+         sock);
+    GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == sock->write_task);
+    transmit_error (sock);
+    return;                     /* connect failed for good, we're finished */
+  }
   GNUNET_assert (sock->write_buffer_off >= sock->write_buffer_pos);
+  if ((sock->nth.notify_ready != NULL) &&
+      (sock->write_buffer_size < sock->nth.notify_size))
+  {
+    sock->write_buffer =
+        GNUNET_realloc (sock->write_buffer, sock->nth.notify_size);
+    sock->write_buffer_size = sock->nth.notify_size;
+  }
   process_notify (sock);
   have = sock->write_buffer_off - sock->write_buffer_pos;
   if (have == 0)
-    {
-       /* no data ready for writing, terminate write loop */
-      return;
-    }
+  {
+    /* no data ready for writing, terminate write loop */
+    return;
+  }
+  GNUNET_assert (have <= sock->write_buffer_size);
+  GNUNET_assert (have + sock->write_buffer_pos <= sock->write_buffer_size);
+  GNUNET_assert (sock->write_buffer_pos <= sock->write_buffer_size);
 RETRY:
-  ret = GNUNET_NETWORK_socket_send (sock->sock,
-                                   &sock->write_buffer[sock->write_buffer_pos],
-                                   have);
+  ret =
+      GNUNET_NETWORK_socket_send (sock->sock,
+                                  &sock->write_buffer[sock->write_buffer_pos],
+                                  have);
   if (ret == -1)
+  {
+    if (errno == EINTR)
+      goto RETRY;
+    LOG_STRERROR (GNUNET_ERROR_TYPE_DEBUG, "send");
+    if (GNUNET_SCHEDULER_NO_TASK != sock->write_task)
     {
-      if (errno == EINTR)
-        goto RETRY;
-#if DEBUG_CONNECTION
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_DEBUG, "send");
-#endif
-      GNUNET_NETWORK_socket_shutdown (sock->sock, SHUT_RDWR);
-      GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock->sock));
-      sock->sock = NULL;
-      transmit_error (sock);
-      return;
+      GNUNET_SCHEDULER_cancel (sock->write_task);
+      sock->write_task = GNUNET_SCHEDULER_NO_TASK;
     }
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "transmit_ready transmitted %u/%u bytes to `%s' (%p)\n",
-             (unsigned int) ret,
-             have,
-             GNUNET_a2s(sock->addr, sock->addrlen),
-             sock);
-#endif
+    transmit_error (sock);
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "transmit_ready transmitted %u/%u bytes to `%s' (%p)\n",
+       (unsigned int) ret, have, GNUNET_a2s (sock->addr, sock->addrlen), sock);
   sock->write_buffer_pos += ret;
   if (sock->write_buffer_pos == sock->write_buffer_off)
-    {
-      /* transmitted all pending data */
-      sock->write_buffer_pos = 0;
-      sock->write_buffer_off = 0;
-    }
-  if ( (sock->write_buffer_off == 0) && 
-       (NULL == sock->nth.notify_ready))
-    return;                     /* all data sent! */    
+  {
+    /* transmitted all pending data */
+    sock->write_buffer_pos = 0;
+    sock->write_buffer_off = 0;
+  }
+  if ((sock->write_buffer_off == 0) && (NULL == sock->nth.notify_ready))
+    return;                     /* all data sent! */
   /* not done writing, schedule more */
 SCHEDULE_WRITE:
-#if DEBUG_CONNECTION
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-             "Re-scheduling transmit_ready (more to do) (%p).\n",
-             sock);
-#endif
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Re-scheduling transmit_ready (more to do) (%p).\n", sock);
+  have = sock->write_buffer_off - sock->write_buffer_pos;
+  GNUNET_assert ((sock->nth.notify_ready != NULL) || (have > 0));
   if (sock->write_task == GNUNET_SCHEDULER_NO_TASK)
     sock->write_task =
-      GNUNET_SCHEDULER_add_write_net (tc->sched,
-                                     GNUNET_NO,
-                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                     GNUNET_SCHEDULER_NO_TASK,
-                                     GNUNET_TIME_absolute_get_remaining (sock->nth.transmit_timeout),
-                                     sock->sock, 
-                                     &transmit_ready, sock);
+        GNUNET_SCHEDULER_add_write_net ((sock->nth.notify_ready ==
+                                         NULL) ? GNUNET_TIME_UNIT_FOREVER_REL :
+                                        GNUNET_TIME_absolute_get_remaining
+                                        (sock->nth.transmit_timeout),
+                                        sock->sock, &transmit_ready, sock);
 }
 
 
@@ -1491,16 +1546,19 @@ SCHEDULE_WRITE:
  *         NULL if we are already going to notify someone else (busy)
  */
 struct GNUNET_CONNECTION_TransmitHandle *
-GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle
-                                      *sock, size_t size,
-                                      struct GNUNET_TIME_Relative timeout,
-                                      GNUNET_CONNECTION_TransmitReadyNotify
-                                      notify, void *notify_cls)
+GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle *sock,
+                                         size_t size,
+                                         struct GNUNET_TIME_Relative timeout,
+                                         GNUNET_CONNECTION_TransmitReadyNotify
+                                         notify, void *notify_cls)
 {
   if (sock->nth.notify_ready != NULL)
+  {
+    GNUNET_assert (0);
     return NULL;
+  }
   GNUNET_assert (notify != NULL);
-  GNUNET_assert (sock->write_buffer_size >= size);
+  GNUNET_assert (size < GNUNET_SERVER_MAX_MESSAGE_SIZE);
   GNUNET_assert (sock->write_buffer_off <= sock->write_buffer_size);
   GNUNET_assert (sock->write_buffer_pos <= sock->write_buffer_size);
   GNUNET_assert (sock->write_buffer_pos <= sock->write_buffer_off);
@@ -1510,83 +1568,64 @@ GNUNET_CONNECTION_notify_transmit_ready (struct GNUNET_CONNECTION_Handle
   sock->nth.notify_size = size;
   sock->nth.transmit_timeout = GNUNET_TIME_relative_to_absolute (timeout);
   GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == sock->nth.timeout_task);
-  if ( (sock->sock == NULL) &&
-       (sock->ap_head == NULL) &&
-       (sock->dns_active != GNUNET_YES) )
-    {     
-      sock->write_task = GNUNET_SCHEDULER_add_delayed (sock->sched,
-                                                      GNUNET_NO,
-                                                      GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                                      GNUNET_SCHEDULER_NO_TASK,
-                                                      GNUNET_TIME_UNIT_ZERO,
-                                                      &connect_error,
-                                                      sock);
-      return &sock->nth;
-    }
+  if ((sock->sock == NULL) && (sock->ap_head == NULL) &&
+      (sock->dns_active == NULL))
+  {
+    if (sock->write_task != GNUNET_SCHEDULER_NO_TASK)
+      GNUNET_SCHEDULER_cancel (sock->write_task);
+    sock->write_task = GNUNET_SCHEDULER_add_now (&connect_error, sock);
+    return &sock->nth;
+  }
   if (GNUNET_SCHEDULER_NO_TASK != sock->write_task)
     return &sock->nth;
   if (sock->sock != NULL)
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "Scheduling transmit_ready (%p).\n",
-                 sock);
-#endif
-      sock->write_task = GNUNET_SCHEDULER_add_write_net (sock->sched,
-                                                        GNUNET_NO,
-                                                        GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                                        GNUNET_SCHEDULER_NO_TASK,
-                                                        GNUNET_TIME_absolute_get_remaining (sock->nth.transmit_timeout),
-                                                        sock->sock,
-                                                        &transmit_ready, sock);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "Scheduling transmit_ready (%p).\n", sock);
+    sock->write_task =
+        GNUNET_SCHEDULER_add_write_net (GNUNET_TIME_absolute_get_remaining
+                                        (sock->nth.transmit_timeout),
+                                        sock->sock, &transmit_ready, sock);
+  }
   else
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "CCS-Scheduling transmit_ready, adding timeout task (%p).\n",
-                 sock);
-#endif
-      sock->ccs |= COCO_TRANSMIT_READY;
-      sock->nth.timeout_task = GNUNET_SCHEDULER_add_delayed (sock->sched,
-                                                            GNUNET_NO,
-                                                            GNUNET_SCHEDULER_PRIORITY_KEEP,
-                                                            GNUNET_SCHEDULER_NO_TASK,
-                                                            timeout,
-                                                            &transmit_timeout,
-                                                            sock);
-    }
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "CCS-Scheduling transmit_ready, adding timeout task (%p).\n", sock);
+    sock->ccs |= COCO_TRANSMIT_READY;
+    sock->nth.timeout_task =
+        GNUNET_SCHEDULER_add_delayed (timeout, &transmit_timeout, sock);
+  }
   return &sock->nth;
 }
 
 
 /**
- * Cancel the specified transmission-ready
- * notification.
+ * Cancel the specified transmission-ready notification.
+ *
+ * @param th notification to cancel
  */
 void
 GNUNET_CONNECTION_notify_transmit_ready_cancel (struct
-                                               GNUNET_CONNECTION_TransmitHandle *h)
+                                                GNUNET_CONNECTION_TransmitHandle
+                                                *th)
 {
-  GNUNET_assert (h->notify_ready != NULL);
-  if (0 != (h->sh->ccs & COCO_TRANSMIT_READY))
-    {
-#if DEBUG_CONNECTION
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
-                 "notify_transmit_ready_cancel cancels timeout_task (%p)\n",
-                 h);
-#endif
-      GNUNET_SCHEDULER_cancel (h->sh->sched, h->timeout_task);
-      h->timeout_task = GNUNET_SCHEDULER_NO_TASK;
-      h->sh->ccs -= COCO_TRANSMIT_READY;
-    }
+  GNUNET_assert (th->notify_ready != NULL);
+  if (0 != (th->sh->ccs & COCO_TRANSMIT_READY))
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "notify_transmit_ready_cancel cancels timeout_task (%p)\n", th);
+    GNUNET_SCHEDULER_cancel (th->timeout_task);
+    th->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+    th->sh->ccs -= COCO_TRANSMIT_READY;
+  }
   else
+  {
+    if (th->sh->write_task != GNUNET_SCHEDULER_NO_TASK)
     {
-      GNUNET_SCHEDULER_cancel (h->sh->sched,
-                              h->sh->write_task);
-      h->sh->write_task = GNUNET_SCHEDULER_NO_TASK;
+      GNUNET_SCHEDULER_cancel (th->sh->write_task);
+      th->sh->write_task = GNUNET_SCHEDULER_NO_TASK;
     }
-  h->notify_ready = NULL;
+  }
+  th->notify_ready = NULL;
 }
 
 /* end of connection.c */