- fix
[oweals/gnunet.git] / src / transport / gnunet-transport.c
index edc253dae409b2646b072454bf4c2321f35f7f2d..4feb773986f7cd55c9b91dc7c08eb123c16fa97b 100644 (file)
@@ -1,6 +1,6 @@
 /*
  This file is part of GNUnet.
(C) 2011 Christian Grothoff (and other contributing authors)
Copyright (C) 2011-2014 Christian Grothoff (and other contributing authors)
 
  GNUnet is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published
@@ -14,8 +14,8 @@
 
  You should have received a copy of the GNU General Public License
  along with GNUnet; see the file COPYING.  If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
  */
 
 /**
@@ -27,7 +27,6 @@
  * This utility can be used to test if a transport mechanism for
  * GNUnet is properly configured.
  */
-
 #include "platform.h"
 #include "gnunet_util_lib.h"
 #include "gnunet_resolver_service.h"
  * Should match NAT_SERVER_TIMEOUT in 'nat_test.c'.
  */
 #define TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 20)
+
+/**
+ * Timeout for a name resolution
+ */
 #define RESOLUTION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
+
+/**
+ * Timeout for an operations
+ */
 #define OP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
 
+
+/**
+ * Context to store name resolutions for valiation
+ */
+struct ValidationResolutionContext
+{
+  /**
+   * Next in DLL
+   */
+  struct ValidationResolutionContext *next;
+
+  /**
+   * Previous in DLL
+   */
+  struct ValidationResolutionContext *prev;
+
+  /**
+   * Address to resolve
+   */
+  struct GNUNET_HELLO_Address *addrcp;
+
+  /**
+   * Time of last validation
+   */
+  struct GNUNET_TIME_Absolute last_validation;
+
+  /**
+   * Address is valid until
+   */
+  struct GNUNET_TIME_Absolute valid_until;
+
+  /**
+   * Time of next validation
+   */
+  struct GNUNET_TIME_Absolute next_validation;
+
+  /**
+   * state of validation process
+   */
+  enum GNUNET_TRANSPORT_ValidationState state;
+
+  /**
+   * Tranport conversion handle
+   */
+  struct GNUNET_TRANSPORT_AddressToStringContext *asc;
+
+  /**
+   * plugin name
+   */
+  char *transport;
+
+  /**
+   * was the entry printed
+   */
+  int printed;
+};
+
+/**
+ * Struct to store information about peers in monitor mode
+ */
+struct MonitoredPeer
+{
+  /**
+   * State of the peer
+   */
+  enum GNUNET_TRANSPORT_PeerState state;
+
+  /**
+   * Timeout
+   */
+  struct GNUNET_TIME_Absolute state_timeout;
+
+  /**
+   * The address to convert
+   */
+  struct GNUNET_HELLO_Address *address;
+};
+
+/**
+ * Context to store name resolutions for valiation
+ */
+struct PeerResolutionContext
+{
+  /**
+   * Next in DLL
+   */
+  struct PeerResolutionContext *next;
+
+  /**
+   * Prev in DLL
+   */
+  struct PeerResolutionContext *prev;
+
+  /**
+   * address to resolve
+   */
+  struct GNUNET_HELLO_Address *addrcp;
+
+  /**
+   * transport conversiion context
+   */
+  struct GNUNET_TRANSPORT_AddressToStringContext *asc;
+
+  /**
+   * peer state
+   */
+  enum GNUNET_TRANSPORT_PeerState state;
+
+  /**
+   * state timeout
+   */
+  struct GNUNET_TIME_Absolute state_timeout;
+
+  /**
+   * transport plugin
+   */
+  char *transport;
+
+  /**
+   * was the entry printed
+   */
+  int printed;
+};
+
+
+/**
+ * Context for a plugin test.
+ */
+struct TestContext
+{
+  /**
+   * Previous in DLL
+   */
+  struct TestContext *prev;
+
+  /**
+   * Next in DLL
+   */
+  struct TestContext *next;
+
+  /**
+   * Handle to the active NAT test.
+   */
+  struct GNUNET_NAT_Test *tst;
+
+  /**
+   * Task identifier for the timeout.
+   */
+  struct GNUNET_SCHEDULER_Task * tsk;
+
+  /**
+   * Name of plugin under test.
+   */
+  char *name;
+
+  /**
+   * Bound port
+   */
+  unsigned long long bnd_port;
+
+  /**
+   * Advertised ports
+   */
+  unsigned long long adv_port;
+
+};
+
+
+/**
+ *
+ */
+enum TestResult
+{
+  /**
+   * NAT returned success
+   */
+  NAT_TEST_SUCCESS = GNUNET_OK,
+
+  /**
+   * NAT returned failure
+   */
+  NAT_TEST_FAIL = GNUNET_NO,
+
+  /**
+   * NAT returned failure while running test
+   */
+  NAT_TEST_INTERNAL_FAIL = GNUNET_SYSERR,
+
+  /**
+   * We could not start the test
+   */
+  NAT_TEST_FAILED_TO_START = 2,
+
+  /**
+   * We had a timeout while running the test
+   */
+  NAT_TEST_TIMEOUT = 3
+};
+
+
 /**
  * Benchmarking block size in KB
  */
@@ -64,9 +271,14 @@ static struct GNUNET_TRANSPORT_Handle *handle;
 static struct GNUNET_CONFIGURATION_Handle *cfg;
 
 /**
- * Try_connect handle
+ * Try connect handle
  */
-struct GNUNET_TRANSPORT_TryConnectHandle * tc_handle;
+struct GNUNET_TRANSPORT_TryConnectHandle *tc_handle;
+
+/**
+ * Try disconnect handle
+ */
+struct GNUNET_TRANSPORT_TryDisconnectHandle *td_handle;
 
 /**
  * Option -s.
@@ -118,6 +330,11 @@ static int monitor_connections;
  */
 static int monitor_validation;
 
+/**
+ * Option -P.
+ */
+static int monitor_plugins;
+
 /**
  * Option -C.
  */
@@ -169,12 +386,25 @@ static struct GNUNET_TRANSPORT_TransmitHandle *th;
 static struct GNUNET_CONTAINER_MultiPeerMap *monitored_peers;
 
 /**
- *
+ * Map storing information about monitored plugins's sessions.
+ */
+static struct GNUNET_CONTAINER_MultiPeerMap *monitored_plugins;
+
+/**
+ * Handle if we are monitoring peers at the transport level.
  */
 static struct GNUNET_TRANSPORT_PeerMonitoringContext *pic;
 
+/**
+ * Handle if we are monitoring transport validation activity.
+ */
 static struct GNUNET_TRANSPORT_ValidationMonitoringContext *vic;
 
+/**
+ * Handle if we are monitoring plugin session activity.
+ */
+static struct GNUNET_TRANSPORT_PluginMonitor *pm;
+
 /**
  * Identity of the peer we transmit to / connect to.
  * (equivalent to 'cpid' string).
@@ -184,12 +414,12 @@ static struct GNUNET_PeerIdentity pid;
 /**
  * Task scheduled for cleanup / termination of the process.
  */
-static GNUNET_SCHEDULER_TaskIdentifier end;
+static struct GNUNET_SCHEDULER_Task * end;
 
 /**
  * Task for operation timeout
  */
-static GNUNET_SCHEDULER_TaskIdentifier op_timeout;
+static struct GNUNET_SCHEDULER_Task * op_timeout;
 
 /**
  * Selected level of verbosity.
@@ -222,94 +452,34 @@ struct TestContext *head;
 struct TestContext *tail;
 
 /**
- * Context for a plugin test.
+ * DLL: head of validation resolution entries
  */
-struct TestContext
-{
-  /**
-   * Previous in DLL
-   */
-  struct TestContext *prev;
-
-  /**
-   * Next in DLL
-   */
-  struct TestContext *next;
-
-  /**
-   * Handle to the active NAT test.
-   */
-  struct GNUNET_NAT_Test *tst;
-
-  /**
-   * Task identifier for the timeout.
-   */
-  GNUNET_SCHEDULER_TaskIdentifier tsk;
-
-  /**
-   * Name of plugin under test.
-   */
-  char *name;
-
-  /**
-   * Bound port
-   */
-  unsigned long long bnd_port;
-
-  /**
-   * Advertised ports
-   */
-  unsigned long long adv_port;
-
-};
-
-enum TestResult
-{
-  /* NAT returned success */
-  NAT_TEST_SUCCESS = GNUNET_OK,
-
-  /* NAT returned failure  */
-  NAT_TEST_FAIL = GNUNET_NO,
-
-  /* NAT returned failure while running test */
-  NAT_TEST_INTERNAL_FAIL = GNUNET_SYSERR,
-
-  /* We could not start the test */
-  NAT_TEST_FAILED_TO_START = 2,
-
-  /* We had a timeout while running the test */
-  NAT_TEST_TIMEOUT = 3,
-};
-
 static struct ValidationResolutionContext *vc_head;
-static struct ValidationResolutionContext *vc_tail;
 
-struct ValidationResolutionContext
-{
-  struct ValidationResolutionContext *next;
-  struct ValidationResolutionContext *prev;
-
-  struct GNUNET_PeerIdentity id;
-  struct GNUNET_HELLO_Address *addrcp;
-  struct GNUNET_TIME_Absolute last_validation;
-  struct GNUNET_TIME_Absolute valid_until;
-  struct GNUNET_TIME_Absolute next_validation;
-  enum GNUNET_TRANSPORT_ValidationState state;
-
-  struct GNUNET_TRANSPORT_AddressToStringContext *asc;
+/**
+ * DLL: tail of validation resolution entries
+ */
+static struct ValidationResolutionContext *vc_tail;
 
-  char *transport;
-  int printed;
-};
+/**
+ * DLL: head of resolution entries
+ */
+static struct PeerResolutionContext *rc_head;
 
-struct MonitoredPeer
-{
-  enum GNUNET_TRANSPORT_PeerState state;
-  struct GNUNET_TIME_Absolute state_timeout;
-  struct GNUNET_HELLO_Address *address;
-};
+/**
+ * DLL: head of resolution entries
+ */
+static struct PeerResolutionContext *rc_tail;
 
 
+/**
+ * Function called to release data stored in the #monitored_peers map.
+ *
+ * @param cls unused
+ * @param key the peer identity
+ * @param value a `struct MonitoredPeer` to release
+ * @return #GNUNET_OK (continue to iterate)
+ */
 static int
 destroy_it (void *cls,
             const struct GNUNET_PeerIdentity *key,
@@ -317,8 +487,10 @@ destroy_it (void *cls,
 {
   struct MonitoredPeer *m = value;
 
-  GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multipeermap_remove (monitored_peers,
-                                                                    key, value));
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CONTAINER_multipeermap_remove (monitored_peers,
+                                                       key,
+                                                       value));
   GNUNET_free_non_null (m->address);
   GNUNET_free (value);
   return GNUNET_OK;
@@ -329,20 +501,23 @@ destroy_it (void *cls,
  * Task run in monitor mode when the user presses CTRL-C to abort.
  * Stops monitoring activity.
  *
- * @param cls the 'struct GNUNET_TRANSPORT_PeerIterateContext *'
+ * @param cls NULL
  * @param tc scheduler context
  */
 static void
-shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+shutdown_task (void *cls,
+               const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct GNUNET_TIME_Relative duration;
   struct ValidationResolutionContext *cur;
   struct ValidationResolutionContext *next;
-  end = GNUNET_SCHEDULER_NO_TASK;
-  if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
+  struct PeerResolutionContext *rc;
+
+  end = NULL;
+  if (NULL != op_timeout)
   {
     GNUNET_SCHEDULER_cancel (op_timeout);
-    op_timeout = GNUNET_SCHEDULER_NO_TASK;
+    op_timeout = NULL;
   }
   if (NULL != tc_handle)
   {
@@ -359,6 +534,11 @@ shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
     GNUNET_TRANSPORT_monitor_validation_entries_cancel (vic);
     vic = NULL;
   }
+  if (NULL != pm)
+  {
+    GNUNET_TRANSPORT_monitor_plugins_cancel (pm);
+    pm = NULL;
+  }
 
   next = vc_head;
   for (cur = next; NULL != cur; cur = next)
@@ -366,12 +546,23 @@ shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
     next = cur->next;
 
     GNUNET_TRANSPORT_address_to_string_cancel (cur->asc);
-    GNUNET_CONTAINER_DLL_remove (vc_head, vc_tail, cur);
+    GNUNET_CONTAINER_DLL_remove (vc_head,
+                                vc_tail,
+                                cur);
     GNUNET_free (cur->transport);
     GNUNET_HELLO_address_free (cur->addrcp);
     GNUNET_free (cur);
   }
-
+  while (NULL != (rc = rc_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (rc_head,
+                                rc_tail,
+                                rc);
+    GNUNET_TRANSPORT_address_to_string_cancel (rc->asc);
+    GNUNET_free (rc->transport);
+    GNUNET_free (rc->addrcp);
+    GNUNET_free (rc);
+  }
   if (NULL != th)
   {
     GNUNET_TRANSPORT_notify_transmit_ready_cancel (th);
@@ -385,18 +576,20 @@ shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
   if (benchmark_send)
   {
     duration = GNUNET_TIME_absolute_get_duration (start_time);
-    FPRINTF (stdout, _("Transmitted %llu bytes/s (%llu bytes in %s)\n"),
-        1000LL * 1000LL * traffic_sent / (1 + duration.rel_value_us),
-        traffic_sent,
-        GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
+    FPRINTF (stdout,
+             _("Transmitted %llu bytes/s (%llu bytes in %s)\n"),
+             1000LL * 1000LL * traffic_sent / (1 + duration.rel_value_us),
+             traffic_sent,
+             GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
   }
   if (benchmark_receive)
   {
     duration = GNUNET_TIME_absolute_get_duration (start_time);
-    FPRINTF (stdout, _("Received %llu bytes/s (%llu bytes in %s)\n"),
-        1000LL * 1000LL * traffic_received / (1 + duration.rel_value_us),
-        traffic_received,
-        GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
+    FPRINTF (stdout,
+             _("Received %llu bytes/s (%llu bytes in %s)\n"),
+             1000LL * 1000LL * traffic_received / (1 + duration.rel_value_us),
+             traffic_received,
+             GNUNET_STRINGS_relative_time_to_string (duration, GNUNET_YES));
   }
 
   if (NULL != monitored_peers)
@@ -405,38 +598,31 @@ shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
     GNUNET_CONTAINER_multipeermap_destroy (monitored_peers);
     monitored_peers = NULL;
   }
+  if (NULL != monitored_plugins)
+  {
+    GNUNET_break (0 ==
+                  GNUNET_CONTAINER_multipeermap_size (monitored_plugins));
+    GNUNET_CONTAINER_multipeermap_destroy (monitored_plugins);
+    monitored_plugins = NULL;
+  }
 }
 
-static struct PeerResolutionContext *rc_head;
-static struct PeerResolutionContext *rc_tail;
-
-struct PeerResolutionContext
-{
-  struct PeerResolutionContext *next;
-  struct PeerResolutionContext *prev;
-  struct GNUNET_PeerIdentity id;
-  struct GNUNET_HELLO_Address *addrcp;
-  struct GNUNET_TRANSPORT_AddressToStringContext *asc;
-  enum GNUNET_TRANSPORT_PeerState state;
-  struct GNUNET_TIME_Absolute state_timeout;
-  char *transport;
-  int printed;
-};
-
-
 
 static void
-operation_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+operation_timeout (void *cls,
+                   const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct PeerResolutionContext *cur;
   struct PeerResolutionContext *next;
-  op_timeout = GNUNET_SCHEDULER_NO_TASK;
+  op_timeout = NULL;
   if ((try_connect) || (benchmark_send) || (benchmark_receive))
   {
-    FPRINTF (stdout, _("Failed to connect to `%s'\n"), GNUNET_i2s_full (&pid));
-    if (GNUNET_SCHEDULER_NO_TASK != end)
+    FPRINTF (stdout,
+             _("Failed to connect to `%s'\n"),
+             GNUNET_i2s_full (&pid));
+    if (NULL != end)
       GNUNET_SCHEDULER_cancel (end);
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
     ret = 1;
     return;
   }
@@ -446,8 +632,9 @@ operation_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
     while (NULL != (cur = next))
     {
       next = cur->next;
-      FPRINTF (stdout, _("Failed to resolve address for peer `%s'\n"),
-          GNUNET_i2s (&cur->addrcp->peer));
+      FPRINTF (stdout,
+               _("Failed to resolve address for peer `%s'\n"),
+               GNUNET_i2s (&cur->addrcp->peer));
 
       GNUNET_CONTAINER_DLL_remove(rc_head, rc_tail, cur);
       GNUNET_TRANSPORT_address_to_string_cancel (cur->asc);
@@ -456,18 +643,21 @@ operation_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
       GNUNET_free(cur);
 
     }
-    FPRINTF (stdout, "%s", _("Failed to list connections, timeout occured\n") );
-    if (GNUNET_SCHEDULER_NO_TASK != end)
+    FPRINTF (stdout,
+             "%s",
+             _("Failed to list connections, timeout occured\n"));
+    if (NULL != end)
       GNUNET_SCHEDULER_cancel (end);
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
     ret = 1;
     return;
   }
-
 }
 
+
 static void
-run_nat_test ();
+run_nat_test (void);
+
 
 /**
  * Display the result of the test.
@@ -476,45 +666,45 @@ run_nat_test ();
  * @param result #GNUNET_YES on success
  */
 static void
-display_test_result (struct TestContext *tc, enum TestResult result)
+display_test_result (struct TestContext *tc,
+                     enum TestResult result)
 {
   switch (result) {
     case NAT_TEST_FAIL:
-      FPRINTF (stderr, _("Configuration for plugin `%s' did not work!\n"),
-          tc->name);
+      FPRINTF (stderr,
+               _("Configuration for plugin `%s' did not work!\n"),
+               tc->name);
       break;
     case NAT_TEST_SUCCESS:
-      FPRINTF (stderr, _("Configuration for plugin `%s' did work!\n"),
-          tc->name);
+      FPRINTF (stderr,
+               _("Configuration for plugin `%s' did work!\n"),
+               tc->name);
       break;
     case NAT_TEST_INTERNAL_FAIL:
-      FPRINTF (stderr, _("Internal NAT error while running test for plugin `%s'\n"),
-          tc->name);
+      FPRINTF (stderr,
+               _("Internal NAT error while running test for plugin `%s'\n"),
+               tc->name);
       break;
     case NAT_TEST_FAILED_TO_START:
-      FPRINTF (stderr, _("Failed to start NAT test for plugin `%s'\n"),
-          tc->name);
+      FPRINTF (stderr,
+               _("Failed to start NAT test for plugin `%s'\n"),
+               tc->name);
       break;
     case NAT_TEST_TIMEOUT:
-      FPRINTF (stderr, _("Timeout while waiting for result of NAT test for plugin `%s'\n"),
-          tc->name);
+      FPRINTF (stderr,
+               _("Timeout while waiting for result of NAT test for plugin `%s'\n"),
+               tc->name);
       break;
     default:
+      FPRINTF (stderr,
+               _("Configuration for plugin `%s' did not work!\n"),
+               tc->name);
       break;
   }
-
-  if (GNUNET_YES != result)
-  {
-    FPRINTF (stderr, "Configuration for plugin `%s' did not work!\n", tc->name);
-  }
-  else
-  {
-    FPRINTF (stderr, "Configuration for plugin `%s' is working!\n", tc->name);
-  }
-  if (GNUNET_SCHEDULER_NO_TASK != tc->tsk)
+  if (NULL != tc->tsk)
   {
     GNUNET_SCHEDULER_cancel (tc->tsk);
-    tc->tsk = GNUNET_SCHEDULER_NO_TASK;
+    tc->tsk = NULL;
   }
   if (NULL != tc->tst)
   {
@@ -528,7 +718,8 @@ display_test_result (struct TestContext *tc, enum TestResult result)
 
   if ((NULL == head) && (NULL != resolver))
   {
-    GNUNET_break(0 == GNUNET_OS_process_kill (resolver, GNUNET_TERM_SIG));
+    GNUNET_break (0 == GNUNET_OS_process_kill (resolver,
+                                               GNUNET_TERM_SIG));
     GNUNET_OS_process_destroy (resolver);
     resolver = NULL;
   }
@@ -536,24 +727,37 @@ display_test_result (struct TestContext *tc, enum TestResult result)
     run_nat_test ();
 }
 
+
 /**
  * Function called by NAT to report the outcome of the nat-test.
  * Clean up and update GUI.
  *
  * @param cls test context
- * @param success currently always #GNUNET_OK
- * @param emsg error message, NULL on success
+ * @param result status code
  */
 static void
-result_callback (void *cls, enum GNUNET_NAT_FailureCode result)
+result_callback (void *cls,
+                 enum GNUNET_NAT_StatusCode result)
 {
   struct TestContext *tc = cls;
-  display_test_result (tc, result);
+
+  display_test_result (tc,
+                      result);
 }
 
+
+/**
+ * Resolve address we got a validation state for to a string.
+ *
+ * @param address the address itself
+ * @param numeric #GNUNET_YES to disable DNS, #GNUNET_NO to try reverse lookup
+ * @param last_validation when was the address validated last
+ * @param valid_until until when is the address valid
+ * @param next_validation when will we try to revalidate the address next
+ * @param state where are we in the validation state machine
+ */
 static void
-resolve_validation_address (const struct GNUNET_PeerIdentity *id,
-                            const struct GNUNET_HELLO_Address *address,
+resolve_validation_address (const struct GNUNET_HELLO_Address *address,
                             int numeric,
                             struct GNUNET_TIME_Absolute last_validation,
                             struct GNUNET_TIME_Absolute valid_until,
@@ -561,104 +765,138 @@ resolve_validation_address (const struct GNUNET_PeerIdentity *id,
                             enum GNUNET_TRANSPORT_ValidationState state);
 
 
+/**
+ * Function to call with a textual representation of an address.  This
+ * function will be called several times with different possible
+ * textual representations, and a last time with @a address being NULL
+ * to signal the end of the iteration.  Note that @a address NULL
+ * always is the last call, regardless of the value in @a res.
+ *
+ * @param cls closure
+ * @param address NULL on end of iteration,
+ *        otherwise 0-terminated printable UTF-8 string,
+ *        in particular an empty string if @a res is #GNUNET_NO
+ * @param res result of the address to string conversion:
+ *        if #GNUNET_OK: conversion successful
+ *        if #GNUNET_NO: address was invalid (or not supported)
+ *        if #GNUNET_SYSERR: communication error (IPC error)
+ */
 static void
-process_validation_string (void *cls, const char *address, int res)
+process_validation_string (void *cls,
+                           const char *address,
+                           int res)
 {
   struct ValidationResolutionContext *vc = cls;
   char *s_valid;
   char *s_last;
   char *s_next;
 
-  if (address != NULL )
+  if (NULL != address)
   {
     if (GNUNET_SYSERR == res)
     {
-      FPRINTF (stderr, "Failed to convert address for peer `%s' plugin `%s' length %lu to string \n",
-          GNUNET_i2s (&vc->id),
-          vc->addrcp->transport_name,
-          vc->addrcp->address_length);
+      FPRINTF (stderr,
+               "Failed to convert address for peer `%s' plugin `%s' length %u to string \n",
+               GNUNET_i2s (&vc->addrcp->peer),
+               vc->addrcp->transport_name,
+               (unsigned int) vc->addrcp->address_length);
     }
     if (GNUNET_TIME_UNIT_ZERO_ABS.abs_value_us == vc->valid_until.abs_value_us)
-      s_valid = GNUNET_strdup("never");
+      s_valid = GNUNET_strdup ("never");
     else
-      s_valid = GNUNET_strdup(GNUNET_STRINGS_absolute_time_to_string (vc->valid_until));
+      s_valid = GNUNET_strdup (GNUNET_STRINGS_absolute_time_to_string (vc->valid_until));
 
     if (GNUNET_TIME_UNIT_ZERO_ABS.abs_value_us == vc->last_validation.abs_value_us)
-      s_last = GNUNET_strdup("never");
+      s_last = GNUNET_strdup ("never");
     else
-      s_last = GNUNET_strdup(GNUNET_STRINGS_absolute_time_to_string (vc->last_validation));
+      s_last = GNUNET_strdup (GNUNET_STRINGS_absolute_time_to_string (vc->last_validation));
 
     if (GNUNET_TIME_UNIT_ZERO_ABS.abs_value_us == vc->next_validation.abs_value_us)
-      s_next = GNUNET_strdup("never");
+      s_next = GNUNET_strdup ("never");
     else
-      s_next = GNUNET_strdup(GNUNET_STRINGS_absolute_time_to_string (vc->next_validation));
+      s_next = GNUNET_strdup (GNUNET_STRINGS_absolute_time_to_string (vc->next_validation));
 
     FPRINTF (stdout,
-        _("Peer `%s' %s %s\n\t%s%s\n\t%s%s\n\t%s%s\n"),
-        GNUNET_i2s (&vc->id),
-        (GNUNET_OK == res) ? address : "<invalid address>",
-        (monitor_validation) ? GNUNET_TRANSPORT_vs2s (vc->state) : "",
-        "Valid until    : ", s_valid,
-        "Last validation: ",s_last,
-        "Next validation: ", s_next);
+             _("Peer `%s' %s %s\n\t%s%s\n\t%s%s\n\t%s%s\n"),
+             GNUNET_i2s (&vc->addrcp->peer),
+             (GNUNET_OK == res) ? address : "<invalid address>",
+             (monitor_validation) ? GNUNET_TRANSPORT_vs2s (vc->state) : "",
+             "Valid until    : ", s_valid,
+             "Last validation: ",s_last,
+             "Next validation: ", s_next);
     GNUNET_free (s_valid);
     GNUNET_free (s_last);
     GNUNET_free (s_next);
     vc->printed = GNUNET_YES;
+    return;
   }
-  else
+  /* last call, we are done */
+  GNUNET_assert (address_resolutions > 0);
+  address_resolutions--;
+  if ( (GNUNET_SYSERR == res) &&
+       (GNUNET_NO == vc->printed))
   {
-    /* done */
-
-    GNUNET_assert(address_resolutions > 0);
-    address_resolutions--;
-    if ((GNUNET_SYSERR == res) && (GNUNET_NO == vc->printed))
+    if (numeric == GNUNET_NO)
     {
-      if (numeric == GNUNET_NO)
-      {
-        /* Failed to resolve address, try numeric lookup */
-        resolve_validation_address (&vc->id, vc->addrcp, GNUNET_NO,
-           vc->last_validation, vc->valid_until, vc->next_validation,
-           vc->state);
-      }
-      else
-      {
-        FPRINTF (stdout, _("Peer `%s' %s `%s' \n"),
-            GNUNET_i2s (&vc->id), "<unable to resolve address>",
-            GNUNET_TRANSPORT_vs2s (vc->state));
-      }
+      /* Failed to resolve address, try numeric lookup
+         (note: this should be unnecessary, as
+         transport should fallback to numeric lookup
+         internally if DNS takes too long anyway) */
+      resolve_validation_address (vc->addrcp,
+                                  GNUNET_NO,
+                                  vc->last_validation,
+                                  vc->valid_until,
+                                  vc->next_validation,
+                                  vc->state);
     }
-    GNUNET_free (vc->transport);
-    GNUNET_free (vc->addrcp);
-    GNUNET_CONTAINER_DLL_remove(vc_head, vc_tail, vc);
-    GNUNET_free(vc);
-    if ((0 == address_resolutions) && (iterate_validation))
+    else
     {
-      if (GNUNET_SCHEDULER_NO_TASK != end)
-      {
-        GNUNET_SCHEDULER_cancel (end);
-        end = GNUNET_SCHEDULER_NO_TASK;
-      }
-      if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
-      {
-        GNUNET_SCHEDULER_cancel (op_timeout);
-        op_timeout = GNUNET_SCHEDULER_NO_TASK;
-      }
-      ret = 0;
-      end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+      FPRINTF (stdout,
+               _("Peer `%s' %s `%s' \n"),
+               GNUNET_i2s (&vc->addrcp->peer),
+               "<unable to resolve address>",
+               GNUNET_TRANSPORT_vs2s (vc->state));
+    }
+  }
+  GNUNET_free (vc->transport);
+  GNUNET_free (vc->addrcp);
+  GNUNET_CONTAINER_DLL_remove (vc_head, vc_tail, vc);
+  GNUNET_free (vc);
+  if ((0 == address_resolutions) && (iterate_validation))
+  {
+    if (NULL != end)
+    {
+      GNUNET_SCHEDULER_cancel (end);
+      end = NULL;
+    }
+    if (NULL != op_timeout)
+    {
+      GNUNET_SCHEDULER_cancel (op_timeout);
+      op_timeout = NULL;
     }
+    ret = 0;
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
   }
 }
 
 
-
+/**
+ * Resolve address we got a validation state for to a string.
+ *
+ * @param address the address itself
+ * @param numeric #GNUNET_YES to disable DNS, #GNUNET_NO to try reverse lookup
+ * @param last_validation when was the address validated last
+ * @param valid_until until when is the address valid
+ * @param next_validation when will we try to revalidate the address next
+ * @param state where are we in the validation state machine
+ */
 static void
-resolve_validation_address (const struct GNUNET_PeerIdentity *id,
-    const struct GNUNET_HELLO_Address *address, int numeric,
-    struct GNUNET_TIME_Absolute last_validation,
-    struct GNUNET_TIME_Absolute valid_until,
-    struct GNUNET_TIME_Absolute next_validation,
-    enum GNUNET_TRANSPORT_ValidationState state)
+resolve_validation_address (const struct GNUNET_HELLO_Address *address,
+                            int numeric,
+                            struct GNUNET_TIME_Absolute last_validation,
+                            struct GNUNET_TIME_Absolute valid_until,
+                            struct GNUNET_TIME_Absolute next_validation,
+                            enum GNUNET_TRANSPORT_ValidationState state)
 {
   struct ValidationResolutionContext *vc;
 
@@ -667,7 +905,6 @@ resolve_validation_address (const struct GNUNET_PeerIdentity *id,
   GNUNET_CONTAINER_DLL_insert(vc_head, vc_tail, vc);
   address_resolutions++;
 
-  vc->id = (*id);
   vc->transport = GNUNET_strdup(address->transport_name);
   vc->addrcp = GNUNET_HELLO_address_copy (address);
   vc->printed = GNUNET_NO;
@@ -677,21 +914,33 @@ resolve_validation_address (const struct GNUNET_PeerIdentity *id,
   vc->next_validation = next_validation;
 
   /* Resolve address to string */
-  vc->asc = GNUNET_TRANSPORT_address_to_string (cfg, address, numeric,
-      RESOLUTION_TIMEOUT, &process_validation_string, vc);
+  vc->asc = GNUNET_TRANSPORT_address_to_string (cfg,
+                                                address,
+                                                numeric,
+                                                RESOLUTION_TIMEOUT,
+                                                &process_validation_string, vc);
 }
 
 
+/**
+ * Resolve address we got a validation state for to a string.
+ *
+ * @param cls NULL
+ * @param address the address itself
+ * @param last_validation when was the address validated last
+ * @param valid_until until when is the address valid
+ * @param next_validation when will we try to revalidate the address next
+ * @param state where are we in the validation state machine
+ */
 static void
 process_validation_cb (void *cls,
-                       const struct GNUNET_PeerIdentity *peer,
                        const struct GNUNET_HELLO_Address *address,
                        struct GNUNET_TIME_Absolute last_validation,
                        struct GNUNET_TIME_Absolute valid_until,
                        struct GNUNET_TIME_Absolute next_validation,
                        enum GNUNET_TRANSPORT_ValidationState state)
 {
-  if ((NULL == peer) && (NULL == address))
+  if (NULL == address)
   {
     if (monitor_validation)
     {
@@ -700,26 +949,18 @@ process_validation_cb (void *cls,
                _("Monitor disconnected from transport service. Reconnecting.\n"));
       return;
     }
-
-    /* done */
-    vic = NULL;
-    if (GNUNET_SCHEDULER_NO_TASK != end)
-      GNUNET_SCHEDULER_cancel (end);
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
-    return;
-  }
-  if ((NULL == peer) || (NULL == address))
-  {
-    /* invalid response */
     vic = NULL;
-    if (GNUNET_SCHEDULER_NO_TASK != end)
+    if (NULL != end)
       GNUNET_SCHEDULER_cancel (end);
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
     return;
   }
-  resolve_validation_address (peer, address,
-     numeric, last_validation,
-     valid_until, next_validation, state);
+  resolve_validation_address (address,
+                              numeric,
+                              last_validation,
+                              valid_until,
+                              next_validation,
+                              state);
 }
 
 
@@ -727,15 +968,18 @@ static void
 run_nat_test ()
 {
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-      "Running test for plugin `%s' using bind port %u and advertised port %u \n",
-      head->name, (uint16_t) head->bnd_port, (uint16_t) head->adv_port);
+              "Running test for plugin `%s' using bind port %u and advertised port %u \n",
+              head->name,
+              (uint16_t) head->bnd_port,
+              (uint16_t) head->adv_port);
 
   head->tst = GNUNET_NAT_test_start (cfg,
-      (0 == strcasecmp (head->name, "udp")) ? GNUNET_NO : GNUNET_YES,
-      (uint16_t) head->bnd_port,
-      (uint16_t) head->adv_port,
-      TIMEOUT,
-      &result_callback, head);
+                                    (0 == strcasecmp (head->name, "udp"))
+                                    ? GNUNET_NO : GNUNET_YES,
+                                    (uint16_t) head->bnd_port,
+                                    (uint16_t) head->adv_port,
+                                    TIMEOUT,
+                                    &result_callback, head);
 }
 
 
@@ -759,7 +1003,7 @@ do_test_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg)
           &plugins))
   {
     FPRINTF (stderr, "%s", _
-    ("No transport plugins configured, peer will never communicate\n") );
+    ("No transport plugins configured, peer will never communicate\n"));
     ret = 4;
     return;
   }
@@ -795,7 +1039,7 @@ do_test_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg)
                                         GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                         NULL, NULL, NULL,
                                         binary,
-                                        "gnunet-service-resolver", NULL );
+                                        "gnunet-service-resolver", NULL);
     if (NULL == resolver)
     {
       FPRINTF (stderr, _("Failed to start resolver!\n"));
@@ -808,6 +1052,7 @@ do_test_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg)
   }
 }
 
+
 /**
  * Function called to notify a client about the socket
  * begin ready to queue more data.  @a buf will be
@@ -820,7 +1065,9 @@ do_test_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg)
  * @return number of bytes written to @a buf
  */
 static size_t
-transmit_data (void *cls, size_t size, void *buf)
+transmit_data (void *cls,
+               size_t size,
+               void *buf)
 {
   struct GNUNET_MessageHeader *m = buf;
 
@@ -839,7 +1086,7 @@ transmit_data (void *cls, size_t size, void *buf)
   th = GNUNET_TRANSPORT_notify_transmit_ready (handle, &pid,
                                                BLOCKSIZE * 1024,
                                                GNUNET_TIME_UNIT_FOREVER_REL,
-                                               &transmit_data, NULL );
+                                               &transmit_data, NULL);
   if (verbosity > 0)
     FPRINTF (stdout, _("Transmitting %u bytes to %s\n"), (unsigned int) size,
         GNUNET_i2s (&pid));
@@ -855,7 +1102,8 @@ transmit_data (void *cls, size_t size, void *buf)
  * @param peer the peer that connected
  */
 static void
-notify_connect (void *cls, const struct GNUNET_PeerIdentity *peer)
+notify_connect (void *cls,
+                const struct GNUNET_PeerIdentity *peer)
 {
   if (0 != memcmp (&pid, peer, sizeof(struct GNUNET_PeerIdentity)))
     return;
@@ -867,23 +1115,23 @@ notify_connect (void *cls, const struct GNUNET_PeerIdentity *peer)
         GNUNET_i2s_full (peer));
     ret = 0;
 
-    if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
+    if (NULL != op_timeout)
     {
       GNUNET_SCHEDULER_cancel (op_timeout);
-      op_timeout = GNUNET_SCHEDULER_NO_TASK;
+      op_timeout = NULL;
     }
 
-    if (GNUNET_SCHEDULER_NO_TASK != end)
+    if (NULL != end)
       GNUNET_SCHEDULER_cancel (end);
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
     return;
   }
   if (benchmark_send)
   {
-    if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
+    if (NULL != op_timeout)
     {
       GNUNET_SCHEDULER_cancel (op_timeout);
-      op_timeout = GNUNET_SCHEDULER_NO_TASK;
+      op_timeout = NULL;
     }
     if (verbosity > 0)
       FPRINTF (stdout,
@@ -902,6 +1150,7 @@ notify_connect (void *cls, const struct GNUNET_PeerIdentity *peer)
   }
 }
 
+
 /**
  * Function called to notify transport users that another
  * peer disconnected from us.
@@ -910,7 +1159,8 @@ notify_connect (void *cls, const struct GNUNET_PeerIdentity *peer)
  * @param peer the peer that disconnected
  */
 static void
-notify_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
+notify_disconnect (void *cls,
+                   const struct GNUNET_PeerIdentity *peer)
 {
   if (0 != memcmp (&pid, peer, sizeof(struct GNUNET_PeerIdentity)))
     return;
@@ -922,15 +1172,15 @@ notify_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
         GNUNET_i2s_full (peer));
     ret = 0;
 
-    if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
+    if (NULL != op_timeout)
     {
       GNUNET_SCHEDULER_cancel (op_timeout);
-      op_timeout = GNUNET_SCHEDULER_NO_TASK;
+      op_timeout = NULL;
     }
 
-    if (GNUNET_SCHEDULER_NO_TASK != end)
+    if (NULL != end)
       GNUNET_SCHEDULER_cancel (end);
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
     return;
   }
 
@@ -943,12 +1193,13 @@ notify_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
   {
     FPRINTF (stdout, _("Disconnected from peer `%s' while benchmarking\n"),
         GNUNET_i2s (&pid));
-    if (GNUNET_SCHEDULER_NO_TASK != end)
+    if (NULL != end)
       GNUNET_SCHEDULER_cancel (end);
     return;
   }
 }
 
+
 /**
  * Function called to notify transport users that another
  * peer connected to us.
@@ -957,14 +1208,19 @@ notify_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
  * @param peer the peer that connected
  */
 static void
-monitor_notify_connect (void *cls, const struct GNUNET_PeerIdentity *peer)
+monitor_notify_connect (void *cls,
+                        const struct GNUNET_PeerIdentity *peer)
 {
   monitor_connect_counter++;
   struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
   const char *now_str = GNUNET_STRINGS_absolute_time_to_string (now);
 
-  FPRINTF (stdout, _("%24s: %-17s %4s   (%u connections in total)\n"), now_str,
-      _("Connected to"), GNUNET_i2s (peer), monitor_connect_counter);
+  FPRINTF (stdout,
+           _("%24s: %-17s %4s   (%u connections in total)\n"),
+           now_str,
+           _("Connected to"),
+           GNUNET_i2s (peer),
+           monitor_connect_counter);
 }
 
 
@@ -976,7 +1232,8 @@ monitor_notify_connect (void *cls, const struct GNUNET_PeerIdentity *peer)
  * @param peer the peer that disconnected
  */
 static void
-monitor_notify_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
+monitor_notify_disconnect (void *cls,
+                           const struct GNUNET_PeerIdentity *peer)
 {
   struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
   const char *now_str = GNUNET_STRINGS_absolute_time_to_string (now);
@@ -984,8 +1241,12 @@ monitor_notify_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
   GNUNET_assert(monitor_connect_counter > 0);
   monitor_connect_counter--;
 
-  FPRINTF (stdout, _("%24s: %-17s %4s   (%u connections in total)\n"), now_str,
-      _("Disconnected from"), GNUNET_i2s (peer), monitor_connect_counter);
+  FPRINTF (stdout,
+           _("%24s: %-17s %4s   (%u connections in total)\n"),
+           now_str,
+           _("Disconnected from"),
+           GNUNET_i2s (peer),
+           monitor_connect_counter);
 }
 
 
@@ -1006,8 +1267,10 @@ notify_receive (void *cls,
     if (GNUNET_MESSAGE_TYPE_DUMMY != ntohs (message->type))
       return;
     if (verbosity > 0)
-      FPRINTF (stdout, _("Received %u bytes from %s\n"),
-          (unsigned int) ntohs (message->size), GNUNET_i2s (peer));
+      FPRINTF (stdout,
+               _("Received %u bytes from %s\n"),
+               (unsigned int) ntohs (message->size),
+               GNUNET_i2s (peer));
 
     if (traffic_received == 0)
       start_time = GNUNET_TIME_absolute_get ();
@@ -1017,9 +1280,17 @@ notify_receive (void *cls,
 }
 
 
+/**
+ * Convert address to a printable format.
+ *
+ * @param address the address
+ * @param numeric #GNUNET_YES to convert to numeric format, #GNUNET_NO
+ *                to try to use reverse DNS
+ * @param state state the peer is in
+ * @param state_timeout when will the peer's state expire
+ */
 static void
-resolve_peer_address (const struct GNUNET_PeerIdentity *id,
-                      const struct GNUNET_HELLO_Address *address,
+resolve_peer_address (const struct GNUNET_HELLO_Address *address,
                       int numeric,
                       enum GNUNET_TRANSPORT_PeerState state,
                       struct GNUNET_TIME_Absolute state_timeout);
@@ -1034,92 +1305,144 @@ print_info (const struct GNUNET_PeerIdentity *id,
 {
 
   if ( ((GNUNET_YES == iterate_connections) && (GNUNET_YES == iterate_all)) ||
-       (GNUNET_YES == monitor_connections) )
+       (GNUNET_YES == monitor_connections))
   {
-    FPRINTF (stdout, _("Peer `%s': %s %s in state `%s' until %s\n"),
-        GNUNET_i2s (id),
-        (NULL == transport) ? "<none>" : transport,
-        (NULL == transport) ? "<none>" : addr,
-        GNUNET_TRANSPORT_ps2s (state),
-        GNUNET_STRINGS_absolute_time_to_string (state_timeout));
+    FPRINTF (stdout,
+             _("Peer `%s': %s %s in state `%s' until %s\n"),
+             GNUNET_i2s (id),
+             (NULL == transport) ? "<none>" : transport,
+             (NULL == transport) ? "<none>" : addr,
+             GNUNET_TRANSPORT_ps2s (state),
+             GNUNET_STRINGS_absolute_time_to_string (state_timeout));
   }
   else if ( (GNUNET_YES == iterate_connections) &&
-             (GNUNET_TRANSPORT_is_connected(state)) )
+             (GNUNET_TRANSPORT_is_connected(state)))
   {
     /* Only connected peers, skip state */
-    FPRINTF (stdout, _("Peer `%s': %s %s\n"), GNUNET_i2s (id), transport, addr);
+    FPRINTF (stdout,
+             _("Peer `%s': %s %s\n"),
+             GNUNET_i2s (id),
+             transport,
+             addr);
   }
 }
 
 
+/**
+ * Function called with a textual representation of an address.  This
+ * function will be called several times with different possible
+ * textual representations, and a last time with @a address being NULL
+ * to signal the end of the iteration.  Note that @a address NULL
+ * always is the last call, regardless of the value in @a res.
+ *
+ * @param cls closure
+ * @param address NULL on end of iteration,
+ *        otherwise 0-terminated printable UTF-8 string,
+ *        in particular an empty string if @a res is #GNUNET_NO
+ * @param res result of the address to string conversion:
+ *        if #GNUNET_OK: conversion successful
+ *        if #GNUNET_NO: address was invalid (or not supported)
+ *        if #GNUNET_SYSERR: communication error (IPC error)
+ */
 static void
-process_peer_string (void *cls, const char *address, int res)
+process_peer_string (void *cls,
+                     const char *address,
+                     int res)
 {
   struct PeerResolutionContext *rc = cls;
 
-  if (GNUNET_SYSERR == res)
+  if (NULL != address)
   {
-    FPRINTF (stderr, "Failed to convert address for peer `%s' plugin `%s' length %lu to string \n",
-        GNUNET_i2s (&rc->id),
-        rc->addrcp->transport_name,
-        rc->addrcp->address_length);
-    print_info (&rc->id, rc->transport, NULL, rc->state, rc->state_timeout);
-    rc->printed = GNUNET_YES;
+    if (GNUNET_SYSERR == res)
+    {
+      FPRINTF (stderr,
+               "Failed to convert address for peer `%s' plugin `%s' length %u to string \n",
+               GNUNET_i2s (&rc->addrcp->peer),
+               rc->addrcp->transport_name,
+               (unsigned int) rc->addrcp->address_length);
+      print_info (&rc->addrcp->peer,
+                  rc->transport,
+                  NULL,
+                  rc->state,
+                  rc->state_timeout);
+      rc->printed = GNUNET_YES;
+      return;
+    }
+    if (GNUNET_OK == res)
+    {
+      print_info (&rc->addrcp->peer,
+                  rc->transport,
+                  address,
+                  rc->state,
+                  rc->state_timeout);
+      rc->printed = GNUNET_YES;
+      return; /* Wait for done call */
+    }
+    /* GNUNET_NO == res: ignore, was simply not supported */
     return;
   }
+  /* NULL == address, last call, we are done */
 
-  if ((GNUNET_OK == res) && (address != NULL))
+  rc->asc = NULL;
+  GNUNET_assert (address_resolutions > 0);
+  address_resolutions--;
+  if (GNUNET_NO == rc->printed)
   {
-    print_info (&rc->id, rc->transport, address, rc->state, rc->state_timeout);
-    rc->printed = GNUNET_YES;
-    return; /* Wait for done call */
+    if (numeric == GNUNET_NO)
+    {
+      /* Failed to resolve address, try numeric lookup
+         (note: this should not be needed, as transport
+         should fallback to numeric conversion if DNS takes
+         too long) */
+      resolve_peer_address (rc->addrcp,
+                            GNUNET_YES,
+                            rc->state,
+                            rc->state_timeout);
+    }
+    else
+    {
+      print_info (&rc->addrcp->peer,
+                  rc->transport,
+                  NULL,
+                  rc->state,
+                  rc->state_timeout);
+    }
   }
-
-  if (NULL == address)
+  GNUNET_free (rc->transport);
+  GNUNET_free (rc->addrcp);
+  GNUNET_CONTAINER_DLL_remove (rc_head, rc_tail, rc);
+  GNUNET_free (rc);
+  if ((0 == address_resolutions) && (iterate_connections))
   {
-    /* done */
-    GNUNET_assert(address_resolutions > 0);
-    address_resolutions--;
-    if (GNUNET_NO == rc->printed)
+    if (NULL != end)
     {
-      if (numeric == GNUNET_NO)
-      {
-        /* Failed to resolve address, try numeric lookup */
-        resolve_peer_address (&rc->id, rc->addrcp, GNUNET_YES,
-            rc->state, rc->state_timeout);
-      }
-      else
-      {
-        print_info (&rc->id, rc->transport, NULL,
-            rc->state, rc->state_timeout);
-      }
+      GNUNET_SCHEDULER_cancel (end);
+      end = NULL;
     }
-    GNUNET_free (rc->transport);
-    GNUNET_free (rc->addrcp);
-    GNUNET_CONTAINER_DLL_remove(rc_head, rc_tail, rc);
-    GNUNET_free(rc);
-    if ((0 == address_resolutions) && (iterate_connections))
+    if (NULL != op_timeout)
     {
-      if (GNUNET_SCHEDULER_NO_TASK != end)
-      {
-        GNUNET_SCHEDULER_cancel (end);
-        end = GNUNET_SCHEDULER_NO_TASK;
-      }
-      if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
-      {
-        GNUNET_SCHEDULER_cancel (op_timeout);
-        op_timeout = GNUNET_SCHEDULER_NO_TASK;
-      }
-      ret = 0;
-      end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+      GNUNET_SCHEDULER_cancel (op_timeout);
+      op_timeout = NULL;
     }
+    ret = 0;
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, 
+                                   NULL);
   }
 }
 
 
+/**
+ * Convert address to a printable format and print it
+ * together with the given state data.
+ *
+ * @param address the address
+ * @param numeric #GNUNET_YES to convert to numeric format, #GNUNET_NO
+ *                to try to use reverse DNS
+ * @param state state the peer is in
+ * @param state_timeout when will the peer's state expire
+ */
 static void
-resolve_peer_address (const struct GNUNET_PeerIdentity *id,
-                      const struct GNUNET_HELLO_Address *address,
+resolve_peer_address (const struct GNUNET_HELLO_Address *address,
                       int numeric,
                       enum GNUNET_TRANSPORT_PeerState state,
                       struct GNUNET_TIME_Absolute state_timeout)
@@ -1127,19 +1450,21 @@ resolve_peer_address (const struct GNUNET_PeerIdentity *id,
   struct PeerResolutionContext *rc;
 
   rc = GNUNET_new (struct PeerResolutionContext);
-  GNUNET_assert(NULL != rc);
-  GNUNET_CONTAINER_DLL_insert(rc_head, rc_tail, rc);
+  GNUNET_CONTAINER_DLL_insert (rc_head, 
+                              rc_tail,
+                              rc);
   address_resolutions++;
-
-  rc->id = (*id);
-  rc->transport = GNUNET_strdup(address->transport_name);
+  rc->transport = GNUNET_strdup (address->transport_name);
   rc->addrcp = GNUNET_HELLO_address_copy (address);
   rc->printed = GNUNET_NO;
   rc->state = state;
   rc->state_timeout = state_timeout;
   /* Resolve address to string */
-  rc->asc = GNUNET_TRANSPORT_address_to_string (cfg, address, numeric,
-      RESOLUTION_TIMEOUT, &process_peer_string, rc);
+  rc->asc = GNUNET_TRANSPORT_address_to_string (cfg,
+                                                address,
+                                                numeric,
+                                                RESOLUTION_TIMEOUT,
+                                                &process_peer_string, rc);
 }
 
 
@@ -1165,42 +1490,243 @@ process_peer_iteration_cb (void *cls,
     /* done */
     address_resolution_in_progress = GNUNET_NO;
     pic = NULL;
-    if (GNUNET_SCHEDULER_NO_TASK != end)
+    if (NULL != end)
       GNUNET_SCHEDULER_cancel (end);
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
     return;
   }
 
   if ( (GNUNET_NO == iterate_all) &&
-       (GNUNET_NO == GNUNET_TRANSPORT_is_connected(state)) )
+       (GNUNET_NO == GNUNET_TRANSPORT_is_connected(state)))
       return; /* Display only connected peers */
 
-  if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
+  if (NULL != op_timeout)
     GNUNET_SCHEDULER_cancel (op_timeout);
-  op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT, &operation_timeout,
+  op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT,
+                                             &operation_timeout,
                                              NULL);
 
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-             "Received address for peer `%s': %s\n",
-             GNUNET_i2s (peer), address->transport_name);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received address for peer `%s': %s\n",
+              GNUNET_i2s (peer),
+              address->transport_name);
 
   if (NULL != address)
-    resolve_peer_address (peer, address, numeric, state, state_timeout);
+    resolve_peer_address (address, 
+                         numeric, 
+                         state,
+                         state_timeout);
   else
-    print_info (peer, NULL, NULL, state, state_timeout);
+    print_info (peer, 
+               NULL,
+               NULL,
+               state,
+               state_timeout);
 }
 
 
 /**
- * Function called with information about a peers
+ * Context for address resolution by #plugin_monitoring_cb().
+ */
+struct PluginMonitorAddress
+{
+
+  /**
+   * Ongoing resolution request.
+   */
+  struct GNUNET_TRANSPORT_AddressToStringContext *asc;
+
+  /**
+   * Resolved address as string.
+   */
+  char *str;
+
+  /**
+   * Last event we got and did not yet print because
+   * @e str was NULL (address not yet resolved).
+   */
+  struct GNUNET_TRANSPORT_SessionInfo si;
+};
+
+
+/**
+ * Print information about a plugin monitoring event.
+ *
+ * @param addr out internal context
+ * @param info the monitoring information
+ */
+static void
+print_plugin_event_info (struct PluginMonitorAddress *addr,
+                        const struct GNUNET_TRANSPORT_SessionInfo *info)
+{
+  const char *state;
+
+  switch (info->state)
+  {
+  case GNUNET_TRANSPORT_SS_INIT:
+    state = "INIT";
+    break;
+  case GNUNET_TRANSPORT_SS_HANDSHAKE:
+    state = "HANDSHAKE";
+    break;
+  case GNUNET_TRANSPORT_SS_UP:
+    state = "UP";
+    break;
+  case GNUNET_TRANSPORT_SS_UPDATE:
+    state = "UPDATE";
+    break;
+  case GNUNET_TRANSPORT_SS_DONE:
+    state = "DONE";
+    break;
+  default:
+    state = "UNKNOWN";
+    break;
+  }
+  fprintf (stdout,
+           "%s: state %s timeout in %s @ %s%s\n",
+           GNUNET_i2s (&info->address->peer),
+           state,
+           GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (info->session_timeout),
+                                                  GNUNET_YES),
+          addr->str,
+           (info->is_inbound == GNUNET_YES) ? " (INBOUND)" : "");
+  fprintf (stdout,
+           "%s: queue has %3u messages and %6u bytes\n",
+           GNUNET_i2s (&info->address->peer),
+           info->num_msg_pending,
+           info->num_bytes_pending);
+  if (0 != GNUNET_TIME_absolute_get_remaining (info->receive_delay).rel_value_us)
+    fprintf (stdout,
+            "%s: receiving blocked until %s\n",
+            GNUNET_i2s (&info->address->peer),
+            GNUNET_STRINGS_absolute_time_to_string (info->receive_delay));
+}
+
+
+/**
+ * Function called with a textual representation of an address.  This
+ * function will be called several times with different possible
+ * textual representations, and a last time with @a address being NULL
+ * to signal the end of the iteration.  Note that @a address NULL
+ * always is the last call, regardless of the value in @a res.
  *
  * @param cls closure
+ * @param address NULL on end of iteration,
+ *        otherwise 0-terminated printable UTF-8 string,
+ *        in particular an empty string if @a res is #GNUNET_NO
+ * @param res result of the address to string conversion:
+ *        if #GNUNET_OK: conversion successful
+ *        if #GNUNET_NO: address was invalid (or not supported)
+ *        if #GNUNET_SYSERR: communication error (IPC error)
+ */
+static void
+address_cb (void *cls,
+            const char *address,
+            int res)
+{
+  struct PluginMonitorAddress *addr = cls;
+
+  if (NULL == address)
+  {
+    addr->asc = NULL;
+    return;
+  }
+  if (NULL != addr->str)
+    return;
+  addr->str = GNUNET_strdup (address);
+  print_plugin_event_info (addr,
+                          &addr->si);
+}
+
+
+/**
+ * Function called by the plugin with information about the
+ * current sessions managed by the plugin (for monitoring).
+ *
+ * @param cls closure (NULL)
+ * @param session session handle this information is about,
+ *        NULL to indicate that we are "in sync" (initial
+ *        iteration complete)
+ * @param session_ctx storage location where the application
+ *        can store data; will point to NULL on #GNUNET_TRANSPORT_SS_INIT,
+ *        and must be reset to NULL on #GNUNET_TRANSPORT_SS_DONE
+ * @param info information about the state of the session,
+ *        NULL if @a session is also NULL and we are
+ *        merely signalling that the initial iteration is over;
+ *        NULL with @a session being non-NULL if the monitor
+ *        was being cancelled while sessions were active
+ */
+static void
+plugin_monitoring_cb (void *cls,
+                      struct GNUNET_TRANSPORT_PluginSession *session,
+                      void **session_ctx,
+                      const struct GNUNET_TRANSPORT_SessionInfo *info)
+{
+  struct PluginMonitorAddress *addr;
+
+  if ( (NULL == info) &&
+       (NULL == session) )
+    return; /* in sync with transport service */
+  addr = *session_ctx;
+  if (NULL == info)
+  {
+    if (NULL != addr)
+    {
+      if (NULL != addr->asc)
+      {
+        GNUNET_TRANSPORT_address_to_string_cancel (addr->asc);
+        addr->asc = NULL;
+      }
+      GNUNET_free_non_null (addr->str);
+      GNUNET_free (addr);
+      *session_ctx = NULL;
+    }
+    return; /* shutdown */
+  }
+  if ( (NULL != cpid) &&
+       (0 != memcmp (&info->address->peer,
+                     cpid,
+                     sizeof (struct GNUNET_PeerIdentity))) )
+    return; /* filtered */
+  if (NULL == addr)
+  {
+    addr = GNUNET_new (struct PluginMonitorAddress);
+    addr->asc = GNUNET_TRANSPORT_address_to_string (cfg,
+                                                    info->address,
+                                                    numeric,
+                                                    GNUNET_TIME_UNIT_FOREVER_REL,
+                                                    &address_cb,
+                                                    addr);
+    *session_ctx = addr;
+  }
+  if (NULL == addr->str)
+    addr->si = *info;
+  else
+    print_plugin_event_info (addr,
+                            info);
+  if (GNUNET_TRANSPORT_SS_DONE == info->state)
+  {
+    if (NULL != addr->asc)
+    {
+      GNUNET_TRANSPORT_address_to_string_cancel (addr->asc);
+      addr->asc = NULL;
+    }
+    GNUNET_free_non_null (addr->str);
+    GNUNET_free (addr);
+    *session_ctx = NULL;
+  }
+}
+
+
+/**
+ * Function called with information about a peers
+ *
+ * @param cls closure, NULL
  * @param peer identity of the peer, NULL for final callback when operation done
  * @param address binary address used to communicate with this peer,
  *  NULL on disconnect or when done
  * @param state current state this peer is in
  * @param state_timeout time out for the current state
- *
  */
 static void
 process_peer_monitoring_cb (void *cls,
@@ -1219,27 +1745,34 @@ process_peer_monitoring_cb (void *cls,
     return;
   }
 
-  if (GNUNET_SCHEDULER_NO_TASK != op_timeout)
+  if (NULL != op_timeout)
     GNUNET_SCHEDULER_cancel (op_timeout);
-  op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT, &operation_timeout,
+  op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT,
+                                             &operation_timeout,
                                              NULL);
 
-  if (NULL == (m = GNUNET_CONTAINER_multipeermap_get (monitored_peers, peer)))
+  if (NULL == (m = GNUNET_CONTAINER_multipeermap_get (monitored_peers, 
+                                                     peer)))
   {
     m = GNUNET_new (struct MonitoredPeer);
-    GNUNET_CONTAINER_multipeermap_put (monitored_peers, peer,
-        m, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
+    GNUNET_CONTAINER_multipeermap_put (monitored_peers,
+                                      peer,
+                                      m,
+                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
   }
   else
   {
     if ( (m->state == state) &&
-      (m->state_timeout.abs_value_us == state_timeout.abs_value_us) &&
-      ((NULL == address) && (NULL == m->address)) )
+        (m->state_timeout.abs_value_us == state_timeout.abs_value_us) &&
+        (NULL == address) &&
+        (NULL == m->address) )
     {
       return; /* No real change */
     }
-    if ( (m->state == state) && ((NULL != address) && (NULL != m->address)) &&
-        (0 == GNUNET_HELLO_address_cmp(m->address, address)) )
+    if ( (m->state == state) &&
+        (NULL != address) && 
+        (NULL != m->address) &&
+        (0 == GNUNET_HELLO_address_cmp(m->address, address)) )
       return; /* No real change */
   }
 
@@ -1254,61 +1787,90 @@ process_peer_monitoring_cb (void *cls,
   m->state_timeout = state_timeout;
 
   if (NULL != address)
-    resolve_peer_address (peer, m->address, numeric, m->state, m->state_timeout);
+    resolve_peer_address (m->address,
+                          numeric,
+                          m->state,
+                          m->state_timeout);
   else
-    print_info (peer, NULL, NULL, m->state, m->state_timeout);
+    print_info (peer,
+                NULL,
+                NULL,
+                m->state,
+                m->state_timeout);
 }
 
+
+/**
+ * Function called with our result of trying to connect to a peer
+ * using the transport service. Will retry 10 times, and if we still
+ * fail to connect terminate with an error message.
+ *
+ * @param cls NULL
+ * @param result #GNUNET_OK if we connected to the service
+ */
 static void
-try_connect_cb (void *cls, const int result)
+try_connect_cb (void *cls,
+                const int result)
 {
   static int retries = 0;
+
+  tc_handle = NULL;
   if (GNUNET_OK == result)
-  {
-    tc_handle = NULL;
     return;
-  }
   retries++;
   if (retries < 10)
-    tc_handle = GNUNET_TRANSPORT_try_connect (handle, &pid, try_connect_cb,
-        NULL );
-  else
   {
-    FPRINTF (stderr, "%s",
-        _("Failed to send connect request to transport service\n") );
-    if (GNUNET_SCHEDULER_NO_TASK != end)
-      GNUNET_SCHEDULER_cancel (end);
-    ret = 1;
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    tc_handle = GNUNET_TRANSPORT_try_connect (handle,
+                                              &pid,
+                                              &try_connect_cb,
+                                              NULL);
     return;
   }
+  FPRINTF (stderr,
+           "%s",
+           _("Failed to send connect request to transport service\n"));
+  if (NULL != end)
+    GNUNET_SCHEDULER_cancel (end);
+  ret = 1;
+  end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 }
 
+
+/**
+ * Function called with our result of trying to disconnect a peer
+ * using the transport service. Will retry 10 times, and if we still
+ * fail to disconnect, terminate with an error message.
+ *
+ * @param cls NULL
+ * @param result #GNUNET_OK if we connected to the service
+ */
 static void
-try_disconnect_cb (void *cls, const int result)
+try_disconnect_cb (void *cls,
+                   const int result)
 {
   static int retries = 0;
+
+  td_handle = NULL;
   if (GNUNET_OK == result)
-  {
-    tc_handle = NULL;
     return;
-  }
   retries++;
   if (retries < 10)
-    tc_handle = GNUNET_TRANSPORT_try_disconnect (handle, &pid, try_disconnect_cb,
-        NULL );
-  else
   {
-    FPRINTF (stderr, "%s",
-        _("Failed to send connect request to transport service\n") );
-    if (GNUNET_SCHEDULER_NO_TASK != end)
-      GNUNET_SCHEDULER_cancel (end);
-    ret = 1;
-    end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL );
+    td_handle = GNUNET_TRANSPORT_try_disconnect (handle,
+                                                 &pid,
+                                                 &try_disconnect_cb,
+                                                 NULL);
     return;
   }
+  FPRINTF (stderr, "%s",
+           _("Failed to send disconnect request to transport service\n"));
+  if (NULL != end)
+    GNUNET_SCHEDULER_cancel (end);
+  ret = 1;
+  end = GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 }
 
+
 /**
  * Function called with the result of the check if the 'transport'
  * service is running.
@@ -1317,7 +1879,8 @@ try_disconnect_cb (void *cls, const int result)
  * @param result #GNUNET_YES if transport is running
  */
 static void
-testservice_task (void *cls, int result)
+testservice_task (void *cls,
+                  int result)
 {
   int counter = 0;
   ret = 1;
@@ -1339,22 +1902,22 @@ testservice_task (void *cls, int result)
 
   counter = benchmark_send + benchmark_receive + iterate_connections
       + monitor_connections + monitor_connects + try_connect + try_disconnect +
-      + iterate_validation + monitor_validation;
+      + iterate_validation + monitor_validation + monitor_plugins;
 
   if (1 < counter)
   {
     FPRINTF (stderr,
-        _("Multiple operations given. Please choose only one operation: %s, %s, %s, %s, %s, %s\n"),
+        _("Multiple operations given. Please choose only one operation: %s, %s, %s, %s, %s, %s %s\n"),
         "connect", "benchmark send", "benchmark receive", "information",
-        "monitor", "events");
+             "monitor", "events", "plugins");
     return;
   }
   if (0 == counter)
   {
     FPRINTF (stderr,
-        _("No operation given. Please choose one operation: %s, %s, %s, %s, %s, %s\n"),
+        _("No operation given. Please choose one operation: %s, %s, %s, %s, %s, %s, %s\n"),
         "connect", "benchmark send", "benchmark receive", "information",
-        "monitor", "events");
+             "monitor", "events", "plugins");
     return;
   }
 
@@ -1371,21 +1934,21 @@ testservice_task (void *cls, int result)
         &notify_connect, &notify_disconnect);
     if (NULL == handle)
     {
-      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n") );
+      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n"));
       ret = 1;
       return;
     }
     tc_handle = GNUNET_TRANSPORT_try_connect (handle, &pid, try_connect_cb,
-        NULL );
+        NULL);
     if (NULL == tc_handle)
     {
       FPRINTF (stderr, "%s",
-          _("Failed to send request to transport service\n") );
+          _("Failed to send request to transport service\n"));
       ret = 1;
       return;
     }
     op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT, &operation_timeout,
-        NULL );
+        NULL);
 
   }
   else if (try_disconnect) /* -D: Disconnect from peer */
@@ -1401,21 +1964,22 @@ testservice_task (void *cls, int result)
         &notify_connect, &notify_disconnect);
     if (NULL == handle)
     {
-      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n") );
+      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n"));
       ret = 1;
       return;
     }
-    tc_handle = GNUNET_TRANSPORT_try_disconnect (handle, &pid, try_disconnect_cb,
-        NULL );
-    if (NULL == tc_handle)
+    td_handle = GNUNET_TRANSPORT_try_disconnect (handle, &pid,
+                                                 &try_disconnect_cb,
+                                                 NULL);
+    if (NULL == td_handle)
     {
       FPRINTF (stderr, "%s",
-          _("Failed to send request to transport service\n") );
+          _("Failed to send request to transport service\n"));
       ret = 1;
       return;
     }
     op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT, &operation_timeout,
-        NULL );
+        NULL);
 
   }
   else if (benchmark_send) /* -s: Benchmark sending */
@@ -1427,39 +1991,44 @@ testservice_task (void *cls, int result)
       ret = 1;
       return;
     }
-    handle = GNUNET_TRANSPORT_connect (cfg, NULL, NULL, &notify_receive,
-        &notify_connect, &notify_disconnect);
+    handle = GNUNET_TRANSPORT_connect (cfg, NULL, NULL,
+                                       &notify_receive,
+                                       &notify_connect,
+                                       &notify_disconnect);
     if (NULL == handle)
     {
-      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n") );
+      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n"));
       ret = 1;
       return;
     }
-    tc_handle = GNUNET_TRANSPORT_try_connect (handle, &pid, try_connect_cb,
-        NULL );
+    tc_handle = GNUNET_TRANSPORT_try_connect (handle,
+                                              &pid,
+                                              &try_connect_cb,
+                                              NULL);
     if (NULL == tc_handle)
     {
       FPRINTF (stderr, "%s",
-          _("Failed to send request to transport service\n") );
+          _("Failed to send request to transport service\n"));
       ret = 1;
       return;
     }
     start_time = GNUNET_TIME_absolute_get ();
-    op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT, &operation_timeout,
-        NULL );
+    op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT,
+                                               &operation_timeout,
+                                               NULL);
   }
   else if (benchmark_receive) /* -b: Benchmark receiving */
   {
     handle = GNUNET_TRANSPORT_connect (cfg, NULL, NULL, &notify_receive, NULL,
-        NULL );
+        NULL);
     if (NULL == handle)
     {
-      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n") );
+      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n"));
       ret = 1;
       return;
     }
     if (verbosity > 0)
-      FPRINTF (stdout, "%s", _("Starting to receive benchmark data\n") );
+      FPRINTF (stdout, "%s", _("Starting to receive benchmark data\n"));
     start_time = GNUNET_TIME_absolute_get ();
 
   }
@@ -1469,26 +2038,39 @@ testservice_task (void *cls, int result)
     pic = GNUNET_TRANSPORT_monitor_peers (cfg, (NULL == cpid) ? NULL : &pid,
         GNUNET_YES, TIMEOUT, &process_peer_iteration_cb, (void *) cfg);
     op_timeout = GNUNET_SCHEDULER_add_delayed (OP_TIMEOUT, &operation_timeout,
-        NULL );
+        NULL);
   }
   else if (monitor_connections) /* -m: List information about peers continuously */
   {
-    monitored_peers = GNUNET_CONTAINER_multipeermap_create (10, GNUNET_NO);
+    monitored_peers = GNUNET_CONTAINER_multipeermap_create (10, 
+                                                           GNUNET_NO);
     address_resolution_in_progress = GNUNET_YES;
-    pic = GNUNET_TRANSPORT_monitor_peers (cfg, (NULL == cpid) ? NULL : &pid,
-        GNUNET_NO, TIMEOUT, &process_peer_monitoring_cb, (void *) cfg);
+    pic = GNUNET_TRANSPORT_monitor_peers (cfg, 
+                                         (NULL == cpid) ? NULL : &pid,
+                                          GNUNET_NO, 
+                                         TIMEOUT,
+                                          &process_peer_monitoring_cb, NULL);
+  }
+  else if (monitor_plugins) /* -P: List information about plugins continuously */
+  {
+    monitored_plugins = GNUNET_CONTAINER_multipeermap_create (10, GNUNET_NO);
+    pm = GNUNET_TRANSPORT_monitor_plugins (cfg,
+                                           &plugin_monitoring_cb,
+                                           NULL);
   }
   else if (iterate_validation) /* -d: Print information about validations */
   {
     vic = GNUNET_TRANSPORT_monitor_validation_entries (cfg,
-        (NULL == cpid) ? NULL : &pid,
-        GNUNET_YES, TIMEOUT, &process_validation_cb, (void *) cfg);
+                                                       (NULL == cpid) ? NULL : &pid,
+                                                       GNUNET_YES, TIMEOUT,
+                                                       &process_validation_cb, (void *) cfg);
   }
   else if (monitor_validation) /* -f: Print information about validations continuously */
   {
     vic = GNUNET_TRANSPORT_monitor_validation_entries (cfg,
-        (NULL == cpid) ? NULL : &pid,
-        GNUNET_NO, TIMEOUT, &process_validation_cb, (void *) cfg);
+                                                       (NULL == cpid) ? NULL : &pid,
+                                                       GNUNET_NO, TIMEOUT,
+                                                       &process_validation_cb, (void *) cfg);
   }
   else if (monitor_connects) /* -e : Monitor (dis)connect events continuously */
   {
@@ -1498,7 +2080,9 @@ testservice_task (void *cls, int result)
                                        &monitor_notify_disconnect);
     if (NULL == handle)
     {
-      FPRINTF (stderr, "%s", _("Failed to connect to transport service\n") );
+      FPRINTF (stderr,
+               "%s",
+               _("Failed to connect to transport service\n"));
       ret = 1;
       return;
     }
@@ -1511,10 +2095,11 @@ testservice_task (void *cls, int result)
   }
 
   end = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
-      &shutdown_task, NULL );
-
+                                      &shutdown_task,
+                                      NULL);
 }
 
+
 /**
  * Main function that will be run by the scheduler.
  *
@@ -1524,8 +2109,10 @@ testservice_task (void *cls, int result)
  * @param mycfg configuration
  */
 static void
-run (void *cls, char * const *args, const char *cfgfile,
-    const struct GNUNET_CONFIGURATION_Handle *mycfg)
+run (void *cls,
+     char * const *args,
+     const char *cfgfile,
+     const struct GNUNET_CONFIGURATION_Handle *mycfg)
 {
   cfg = (struct GNUNET_CONFIGURATION_Handle *) mycfg;
   if (test_configuration)
@@ -1541,53 +2128,62 @@ int
 main (int argc, char * const *argv)
 {
   int res;
-  static const struct GNUNET_GETOPT_CommandLineOption options[] =
-      {
-          { 'a', "all", NULL,
-              gettext_noop ("print information for all peers (instead of only connected peers )"),
-              0, &GNUNET_GETOPT_set_one, &iterate_all },
-          { 'b', "benchmark", NULL,
-              gettext_noop ("measure how fast we are receiving data from all peers (until CTRL-C)"),
-              0, &GNUNET_GETOPT_set_one, &benchmark_receive },
-          { 'C', "connect",
-              NULL, gettext_noop ("connect to a peer"), 0,
-              &GNUNET_GETOPT_set_one, &try_connect },
-          { 'D', "disconnect",
-              NULL, gettext_noop ("disconnect to a peer"), 0,
-              &GNUNET_GETOPT_set_one, &try_disconnect },
-          { 'd', "validation", NULL,
-              gettext_noop ("print information for all pending validations "),
-              0, &GNUNET_GETOPT_set_one, &iterate_validation },
-          { 'f', "monitorvalidation", NULL,
-              gettext_noop ("print information for all pending validations continously"),
-              0, &GNUNET_GETOPT_set_one, &monitor_validation },
-          { 'i', "information", NULL,
-              gettext_noop ("provide information about all current connections (once)"),
-              0, &GNUNET_GETOPT_set_one, &iterate_connections },
-          { 'm', "monitor", NULL,
-              gettext_noop ("provide information about all current connections (continuously)"),
-              0, &GNUNET_GETOPT_set_one, &monitor_connections },
-          { 'e', "events", NULL,
-              gettext_noop ("provide information about all connects and disconnect events (continuously)"),
-              0, &GNUNET_GETOPT_set_one, &monitor_connects }, { 'n', "numeric",
-              NULL, gettext_noop ("do not resolve hostnames"), 0,
-              &GNUNET_GETOPT_set_one, &numeric }, { 'p', "peer", "PEER",
-              gettext_noop ("peer identity"), 1, &GNUNET_GETOPT_set_string,
-              &cpid }, { 's', "send", NULL, gettext_noop
-          ("send data for benchmarking to the other peer (until CTRL-C)"), 0,
-              &GNUNET_GETOPT_set_one, &benchmark_send },
-          { 't', "test", NULL,
-              gettext_noop ("test transport configuration (involves external server)"),
-              0, &GNUNET_GETOPT_set_one, &test_configuration },
-              GNUNET_GETOPT_OPTION_VERBOSE (&verbosity),
-              GNUNET_GETOPT_OPTION_END };
+  static const struct GNUNET_GETOPT_CommandLineOption options[] = {
+    { 'a', "all", NULL,
+      gettext_noop ("print information for all peers (instead of only connected peers)"),
+      0, &GNUNET_GETOPT_set_one, &iterate_all },
+    { 'b', "benchmark", NULL,
+      gettext_noop ("measure how fast we are receiving data from all peers (until CTRL-C)"),
+      0, &GNUNET_GETOPT_set_one, &benchmark_receive },
+    { 'C', "connect",
+      NULL, gettext_noop ("connect to a peer"), 0,
+      &GNUNET_GETOPT_set_one, &try_connect },
+    { 'D', "disconnect",
+      NULL, gettext_noop ("disconnect to a peer"), 0,
+      &GNUNET_GETOPT_set_one, &try_disconnect },
+    { 'd', "validation", NULL,
+      gettext_noop ("print information for all pending validations "),
+      0, &GNUNET_GETOPT_set_one, &iterate_validation },
+    { 'f', "monitorvalidation", NULL,
+      gettext_noop ("print information for all pending validations continuously"),
+      0, &GNUNET_GETOPT_set_one, &monitor_validation },
+    { 'i', "information", NULL,
+      gettext_noop ("provide information about all current connections (once)"),
+      0, &GNUNET_GETOPT_set_one, &iterate_connections },
+    { 'm', "monitor", NULL,
+      gettext_noop ("provide information about all current connections (continuously)"),
+      0, &GNUNET_GETOPT_set_one, &monitor_connections },
+    { 'e', "events", NULL,
+      gettext_noop ("provide information about all connects and disconnect events (continuously)"),
+      0, &GNUNET_GETOPT_set_one, &monitor_connects },
+    { 'n', "numeric",
+      NULL, gettext_noop ("do not resolve hostnames"), 0,
+      &GNUNET_GETOPT_set_one, &numeric },
+    { 'p', "peer", "PEER",
+      gettext_noop ("peer identity"), 1, &GNUNET_GETOPT_set_string,
+      &cpid },
+    { 'P', "plugins", NULL,
+      gettext_noop ("monitor plugin sessions"), 0, &GNUNET_GETOPT_set_one,
+      &monitor_plugins },
+    { 's', "send", NULL, gettext_noop
+      ("send data for benchmarking to the other peer (until CTRL-C)"), 0,
+      &GNUNET_GETOPT_set_one, &benchmark_send },
+    { 't', "test", NULL,
+      gettext_noop ("test transport configuration (involves external server)"),
+      0, &GNUNET_GETOPT_set_one, &test_configuration },
+    GNUNET_GETOPT_OPTION_VERBOSE (&verbosity),
+    GNUNET_GETOPT_OPTION_END
+  };
 
   if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
     return 2;
 
-  res = GNUNET_PROGRAM_run (argc, argv, "gnunet-transport", gettext_noop
-  ("Direct access to transport service."), options, &run, NULL );
-  GNUNET_free((void * ) argv);
+  res = GNUNET_PROGRAM_run (argc, argv,
+                            "gnunet-transport",
+                            gettext_noop ("Direct access to transport service."),
+                            options,
+                            &run, NULL);
+  GNUNET_free((void *) argv);
   if (GNUNET_OK == res)
     return ret;
   return 1;