ats_api_connectivity.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2010-2016 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_ats_service.h"
#include "ats.h"
 
 
#define LOG(kind, ...) GNUNET_log_from (kind, "ats-connectivity-api", \
                                        __VA_ARGS__)
 
 
struct GNUNET_ATS_ConnectivitySuggestHandle
{
  struct GNUNET_PeerIdentity id;
 
  struct GNUNET_ATS_ConnectivityHandle *ch;
 
  uint32_t strength;
};
 
 
struct GNUNET_ATS_ConnectivityHandle
{
  const struct GNUNET_CONFIGURATION_Handle *cfg;
 
  struct GNUNET_CONTAINER_MultiPeerMap *sug_requests;
 
  struct GNUNET_MQ_Handle *mq;
 
  struct GNUNET_SCHEDULER_Task *task;
 
  struct GNUNET_TIME_Relative backoff;
};
 
 
static void
reconnect (struct GNUNET_ATS_ConnectivityHandle *ch);
 
 
static void
reconnect_task (void *cls)
{
  struct GNUNET_ATS_ConnectivityHandle *ch = cls;
 
  ch->task = NULL;
  reconnect (ch);
}
 
 
static void
force_reconnect (struct GNUNET_ATS_ConnectivityHandle *ch)
{
  if (NULL != ch->mq)
  {
    GNUNET_MQ_destroy (ch->mq);
    ch->mq = NULL;
  }
  ch->backoff = GNUNET_TIME_STD_BACKOFF (ch->backoff);
  ch->task = GNUNET_SCHEDULER_add_delayed (ch->backoff,
                                           &reconnect_task,
                                           ch);
}
 
 
static void
error_handler (void *cls,
               enum GNUNET_MQ_Error error)
{
  struct GNUNET_ATS_ConnectivityHandle *ch = cls;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "ATS connection died (code %d), reconnecting\n",
       (int) error);
  force_reconnect (ch);
}
 
 
static int
transmit_suggestion (void *cls,
                     const struct GNUNET_PeerIdentity *peer,
                     void *value)
{
  struct GNUNET_ATS_ConnectivityHandle *ch = cls;
  struct GNUNET_ATS_ConnectivitySuggestHandle *sh = value;
  struct GNUNET_MQ_Envelope *ev;
  struct RequestAddressMessage *m;
 
  if (NULL == ch->mq)
    return GNUNET_SYSERR;
  ev = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
  m->strength = htonl (sh->strength);
  m->peer = *peer;
  GNUNET_MQ_send (ch->mq, ev);
  return GNUNET_OK;
}
 
 
static void
reconnect (struct GNUNET_ATS_ConnectivityHandle *ch)
{
  static const struct GNUNET_MQ_MessageHandler handlers[] =
  { { NULL, 0, 0 } };
  struct GNUNET_MQ_Envelope *ev;
  struct ClientStartMessage *init;
 
  GNUNET_assert (NULL == ch->mq);
  ch->mq = GNUNET_CLIENT_connect (ch->cfg,
                                  "ats",
                                  handlers,
                                  &error_handler,
                                  ch);
  if (NULL == ch->mq)
  {
    force_reconnect (ch);
    return;
  }
  ev = GNUNET_MQ_msg (init,
                      GNUNET_MESSAGE_TYPE_ATS_START);
  init->start_flag = htonl (START_FLAG_CONNECTION_SUGGESTION);
  GNUNET_MQ_send (ch->mq, ev);
  if (NULL == ch->mq)
    return;
  GNUNET_CONTAINER_multipeermap_iterate (ch->sug_requests,
                                         &transmit_suggestion,
                                         ch);
}
 
 
struct GNUNET_ATS_ConnectivityHandle *
GNUNET_ATS_connectivity_init (const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  struct GNUNET_ATS_ConnectivityHandle *ch;
 
  ch = GNUNET_new (struct GNUNET_ATS_ConnectivityHandle);
  ch->cfg = cfg;
  ch->sug_requests = GNUNET_CONTAINER_multipeermap_create (32,
                                                           GNUNET_YES);
  reconnect (ch);
  return ch;
}
 
 
static int
free_sug_handle (void *cls,
                 const struct GNUNET_PeerIdentity *key,
                 void *value)
{
  struct GNUNET_ATS_ConnectivitySuggestHandle *cur = value;
 
  GNUNET_free (cur);
  return GNUNET_OK;
}
 
 
void
GNUNET_ATS_connectivity_done (struct GNUNET_ATS_ConnectivityHandle *ch)
{
  if (NULL != ch->mq)
  {
    GNUNET_MQ_destroy (ch->mq);
    ch->mq = NULL;
  }
  if (NULL != ch->task)
  {
    GNUNET_SCHEDULER_cancel (ch->task);
    ch->task = NULL;
  }
  GNUNET_CONTAINER_multipeermap_iterate (ch->sug_requests,
                                         &free_sug_handle,
                                         NULL);
  GNUNET_CONTAINER_multipeermap_destroy (ch->sug_requests);
  GNUNET_free (ch);
}
 
 
struct GNUNET_ATS_ConnectivitySuggestHandle *
GNUNET_ATS_connectivity_suggest (struct GNUNET_ATS_ConnectivityHandle *ch,
                                 const struct GNUNET_PeerIdentity *peer,
                                 uint32_t strength)
{
  struct GNUNET_ATS_ConnectivitySuggestHandle *s;
 
  s = GNUNET_new (struct GNUNET_ATS_ConnectivitySuggestHandle);
  s->ch = ch;
  s->id = *peer;
  s->strength = strength;
  if (GNUNET_OK !=
      GNUNET_CONTAINER_multipeermap_put (ch->sug_requests,
                                         &s->id,
                                         s,
                                         GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Not requesting ATS to suggest address for `%s', request already pending\n",
         GNUNET_i2s (peer));
    GNUNET_free (s);
    return NULL;
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Requesting ATS to suggest address for `%s'\n",
       GNUNET_i2s (peer));
  if (NULL == ch->mq)
    return s;
  (void) transmit_suggestion (ch,
                              &s->id,
                              s);
  return s;
}
 
 
void
GNUNET_ATS_connectivity_suggest_cancel (struct
                                        GNUNET_ATS_ConnectivitySuggestHandle *sh)
{
  struct GNUNET_ATS_ConnectivityHandle *ch = sh->ch;
  struct GNUNET_MQ_Envelope *ev;
  struct RequestAddressMessage *m;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Telling ATS we no longer care for an address for `%s'\n",
       GNUNET_i2s (&sh->id));
  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CONTAINER_multipeermap_remove (ch->sug_requests,
                                                       &sh->id,
                                                       sh));
  if (NULL == ch->mq)
  {
    GNUNET_free (sh);
    return;
  }
  ev = GNUNET_MQ_msg (m,
                      GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS_CANCEL);
  m->strength = htonl (0);
  m->peer = sh->id;
  GNUNET_MQ_send (ch->mq, ev);
  GNUNET_free (sh);
}
 
 
/* end of ats_api_connectivity.c */