- fix
[oweals/gnunet.git] / src / transport / gnunet-service-transport_validation.c
index d0a731789f070f4b1a9d8a7786c7e4032bf1a63a..314eefaec2fb7d25dd7a80ab0b8d9373ea7b4f55 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2010-2015 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2010-2015 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.
 */
 
 /**
@@ -251,7 +251,7 @@ struct ValidationEntry
   uint32_t challenge;
 
   /**
-   * When passing the address in 'add_valid_peer_address', did we
+   * When passing the address in #add_valid_peer_address(), did we
    * copy the address to the HELLO yet?
    */
   int copied;
@@ -278,41 +278,6 @@ struct ValidationEntry
 };
 
 
-/**
- * Context of currently active requests to peerinfo
- * for validation of HELLOs.
- */
-struct CheckHelloValidatedContext
-{
-
-  /**
-   * This is a doubly-linked list.
-   */
-  struct CheckHelloValidatedContext *next;
-
-  /**
-   * This is a doubly-linked list.
-   */
-  struct CheckHelloValidatedContext *prev;
-
-  /**
-   * Hello that we are validating.
-   */
-  const struct GNUNET_HELLO_Message *hello;
-
-};
-
-
-/**
- * Head of linked list of HELLOs awaiting validation.
- */
-static struct CheckHelloValidatedContext *chvc_head;
-
-/**
- * Tail of linked list of HELLOs awaiting validation
- */
-static struct CheckHelloValidatedContext *chvc_tail;
-
 /**
  * Map of PeerIdentities to 'struct ValidationEntry*'s (addresses
  * of the given peer that we are currently validating, have validated
@@ -366,6 +331,21 @@ struct ValidationEntryMatchContext
 };
 
 
+/**
+ * Provide an update on the `validation_map` map size to statistics.
+ * This function should be called whenever the `validation_map`
+ * is changed.
+ */
+static void
+publish_ve_stat_update ()
+{
+  GNUNET_STATISTICS_set (GST_stats,
+                        gettext_noop ("# Addresses in validation map"),
+                        GNUNET_CONTAINER_multipeermap_size (validation_map),
+                        GNUNET_NO);
+}
+
+
 /**
  * Iterate over validation entries until a matching one is found.
  *
@@ -433,7 +413,8 @@ cleanup_validation_entry (void *cls,
   ve->valid_until = GNUNET_TIME_UNIT_ZERO_ABS;
 
   /* Notify about deleted entry */
-  validation_entry_changed (ve, GNUNET_TRANSPORT_VS_REMOVE);
+  validation_entry_changed (ve,
+                            GNUNET_TRANSPORT_VS_REMOVE);
 
   if (NULL != ve->bc)
   {
@@ -444,6 +425,7 @@ cleanup_validation_entry (void *cls,
                 GNUNET_CONTAINER_multipeermap_remove (validation_map,
                                                       &ve->address->peer,
                                                      ve));
+  publish_ve_stat_update ();
   if (GNUNET_YES == ve->known_to_ats)
   {
     GST_ats_expire_address (ve->address);
@@ -463,14 +445,11 @@ cleanup_validation_entry (void *cls,
   if ( (GNUNET_YES == ve->expecting_pong) &&
        (validations_running > 0) )
   {
-    validations_running --;
+    validations_running--;
     GNUNET_STATISTICS_set (GST_stats,
                            gettext_noop ("# validations running"),
                            validations_running,
                            GNUNET_NO);
-    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                "Validation finished, %u validation processes running\n",
-                validations_running);
   }
   GNUNET_free (ve);
   return GNUNET_OK;
@@ -493,20 +472,30 @@ timeout_hello_validation (void *cls,
   struct GNUNET_TIME_Relative left;
 
   ve->timeout_task = NULL;
+  /* For valid addresses, we want to wait until the expire;
+     for addresses under PING validation, we want to wait
+     until we give up on the PING */
   max = GNUNET_TIME_absolute_max (ve->valid_until,
                                   ve->revalidation_block);
   left = GNUNET_TIME_absolute_get_remaining (max);
   if (left.rel_value_us > 0)
   {
-    /* should wait a bit longer */
+    /* We should wait a bit longer. This happens when
+       address lifetimes are extended due to successful
+       validations. */
     ve->timeout_task =
-        GNUNET_SCHEDULER_add_delayed (left, &timeout_hello_validation, ve);
+        GNUNET_SCHEDULER_add_delayed (left,
+                                      &timeout_hello_validation,
+                                      ve);
     return;
   }
   GNUNET_STATISTICS_update (GST_stats,
-                            gettext_noop ("# address records discarded"), 1,
+                            gettext_noop ("# address records discarded (timeout)"),
+                            1,
                             GNUNET_NO);
-  cleanup_validation_entry (NULL, &ve->address->peer, ve);
+  cleanup_validation_entry (NULL,
+                            &ve->address->peer,
+                            ve);
 }
 
 
@@ -516,11 +505,17 @@ timeout_hello_validation (void *cls,
  *
  * @param cls our `struct ValidationEntry`
  * @param pid identity of the other peer
- * @param result #GNUNET_OK if the connection is allowed, #GNUNET_NO if not
+ * @param address_null address associated with the request, always NULL
+ * @param session_null session associated with the request, always NULL
+ * @param result #GNUNET_OK if the connection is allowed,
+ *               #GNUNET_NO if not,
+ *               #GNUNET_SYSERR if operation was aborted
  */
 static void
 transmit_ping_if_allowed (void *cls,
                           const struct GNUNET_PeerIdentity *pid,
+                         const struct GNUNET_HELLO_Address *address_null,
+                         struct Session *session_null,
                           int result)
 {
   struct ValidationEntry *ve = cls;
@@ -528,35 +523,35 @@ transmit_ping_if_allowed (void *cls,
   struct GNUNET_TRANSPORT_PluginFunctions *papi;
   struct GNUNET_TIME_Absolute next;
   const struct GNUNET_MessageHeader *hello;
-  enum GNUNET_ATS_Network_Type network;
   ssize_t ret;
   size_t tsize;
   size_t slen;
   uint16_t hsize;
+  struct Session *session;
 
   ve->bc = NULL;
-  if (GNUNET_NO == result)
+  if (GNUNET_OK != result)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                "Blacklist denies to send PING to `%s' `%s' `%s'\n",
+                "Blacklist denies sending PING to `%s' `%s' `%s'\n",
                 GNUNET_i2s (pid),
                 GST_plugins_a2s (ve->address),
                 ve->address->transport_name);
+    GNUNET_STATISTICS_update (GST_stats,
+                              gettext_noop ("# address records discarded (blacklist)"),
+                              1,
+                              GNUNET_NO);
+    cleanup_validation_entry (NULL,
+                              pid,
+                              ve);
     return;
   }
-
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Transmitting plain PING to `%s' `%s' `%s'\n",
-              GNUNET_i2s (pid),
-              GST_plugins_a2s (ve->address),
-              ve->address->transport_name);
-
-  slen = strlen (ve->address->transport_name) + 1;
   hello = GST_hello_get ();
+  GNUNET_assert (NULL != hello);
+  slen = strlen (ve->address->transport_name) + 1;
   hsize = ntohs (hello->size);
-  tsize =
-      sizeof (struct TransportPingMessage) + ve->address->address_length +
-      slen + hsize;
+  tsize = sizeof (struct TransportPingMessage) +
+    ve->address->address_length + slen + hsize;
 
   ping.header.size =
       htons (sizeof (struct TransportPingMessage) +
@@ -574,11 +569,11 @@ transmit_ping_if_allowed (void *cls,
         slen + hsize;
   }
   {
-    char message_buf[tsize];
+    char message_buf[tsize] GNUNET_ALIGN;
 
-    /* build message with structure:
-     *  [HELLO][TransportPingMessage][Transport name][Address] */
-    memcpy (message_buf, hello, hsize);
+    memcpy (message_buf,
+            hello,
+            hsize);
     memcpy (&message_buf[hsize],
            &ping,
            sizeof (struct TransportPingMessage));
@@ -589,51 +584,43 @@ transmit_ping_if_allowed (void *cls,
             ve->address->address,
            ve->address->address_length);
     papi = GST_plugins_find (ve->address->transport_name);
-    if (NULL == papi)
+    GNUNET_assert (NULL != papi);
+    session = papi->get_session (papi->cls,
+                                 ve->address);
+    if (NULL == session)
     {
-      ret = -1;
-      GNUNET_STATISTICS_update (GST_stats,
-                                gettext_noop ("# validations not attempted (no plugin)"),
-                                1,
-                                GNUNET_NO);
+      /* Could not get a valid session */
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Failed to get session to send PING to `%s' at `%s'\n",
+                  GNUNET_i2s (pid),
+                  GST_plugins_a2s (ve->address));
+      return;
     }
-    else
+
+    ret = papi->send (papi->cls, session,
+                      message_buf, tsize,
+                      PING_PRIORITY,
+                      ACCEPTABLE_PING_DELAY,
+                      NULL, NULL);
+    if (-1 == ret)
     {
-      GNUNET_assert (NULL != papi->send);
-      struct Session *session = papi->get_session (papi->cls,
-                                                   ve->address);
-
-      if (NULL != session)
-      {
-        ret = papi->send (papi->cls, session,
-                          message_buf, tsize,
-                          PING_PRIORITY,
-                          ACCEPTABLE_PING_DELAY,
-                          NULL, NULL);
-        network = papi->get_network (papi->cls, session);
-        if (GNUNET_ATS_NET_UNSPECIFIED == network)
-        {
-          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                      "Could not obtain a valid network for `%s' `%s'\n",
-                      GNUNET_i2s (pid),
-                      GST_plugins_a2s (ve->address));
-          GNUNET_break(0);
-        }
-        GST_neighbours_notify_data_sent (ve->address, session, tsize);
-      }
-      else
-      {
-        /* Could not get a valid session */
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    "Could not get a valid session for `%s' `%s'\n",
-                    GNUNET_i2s (pid),
-                    GST_plugins_a2s (ve->address));
-        ret = -1;
-      }
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "Failed to send PING to `%s' at `%s'\n",
+                  GNUNET_i2s (pid),
+                  GST_plugins_a2s (ve->address));
+      return;
     }
-  }
-  if (-1 != ret)
-  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Transmitted plain PING to `%s' `%s' `%s'\n",
+                GNUNET_i2s (pid),
+                GST_plugins_a2s (ve->address),
+                ve->address->transport_name);
+    ve->network = papi->get_network (papi->cls,
+                                     session);
+    GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != ve->network);
+    GST_neighbours_notify_data_sent (ve->address,
+                                     session,
+                                     tsize);
     next = GNUNET_TIME_relative_to_absolute (validation_delay);
     validation_next = GNUNET_TIME_absolute_max (next,
                                                 validation_next);
@@ -642,7 +629,6 @@ transmit_ping_if_allowed (void *cls,
                               gettext_noop ("# PINGs for address validation sent"),
                               1,
                               GNUNET_NO);
-    ve->network = network;
     ve->expecting_pong = GNUNET_YES;
     validations_running++;
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
@@ -653,7 +639,9 @@ transmit_ping_if_allowed (void *cls,
                            validations_running,
                            GNUNET_NO);
     /*  Notify about PING sent */
-    validation_entry_changed (ve, GNUNET_TRANSPORT_VS_UPDATE);
+    validation_entry_changed (ve,
+                              GNUNET_TRANSPORT_VS_UPDATE);
+
   }
 }
 
@@ -697,7 +685,7 @@ revalidate_address (void *cls,
   {
     /* should wait a bit longer */
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                "Waiting for %s longer before validating address `%s'\n",
+                "Waiting for %s longer before (re)validating address `%s'\n",
                 GNUNET_STRINGS_relative_time_to_string (delay,
                                                         GNUNET_YES),
                 GST_plugins_a2s (ve->address));
@@ -719,8 +707,14 @@ revalidate_address (void *cls,
                 GNUNET_STRINGS_relative_time_to_string (blocked_for,
                                                         GNUNET_YES),
                 GST_plugins_a2s (ve->address));
+    GNUNET_STATISTICS_update (GST_stats,
+                              gettext_noop ("# validations delayed by global throttle"),
+                              1,
+                              GNUNET_NO);
     ve->revalidation_task =
-      GNUNET_SCHEDULER_add_delayed (blocked_for, &revalidate_address, ve);
+      GNUNET_SCHEDULER_add_delayed (blocked_for,
+                                    &revalidate_address,
+                                    ve);
     ve->next_validation = GNUNET_TIME_relative_to_absolute (blocked_for);
     return;
   }
@@ -735,7 +729,8 @@ revalidate_address (void *cls,
 
   delay = GNUNET_TIME_relative_add (canonical_delay,
                                     GNUNET_TIME_relative_multiply
-                                    (GNUNET_TIME_UNIT_MICROSECONDS, rdelay));
+                                    (GNUNET_TIME_UNIT_MICROSECONDS,
+                                     rdelay));
 
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Validating now, next scheduled for %s, now validating address `%s'\n",
@@ -743,7 +738,9 @@ revalidate_address (void *cls,
                                                       GNUNET_YES),
               GST_plugins_a2s (ve->address));
   ve->revalidation_task =
-      GNUNET_SCHEDULER_add_delayed (delay, &revalidate_address, ve);
+      GNUNET_SCHEDULER_add_delayed (delay,
+                                    &revalidate_address,
+                                    ve);
   ve->next_validation = GNUNET_TIME_relative_to_absolute (delay);
 
   /* start PINGing by checking blacklist */
@@ -752,7 +749,10 @@ revalidate_address (void *cls,
                             GNUNET_NO);
   bc = GST_blacklist_test_allowed (&ve->address->peer,
                                   ve->address->transport_name,
-                                   &transmit_ping_if_allowed, ve);
+                                   &transmit_ping_if_allowed,
+                                  ve,
+                                  NULL,
+                                  NULL);
   if (NULL != bc)
     ve->bc = bc;                /* only set 'bc' if 'transmit_ping_if_allowed' was not already
                                  * called... */
@@ -784,18 +784,22 @@ find_validation_entry (const struct GNUNET_HELLO_Address *address)
   ve = GNUNET_new (struct ValidationEntry);
   ve->in_use = GNUNET_SYSERR; /* not defined */
   ve->address = GNUNET_HELLO_address_copy (address);
-  ve->pong_sig_valid_until = GNUNET_TIME_absolute_get_zero_();
+  ve->pong_sig_valid_until = GNUNET_TIME_UNIT_ZERO_ABS;
   memset (&ve->pong_sig_cache, '\0', sizeof (struct GNUNET_CRYPTO_EddsaSignature));
   ve->latency = GNUNET_TIME_UNIT_FOREVER_REL;
   ve->challenge =
       GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX);
   ve->timeout_task =
       GNUNET_SCHEDULER_add_delayed (UNVALIDATED_PING_KEEPALIVE,
-                                    &timeout_hello_validation, ve);
-  GNUNET_CONTAINER_multipeermap_put (validation_map, &address->peer,
+                                    &timeout_hello_validation,
+                                    ve);
+  GNUNET_CONTAINER_multipeermap_put (validation_map,
+                                     &address->peer,
                                      ve,
                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
-  validation_entry_changed (ve, GNUNET_TRANSPORT_VS_NEW);
+  publish_ve_stat_update ();
+  validation_entry_changed (ve,
+                            GNUNET_TRANSPORT_VS_NEW);
   return ve;
 }
 
@@ -807,7 +811,9 @@ find_validation_entry (const struct GNUNET_HELLO_Address *address)
  * @param cls original HELLO message
  * @param address the address
  * @param expiration expiration time
- * @return #GNUNET_OK (keep the address)
+ * @return #GNUNET_OK (keep the address), could return
+ *         #GNUNET_NO (delete address, but this is ignored);
+ *         #GNUNET_SYSERR would abort iteration (but we always iterate all)
  */
 static int
 add_valid_address (void *cls,
@@ -817,7 +823,7 @@ add_valid_address (void *cls,
   const struct GNUNET_HELLO_Message *hello = cls;
   struct ValidationEntry *ve;
   struct GNUNET_PeerIdentity pid;
-  struct GNUNET_ATS_Information ats;
+  struct GNUNET_ATS_Properties prop;
 
   if (0 == GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us)
     return GNUNET_OK;           /* expired */
@@ -826,13 +832,6 @@ add_valid_address (void *cls,
     GNUNET_break (0);
     return GNUNET_OK;           /* invalid HELLO !? */
   }
-  if (0 == memcmp (&GST_my_identity,
-                   &pid,
-                   sizeof (struct GNUNET_PeerIdentity)))
-  {
-    /* Peerinfo returned own identity, skip validation */
-    return GNUNET_OK;
-  }
   if (NULL == GST_plugins_find (address->transport_name))
   {
     /* might have been valid in the past, but we don't have that
@@ -851,14 +850,15 @@ add_valid_address (void *cls,
     ve->next_validation = GNUNET_TIME_absolute_get();
     ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
   }
-  validation_entry_changed (ve, GNUNET_TRANSPORT_VS_UPDATE);
-
-  ats.type = htonl (GNUNET_ATS_NETWORK_TYPE);
-  ats.value = htonl (ve->network);
+  validation_entry_changed (ve,
+                            GNUNET_TRANSPORT_VS_UPDATE);
+  memset (&prop, 0, sizeof (prop));
+  prop.scope = ve->network;
+  prop.delay = GNUNET_TIME_relative_divide (ve->latency, 2);
   if (GNUNET_YES != ve->known_to_ats)
   {
     ve->known_to_ats = GNUNET_YES;
-    GST_ats_add_address (address, NULL, &ats, 1);
+    GST_ats_add_address (address, &prop);
   }
   return GNUNET_OK;
 }
@@ -867,19 +867,28 @@ add_valid_address (void *cls,
 /**
  * Function called for any HELLO known to PEERINFO.
  *
- * @param cls unused
- * @param peer id of the peer, NULL for last call
+ * @param cls unused (NULL)
+ * @param peer id of the peer, NULL for last call (during iteration,
+ *             as we are monitoring, this should never happen)
  * @param hello hello message for the peer (can be NULL)
  * @param err_msg error message
  */
 static void
-process_peerinfo_hello (void *cls, const struct GNUNET_PeerIdentity *peer,
+process_peerinfo_hello (void *cls,
+                        const struct GNUNET_PeerIdentity *peer,
                         const struct GNUNET_HELLO_Message *hello,
                         const char *err_msg)
 {
   GNUNET_assert (NULL != peer);
   if (NULL == hello)
     return;
+  if (0 == memcmp (&GST_my_identity,
+                   peer,
+                   sizeof (struct GNUNET_PeerIdentity)))
+  {
+    /* Peerinfo returned own identity, skip validation */
+    return;
+  }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Handling HELLO for peer `%s'\n",
               GNUNET_i2s (peer));
@@ -919,7 +928,7 @@ GST_validation_start (unsigned int max_fds)
                          validations_running,
                          GNUNET_NO);
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Validation uses a fast start threshold of %u connections and a delay between of %s\n ",
+              "Validation uses a fast start threshold of %u connections and a delay of %s\n",
               validations_fast_start_threshold,
               GNUNET_STRINGS_relative_time_to_string (validation_delay,
                                                       GNUNET_YES));
@@ -936,17 +945,11 @@ GST_validation_start (unsigned int max_fds)
 void
 GST_validation_stop ()
 {
-  struct CheckHelloValidatedContext *chvc;
-
   GNUNET_CONTAINER_multipeermap_iterate (validation_map,
-                                         &cleanup_validation_entry, NULL);
+                                         &cleanup_validation_entry,
+                                         NULL);
   GNUNET_CONTAINER_multipeermap_destroy (validation_map);
   validation_map = NULL;
-  while (NULL != (chvc = chvc_head))
-  {
-    GNUNET_CONTAINER_DLL_remove (chvc_head, chvc_tail, chvc);
-    GNUNET_free (chvc);
-  }
   GNUNET_PEERINFO_notify_cancel (pnc);
 }
 
@@ -974,8 +977,12 @@ multicast_pong (void *cls,
 
   papi = GST_plugins_find (address->transport_name);
   if (NULL == papi)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Plugin %s not supported, cannot send PONG\n",
+                address->transport_name);
     return;
-
+  }
   GNUNET_assert (NULL != papi->send);
   GNUNET_assert (NULL != papi->get_session);
   session = papi->get_session(papi->cls, address);
@@ -994,7 +1001,6 @@ multicast_pong (void *cls,
   GST_neighbours_notify_data_sent (address,
                                    session,
                                    pong->header.size);
-
 }
 
 
@@ -1025,7 +1031,6 @@ GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
   size_t len_address;
   size_t len_plugin;
   ssize_t ret;
-  int buggy = GNUNET_NO;
   struct GNUNET_HELLO_Address address;
 
   if (ntohs (hdr->size) < sizeof (struct TransportPingMessage))
@@ -1097,7 +1102,10 @@ GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
       return GNUNET_SYSERR;
     }
     GNUNET_free (plugin_name);
-    if (GNUNET_OK != papi->check_address (papi->cls, addrend, len_address))
+    if (GNUNET_OK !=
+        papi->check_address (papi->cls,
+                             addrend,
+                             len_address))
     {
       GNUNET_STATISTICS_update (GST_stats,
                                 gettext_noop
@@ -1119,22 +1127,16 @@ GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
                   GST_plugins_a2s (&address));
     }
 
-    if (GNUNET_YES != GST_hello_test_address (&address, &sig_cache, &sig_cache_exp))
+    if (GNUNET_YES !=
+        GST_hello_test_address (&address,
+                                &sig_cache,
+                                &sig_cache_exp))
     {
-      if (GNUNET_NO == buggy)
-      {
-        GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                    _("Not confirming PING from peer `%s' with address `%s' since I cannot confirm having this address.\n"),
-                    GNUNET_i2s (sender),
-                    GST_plugins_a2s (&address));
-        return GNUNET_SYSERR;
-      }
-      else
-      {
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    _("Received a PING message with validation bug from `%s'\n"),
-                    GNUNET_i2s (sender));
-      }
+      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                  _("Not confirming PING from peer `%s' with address `%s' since I cannot confirm having this address.\n"),
+                  GNUNET_i2s (sender),
+                  GST_plugins_a2s (&address));
+      return GNUNET_SYSERR;
     }
   }
   else
@@ -1195,7 +1197,7 @@ GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
   }
   pong->signature = *sig_cache;
 
-  GNUNET_assert (sender_address != NULL);
+  GNUNET_assert (NULL != sender_address);
 
   /* first see if the session we got this PING from can be used to transmit
    * a response reliably */
@@ -1255,6 +1257,35 @@ GST_validation_handle_ping (const struct GNUNET_PeerIdentity *sender,
 }
 
 
+/**
+ * Validate an individual address.
+ *
+ * @param address address we should try to validate
+ */
+void
+GST_validation_handle_address (const struct GNUNET_HELLO_Address *address)
+{
+  struct GNUNET_TRANSPORT_PluginFunctions *papi;
+  struct ValidationEntry *ve;
+
+  papi = GST_plugins_find (address->transport_name);
+  if (NULL == papi)
+  {
+    /* This plugin is currently unvailable ... ignore */
+    return;
+  }
+  ve = find_validation_entry (address);
+  if (NULL == ve->revalidation_task)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                "Validation process started for fresh address `%s' of %s\n",
+                GST_plugins_a2s (ve->address),
+                GNUNET_i2s (&ve->address->peer));
+    ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
+  }
+}
+
+
 /**
  * Iterator callback to go over all addresses and try to validate them
  * (unless blocked or already validated).
@@ -1269,29 +1300,13 @@ validate_address_iterator (void *cls,
                            const struct GNUNET_HELLO_Address *address,
                            struct GNUNET_TIME_Absolute expiration)
 {
-  struct GNUNET_TRANSPORT_PluginFunctions * papi;
-  struct ValidationEntry *ve;
-
   if (0 == GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                 "Skipping expired address from HELLO\n");
     return GNUNET_OK;           /* expired */
   }
-  papi = GST_plugins_find (address->transport_name);
-  if (NULL == papi)
-  {
-    /* This plugin is currently unvailable ... ignore */
-    return GNUNET_OK;
-  }
-  ve = find_validation_entry (address);
-  if (NULL == ve->revalidation_task)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                "Validation process started for fresh address `%s'\n",
-                GST_plugins_a2s (ve->address));
-    ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
-  }
+  GST_validation_handle_address (address);
   return GNUNET_OK;
 }
 
@@ -1315,7 +1330,10 @@ add_valid_peer_address (void *cls,
   if (GNUNET_YES == ve->copied)
     return GNUNET_SYSERR; /* Done */
   ve->copied = GNUNET_YES;
-  return GNUNET_HELLO_add_address (ve->address, ve->valid_until, buf, max);
+  return GNUNET_HELLO_add_address (ve->address,
+                                   ve->valid_until,
+                                   buf,
+                                   max);
 }
 
 
@@ -1367,6 +1385,16 @@ GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
   addr++;
   slen = strlen (tname) + 1;
   addrlen = size - slen;
+
+  if (NULL == GST_plugins_find (tname))
+  {
+    /* we got the PONG, but the transport plugin specified in it
+       is not supported by this peer, so this cannot be a good
+       PONG for us. */
+    GNUNET_break_op (0);
+    return GNUNET_OK;
+  }
+
   address.peer = *sender;
   address.address = addr;
   address.address_length = addrlen;
@@ -1406,7 +1434,9 @@ GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
   {
     /* We have a cached and valid signature for this peer,
      * try to compare instead of verify */
-    if (0 == memcmp (&ve->pong_sig_cache, &pong->signature, sizeof (struct GNUNET_CRYPTO_EddsaSignature)))
+    if (0 == memcmp (&ve->pong_sig_cache,
+                     &pong->signature,
+                     sizeof (struct GNUNET_CRYPTO_EddsaSignature)))
     {
       /* signatures are identical, we can skip verification */
       sig_res = GNUNET_OK;
@@ -1423,7 +1453,8 @@ GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
   {
     /* Do expensive verification */
     sig_res = GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_TRANSPORT_PONG_OWN,
-                                          &pong->purpose, &pong->signature,
+                                          &pong->purpose,
+                                          &pong->signature,
                                           &ve->address->peer.public_key);
     if (sig_res == GNUNET_SYSERR)
     {
@@ -1454,28 +1485,28 @@ GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
   ve->expecting_pong = GNUNET_NO;
   ve->valid_until = GNUNET_TIME_relative_to_absolute (HELLO_ADDRESS_EXPIRATION);
   ve->pong_sig_cache = pong->signature;
-       ve->pong_sig_valid_until = GNUNET_TIME_absolute_ntoh (pong->expiration);
+  ve->pong_sig_valid_until = GNUNET_TIME_absolute_ntoh (pong->expiration);
   ve->latency = GNUNET_TIME_absolute_get_duration (ve->send_time);
   {
-    struct GNUNET_ATS_Information ats[2];
-
-    ats[0].type = htonl (GNUNET_ATS_QUALITY_NET_DELAY);
-    ats[0].value = htonl ((uint32_t) ve->latency.rel_value_us);
-    ats[1].type = htonl (GNUNET_ATS_NETWORK_TYPE);
-    ats[1].value = htonl ((uint32_t) ve->network);
     if (GNUNET_YES == ve->known_to_ats)
     {
-      GST_ats_update_metrics (ve->address, NULL, ats, 2);
+      GST_ats_update_delay (ve->address,
+                            GNUNET_TIME_relative_divide (ve->latency, 2));
     }
     else
     {
+      struct GNUNET_ATS_Properties prop;
+
+      memset (&prop, 0, sizeof (prop));
+      prop.scope = ve->network;
+      prop.delay = GNUNET_TIME_relative_divide (ve->latency, 2);
       ve->known_to_ats = GNUNET_YES;
-      GST_ats_add_address (ve->address, NULL, ats, 2);
+      GST_ats_add_address (ve->address, &prop);
     }
   }
   if (validations_running > 0)
   {
-    validations_running --;
+    validations_running--;
     GNUNET_STATISTICS_set (GST_stats,
                            gettext_noop ("# validations running"),
                            validations_running,
@@ -1490,14 +1521,19 @@ GST_validation_handle_pong (const struct GNUNET_PeerIdentity *sender,
   }
 
   /* Notify about new validity */
-  validation_entry_changed (ve, GNUNET_TRANSPORT_VS_UPDATE);
+  validation_entry_changed (ve,
+                            GNUNET_TRANSPORT_VS_UPDATE);
 
   /* build HELLO to store in PEERINFO */
   ve->copied = GNUNET_NO;
   hello = GNUNET_HELLO_create (&ve->address->peer.public_key,
-                               &add_valid_peer_address, ve,
+                               &add_valid_peer_address,
+                              ve,
                                GNUNET_NO);
-  GNUNET_PEERINFO_add_peer (GST_peerinfo, hello, NULL, NULL);
+  GNUNET_PEERINFO_add_peer (GST_peerinfo,
+                           hello,
+                           NULL,
+                           NULL);
   GNUNET_free (hello);
   return GNUNET_OK;
 }
@@ -1516,7 +1552,6 @@ GST_validation_handle_hello (const struct GNUNET_MessageHeader *hello)
   const struct GNUNET_HELLO_Message *hm =
       (const struct GNUNET_HELLO_Message *) hello;
   struct GNUNET_PeerIdentity pid;
-  struct GNUNET_HELLO_Message *h;
   int friend;
 
   friend = GNUNET_HELLO_is_friend_only (hm);
@@ -1532,21 +1567,14 @@ GST_validation_handle_hello (const struct GNUNET_MessageHeader *hello)
       memcmp (&GST_my_identity,
              &pid,
              sizeof (struct GNUNET_PeerIdentity)))
+  {
+    /* got our own HELLO, how boring */
     return GNUNET_OK;
-  /* Add peer identity without addresses to peerinfo service */
-  h = GNUNET_HELLO_create (&pid.public_key, NULL, NULL, friend);
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              _("Validation received new %s message for peer `%s' with size %u\n"),
-              "HELLO",
-              GNUNET_i2s (&pid),
-              ntohs (hello->size));
-  GNUNET_PEERINFO_add_peer (GST_peerinfo, h, NULL, NULL);
-
+  }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Adding `%s' without addresses for peer `%s'\n"), "HELLO",
-              GNUNET_i2s (&pid));
-
-  GNUNET_free (h);
+             "Validation received HELLO message for peer `%s' with size %u, checking for new addresses\n",
+             GNUNET_i2s (&pid),
+             ntohs (hello->size));
   GNUNET_assert (NULL ==
                  GNUNET_HELLO_iterate_addresses (hm,
                                                 GNUNET_NO,
@@ -1626,14 +1654,12 @@ GST_validation_get_addresses (const struct GNUNET_PeerIdentity *target,
  * Based on this, the validation module will measure latency for the
  * address more or less often.
  *
- * @param address the address
- * @param session the session
+ * @param address the address that we are now using (or not)
  * @param in_use #GNUNET_YES if we are now using the address for a connection,
  *               #GNUNET_NO if we are no longer using the address for a connection
  */
 void
 GST_validation_set_address_use (const struct GNUNET_HELLO_Address *address,
-                                struct Session *session,
                                 int in_use)
 {
   struct ValidationEntry *ve;
@@ -1641,69 +1667,32 @@ GST_validation_set_address_use (const struct GNUNET_HELLO_Address *address,
   if (GNUNET_HELLO_address_check_option (address,
                                          GNUNET_HELLO_ADDRESS_INFO_INBOUND))
     return; /* ignore inbound for validation */
-  if (NULL != address)
-    ve = find_validation_entry (address);
-  else
-    ve = NULL;                  /* FIXME: lookup based on session... */
-  if (NULL == ve)
+  if (NULL == GST_plugins_find (address->transport_name))
   {
-    /* this can happen for inbound connections (sender_address_len == 0); */
+    /* How can we use an address for which we don't have the plugin? */
+    GNUNET_break (0);
     return;
   }
-  if (ve->in_use == in_use)
+  ve = find_validation_entry (address);
+  if (NULL == ve)
   {
-    if (GNUNET_YES == in_use)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                  "Error setting address in use for peer `%s' `%s' to USED\n",
-                  GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
-    }
-    if (GNUNET_NO == in_use)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                  "Error setting address in use for peer `%s' `%s' to NOT_USED\n",
-                  GNUNET_i2s (&address->peer), GST_plugins_a2s (address));
-    }
+    GNUNET_break (0);
+    return;
   }
-
-  GNUNET_break (ve->in_use != in_use);  /* should be different... */
+  if (in_use == ve->in_use)
+    return;
   ve->in_use = in_use;
-  if (in_use == GNUNET_YES)
+  if (GNUNET_YES == in_use)
   {
     /* from now on, higher frequeny, so reschedule now */
     if (NULL != ve->revalidation_task)
       GNUNET_SCHEDULER_cancel (ve->revalidation_task);
-    ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address, ve);
+    ve->revalidation_task = GNUNET_SCHEDULER_add_now (&revalidate_address,
+                                                      ve);
   }
 }
 
 
-/**
- * Query validation about the latest observed latency on a given
- * address.
- *
- * @param address the address
- * @param session session
- * @return observed latency of the address, FOREVER if the address was
- *         never successfully validated
- */
-struct GNUNET_TIME_Relative
-GST_validation_get_address_latency (const struct GNUNET_HELLO_Address *address,
-                                    struct Session *session)
-{
-  struct ValidationEntry *ve;
-
-  if (NULL == address)
-  {
-    GNUNET_break (0);           // FIXME: support having latency only with session...
-    return GNUNET_TIME_UNIT_FOREVER_REL;
-  }
-  ve = find_validation_entry (address);
-  if (NULL == ve)
-    return GNUNET_TIME_UNIT_FOREVER_REL;
-  return ve->latency;
-}
-
 /**
  * Closure for the validation_entries_iterate function.
  */
@@ -1757,7 +1746,7 @@ validation_entries_iterate (void *cls,
  * Iterate over all iteration entries
  *
  * @param cb function to call
- * @param cb_cls closure for cb
+ * @param cb_cls closure for @a cb
  */
 void
 GST_validation_iterate (GST_ValidationChangedCallback cb,