fix debug levels
[oweals/gnunet.git] / src / util / resolver_api.c
index 9e54282fa8b996b64eca1d7084e38001c4d269b9..f33c31f1c8ccedf328f4526ba6096088b004a594 100644 (file)
@@ -1,10 +1,10 @@
 /*
      This file is part of GNUnet.
-     (C) 2009 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2009-2016 GNUnet e.V.
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
-     by the Free Software Foundation; either version 2, or (at your
+     by the Free Software Foundation; either version 3, or (at your
      option) any later version.
 
      GNUnet is distributed in the hope that it will be useful, but
@@ -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.
 */
 
 /**
  * @author Christian Grothoff
  */
 #include "platform.h"
-#include "gnunet_getopt_lib.h"
-#include "gnunet_os_lib.h"
-#include "gnunet_client_lib.h"
+#include "gnunet_util_lib.h"
 #include "gnunet_protocols.h"
 #include "gnunet_resolver_service.h"
-#include "gnunet_server_lib.h"
 #include "resolver.h"
 
+#define LOG(kind,...) GNUNET_log_from (kind, "util-resolver-api", __VA_ARGS__)
+
+#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util-resolver-api", syscall)
 
 /**
  * Maximum supported length for a hostname
@@ -49,6 +49,44 @@ static const char *loopback[] = {
 };
 
 
+/**
+ * Configuration.
+ */
+static const struct GNUNET_CONFIGURATION_Handle *resolver_cfg;
+
+/**
+ * Our connection to the resolver service, created on-demand, but then
+ * persists until error or shutdown.
+ */
+static struct GNUNET_MQ_Handle *mq;
+
+/**
+ * Head of DLL of requests.
+ */
+static struct GNUNET_RESOLVER_RequestHandle *req_head;
+
+/**
+ * Tail of DLL of requests.
+ */
+static struct GNUNET_RESOLVER_RequestHandle *req_tail;
+
+/**
+ * How long should we wait to reconnect?
+ */
+static struct GNUNET_TIME_Relative backoff;
+
+/**
+ * Task for reconnecting.
+ */
+static struct GNUNET_SCHEDULER_Task *r_task;
+
+/**
+ * Task ID of shutdown task; only present while we have a
+ * connection to the resolver service.
+ */
+static struct GNUNET_SCHEDULER_Task *s_task;
+
+
 /**
  * Handle to a request given to the resolver.  Can be used to cancel
  * the request prior to the timeout or successful execution.  Also
@@ -57,6 +95,16 @@ static const char *loopback[] = {
 struct GNUNET_RESOLVER_RequestHandle
 {
 
+  /**
+   * Next entry in DLL of requests.
+   */
+  struct GNUNET_RESOLVER_RequestHandle *next;
+
+  /**
+   * Previous entry in DLL of requests.
+   */
+  struct GNUNET_RESOLVER_RequestHandle *prev;
+
   /**
    * Callback if this is an name resolution request,
    * otherwise NULL.
@@ -70,54 +118,65 @@ struct GNUNET_RESOLVER_RequestHandle
   GNUNET_RESOLVER_HostnameCallback name_callback;
 
   /**
-   * Closure for the respective "callback".
+   * Closure for the callbacks.
    */
   void *cls;
 
   /**
-   * Our connection to the resolver service.
+   * When should this request time out?
    */
-  struct GNUNET_CLIENT_Connection *client;
+  struct GNUNET_TIME_Absolute timeout;
 
   /**
-   * Our scheduler.
+   * Task handle for making reply callbacks in numeric lookups
+   * asynchronous, and for timeout handling.
    */
-  struct GNUNET_SCHEDULER_Handle *sched;
+  struct GNUNET_SCHEDULER_Task *task;
 
   /**
-   * Name of the host that we are resolving.
+   * Desired address family.
    */
-  const char *hostname;
+  int af;
 
   /**
-   * When should this request time out?
+   * Has this request been transmitted to the service?
+   * #GNUNET_YES if transmitted
+   * #GNUNET_YES if not transmitted
+   * #GNUNET_SYSERR when request was canceled
    */
-  struct GNUNET_TIME_Absolute timeout;
+  int was_transmitted;
 
   /**
-   * Task handle for numeric lookups.
+   * Did we add this request to the queue?
    */
-  GNUNET_SCHEDULER_TaskIdentifier task;
+  int was_queued;
 
   /**
-   * Desired address family.
+   * Desired direction (IP to name or name to IP)
    */
-  int domain;
+  int direction;
 
   /**
-   * Length of the "struct sockaddr" that follows this
-   * struct (only for reverse lookup).
+   * #GNUNET_YES if a response was received
    */
-  socklen_t salen;
+  int received_response;
+
+  /**
+   * Length of the data that follows this struct.
+   */
+  size_t data_len;
 };
 
 
 /**
  * Check that the resolver service runs on localhost
  * (or equivalent).
+ *
+ * @return #GNUNET_OK if the resolver is properly configured,
+ *         #GNUNET_SYSERR otherwise.
  */
-static void
-check_config (const struct GNUNET_CONFIGURATION_Handle *cfg)
+static int
+check_config ()
 {
   char *hostname;
   unsigned int i;
@@ -136,170 +195,411 @@ check_config (const struct GNUNET_CONFIGURATION_Handle *cfg)
   v6.sin6_len = sizeof (v6);
 #endif
   if (GNUNET_OK !=
-      GNUNET_CONFIGURATION_get_value_string (cfg,
+      GNUNET_CONFIGURATION_get_value_string (resolver_cfg,
                                              "resolver",
-                                             "HOSTNAME", &hostname))
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                  _("Must specify `%s' for `%s' in configuration!\n"),
-                  "HOSTNAME", "resolver");
-      GNUNET_assert (0);
-    }
-  if ((1 != inet_pton (AF_INET,
-                       hostname,
-                       &v4)) || (1 != inet_pton (AF_INET6, hostname, &v6)))
+                                             "HOSTNAME",
+                                             &hostname))
+  {
+    LOG (GNUNET_ERROR_TYPE_INFO,
+         _("Missing `%s' for `%s' in configuration, DNS resolution will be unavailable.\n"),
+         "HOSTNAME",
+         "resolver");
+    return GNUNET_SYSERR;
+  }
+  if ((1 == inet_pton (AF_INET, hostname, &v4)) ||
+      (1 == inet_pton (AF_INET6, hostname, &v6)))
+  {
+    GNUNET_free (hostname);
+    return GNUNET_OK;
+  }
+  i = 0;
+  while (NULL != loopback[i])
+    if (0 == strcasecmp (loopback[i++], hostname))
     {
       GNUNET_free (hostname);
-      return;
+      return GNUNET_OK;
     }
-  i = 0;
-  while (loopback[i] != NULL)
-    if (0 == strcasecmp (loopback[i++], hostname))
-      {
-        GNUNET_free (hostname);
-        return;
-      }
-  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-              _
-              ("Must specify `%s' or numeric IP address for `%s' of `%s' in configuration!\n"),
-              "localhost", "HOSTNAME", "resolver");
+  LOG (GNUNET_ERROR_TYPE_INFO,
+       _("Missing `%s' or numeric IP address for `%s' of `%s' in configuration, DNS resolution will be unavailable.\n"),
+       "localhost",
+       "HOSTNAME",
+       "resolver");
   GNUNET_free (hostname);
-  GNUNET_assert (0);
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Create the connection to the resolver service.
+ *
+ * @param cfg configuration to use
+ */
+void
+GNUNET_RESOLVER_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  GNUNET_assert (NULL != cfg);
+  backoff = GNUNET_TIME_UNIT_MILLISECONDS;
+  resolver_cfg = cfg;
+}
+
+
+/**
+ * Destroy the connection to the resolver service.
+ */
+void
+GNUNET_RESOLVER_disconnect ()
+{
+  struct GNUNET_RESOLVER_RequestHandle *rh;
+
+  while (NULL != (rh = req_head))
+  {
+    GNUNET_assert (GNUNET_SYSERR == rh->was_transmitted);
+    GNUNET_CONTAINER_DLL_remove (req_head,
+                                req_tail,
+                                rh);
+    GNUNET_free (rh);
+  }
+  if (NULL != mq)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Disconnecting from DNS service\n");
+    GNUNET_MQ_destroy (mq);
+    mq = NULL;
+  }
+  if (NULL != r_task)
+  {
+    GNUNET_SCHEDULER_cancel (r_task);
+    r_task = NULL;
+  }
+  if (NULL != s_task)
+  {
+    GNUNET_SCHEDULER_cancel (s_task);
+    s_task = NULL;
+  }
+}
+
+
+/**
+ * Task executed on system shutdown.
+ */
+static void
+shutdown_task (void *cls)
+{
+  s_task = NULL;
+  GNUNET_RESOLVER_disconnect ();
+  backoff = GNUNET_TIME_UNIT_MILLISECONDS;
+}
+
+
+/**
+ * Consider disconnecting if we have no further requests pending.
+ */
+static void
+check_disconnect ()
+{
+  struct GNUNET_RESOLVER_RequestHandle *rh;
+
+  for (rh = req_head; NULL != rh; rh = rh->next)
+    if (GNUNET_SYSERR != rh->was_transmitted)
+      return;
+  if (NULL != r_task)
+  {
+    GNUNET_SCHEDULER_cancel (r_task);
+    r_task = NULL;
+  }
+  if (NULL != s_task)
+    return;
+  s_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS,
+                                        &shutdown_task,
+                                        NULL);
 }
 
 
 /**
  * Convert IP address to string without DNS resolution.
  *
- * @param sa the address 
- * @param salen number of bytes in sa
+ * @param af address family
+ * @param ip the address
+ * @param ip_len number of bytes in @a ip
  * @return address as a string, NULL on error
  */
 static char *
-no_resolve (const struct sockaddr *sa, socklen_t salen)
+no_resolve (int af,
+           const void *ip,
+            socklen_t ip_len)
 {
-  char *ret;
-  char inet4[INET_ADDRSTRLEN];
-  char inet6[INET6_ADDRSTRLEN];
+  char buf[INET6_ADDRSTRLEN];
 
-  if (salen < sizeof (struct sockaddr))
-    return NULL;
-  switch (sa->sa_family)
+  switch (af)
+  {
+  case AF_INET:
+    if (ip_len != sizeof (struct in_addr))
+      return NULL;
+    if (NULL ==
+        inet_ntop (AF_INET, ip, buf, sizeof (buf)))
     {
-    case AF_INET:
-      if (salen != sizeof (struct sockaddr_in))
-        return NULL;
-      inet_ntop (AF_INET,
-                 &((struct sockaddr_in *) sa)->sin_addr,
-                 inet4, INET_ADDRSTRLEN);
-      ret = GNUNET_strdup (inet4);
-      break;
-    case AF_INET6:
-      if (salen != sizeof (struct sockaddr_in6))
-        return NULL;
-      inet_ntop (AF_INET6,
-                 &((struct sockaddr_in6 *) sa)->sin6_addr,
-                 inet6, INET6_ADDRSTRLEN);
-      ret = GNUNET_strdup (inet6);
-      break;
-    default:
-      ret = NULL;
-      break;
+      LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
+                    "inet_ntop");
+      return NULL;
+    }
+    break;
+  case AF_INET6:
+    if (ip_len != sizeof (struct in6_addr))
+      return NULL;
+    if (NULL ==
+        inet_ntop (AF_INET6, ip, buf, sizeof (buf)))
+    {
+      LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
+                    "inet_ntop");
+      return NULL;
     }
-  return ret;
+    break;
+  default:
+    GNUNET_break (0);
+    return NULL;
+  }
+  return GNUNET_strdup (buf);
 }
 
 
 /**
- * Process the reply from the resolver (which is presumably
- * the numeric IP address for a name resolution request).
+ * Adjust exponential back-off and reconnect to the service.
+ */
+static void
+reconnect (void);
+
+
+/**
+ * Generic error handler, called with the appropriate error code and
+ * the same closure specified at the creation of the message queue.
+ * Not every message queue implementation supports an error handler.
  *
- * @param cls the "GNUNET_RESOLVER_RequestHandle" for which this is a reply
- * @param msg reply from the resolver or NULL on error
+ * @param cls NULL
+ * @param error error code
  */
 static void
-handle_address_response (void *cls, const struct GNUNET_MessageHeader *msg)
+mq_error_handler (void *cls,
+                  enum GNUNET_MQ_Error error)
 {
-  struct GNUNET_RESOLVER_RequestHandle *rh = cls;
-  uint16_t size;
-  const struct sockaddr *sa;
-  socklen_t salen;
+  GNUNET_MQ_destroy (mq);
+  mq = NULL;
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "MQ error, reconnecting\n");
+  reconnect ();
+}
+
+
+/**
+ * Process pending requests to the resolver.
+ */
+static void
+process_requests ()
+{
+  struct GNUNET_RESOLVER_GetMessage *msg;
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_RESOLVER_RequestHandle *rh = req_head;
+
+  if (NULL == mq)
+  {
+    reconnect ();
+    return;
+  }
+  if (NULL == rh)
+  {
+    /* nothing to do, release socket really soon if there is nothing
+     * else happening... */
+    s_task =
+      GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS,
+                                    &shutdown_task,
+                                    NULL);
+    return;
+  }
+  if (GNUNET_NO != rh->was_transmitted)
+    return;                     /* waiting for reply */
+  env = GNUNET_MQ_msg_extra (msg,
+                             rh->data_len,
+                             GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
+  msg->direction = htonl (rh->direction);
+  msg->af = htonl (rh->af);
+  GNUNET_memcpy (&msg[1],
+          &rh[1],
+          rh->data_len);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Transmitting DNS resolution request to DNS service\n");
+  GNUNET_MQ_send (mq,
+                  env);
+  rh->was_transmitted = GNUNET_YES;
+}
+
+
+/**
+ * Check validity of response with a hostname for a DNS lookup.
+ *
+ * @param cls NULL
+ * @param msg message with the hostname
+ */
+static int
+check_response (void *cls,
+                const struct GNUNET_MessageHeader *msg)
+{
+  /* implemented in #handle_response() for now */
+  return GNUNET_OK;
+}
+
 
+/**
+ * Check validity of response with a hostname for a DNS lookup.
+ * NOTE: right now rather messy, might want to use different
+ * message types for different response formats in the future.
+ *
+ * @param cls NULL
+ * @param msg message with the response
+ */
+static void
+handle_response (void *cls,
+                 const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_RESOLVER_RequestHandle *rh = req_head;
+  uint16_t size;
+  char *nret;
 
-  if (msg == NULL)
+  size = ntohs (msg->size);
+  if (size == sizeof (struct GNUNET_MessageHeader))
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Received empty response from DNS service\n");
+    /* message contains not data, just header; end of replies */
+    /* check if request was canceled */
+    if (GNUNET_SYSERR != rh->was_transmitted)
     {
-      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                  _("Timeout trying to resolve hostname `%s'.\n"),
-                 rh->hostname);
-      rh->addr_callback (rh->cls, NULL, 0);
-      GNUNET_CLIENT_disconnect (rh->client, GNUNET_NO);
-      GNUNET_free (rh);
-      return;
+      /* no reverse lookup was successful, return IP as string */
+      if (NULL != rh->name_callback)
+      {
+        if (GNUNET_NO == rh->received_response)
+        {
+          nret = no_resolve (rh->af,
+                             &rh[1],
+                             rh->data_len);
+          rh->name_callback (rh->cls, nret);
+          GNUNET_free (nret);
+        }
+        /* finally, make termination call */
+        rh->name_callback (rh->cls,
+                           NULL);
+      }
+      if (NULL != rh->addr_callback)
+        rh->addr_callback (rh->cls,
+                           NULL,
+                           0);
     }
-  if (GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE != ntohs (msg->type))
+    rh->was_transmitted = GNUNET_NO;
+    GNUNET_RESOLVER_request_cancel (rh);
+    process_requests ();
+    return;
+  }
+  /* return reverse lookup results to caller */
+  if (NULL != rh->name_callback)
+  {
+    const char *hostname;
+
+    hostname = (const char *) &msg[1];
+    if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
     {
       GNUNET_break (0);
-      rh->addr_callback (rh->cls, NULL, 0);
-      GNUNET_CLIENT_disconnect (rh->client, GNUNET_NO);
-      GNUNET_free (rh);
+      if (GNUNET_SYSERR != rh->was_transmitted)
+        rh->name_callback (rh->cls,
+                           NULL);
+      rh->was_transmitted = GNUNET_NO;
+      GNUNET_RESOLVER_request_cancel (rh);
+      GNUNET_MQ_destroy (mq);
+      mq = NULL;
+      reconnect ();
       return;
     }
-
-  size = ntohs (msg->size);
-  if (size == sizeof (struct GNUNET_MessageHeader))
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Resolver returns `%s' for IP `%s'.\n",
+         hostname,
+         GNUNET_a2s ((const void *) &rh[1],
+                     rh->data_len));
+    if (rh->was_transmitted != GNUNET_SYSERR)
+      rh->name_callback (rh->cls,
+                         hostname);
+    rh->received_response = GNUNET_YES;
+  }
+  /* return lookup results to caller */
+  if (NULL != rh->addr_callback)
+  {
+    struct sockaddr_in v4;
+    struct sockaddr_in6 v6;
+    const struct sockaddr *sa;
+    socklen_t salen;
+    const void *ip;
+    size_t ip_len;
+
+    ip = &msg[1];
+    ip_len = size - sizeof (struct GNUNET_MessageHeader);
+    if (ip_len == sizeof (struct in_addr))
     {
-#if DEBUG_RESOLVER
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  _("Received end message resolving hostname `%s'.\n"),
-                 rh->hostname);
+      memset (&v4, 0, sizeof (v4));
+      v4.sin_family = AF_INET;
+      v4.sin_addr = *(struct in_addr*) ip;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+      v4.sin_len = sizeof (v4);
 #endif
-      rh->addr_callback (rh->cls, NULL, 0);
-      GNUNET_CLIENT_disconnect (rh->client, GNUNET_NO);
-      GNUNET_free (rh);
-      return;
+      salen = sizeof (v4);
+      sa = (const struct sockaddr *) &v4;
     }
-  sa = (const struct sockaddr *) &msg[1];
-  salen = size - sizeof (struct GNUNET_MessageHeader);
-  if (salen < sizeof (struct sockaddr))
+    else if (ip_len == sizeof (struct in6_addr))
+    {
+      memset (&v6, 0, sizeof (v6));
+      v6.sin6_family = AF_INET6;
+      v6.sin6_addr = *(struct in6_addr*) ip;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+      v6.sin6_len = sizeof (v6);
+#endif
+      salen = sizeof (v6);
+      sa = (const struct sockaddr *) &v6;
+    }
+    else
     {
       GNUNET_break (0);
-      rh->addr_callback (rh->cls, NULL, 0);
-      GNUNET_CLIENT_disconnect (rh->client, GNUNET_NO);
-      GNUNET_free (rh);
+      if (GNUNET_SYSERR != rh->was_transmitted)
+        rh->addr_callback (rh->cls,
+                           NULL,
+                           0);
+      rh->was_transmitted = GNUNET_NO;
+      GNUNET_RESOLVER_request_cancel (rh);
+      GNUNET_MQ_destroy (mq);
+      mq = NULL;
+      reconnect ();
       return;
     }
-#if DEBUG_RESOLVER
-  {
-    char *ips = no_resolve (sa, salen);
-    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-               "Resolver returns `%s' for `%s'.\n", ips,
-               rh->hostname);
-    GNUNET_free (ips);
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Received IP from DNS service\n");
+    if (GNUNET_SYSERR != rh->was_transmitted)
+      rh->addr_callback (rh->cls,
+                         sa,
+                         salen);
   }
-#endif
-  rh->addr_callback (rh->cls, sa, salen);
-  GNUNET_CLIENT_receive (rh->client,
-                         &handle_address_response,
-                         rh,
-                         GNUNET_TIME_absolute_get_remaining (rh->timeout));
 }
 
 
 /**
- * We've been asked to lookup the address for a hostname and were 
+ * We've been asked to lookup the address for a hostname and were
  * given a valid numeric string.  Perform the callbacks for the
  * numeric addresses.
  *
- * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
- * @param tc unused scheduler context
+ * @param cls `struct GNUNET_RESOLVER_RequestHandle` for the request
  */
 static void
-numeric_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+numeric_resolution (void *cls)
 {
   struct GNUNET_RESOLVER_RequestHandle *rh = cls;
   struct sockaddr_in v4;
   struct sockaddr_in6 v6;
+  const char *hostname;
 
+  rh->task = NULL;
   memset (&v4, 0, sizeof (v4));
   v4.sin_family = AF_INET;
 #if HAVE_SOCKADDR_IN_SIN_LEN
@@ -310,52 +610,63 @@ numeric_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 #if HAVE_SOCKADDR_IN_SIN_LEN
   v6.sin6_len = sizeof (v6);
 #endif
-
-  if (((rh->domain == AF_UNSPEC) || (rh->domain == AF_INET)) &&
-      (1 == inet_pton (AF_INET, rh->hostname, &v4.sin_addr)))
-    {
-      rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
-      if ((rh->domain == AF_UNSPEC) &&
-          (1 == inet_pton (AF_INET6, rh->hostname, &v6.sin6_addr)))
-        {
-          /* this can happen on some systems IF "hostname" is "localhost" */
-          rh->addr_callback (rh->cls,
-                             (const struct sockaddr *) &v6, sizeof (v6));
-        }
-      rh->addr_callback (rh->cls, NULL, 0);
-      GNUNET_free (rh);
-      return;
-    }
-  if (((rh->domain == AF_UNSPEC) || (rh->domain == AF_INET6)) &&
-      (1 == inet_pton (AF_INET6, rh->hostname, &v6.sin6_addr)))
+  hostname = (const char *) &rh[1];
+  if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET)) &&
+      (1 == inet_pton (AF_INET, hostname, &v4.sin_addr)))
+  {
+    rh->addr_callback (rh->cls,
+                       (const struct sockaddr *) &v4,
+                       sizeof (v4));
+    if ((rh->af == AF_UNSPEC) &&
+        (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
     {
-      rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
-      rh->addr_callback (rh->cls, NULL, 0);
-      GNUNET_free (rh);
-      return;
+      /* this can happen on some systems IF "hostname" is "localhost" */
+      rh->addr_callback (rh->cls,
+                         (const struct sockaddr *) &v6,
+                         sizeof (v6));
     }
+    rh->addr_callback (rh->cls,
+                       NULL,
+                       0);
+    GNUNET_free (rh);
+    return;
+  }
+  if ( ( (rh->af == AF_UNSPEC) ||
+         (rh->af == AF_INET6) ) &&
+       (1 == inet_pton (AF_INET6,
+                       hostname,
+                       &v6.sin6_addr) ) )
+  {
+    rh->addr_callback (rh->cls,
+                       (const struct sockaddr *) &v6,
+                       sizeof (v6));
+    rh->addr_callback (rh->cls,
+                       NULL,
+                       0);
+    GNUNET_free (rh);
+    return;
+  }
   /* why are we here? this task should not have been scheduled! */
   GNUNET_assert (0);
   GNUNET_free (rh);
 }
 
 
-
 /**
- * We've been asked to lookup the address for a hostname and were 
+ * We've been asked to lookup the address for a hostname and were
  * given a variant of "loopback".  Perform the callbacks for the
  * respective loopback numeric addresses.
  *
- * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
- * @param tc unused scheduler context
+ * @param cls `struct GNUNET_RESOLVER_RequestHandle` for the request
  */
 static void
-loopback_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+loopback_resolution (void *cls)
 {
   struct GNUNET_RESOLVER_RequestHandle *rh = cls;
   struct sockaddr_in v4;
   struct sockaddr_in6 v6;
 
+  rh->task = NULL;
   memset (&v4, 0, sizeof (v4));
   v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
   v4.sin_family = AF_INET;
@@ -368,365 +679,488 @@ loopback_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
   v6.sin6_len = sizeof (v6);
 #endif
   v6.sin6_addr = in6addr_loopback;
-  switch (rh->domain)
+  switch (rh->af)
+  {
+  case AF_INET:
+    rh->addr_callback (rh->cls,
+                       (const struct sockaddr *) &v4,
+                       sizeof (v4));
+    break;
+  case AF_INET6:
+    rh->addr_callback (rh->cls,
+                       (const struct sockaddr *) &v6,
+                       sizeof (v6));
+    break;
+  case AF_UNSPEC:
+    rh->addr_callback (rh->cls,
+                       (const struct sockaddr *) &v6,
+                       sizeof (v6));
+    rh->addr_callback (rh->cls,
+                       (const struct sockaddr *) &v4,
+                       sizeof (v4));
+
+    break;
+  default:
+    GNUNET_break (0);
+    break;
+  }
+  rh->addr_callback (rh->cls,
+                     NULL,
+                     0);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Finished resolving hostname `%s'.\n",
+       (const char *) &rh[1]);
+  GNUNET_free (rh);
+}
+
+
+/**
+ * Now try to reconnect to the resolver service.
+ *
+ * @param cls NULL
+ */
+static void
+reconnect_task (void *cls)
+{
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_var_size (response,
+                           GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE,
+                           struct GNUNET_MessageHeader,
+                           NULL),
+    GNUNET_MQ_handler_end ()
+  };
+
+  r_task = NULL;
+  if (NULL == req_head)
+    return;                     /* no work pending */
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Trying to connect to DNS service\n");
+  mq = GNUNET_CLIENT_connect (resolver_cfg,
+                              "resolver",
+                              handlers,
+                              &mq_error_handler,
+                              NULL);
+  if (NULL == mq)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+        "Failed to connect, will try again later\n");
+    reconnect ();
+    return;
+  }
+  process_requests ();
+}
+
+
+/**
+ * Adjust exponential back-off and reconnect to the service.
+ */
+static void
+reconnect ()
+{
+  struct GNUNET_RESOLVER_RequestHandle *rh;
+
+  if (NULL != r_task)
+    return;
+  GNUNET_assert (NULL == mq);
+  if (NULL != (rh = req_head))
+  {
+    switch (rh->was_transmitted)
     {
-    case AF_INET:
-      rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
+    case GNUNET_NO:
+      /* nothing more to do */
       break;
-    case AF_INET6:
-      rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
+    case GNUNET_YES:
+      /* disconnected, transmit again! */
+      rh->was_transmitted = GNUNET_NO;
       break;
-    case AF_UNSPEC:
-      rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
-      rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
+    case GNUNET_SYSERR:
+      /* request was cancelled, remove entirely */
+      GNUNET_CONTAINER_DLL_remove (req_head,
+                                  req_tail,
+                                  rh);
+      GNUNET_free (rh);
+      check_disconnect ();
       break;
     default:
-      GNUNET_break (0);
+      GNUNET_assert (0);
       break;
     }
-  rh->addr_callback (rh->cls, NULL, 0);
-  GNUNET_free (rh);
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Will try to connect to DNS service in %s\n",
+       GNUNET_STRINGS_relative_time_to_string (backoff,
+                                               GNUNET_YES));
+  GNUNET_assert (NULL != resolver_cfg);
+  r_task = GNUNET_SCHEDULER_add_delayed (backoff,
+                                         &reconnect_task,
+                                         NULL);
+  backoff = GNUNET_TIME_STD_BACKOFF (backoff);
+}
+
+
+/**
+ * A DNS resolution timed out. Notify the application.
+ *
+ * @param cls the `struct GNUNET_RESOLVER_RequestHandle *`
+ */
+static void
+handle_lookup_timeout (void *cls)
+{
+  struct GNUNET_RESOLVER_RequestHandle *rh = cls;
+
+  rh->task = NULL;
+  if (GNUNET_NO == rh->direction)
+  {
+    LOG (GNUNET_ERROR_TYPE_INFO,
+         _("Timeout trying to resolve hostname `%s'.\n"),
+         (const char *) &rh[1]);
+    if (NULL != rh->addr_callback)
+      rh->addr_callback (rh->cls,
+                         NULL,
+                         0);
+  }
+  else
+  {
+    char buf[INET6_ADDRSTRLEN];
+
+    LOG (GNUNET_ERROR_TYPE_INFO,
+         _("Timeout trying to resolve IP address `%s'.\n"),
+         inet_ntop (rh->af,
+                    (const void *) &rh[1],
+                    buf,
+                    sizeof(buf)));
+    if (GNUNET_NO == rh->received_response)
+    {
+      char *nret;
+
+      nret = no_resolve (rh->af,
+                         &rh[1],
+                         rh->data_len);
+      if (NULL != rh->name_callback)
+        rh->name_callback (rh->cls, nret);
+      GNUNET_free (nret);
+    }
+    /* finally, make termination call */
+    if (NULL != rh->name_callback)
+      rh->name_callback (rh->cls,
+                         NULL);
+  }
+  rh->was_transmitted = GNUNET_NO;
+  GNUNET_RESOLVER_request_cancel (rh);
+  process_requests ();
 }
 
 
 /**
  * Convert a string to one or more IP addresses.
  *
- * @param sched scheduler to use
- * @param cfg configuration to use
  * @param hostname the hostname to resolve
- * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any"
+ * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
  * @param callback function to call with addresses
- * @param callback_cls closure for callback
+ * @param callback_cls closure for @a callback
  * @param timeout how long to try resolving
  * @return handle that can be used to cancel the request, NULL on error
  */
 struct GNUNET_RESOLVER_RequestHandle *
-GNUNET_RESOLVER_ip_get (struct GNUNET_SCHEDULER_Handle *sched,
-                        const struct GNUNET_CONFIGURATION_Handle *cfg,
-                        const char *hostname,
-                        int domain,
+GNUNET_RESOLVER_ip_get (const char *hostname,
+                        int af,
                         struct GNUNET_TIME_Relative timeout,
                         GNUNET_RESOLVER_AddressCallback callback,
                         void *callback_cls)
 {
-  struct GNUNET_CLIENT_Connection *client;
-  struct GNUNET_RESOLVER_GetMessage *msg;
   struct GNUNET_RESOLVER_RequestHandle *rh;
   size_t slen;
   unsigned int i;
   struct in_addr v4;
   struct in6_addr v6;
-  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE];
 
-  check_config (cfg);
   slen = strlen (hostname) + 1;
-  if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >
+  if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >=
       GNUNET_SERVER_MAX_MESSAGE_SIZE)
-    {
-      GNUNET_break (0);
-      return NULL;
-    }
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Trying to resolve hostname `%s'.\n",
+       hostname);
   rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + slen);
-  rh->sched = sched;
-  rh->domain = domain;
+  rh->af = af;
   rh->addr_callback = callback;
   rh->cls = callback_cls;
-  memcpy (&rh[1], hostname, slen);
-  rh->hostname = (const char *) &rh[1];
+  GNUNET_memcpy (&rh[1],
+                hostname,
+                slen);
+  rh->data_len = slen;
   rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
-
+  rh->direction = GNUNET_NO;
   /* first, check if this is a numeric address */
-  if (((1 == inet_pton (AF_INET,
-                        hostname,
-                        &v4)) &&
-       ((domain == AF_INET) || (domain == AF_UNSPEC))) ||
-      ((1 == inet_pton (AF_INET6,
-                        hostname,
-                        &v6)) &&
-       ((domain == AF_INET6) || (domain == AF_UNSPEC))))
-    {
-      rh->task = GNUNET_SCHEDULER_add_now (sched,
-                                          &numeric_resolution, rh);
-      return rh;
-    }
+  if (((1 == inet_pton (AF_INET, hostname, &v4)) &&
+       ((af == AF_INET) || (af == AF_UNSPEC))) ||
+      ((1 == inet_pton (AF_INET6, hostname, &v6)) &&
+       ((af == AF_INET6) || (af == AF_UNSPEC))))
+  {
+    rh->task = GNUNET_SCHEDULER_add_now (&numeric_resolution,
+                                         rh);
+    return rh;
+  }
   /* then, check if this is a loopback address */
   i = 0;
-  while (loopback[i] != NULL)
-    if (0 == strcasecmp (loopback[i++], hostname))
-      {
-        rh->task = GNUNET_SCHEDULER_add_now (sched,
-                                            &loopback_resolution, rh);
-        return rh;
-      }
-
-  client = GNUNET_CLIENT_connect (sched, "resolver", cfg);
-  if (client == NULL)
-    {
-      GNUNET_free (rh);
-      return NULL;
-    }
-  rh->client = client;
-
-  msg = (struct GNUNET_RESOLVER_GetMessage *) buf;
-  msg->header.size =
-    htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + slen);
-  msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
-  msg->direction = htonl (GNUNET_NO);
-  msg->domain = htonl (domain);
-  memcpy (&msg[1], hostname, slen);
-
-#if DEBUG_RESOLVER
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Resolver requests DNS resolution of hostname `%s'.\n"),
-              hostname);
-#endif
-  if (GNUNET_OK !=
-      GNUNET_CLIENT_transmit_and_get_response (client,
-                                               &msg->header,
-                                               timeout,
-                                               GNUNET_YES,
-                                               &handle_address_response, rh))
+  while (NULL != loopback[i])
+    if (0 == strcasecmp (loopback[i++],
+                         hostname))
     {
-      GNUNET_free (rh);
-      GNUNET_CLIENT_disconnect (client, GNUNET_NO);
-      return NULL;
+      rh->task = GNUNET_SCHEDULER_add_now (&loopback_resolution,
+                                           rh);
+      return rh;
     }
+  if (GNUNET_OK != check_config ())
+  {
+    GNUNET_free (rh);
+    return NULL;
+  }
+  rh->task = GNUNET_SCHEDULER_add_delayed (timeout,
+                                           &handle_lookup_timeout,
+                                           rh);
+  GNUNET_CONTAINER_DLL_insert_tail (req_head,
+                                    req_tail,
+                                    rh);
+  rh->was_queued = GNUNET_YES;
+  if (NULL != s_task)
+  {
+    GNUNET_SCHEDULER_cancel (s_task);
+    s_task = NULL;
+  }
+  process_requests ();
   return rh;
 }
 
 
-/**
- * Process response with a hostname for a reverse DNS lookup.
- *
- * @param cls our "struct GNUNET_RESOLVER_RequestHandle" context
- * @param msg message with the hostname, NULL on error
- */
-static void
-handle_hostname_response (void *cls, const struct GNUNET_MessageHeader *msg)
-{
-  struct GNUNET_RESOLVER_RequestHandle *rh = cls;
-  uint16_t size;
-  const char *hostname;
-
-  if (msg == NULL)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                  _("Timeout trying to resolve IP address `%s'.\n"),
-                 GNUNET_a2s ((const void*) &rh[1], rh->salen));
-      rh->name_callback (rh->cls, NULL);
-      GNUNET_CLIENT_disconnect (rh->client, GNUNET_NO);
-      GNUNET_free (rh);
-      return;
-    }
-  size = ntohs (msg->size);
-  if (size == sizeof (struct GNUNET_MessageHeader))
-    {
-#if DEBUG_RESOLVER
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  _("Received end message resolving IP address `%s'.\n"),
-                 GNUNET_a2s ((const void*) &rh[1], rh->salen));
-#endif
-      rh->name_callback (rh->cls, NULL);
-      GNUNET_CLIENT_disconnect (rh->client, GNUNET_NO);
-      GNUNET_free (rh);
-      return;
-    }
-  hostname = (const char *) &msg[1];
-  if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
-    {
-      GNUNET_break (0);
-      rh->name_callback (rh->cls, NULL);
-      GNUNET_CLIENT_disconnect (rh->client, GNUNET_NO);
-      GNUNET_free (rh);
-      return;
-    }
-#if DEBUG_RESOLVER
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Resolver returns `%s' for IP `%s'.\n"), 
-             hostname,
-             GNUNET_a2s ((const void*) &rh[1], rh->salen));
-#endif
-  rh->name_callback (rh->cls, hostname);
-  GNUNET_CLIENT_receive (rh->client,
-                         &handle_hostname_response,
-                         rh,
-                         GNUNET_TIME_absolute_get_remaining (rh->timeout));
-}
-
-
-
 /**
  * We've been asked to convert an address to a string without
- * a reverse lookup.  Do it.
+ * a reverse lookup, either because the client asked for it
+ * or because the DNS lookup hit a timeout.  Do the numeric
+ * conversion and invoke the callback.
  *
- * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
- * @param tc unused scheduler context
+ * @param cls `struct GNUNET_RESOLVER_RequestHandle` for the request
  */
 static void
-numeric_reverse (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+numeric_reverse (void *cls)
 {
   struct GNUNET_RESOLVER_RequestHandle *rh = cls;
   char *result;
 
-  result = no_resolve ((const struct sockaddr *) &rh[1], rh->salen);
-#if DEBUG_RESOLVER
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s'.\n"), result);
-#endif
-  if (result != NULL)
-    {
-      rh->name_callback (rh->cls, result);
-      GNUNET_free (result);
-    }
-  rh->name_callback (rh->cls, NULL);
+  rh->task = NULL;
+  result = no_resolve (rh->af,
+                       &rh[1],
+                       rh->data_len);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Resolver returns `%s'.\n",
+       result);
+  if (NULL != result)
+  {
+    rh->name_callback (rh->cls,
+                       result);
+    GNUNET_free (result);
+  }
+  rh->name_callback (rh->cls,
+                     NULL);
+  if (NULL != rh->task)
+  {
+    GNUNET_SCHEDULER_cancel (rh->task);
+    rh->task = NULL;
+  }
   GNUNET_free (rh);
 }
 
 
-
 /**
  * Get an IP address as a string.
  *
- * @param sched scheduler to use
- * @param cfg configuration to use
  * @param sa host address
- * @param salen length of host address
- * @param do_resolve use GNUNET_NO to return numeric hostname
+ * @param salen length of host address in @a sa
+ * @param do_resolve use #GNUNET_NO to return numeric hostname
  * @param timeout how long to try resolving
  * @param callback function to call with hostnames
- * @param cls closure for callback
+ *        last callback is NULL when finished
+ * @param cls closure for @a callback
  * @return handle that can be used to cancel the request
  */
 struct GNUNET_RESOLVER_RequestHandle *
-GNUNET_RESOLVER_hostname_get (struct GNUNET_SCHEDULER_Handle *sched,
-                              const struct GNUNET_CONFIGURATION_Handle *cfg,
-                              const struct sockaddr *sa,
+GNUNET_RESOLVER_hostname_get (const struct sockaddr *sa,
                               socklen_t salen,
                               int do_resolve,
                               struct GNUNET_TIME_Relative timeout,
                               GNUNET_RESOLVER_HostnameCallback callback,
                               void *cls)
 {
-  struct GNUNET_CLIENT_Connection *client;
-  struct GNUNET_RESOLVER_GetMessage *msg;
   struct GNUNET_RESOLVER_RequestHandle *rh;
-  char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE];
+  size_t ip_len;
+  const void *ip;
+
+  if (GNUNET_OK != check_config ())
+  {
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _("Resolver not configured correctly.\n"));
+    return NULL;
+  }
 
-  check_config (cfg);
+  switch (sa->sa_family)
+  {
+  case AF_INET:
+    GNUNET_assert (salen == sizeof (struct sockaddr_in));
+    ip_len = sizeof (struct in_addr);
+    ip = &((const struct sockaddr_in*)sa)->sin_addr;
+    break;
+  case AF_INET6:
+    GNUNET_assert (salen == sizeof (struct sockaddr_in6));
+    ip_len = sizeof (struct in6_addr);
+    ip = &((const struct sockaddr_in6*)sa)->sin6_addr;
+    break;
+  default:
+    GNUNET_break (0);
+    return NULL;
+  }
   rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + salen);
   rh->name_callback = callback;
   rh->cls = cls;
+  rh->af = sa->sa_family;
   rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
-  rh->sched = sched;
-  rh->salen = salen;
-  memcpy (&rh[1], sa, salen);
-
+  GNUNET_memcpy (&rh[1],
+          ip,
+          ip_len);
+  rh->data_len = ip_len;
+  rh->direction = GNUNET_YES;
+  rh->received_response = GNUNET_NO;
   if (GNUNET_NO == do_resolve)
-    {
-      rh->task = GNUNET_SCHEDULER_add_now (sched,
-                                          &numeric_reverse, rh);
-      return rh;
-    }
-  if (salen + sizeof (struct GNUNET_RESOLVER_GetMessage) >
-      GNUNET_SERVER_MAX_MESSAGE_SIZE)
-    {
-      GNUNET_break (0);
-      GNUNET_free (rh);
-      return NULL;
-    }
-  client = GNUNET_CLIENT_connect (sched, "resolver", cfg);
-  if (client == NULL)
-    {
-      GNUNET_free (rh);
-      return NULL;
-    }
-  rh->client = client;
-
-  msg = (struct GNUNET_RESOLVER_GetMessage *) buf;
-  msg->header.size =
-    htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + salen);
-  msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
-  msg->direction = htonl (GNUNET_YES);
-  msg->domain = htonl (sa->sa_family);
-  memcpy (&msg[1], sa, salen);
-#if DEBUG_RESOLVER
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Resolver requests DNS resolution of IP address.\n"));
-#endif
-  if (GNUNET_OK !=
-      GNUNET_CLIENT_transmit_and_get_response (client,
-                                               &msg->header,
-                                               timeout,
-                                               GNUNET_YES,
-                                               &handle_hostname_response, rh))
-    {
-      GNUNET_CLIENT_disconnect (client, GNUNET_NO);
-      GNUNET_free (rh);
-      return NULL;
-    }
+  {
+    rh->task = GNUNET_SCHEDULER_add_now (&numeric_reverse,
+                                         rh);
+    return rh;
+  }
+  rh->task = GNUNET_SCHEDULER_add_delayed (timeout,
+                                           &handle_lookup_timeout,
+                                           rh);
+  GNUNET_CONTAINER_DLL_insert_tail (req_head,
+                                    req_tail,
+                                    rh);
+  rh->was_queued = GNUNET_YES;
+  if (NULL != s_task)
+  {
+    GNUNET_SCHEDULER_cancel (s_task);
+    s_task = NULL;
+  }
+  process_requests ();
   return rh;
 }
 
 
 /**
- * Get local hostname
+ * Get local fully qualified af name
  *
- * @param
+ * @return fqdn
  */
 char *
-GNUNET_RESOLVER_local_hostname_get ( )
+GNUNET_RESOLVER_local_fqdn_get ()
 {
-
-  char hostname[GNUNET_OS_get_hostname_max_length() + 1];
-
+  char hostname[GNUNET_OS_get_hostname_max_length () + 1];
 
   if (0 != gethostname (hostname, sizeof (hostname) - 1))
+  {
+    LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "gethostname");
+    return NULL;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Resolving our FQDN `%s'\n",
+       hostname);
+#if HAVE_GETADDRINFO
+  {
+    struct addrinfo *ai;
+    int ret;
+    char *rval;
+
+    if (0 != (ret = getaddrinfo (hostname, NULL, NULL, &ai)))
     {
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR |
-                           GNUNET_ERROR_TYPE_BULK, "gethostname");
+      LOG (GNUNET_ERROR_TYPE_ERROR,
+           _("Could not resolve our FQDN: %s\n"),
+           gai_strerror (ret));
       return NULL;
     }
-#if DEBUG_RESOLVER
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Resolving our hostname `%s'\n"), hostname);
-#endif
+    if (NULL != ai->ai_canonname)
+      rval = GNUNET_strdup (ai->ai_canonname);
+    else
+      rval = GNUNET_strdup (hostname);
+    freeaddrinfo (ai);
+    return rval;
+  }
+#elif HAVE_GETHOSTBYNAME2
+  {
+    struct hostent *host;
+
+    host = gethostbyname2 (hostname, AF_INET);
+    if (NULL == host)
+      host = gethostbyname2 (hostname, AF_INET6);
+    if (NULL == host)
+      {
+        LOG (GNUNET_ERROR_TYPE_ERROR,
+             _("Could not resolve our FQDN: %s\n"),
+             hstrerror (h_errno));
+        return NULL;
+      }
+    return GNUNET_strdup (host->h_name);
+  }
+#elif HAVE_GETHOSTBYNAME
+  {
+    struct hostent *host;
+
+    host = gethostbyname (hostname);
+    if (NULL == host)
+      {
+        LOG (GNUNET_ERROR_TYPE_ERROR,
+             _("Could not resolve our FQDN: %s\n"),
+             hstrerror (h_errno));
+        return NULL;
+      }
+    return GNUNET_strdup (host->h_name);
+  }
+#else
+  /* fallback: just hope name is already FQDN */
   return GNUNET_strdup (hostname);
+#endif
 }
 
+
 /**
  * Looking our own hostname.
  *
- * @param sched scheduler to use
- * @param cfg configuration to use
- * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any"
- * @param callback function to call with addresses
- * @param cls closure for callback
+ * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
  * @param timeout how long to try resolving
+ * @param callback function to call with addresses
+ * @param cls closure for @a callback
  * @return handle that can be used to cancel the request, NULL on error
  */
 struct GNUNET_RESOLVER_RequestHandle *
-GNUNET_RESOLVER_hostname_resolve (struct GNUNET_SCHEDULER_Handle *sched,
-                                  const struct GNUNET_CONFIGURATION_Handle
-                                  *cfg, int domain,
+GNUNET_RESOLVER_hostname_resolve (int af,
                                   struct GNUNET_TIME_Relative timeout,
                                   GNUNET_RESOLVER_AddressCallback callback,
                                   void *cls)
 {
-  char hostname[GNUNET_OS_get_hostname_max_length() + 1];
+  char hostname[GNUNET_OS_get_hostname_max_length () + 1];
 
-  check_config (cfg);
   if (0 != gethostname (hostname, sizeof (hostname) - 1))
-    {
-      GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR |
-                           GNUNET_ERROR_TYPE_BULK, "gethostname");
-      return NULL;
-    }
-#if DEBUG_RESOLVER
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Resolving our hostname `%s'\n"), hostname);
-#endif
-  return GNUNET_RESOLVER_ip_get (sched,
-                                 cfg, hostname, domain, timeout, callback,
+  {
+    LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "gethostname");
+    return NULL;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Resolving our hostname `%s'\n",
+       hostname);
+  return GNUNET_RESOLVER_ip_get (hostname,
+                                 af,
+                                 timeout,
+                                 callback,
                                  cls);
 }
 
@@ -737,18 +1171,34 @@ GNUNET_RESOLVER_hostname_resolve (struct GNUNET_SCHEDULER_Handle *sched,
  * been completed (i.e, the callback has been called to
  * signal timeout or the final result).
  *
- * @param h handle of request to cancel
+ * @param rh handle of request to cancel
  */
 void
-GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *h)
+GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *rh)
 {
-  if (h->client != NULL)
-    GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
-  if (h->task != GNUNET_SCHEDULER_NO_TASK)
-    GNUNET_SCHEDULER_cancel (h->sched, h->task);
-  GNUNET_free (h);
+  if (GNUNET_NO == rh->direction)
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+        "Asked to cancel request to resolve hostname `%s'.\n",
+        (const char *) &rh[1]);
+  if (NULL != rh->task)
+  {
+    GNUNET_SCHEDULER_cancel (rh->task);
+    rh->task = NULL;
+  }
+  if (GNUNET_NO == rh->was_transmitted)
+  {
+    if (GNUNET_YES == rh->was_queued)
+      GNUNET_CONTAINER_DLL_remove (req_head,
+                                   req_tail,
+                                   rh);
+    GNUNET_free (rh);
+    check_disconnect ();
+    return;
+  }
+  GNUNET_assert (GNUNET_YES == rh->was_transmitted);
+  rh->was_transmitted = GNUNET_SYSERR;  /* mark as cancelled */
+  check_disconnect ();
 }
 
 
-
 /* end of resolver_api.c */