X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Ftransport%2Fgnunet-service-transport_ats.c;h=01e115bfca35fbab6d8b8a7840534480ec0ff9c4;hb=0d24b1ba329faa35990034fcc861a264bb985fb1;hp=4fcf7c9dc54df22c20ba0c80be5f666fbf4282b1;hpb=9750132ba19a96ab1756de15e91c62405a1918fb;p=oweals%2Fgnunet.git

diff --git a/src/transport/gnunet-service-transport_ats.c b/src/transport/gnunet-service-transport_ats.c
index 4fcf7c9dc..01e115bfc 100644
--- a/src/transport/gnunet-service-transport_ats.c
+++ b/src/transport/gnunet-service-transport_ats.c
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2015 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2015 GNUnet e.V.
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -14,11 +14,11 @@
 
      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.
 */
 /**
- * @file transport/gnunet-service-transport_ats.h
+ * @file transport/gnunet-service-transport_ats.c
  * @brief interfacing between transport and ATS service
  * @author Christian Grothoff
  */
@@ -29,6 +29,11 @@
 #include "gnunet-service-transport_plugins.h"
 #include "gnunet_ats_service.h"
 
+/**
+ * Log convenience function.
+ */
+#define LOG(kind,...) GNUNET_log_from(kind, "transport-ats", __VA_ARGS__)
+
 
 /**
  * Information we track for each address known to ATS.
@@ -37,19 +42,54 @@ struct AddressInfo
 {
 
   /**
-   * The address (with peer identity).
+   * The address (with peer identity).  Must never change
+   * while this struct is in the #p2a map.
    */
   struct GNUNET_HELLO_Address *address;
 
   /**
    * Session (can be NULL)
    */
-  struct Session *session;
+  struct GNUNET_ATS_Session *session;
 
   /**
    * Record with ATS API for the address.
    */
   struct GNUNET_ATS_AddressRecord *ar;
+
+  /**
+   * Performance properties of this address.
+   */
+  struct GNUNET_ATS_Properties properties;
+
+  /**
+   * Time until when this address is blocked and should thus not be
+   * made available to ATS (@e ar should be NULL until this time).
+   * Used when transport determines that for some reason it
+   * (temporarily) cannot use an address, even though it has been
+   * validated.
+   */
+  struct GNUNET_TIME_Absolute blocked;
+
+  /**
+   * If an address is blocked as part of an exponential back-off,
+   * we track the current size of the backoff here.
+   */
+  struct GNUNET_TIME_Relative back_off;
+
+  /**
+   * Task scheduled to unblock an ATS-blocked address at
+   * @e blocked time, or NULL if the address is not blocked
+   * (and thus @e ar is non-NULL).
+   */
+  struct GNUNET_SCHEDULER_Task *unblock_task;
+
+  /**
+   * Set to #GNUNET_YES if the address has expired but we could
+   * not yet remove it because we still have a valid session.
+   */
+  int expired;
+
 };
 
 
@@ -59,9 +99,14 @@ struct AddressInfo
  */
 static struct GNUNET_CONTAINER_MultiPeerMap *p2a;
 
+/**
+ * Number of blocked addresses.
+ */
+static unsigned int num_blocked;
+
 
 /**
- * Closure for #find_ai().
+ * Closure for #find_ai_cb() and #find_ai_no_session_cb().
  */
 struct FindClosure
 {
@@ -69,7 +114,7 @@ struct FindClosure
   /**
    * Session to look for (only used if the address is inbound).
    */
-  struct Session *session;
+  struct GNUNET_ATS_Session *session;
 
   /**
    * Address to look for.
@@ -85,7 +130,28 @@ struct FindClosure
 
 
 /**
- * Find matching address info.
+ * Provide an update on the `p2a` map size to statistics.
+ * This function should be called whenever the `p2a` map
+ * is changed.
+ */
+static void
+publish_p2a_stat_update ()
+{
+  GNUNET_STATISTICS_set (GST_stats,
+			 gettext_noop ("# Addresses given to ATS"),
+			 GNUNET_CONTAINER_multipeermap_size (p2a) - num_blocked,
+			 GNUNET_NO);
+  GNUNET_STATISTICS_set (GST_stats,
+                         "# blocked addresses",
+                         num_blocked,
+                         GNUNET_NO);
+}
+
+
+/**
+ * Find matching address info.  Both the address and the session
+ * must match; note that expired addresses are still found (as
+ * the session kind-of keeps those alive).
  *
  * @param cls the `struct FindClosure`
  * @param key which peer is this about
@@ -114,7 +180,7 @@ find_ai_cb (void *cls,
 
 /**
  * Find the address information struct for the
- * given address and session.
+ * given @a address and @a session.
  *
  * @param address address to look for
  * @param session session to match for inbound connections
@@ -122,7 +188,7 @@ find_ai_cb (void *cls,
  */
 static struct AddressInfo *
 find_ai (const struct GNUNET_HELLO_Address *address,
-         struct Session *session)
+         struct GNUNET_ATS_Session *session)
 {
   struct FindClosure fc;
 
@@ -138,146 +204,448 @@ find_ai (const struct GNUNET_HELLO_Address *address,
 
 
 /**
- * Notify ATS about the new address including the network this address is
- * located in.
+ * Find matching address info, ignoring sessions and expired
+ * addresses.
+ *
+ * @param cls the `struct FindClosure`
+ * @param key which peer is this about
+ * @param value the `struct AddressInfo`
+ * @return #GNUNET_YES to continue to iterate, #GNUNET_NO if we found the value
+ */
+static int
+find_ai_no_session_cb (void *cls,
+                       const struct GNUNET_PeerIdentity *key,
+                       void *value)
+{
+  struct FindClosure *fc = cls;
+  struct AddressInfo *ai = value;
+
+  if (ai->expired)
+    return GNUNET_YES; /* expired do not count here */
+  if (0 ==
+      GNUNET_HELLO_address_cmp (fc->address,
+                                ai->address))
+  {
+    fc->ret = ai;
+    return GNUNET_NO;
+  }
+  return GNUNET_YES;
+}
+
+
+/**
+ * Find the address information struct for the
+ * given address (ignoring sessions)
+ *
+ * @param address address to look for
+ * @return NULL if this combination is unknown
+ */
+static struct AddressInfo *
+find_ai_no_session (const struct GNUNET_HELLO_Address *address)
+{
+  struct FindClosure fc;
+
+  fc.address = address;
+  fc.session = NULL;
+  fc.ret = NULL;
+  GNUNET_CONTAINER_multipeermap_get_multiple (p2a,
+                                              &address->peer,
+                                              &find_ai_no_session_cb,
+                                              &fc);
+  return fc.ret;
+}
+
+
+/**
+ * Test if ATS knows about this @a address and @a session.
+ * Note that even if the address is expired, we return
+ * #GNUNET_YES if the respective session matches.
  *
  * @param address the address
  * @param session the session
- * @param ats ats information
- * @param ats_count number of @a ats information
+ * @return #GNUNET_YES if @a address is known, #GNUNET_NO if not.
+ */
+int
+GST_ats_is_known (const struct GNUNET_HELLO_Address *address,
+                  struct GNUNET_ATS_Session *session)
+{
+  return (NULL != find_ai (address, session)) ? GNUNET_YES : GNUNET_NO;
+}
+
+
+/**
+ * Test if ATS knows about this @a address.  Note that
+ * expired addresses do not count.
+ *
+ * @param address the address
+ * @return #GNUNET_YES if @a address is known, #GNUNET_NO if not.
+ */
+int
+GST_ats_is_known_no_session (const struct GNUNET_HELLO_Address *address)
+{
+  return (NULL != find_ai_no_session (address))
+    ? GNUNET_YES
+    : GNUNET_NO;
+}
+
+
+/**
+ * The blocking time for an address has expired, allow ATS to
+ * suggest it again.
+ *
+ * @param cls the `struct AddressInfo` of the address to unblock
+ */
+static void
+unblock_address (void *cls)
+{
+  struct AddressInfo *ai = cls;
+
+  ai->unblock_task = NULL;
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Unblocking address %s of peer %s\n",
+       GST_plugins_a2s (ai->address),
+       GNUNET_i2s (&ai->address->peer));
+  ai->ar = GNUNET_ATS_address_add (GST_ats,
+                                   ai->address,
+                                   ai->session,
+                                   &ai->properties);
+  GNUNET_break (NULL != ai->ar);
+  num_blocked--;
+  publish_p2a_stat_update ();
+}
+
+
+/**
+ * Temporarily block a valid address for use by ATS for address
+ * suggestions.  This function should be called if an address was
+ * suggested by ATS but failed to perform (i.e. failure to establish a
+ * session or to exchange the PING/PONG).
+ *
+ * @param address the address to block
+ * @param session the session (can be NULL)
  */
 void
-GST_ats_add_address (const struct GNUNET_HELLO_Address *address,
-                     struct Session *session,
-                     const struct GNUNET_ATS_Information *ats,
-                     uint32_t ats_count)
+GST_ats_block_address (const struct GNUNET_HELLO_Address *address,
+                       struct GNUNET_ATS_Session *session)
 {
-  struct GNUNET_TRANSPORT_PluginFunctions *papi;
-  struct GNUNET_ATS_Information ats2[ats_count + 1];
-  struct GNUNET_ATS_AddressRecord *ar;
   struct AddressInfo *ai;
-  uint32_t net;
 
-  /* valid new address, let ATS know! */
-  if (NULL == address->transport_name)
+  if (0 ==
+      memcmp (&GST_my_identity,
+              &address->peer,
+              sizeof (struct GNUNET_PeerIdentity)))
+    return; /* our own, ignore! */
+  ai = find_ai (address,
+                session);
+  if (NULL == ai || NULL == ai->ar)
   {
-    GNUNET_break(0);
+    /* The address is already gone/blocked, this can happen during a blacklist
+     * callback. */
     return;
   }
+  ai->back_off = GNUNET_TIME_STD_BACKOFF (ai->back_off);
   if (GNUNET_YES ==
       GNUNET_HELLO_address_check_option (address,
                                          GNUNET_HELLO_ADDRESS_INFO_INBOUND))
-  {
-    GNUNET_break (NULL != session);
-  }
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Removing address %s of peer %s from use (inbound died)\n",
+         GST_plugins_a2s (address),
+         GNUNET_i2s (&address->peer));
   else
+    LOG (GNUNET_ERROR_TYPE_INFO,
+         "Blocking address %s of peer %s from use for %s\n",
+         GST_plugins_a2s (address),
+         GNUNET_i2s (&address->peer),
+         GNUNET_STRINGS_relative_time_to_string (ai->back_off,
+                                                 GNUNET_YES));
+  /* destroy session and address */
+  if ( (NULL == session) ||
+       (GNUNET_NO ==
+        GNUNET_ATS_address_del_session (ai->ar,
+                                        session)) )
   {
-    GNUNET_break (NULL == session);
+    GNUNET_ATS_address_destroy (ai->ar);
   }
+  /* "ar" has been freed, regardless how the branch
+     above played out: it was either freed in
+     #GNUNET_ATS_address_del_session() because it was
+     incoming, or explicitly in
+     #GNUNET_ATS_address_del_session(). */
+  ai->ar = NULL;
+
+  /* determine when the address should come back to life */
+  ai->blocked = GNUNET_TIME_relative_to_absolute (ai->back_off);
+  ai->unblock_task = GNUNET_SCHEDULER_add_delayed (ai->back_off,
+                                                   &unblock_address,
+                                                   ai);
+  num_blocked++;
+  publish_p2a_stat_update ();
+}
+
+
+/**
+ * Reset address blocking time.  Resets the exponential
+ * back-off timer for this address to zero.  Called when
+ * an address was used to create a successful connection.
+ *
+ * @param address the address to reset the blocking timer
+ * @param session the session (can be NULL)
+ */
+void
+GST_ats_block_reset (const struct GNUNET_HELLO_Address *address,
+                     struct GNUNET_ATS_Session *session)
+{
+  struct AddressInfo *ai;
+
+  if (0 ==
+      memcmp (&GST_my_identity,
+              &address->peer,
+              sizeof (struct GNUNET_PeerIdentity)))
+    return; /* our own, ignore! */
   ai = find_ai (address, session);
-  if (NULL != ai)
+  if (NULL == ai)
   {
     GNUNET_break (0);
     return;
   }
-  if (NULL == (papi = GST_plugins_find (address->transport_name)))
+  /* address is in successful use, so it should not be blocked right now */
+  GNUNET_break (NULL == ai->unblock_task);
+  ai->back_off = GNUNET_TIME_UNIT_ZERO;
+}
+
+
+/**
+ * Notify ATS about a new inbound @a address. The @a address in
+ * combination with the @a session must be new, but this function will
+ * perform a santiy check.  If the @a address is indeed new, make it
+ * available to ATS.
+ *
+ * @param address the address
+ * @param session the session
+ * @param prop performance information
+ */
+void
+GST_ats_add_inbound_address (const struct GNUNET_HELLO_Address *address,
+                             struct GNUNET_ATS_Session *session,
+                             const struct GNUNET_ATS_Properties *prop)
+{
+  struct GNUNET_ATS_AddressRecord *ar;
+  struct AddressInfo *ai;
+
+  if (0 ==
+      memcmp (&GST_my_identity,
+              &address->peer,
+              sizeof (struct GNUNET_PeerIdentity)))
+    return; /* our own, ignore! */
+
+  /* Sanity checks for a valid inbound address */
+  if (NULL == address->transport_name)
   {
-    /* we don't have the plugin for this address */
     GNUNET_break(0);
     return;
   }
-  if (NULL != session)
+  GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_HELLO_address_check_option (address,
+                                                    GNUNET_HELLO_ADDRESS_INFO_INBOUND));
+  GNUNET_assert (NULL != session);
+  ai = find_ai (address, session);
+  if (NULL != ai)
   {
-    net = papi->get_network (papi->cls, session);
-    if (GNUNET_ATS_NET_UNSPECIFIED == net)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                  _ ("Could not obtain a valid network for `%s' %s (%s)\n"),
-                  GNUNET_i2s (&address->peer),
-                  GST_plugins_a2s (address),
-                  address->transport_name);
-      return;
-    }
-    ats2[0].type = htonl (GNUNET_ATS_NETWORK_TYPE);
-    ats2[0].value = htonl (net);
-    memcpy (&ats2[1],
-            ats,
-            sizeof(struct GNUNET_ATS_Information) * ats_count);
+    /* This should only be called for new sessions, and thus
+       we should not already have the address */
+    GNUNET_break (0);
+    return;
   }
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              "Notifying ATS about peer `%s''s new address `%s' session %p in network %s\n",
-              GNUNET_i2s (&address->peer),
-              (0 == address->address_length)
-              ? "<inbound>"
-              : GST_plugins_a2s (address),
-              session,
-              GNUNET_ATS_print_network_type (net));
+  /* Is indeed new, let's tell ATS */
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Notifying ATS about peer `%s''s new inbound address `%s' session %p in network %s\n",
+       GNUNET_i2s (&address->peer),
+       GST_plugins_a2s (address),
+       session,
+       GNUNET_ATS_print_network_type (prop->scope));
   ar = GNUNET_ATS_address_add (GST_ats,
                                address,
                                session,
-                               (NULL != session) ? ats2 : ats,
-                               (NULL != session) ? ats_count + 1 : ats_count);
+                               prop);
+  GNUNET_assert (NULL != ar);
   ai = GNUNET_new (struct AddressInfo);
   ai->address = GNUNET_HELLO_address_copy (address);
   ai->session = session;
+  ai->properties = *prop;
+  ai->ar = ar;
+  (void) GNUNET_CONTAINER_multipeermap_put (p2a,
+                                            &ai->address->peer,
+                                            ai,
+                                            GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
+  publish_p2a_stat_update ();
+}
+
+
+/**
+ * Notify ATS about the new address including the network this address is
+ * located in.  The address must NOT be inbound and must be new to ATS.
+ *
+ * @param address the address
+ * @param prop performance information
+ */
+void
+GST_ats_add_address (const struct GNUNET_HELLO_Address *address,
+                     const struct GNUNET_ATS_Properties *prop)
+{
+  struct GNUNET_ATS_AddressRecord *ar;
+  struct AddressInfo *ai;
+
+  if (0 ==
+      memcmp (&GST_my_identity,
+              &address->peer,
+              sizeof (struct GNUNET_PeerIdentity)))
+    return; /* our own, ignore! */
+  /* validadte address */
+  if (NULL == address->transport_name)
+  {
+    GNUNET_break(0);
+    return;
+  }
+  GNUNET_assert (GNUNET_YES !=
+                 GNUNET_HELLO_address_check_option (address,
+                                                    GNUNET_HELLO_ADDRESS_INFO_INBOUND));
+  ai = find_ai_no_session (address);
+  GNUNET_assert (NULL == ai);
+  GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
+
+  /* address seems sane, let's tell ATS */
+  LOG (GNUNET_ERROR_TYPE_INFO,
+       "Notifying ATS about peer %s's new address `%s'\n",
+       GNUNET_i2s (&address->peer),
+       GST_plugins_a2s (address));
+  ar = GNUNET_ATS_address_add (GST_ats,
+                               address,
+                               NULL,
+                               prop);
+  GNUNET_assert (NULL != ar);
+  ai = GNUNET_new (struct AddressInfo);
+  ai->address = GNUNET_HELLO_address_copy (address);
   ai->ar = ar;
+  ai->properties = *prop;
   (void) GNUNET_CONTAINER_multipeermap_put (p2a,
                                             &ai->address->peer,
                                             ai,
                                             GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
+  publish_p2a_stat_update ();
 }
 
 
 /**
- * Notify ATS about a new session now existing for the given
- * address.
+ * Notify ATS about a new @a session now existing for the given
+ * @a address.  Essentially, an outbound @a address was used
+ * to establish a @a session.  It is safe to call this function
+ * repeatedly for the same @a address and @a session pair.
  *
  * @param address the address
  * @param session the session
  */
 void
 GST_ats_new_session (const struct GNUNET_HELLO_Address *address,
-                     struct Session *session)
+                     struct GNUNET_ATS_Session *session)
 {
   struct AddressInfo *ai;
 
+  if (0 ==
+      memcmp (&GST_my_identity,
+              &address->peer,
+              sizeof (struct GNUNET_PeerIdentity)))
+    return; /* our own, ignore! */
   ai = find_ai (address, NULL);
   if (NULL == ai)
   {
-    GNUNET_break (NULL != (find_ai (address, session)));
+    /* We may simply already be aware of the session, even if some
+       other part of the code could not tell if it just created a new
+       session or just got one recycled from the plugin; hence, we may
+       be called with "new" session even for an "old" session; in that
+       case, check that this is the case, but just ignore it. */
+    GNUNET_assert (NULL != (find_ai (address, session)));
     return;
   }
-  GNUNET_break (NULL == ai->session);
+  GNUNET_assert (NULL == ai->session);
   ai->session = session;
-  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
-                   "transport-ats",
-                   "Telling ATS about new session %p for peer %s\n",
-                   session,
-                   GNUNET_i2s (&address->peer));
-  GNUNET_ATS_address_add_session (ai->ar,
-                                  session);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Telling ATS about new session for peer %s\n",
+       GNUNET_i2s (&address->peer));
+  /* Note that the address might currently be blocked; we only
+     tell ATS about the session if the address is currently not
+     blocked; otherwise, ATS will be told about the session on
+     unblock. */
+  if (NULL != ai->ar)
+    GNUNET_ATS_address_add_session (ai->ar,
+                                    session);
+  else
+    GNUNET_assert (NULL != ai->unblock_task);
 }
 
 
 /**
- * Notify ATS that the session (but not the address) of
- * a given address is no longer relevant.
+ * Release memory used by the given address data.
+ *
+ * @param ai the `struct AddressInfo`
+ */
+static void
+destroy_ai (struct AddressInfo *ai)
+{
+  GNUNET_assert (NULL == ai->session);
+  if (NULL != ai->unblock_task)
+  {
+    GNUNET_SCHEDULER_cancel (ai->unblock_task);
+    ai->unblock_task = NULL;
+    num_blocked--;
+  }
+  GNUNET_assert (GNUNET_YES ==
+                 GNUNET_CONTAINER_multipeermap_remove (p2a,
+                                                       &ai->address->peer,
+                                                       ai));
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Telling ATS to destroy address from peer %s\n",
+       GNUNET_i2s (&ai->address->peer));
+  if (NULL != ai->ar)
+  {
+    GNUNET_ATS_address_destroy (ai->ar);
+    ai->ar = NULL;
+  }
+  publish_p2a_stat_update ();
+  GNUNET_HELLO_address_free (ai->address);
+  GNUNET_free (ai);
+}
+
+
+/**
+ * Notify ATS that the @a session (but not the @a address) of
+ * a given @a address is no longer relevant. (The @a session
+ * went down.)  This function may be called even if for the
+ * respective outbound address #GST_ats_new_session() was
+ * never called and thus the pair is unknown to ATS. In this
+ * case, the call is simply ignored.
  *
  * @param address the address
  * @param session the session
  */
 void
 GST_ats_del_session (const struct GNUNET_HELLO_Address *address,
-                     struct Session *session)
+                     struct GNUNET_ATS_Session *session)
 {
   struct AddressInfo *ai;
 
+  if (0 ==
+      memcmp (&GST_my_identity,
+              &address->peer,
+              sizeof (struct GNUNET_PeerIdentity)))
+    return; /* our own, ignore! */
   if (NULL == session)
   {
     GNUNET_break (0);
     return;
   }
-  ai = find_ai (address, session);
+  ai = find_ai (address,
+                session);
   if (NULL == ai)
   {
     /* We sometimes create sessions just for sending a PING,
@@ -287,95 +655,188 @@ GST_ats_del_session (const struct GNUNET_HELLO_Address *address,
     GNUNET_break (GNUNET_YES !=
                   GNUNET_HELLO_address_check_option (address,
                                                      GNUNET_HELLO_ADDRESS_INFO_INBOUND));
-
     return;
   }
   GNUNET_assert (session == ai->session);
   ai->session = NULL;
-  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
-                   "transport-ats",
-                   "Telling ATS to destroy session %p from peer %s\n",
-                   session,
-                   GNUNET_i2s (&address->peer));
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Telling ATS to destroy session %p from peer %s\n",
+       session,
+       GNUNET_i2s (&address->peer));
+  if (GNUNET_YES == ai->expired)
+  {
+    /* last reason to keep this 'ai' around is now gone, the
+       session is dead as well, clean up */
+    if (NULL != ai->ar)
+    {
+      /* Address expired but not blocked, and thus 'ar' was still
+         live because of the session; deleting just the session
+         will do for an inbound session, but for an outbound we
+         then also need to destroy the address with ATS. */
+      if (GNUNET_NO ==
+          GNUNET_ATS_address_del_session (ai->ar,
+                                          session))
+      {
+        GNUNET_ATS_address_destroy (ai->ar);
+      }
+      /* "ar" has been freed, regardless how the branch
+         above played out: it was either freed in
+         #GNUNET_ATS_address_del_session() because it was
+         incoming, or explicitly in
+         #GNUNET_ATS_address_del_session(). */
+      ai->ar = NULL;
+    }
+    destroy_ai (ai);
+    return;
+  }
+
+  if (NULL == ai->ar)
+  {
+    /* If ATS doesn't know about the address/session, this means
+       this address was blocked. */
+    if (GNUNET_YES ==
+	GNUNET_HELLO_address_check_option (address,
+					   GNUNET_HELLO_ADDRESS_INFO_INBOUND))
+    {
+      /* This was a blocked inbound session, which now lost the
+         session.  But inbound addresses are by themselves useless,
+         so we must forget about the address as well. */
+      destroy_ai (ai);
+      return;
+    }
+    /* Otherwise, we are done as we have set `ai->session` to NULL
+       already and ATS will simply not be told about the session when
+       the connection is unblocked and the outbound address becomes
+       available again. . */
+    return;
+  }
+
+  /* This is the "simple" case where ATS knows about the session and
+     the address is neither blocked nor expired.  Delete the session,
+     and if it was inbound, free the address as well. */
   if (GNUNET_YES ==
-      GNUNET_ATS_address_del_session (ai->ar, session))
+      GNUNET_ATS_address_del_session (ai->ar,
+                                      session))
   {
+    /* This was an inbound address, the session is now gone, so we
+       need to also forget about the address itself. */
     ai->ar = NULL;
-    GST_ats_expire_address (address);
+    destroy_ai (ai);
   }
 }
 
 
 /**
- * Notify ATS about property changes to an address.
+ * Notify ATS about DV @a distance change to an @a address.
+ * Does nothing if the @a address is not known to us.
  *
- * @param address our information about the address
- * @param session the session
- * @param ats performance information
- * @param ats_count number of elements in @a ats
+ * @param address the address
+ * @param distance new distance value
  */
 void
-GST_ats_update_metrics (const struct GNUNET_HELLO_Address *address,
-                        struct Session *session,
-                        const struct GNUNET_ATS_Information *ats,
-                        uint32_t ats_count)
+GST_ats_update_distance (const struct GNUNET_HELLO_Address *address,
+                         uint32_t distance)
 {
-  struct GNUNET_ATS_Information *ats_new;
   struct AddressInfo *ai;
 
-  ai = find_ai (address, session);
+  ai = find_ai_no_session (address);
   if (NULL == ai)
   {
-    /* We sometimes create sessions just for sending a PING,
-       and if we get metrics for those, they were never known to
-       ATS which means we end up here (however, in this
-       case, the address must be an outbound address). */
-    GNUNET_break (GNUNET_YES !=
-                  GNUNET_HELLO_address_check_option (address,
-                                                     GNUNET_HELLO_ADDRESS_INFO_INBOUND));
-
+    /* We do not know about this address, do nothing. */
     return;
   }
-  /* Call to manipulation to manipulate ATS information */
-  GNUNET_assert (NULL != GST_ats);
-  if ((NULL == ats) || (0 == ats_count))
-    return;
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Updating metrics for peer `%s' address %s session %p\n",
-              GNUNET_i2s (&address->peer),
-              GST_plugins_a2s (address),
-              session);
-  ats_new = GST_manipulation_manipulate_metrics (address,
-                                                 session,
-                                                 ats,
-                                                 ats_count);
-  GNUNET_ATS_address_update (ai->ar,
-                             ats_new, ats_count);
-  GNUNET_free_non_null (ats_new);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Updated distance for peer `%s' to %u\n",
+       GNUNET_i2s (&address->peer),
+       distance);
+  ai->properties.distance = distance;
+  /* Give manipulation its chance to change metrics */
+  GST_manipulation_manipulate_metrics (address,
+                                       ai->session,
+                                       &ai->properties);
+  /* Address may be blocked, only give ATS if address is
+     currently active. */
+  if (NULL != ai->ar)
+    GNUNET_ATS_address_update (ai->ar,
+                               &ai->properties);
 }
 
 
 /**
- * Notify ATS about a new session now being in use (or not).
+ * Notify ATS about @a delay changes to properties of an @a address.
+ * Does nothing if the @a address is not known to us.
  *
  * @param address the address
- * @param session the session
- * @param in_use #GNUNET_YES or #GNUNET_NO
+ * @param delay new delay value
  */
 void
-GST_ats_set_in_use (const struct GNUNET_HELLO_Address *address,
-                    struct Session *session,
-                    int in_use)
+GST_ats_update_delay (const struct GNUNET_HELLO_Address *address,
+                      struct GNUNET_TIME_Relative delay)
 {
   struct AddressInfo *ai;
 
-  ai = find_ai (address, session);
+  ai = find_ai_no_session (address);
   if (NULL == ai)
   {
-    GNUNET_break (0);
+    /* We do not know about this address, do nothing. */
     return;
   }
-  GNUNET_ATS_address_set_in_use (ai->ar, in_use);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Updated latency for peer `%s' to %s\n",
+       GNUNET_i2s (&address->peer),
+       GNUNET_STRINGS_relative_time_to_string (delay,
+                                               GNUNET_YES));
+  ai->properties.delay = delay;
+  /* Give manipulation its chance to change metrics */
+  GST_manipulation_manipulate_metrics (address,
+                                       ai->session,
+                                       &ai->properties);
+  /* Address may be blocked, only give ATS if address is
+     currently active. */
+  if (NULL != ai->ar)
+    GNUNET_ATS_address_update (ai->ar,
+                               &ai->properties);
+}
+
+
+/**
+ * Notify ATS about utilization changes to an @a address.
+ * Does nothing if the @a address is not known to us.
+ *
+ * @param address our information about the address
+ * @param bps_in new utilization inbound
+ * @param bps_out new utilization outbound
+ */
+void
+GST_ats_update_utilization (const struct GNUNET_HELLO_Address *address,
+                            uint32_t bps_in,
+                            uint32_t bps_out)
+{
+  struct AddressInfo *ai;
+
+  ai = find_ai_no_session (address);
+  if (NULL == ai)
+  {
+    /* We do not know about this address, do nothing. */
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Updating utilization for peer `%s' address %s: %u/%u\n",
+       GNUNET_i2s (&address->peer),
+       GST_plugins_a2s (address),
+       (unsigned int) bps_in,
+       (unsigned int) bps_out);
+  ai->properties.utilization_in = bps_in;
+  ai->properties.utilization_out = bps_out;
+  /* Give manipulation its chance to change metrics */
+  GST_manipulation_manipulate_metrics (address,
+                                       ai->session,
+                                       &ai->properties);
+  /* Address may be blocked, only give ATS if address is
+     currently active. */
+  if (NULL != ai->ar)
+    GNUNET_ATS_address_update (ai->ar,
+                               &ai->properties);
 }
 
 
@@ -391,25 +852,30 @@ GST_ats_expire_address (const struct GNUNET_HELLO_Address *address)
 {
   struct AddressInfo *ai;
 
-  ai = find_ai (address, NULL);
+  if (0 ==
+      memcmp (&GST_my_identity,
+              &address->peer,
+              sizeof (struct GNUNET_PeerIdentity)))
+    return; /* our own, ignore! */
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Address %s of peer %s expired\n",
+       GST_plugins_a2s (address),
+       GNUNET_i2s (&address->peer));
+  ai = find_ai_no_session (address);
   if (NULL == ai)
   {
-    GNUNET_break (0);
+    GNUNET_assert (0);
     return;
   }
-  GNUNET_assert (GNUNET_YES ==
-                 GNUNET_CONTAINER_multipeermap_remove (p2a,
-                                                       &address->peer,
-                                                       ai));
-  GNUNET_break (NULL == ai->session);
-  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
-                   "transport-ats",
-                   "Telling ATS to destroy address from peer %s\n",
-                   GNUNET_i2s (&address->peer));
-  if (NULL != ai->ar)
-    GNUNET_ATS_address_destroy (ai->ar);
-  GNUNET_HELLO_address_free (ai->address);
-  GNUNET_free (ai);
+  if (NULL != ai->session)
+  {
+    /* Got an active session, just remember the expiration
+       and act upon it when the session goes down. */
+    ai->expired = GNUNET_YES;
+    return;
+  }
+  /* Address expired, no session, free resources */
+  destroy_ai (ai);
 }
 
 
@@ -432,14 +898,13 @@ GST_ats_init ()
  * @return #GNUNET_OK (continue to iterate)
  */
 static int
-destroy_ai (void *cls,
-            const struct GNUNET_PeerIdentity *key,
-            void *value)
+destroy_ai_cb (void *cls,
+	       const struct GNUNET_PeerIdentity *key,
+	       void *value)
 {
   struct AddressInfo *ai = value;
 
-  GNUNET_HELLO_address_free (ai->address);
-  GNUNET_free (ai);
+  destroy_ai (ai);
   return GNUNET_OK;
 }
 
@@ -451,8 +916,9 @@ void
 GST_ats_done ()
 {
   GNUNET_CONTAINER_multipeermap_iterate (p2a,
-                                         &destroy_ai,
+                                         &destroy_ai_cb,
                                          NULL);
+  publish_p2a_stat_update ();
   GNUNET_CONTAINER_multipeermap_destroy (p2a);
   p2a = NULL;
 }