gnunet-service-transport_ats.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2015 GNUnet e.V.

     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.

     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Affero General Public License for more details.
    
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
*/
#include "platform.h"
#include "gnunet-service-transport.h"
#include "gnunet-service-transport_ats.h"
#include "gnunet-service-transport_manipulation.h"
#include "gnunet-service-transport_plugins.h"
#include "gnunet_ats_service.h"

#define LOG(kind,...) GNUNET_log_from(kind, "transport-ats", __VA_ARGS__)


struct AddressInfo
{

  struct GNUNET_HELLO_Address *address;

  struct GNUNET_ATS_Session *session;

  struct GNUNET_ATS_AddressRecord *ar;

  struct GNUNET_ATS_Properties properties;

  struct GNUNET_TIME_Absolute blocked;

  struct GNUNET_TIME_Relative back_off;

  struct GNUNET_SCHEDULER_Task *unblock_task;

  int expired;

};


static struct GNUNET_CONTAINER_MultiPeerMap *p2a;

static unsigned int num_blocked;


struct FindClosure
{

  struct GNUNET_ATS_Session *session;

  const struct GNUNET_HELLO_Address *address;

  struct AddressInfo *ret;

};


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);
}


static int
find_ai_cb (void *cls,
            const struct GNUNET_PeerIdentity *key,
            void *value)
{
  struct FindClosure *fc = cls;
  struct AddressInfo *ai = value;

  if ( (0 ==
        GNUNET_HELLO_address_cmp (fc->address,
                                  ai->address) ) &&
       (fc->session == ai->session) )
  {
    fc->ret = ai;
    return GNUNET_NO;
  }
  return GNUNET_YES;
}


static struct AddressInfo *
find_ai (const struct GNUNET_HELLO_Address *address,
         struct GNUNET_ATS_Session *session)
{
  struct FindClosure fc;

  fc.address = address;
  fc.session = session;
  fc.ret = NULL;
  GNUNET_CONTAINER_multipeermap_get_multiple (p2a,
                                              &address->peer,
                                              &find_ai_cb,
                                              &fc);
  return fc.ret;
}


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;
}


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;
}


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;
}


int
GST_ats_is_known_no_session (const struct GNUNET_HELLO_Address *address)
{
  return (NULL != find_ai_no_session (address))
    ? GNUNET_YES
    : GNUNET_NO;
}


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 ();
}


void
GST_ats_block_address (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 || NULL == ai->ar)
  {
    /* 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))
    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_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 ();
}


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)
  {
    GNUNET_break (0);
    return;
  }
  /* 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;
}


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)
  {
    GNUNET_break(0);
    return;
  }
  GNUNET_break (GNUNET_NT_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)
  {
    /* This should only be called for new sessions, and thus
       we should not already have the address */
    GNUNET_break (0);
    return;
  }
  /* 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_NT_to_string (prop->scope));
  ar = GNUNET_ATS_address_add (GST_ats,
                               address,
                               session,
                               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 ();
}


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_NT_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 ();
}


void
GST_ats_new_session (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, NULL);
  if (NULL == ai)
  {
    /* 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_assert (NULL == ai->session);
  ai->session = 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);
}


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);
}


void
GST_ats_del_session (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! */
  if (NULL == session)
  {
    GNUNET_break (0);
    return;
  }
  ai = find_ai (address,
                session);
  if (NULL == ai)
  {
    /* We sometimes create sessions just for sending a PING,
       and if those are destroyed 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));
    return;
  }
  GNUNET_assert (session == ai->session);
  ai->session = NULL;
  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))
  {
    /* This was an inbound address, the session is now gone, so we
       need to also forget about the address itself. */
    ai->ar = NULL;
    destroy_ai (ai);
  }
}


void
GST_ats_update_distance (const struct GNUNET_HELLO_Address *address,
                         uint32_t distance)
{
  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,
       "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);
}


void
GST_ats_update_delay (const struct GNUNET_HELLO_Address *address,
                      struct GNUNET_TIME_Relative delay)
{
  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,
       "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);
}


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);
}


void
GST_ats_expire_address (const struct GNUNET_HELLO_Address *address)
{
  struct AddressInfo *ai;

  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_assert (0);
    return;
  }
  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);
}


void
GST_ats_init ()
{
  p2a = GNUNET_CONTAINER_multipeermap_create (4, GNUNET_YES);
}


static int
destroy_ai_cb (void *cls,
               const struct GNUNET_PeerIdentity *key,
               void *value)
{
  struct AddressInfo *ai = value;

  destroy_ai (ai);
  return GNUNET_OK;
}


void
GST_ats_done ()
{
  GNUNET_CONTAINER_multipeermap_iterate (p2a,
                                         &destroy_ai_cb,
                                         NULL);
  publish_p2a_stat_update ();
  GNUNET_CONTAINER_multipeermap_destroy (p2a);
  p2a = NULL;
}

/* end of gnunet-service-transport_ats.c */