gnunet-service-cadet.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2001-2013, 2017 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 "gnunet_util_lib.h"
#include "cadet.h"
#include "gnunet_statistics_service.h"
#include "gnunet_transport_application_service.h"
#include "gnunet-service-cadet.h"
#include "gnunet-service-cadet_channel.h"
#include "gnunet-service-cadet_core.h"
#include "gnunet-service-cadet_dht.h"
#include "gnunet-service-cadet_hello.h"
#include "gnunet-service-cadet_tunnels.h"
#include "gnunet-service-cadet_peer.h"
#include "gnunet-service-cadet_paths.h"
#include "gnunet_constants.h"
 
 
#define LOG(level, ...) GNUNET_log (level, __VA_ARGS__)
 
 
struct CadetClient
{
  struct CadetClient *next;
 
  struct CadetClient *prev;
 
  struct GNUNET_CONTAINER_MultiHashMap32 *channels;
 
  struct GNUNET_MQ_Handle *mq;
 
  struct GNUNET_SERVICE_Client *client;
 
  struct GNUNET_CONTAINER_MultiHashMap *ports;
 
  struct GNUNET_CADET_ClientChannelNumber next_ccn;
 
  unsigned int id;
};
 
 
/******************************************************************************/
/***********************      GLOBAL VARIABLES     ****************************/
/******************************************************************************/
 
/****************************** Global variables ******************************/
 
const struct GNUNET_CONFIGURATION_Handle *cfg;
 
struct GNUNET_STATISTICS_Handle *stats;
 
struct GNUNET_TRANSPORT_ApplicationHandle *transport;
 
struct GNUNET_PeerIdentity my_full_id;
 
struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
 
int shutting_down;
 
static struct CadetClient *clients_head;
 
static struct CadetClient *clients_tail;
 
static unsigned int next_client_id;
 
struct GNUNET_CONTAINER_MultiHashMap *open_ports;
 
struct GNUNET_CONTAINER_MultiHashMap *loose_channels;
 
struct GNUNET_CONTAINER_MultiPeerMap *peers;
 
struct GNUNET_CONTAINER_MultiShortmap *connections;
 
unsigned long long ratchet_messages;
 
struct GNUNET_TIME_Relative ratchet_time;
 
struct GNUNET_TIME_Relative keepalive_period;
 
unsigned long long drop_percent;
 
 
void
GSC_send_to_client (struct CadetClient *c,
                    struct GNUNET_MQ_Envelope *env)
{
  GNUNET_MQ_send (c->mq,
                  env);
}
 
 
const char *
GSC_2s (struct CadetClient *c)
{
  static char buf[32];
 
  GNUNET_snprintf (buf,
                   sizeof(buf),
                   "Client(%u)",
                   c->id);
  return buf;
}
 
 
static struct CadetChannel *
lookup_channel (struct CadetClient *c,
                struct GNUNET_CADET_ClientChannelNumber ccn)
{
  return GNUNET_CONTAINER_multihashmap32_get (c->channels,
                                              ntohl (ccn.channel_of_client));
}
 
 
static struct GNUNET_CADET_ClientChannelNumber
client_get_next_ccn (struct CadetClient *c)
{
  struct GNUNET_CADET_ClientChannelNumber ccn = c->next_ccn;
 
  /* increment until we have a free one... */
  while (NULL !=
         lookup_channel (c,
                         ccn))
  {
    ccn.channel_of_client
      = htonl (1 + (ntohl (ccn.channel_of_client)));
    if (ntohl (ccn.channel_of_client) >=
        GNUNET_CADET_LOCAL_CHANNEL_ID_CLI)
      ccn.channel_of_client = htonl (0);
  }
  c->next_ccn.channel_of_client
    = htonl (1 + (ntohl (ccn.channel_of_client)));
  return ccn;
}
 
 
struct GNUNET_CADET_ClientChannelNumber
GSC_bind (struct CadetClient *c,
          struct CadetChannel *ch,
          struct CadetPeer *dest,
          const struct GNUNET_HashCode *port,
          uint32_t options)
{
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_CADET_LocalChannelCreateMessage *cm;
  struct GNUNET_CADET_ClientChannelNumber ccn;
 
  ccn = client_get_next_ccn (c);
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap32_put (c->channels,
                                                      ntohl (
                                                        ccn.channel_of_client),
                                                      ch,
                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Accepting incoming %s from %s on open port %s (%u), assigning ccn %X\n",
       GCCH_2s (ch),
       GCP_2s (dest),
       GNUNET_h2s (port),
       (uint32_t) ntohl (options),
       (uint32_t) ntohl (ccn.channel_of_client));
  /* notify local client about incoming connection! */
  env = GNUNET_MQ_msg (cm,
                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_CREATE);
  cm->ccn = ccn;
  cm->port = *port;
  cm->opt = htonl (options);
  cm->peer = *GCP_get_id (dest);
  GSC_send_to_client (c,
                      env);
  return ccn;
}
 
 
static int
destroy_tunnels_now (void *cls,
                     const struct GNUNET_PeerIdentity *pid,
                     void *value)
{
  struct CadetPeer *cp = value;
  struct CadetTunnel *t = GCP_get_tunnel (cp,
                                          GNUNET_NO);
 
  if (NULL != t)
    GCT_destroy_tunnel_now (t);
  return GNUNET_OK;
}
 
 
static int
destroy_paths_now (void *cls,
                   const struct GNUNET_PeerIdentity *pid,
                   void *value)
{
  struct CadetPeer *cp = value;
 
  GCP_drop_owned_paths (cp);
  return GNUNET_OK;
}
 
 
static void
shutdown_rest ()
{
  if (NULL != stats)
  {
    GNUNET_STATISTICS_destroy (stats,
                               GNUNET_NO);
    stats = NULL;
  }
  /* Destroy tunnels.  Note that all channels must be destroyed first! */
  GCP_iterate_all (&destroy_tunnels_now,
                   NULL);
  /* All tunnels, channels, connections and CORE must be down before this point. */
  GCP_iterate_all (&destroy_paths_now,
                   NULL);
  /* All paths, tunnels, channels, connections and CORE must be down before this point. */
  GCP_destroy_all_peers ();
  if (NULL != open_ports)
  {
    GNUNET_CONTAINER_multihashmap_destroy (open_ports);
    open_ports = NULL;
  }
  if (NULL != loose_channels)
  {
    GNUNET_CONTAINER_multihashmap_destroy (loose_channels);
    loose_channels = NULL;
  }
  if (NULL != peers)
  {
    GNUNET_CONTAINER_multipeermap_destroy (peers);
    peers = NULL;
  }
  if (NULL != connections)
  {
    GNUNET_CONTAINER_multishortmap_destroy (connections);
    connections = NULL;
  }
  if (NULL != transport)
  {
    GNUNET_TRANSPORT_application_done (transport);
    transport = NULL;
  }
  GCD_shutdown ();
  GCH_shutdown ();
  GNUNET_free (my_private_key);
  my_private_key = NULL;
}
 
 
static void
shutdown_task (void *cls)
{
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Shutting down\n");
  shutting_down = GNUNET_YES;
  GCO_shutdown ();
  if (NULL == clients_head)
    shutdown_rest ();
}
 
 
static int
bind_loose_channel (void *cls,
                    const struct GNUNET_HashCode *port,
                    void *value)
{
  struct OpenPort *op = cls;
  struct CadetChannel *ch = value;
 
  GCCH_bind (ch,
             op->c,
             &op->port);
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (loose_channels,
                                                       &op->h_port,
                                                       ch));
  return GNUNET_YES;
}
 
 
static void
handle_port_open (void *cls,
                  const struct GNUNET_CADET_PortMessage *pmsg)
{
  struct CadetClient *c = cls;
  struct OpenPort *op;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Open port %s requested by %s\n",
       GNUNET_h2s (&pmsg->port),
       GSC_2s (c));
  if (NULL == c->ports)
    c->ports = GNUNET_CONTAINER_multihashmap_create (4,
                                                     GNUNET_NO);
  op = GNUNET_new (struct OpenPort);
  op->c = c;
  op->port = pmsg->port;
  GCCH_hash_port (&op->h_port,
                  &pmsg->port,
                  &my_full_id);
  if (GNUNET_OK !=
      GNUNET_CONTAINER_multihashmap_put (c->ports,
                                         &op->port,
                                         op,
                                         GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
  {
    GNUNET_break (0);
    GNUNET_SERVICE_client_drop (c->client);
    return;
  }
  (void) GNUNET_CONTAINER_multihashmap_put (open_ports,
                                            &op->h_port,
                                            op,
                                            GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
  GNUNET_CONTAINER_multihashmap_get_multiple (loose_channels,
                                              &op->h_port,
                                              &bind_loose_channel,
                                              op);
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static void
handle_port_close (void *cls,
                   const struct GNUNET_CADET_PortMessage *pmsg)
{
  struct CadetClient *c = cls;
  struct OpenPort *op;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Closing port %s as requested by %s\n",
       GNUNET_h2s (&pmsg->port),
       GSC_2s (c));
  if (NULL == c->ports)
  {
    /* Client closed a port despite _never_ having opened one? */
    GNUNET_break (0);
    GNUNET_SERVICE_client_drop (c->client);
    return;
  }
  op = GNUNET_CONTAINER_multihashmap_get (c->ports,
                                          &pmsg->port);
  if (NULL == op)
  {
    GNUNET_break (0);
    GNUNET_SERVICE_client_drop (c->client);
    return;
  }
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (c->ports,
                                                       &op->port,
                                                       op));
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (open_ports,
                                                       &op->h_port,
                                                       op));
  GNUNET_free (op);
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static void
handle_channel_create (void *cls,
                       const struct GNUNET_CADET_LocalChannelCreateMessage *tcm)
{
  struct CadetClient *c = cls;
  struct CadetChannel *ch;
 
  if (ntohl (tcm->ccn.channel_of_client) < GNUNET_CADET_LOCAL_CHANNEL_ID_CLI)
  {
    /* Channel ID not in allowed range. */
    LOG (GNUNET_ERROR_TYPE_DEBUG,"Channel ID not in allowed range.");
    GNUNET_break (0);
    GNUNET_SERVICE_client_drop (c->client);
    return;
  }
  ch = lookup_channel (c,
                       tcm->ccn);
  if (NULL != ch)
  {
    /* Channel ID already in use. Not allowed. */
    LOG (GNUNET_ERROR_TYPE_DEBUG,"Channel ID already in use. Not allowed.");
    GNUNET_break (0);
    GNUNET_SERVICE_client_drop (c->client);
    return;
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "New channel to %s at port %s requested by %s\n",
       GNUNET_i2s (&tcm->peer),
       GNUNET_h2s (&tcm->port),
       GSC_2s (c));
 
  /* Create channel */
  ch = GCCH_channel_local_new (c,
                               tcm->ccn,
                               GCP_get (&tcm->peer,
                                        GNUNET_YES),
                               &tcm->port,
                               ntohl (tcm->opt));
  if (NULL == ch)
  {
    GNUNET_break (0);
    GNUNET_SERVICE_client_drop (c->client);
    return;
  }
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap32_put (c->channels,
                                                      ntohl (
                                                        tcm->ccn.
                                                        channel_of_client),
                                                      ch,
                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
 
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static void
handle_channel_destroy (void *cls,
                        const struct
                        GNUNET_CADET_LocalChannelDestroyMessage *msg)
{
  struct CadetClient *c = cls;
  struct CadetChannel *ch;
 
  ch = lookup_channel (c,
                       msg->ccn);
  if (NULL == ch)
  {
    /* Client attempted to destroy unknown channel.
       Can happen if the other side went down at the same time.*/
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "%s tried to destroy unknown channel %X\n",
         GSC_2s (c),
         (uint32_t) ntohl (msg->ccn.channel_of_client));
    GNUNET_SERVICE_client_continue (c->client);
    return;
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "%s is destroying %s\n",
       GSC_2s (c),
       GCCH_2s (ch));
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap32_remove (c->channels,
                                                         ntohl (
                                                           msg->ccn.
                                                           channel_of_client),
                                                         ch));
  GCCH_channel_local_destroy (ch,
                              c,
                              msg->ccn);
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static int
check_local_data (void *cls,
                  const struct GNUNET_CADET_LocalData *msg)
{
  size_t payload_size;
  size_t payload_claimed_size;
  const char *buf;
  struct GNUNET_MessageHeader pa;
 
  /* FIXME: what is the format we shall allow for @a msg?
     ONE payload item or multiple? Seems current cadet_api
     at least in theory allows more than one. Next-gen
     cadet_api will likely no more, so we could then
     simplify this mess again. *//* Sanity check for message size */payload_size = ntohs (msg->header.size) - sizeof(*msg);
  buf = (const char *) &msg[1];
  while (payload_size >= sizeof(struct GNUNET_MessageHeader))
  {
    /* need to memcpy() for alignment */
    GNUNET_memcpy (&pa,
                   buf,
                   sizeof(pa));
    payload_claimed_size = ntohs (pa.size);
    if ((payload_size < payload_claimed_size) ||
        (payload_claimed_size < sizeof(struct GNUNET_MessageHeader)) ||
        (GNUNET_CONSTANTS_MAX_CADET_MESSAGE_SIZE < payload_claimed_size))
    {
      GNUNET_break (0);
      LOG (GNUNET_ERROR_TYPE_DEBUG,
           "Local data of %u total size had sub-message %u at %u with %u bytes\n",
           ntohs (msg->header.size),
           ntohs (pa.type),
           (unsigned int) (buf - (const char *) &msg[1]),
           (unsigned int) payload_claimed_size);
      return GNUNET_SYSERR;
    }
    payload_size -= payload_claimed_size;
    buf += payload_claimed_size;
  }
  if (0 != payload_size)
  {
    GNUNET_break_op (0);
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}
 
 
static void
handle_local_data (void *cls,
                   const struct GNUNET_CADET_LocalData *msg)
{
  struct CadetClient *c = cls;
  struct CadetChannel *ch;
  size_t payload_size;
  const char *buf;
 
  ch = lookup_channel (c,
                       msg->ccn);
  if (NULL == ch)
  {
    /* Channel does not exist (anymore) */
    LOG (GNUNET_ERROR_TYPE_WARNING,
         "Dropping payload for channel %u from client (channel unknown, other endpoint may have disconnected)\n",
         (unsigned int) ntohl (msg->ccn.channel_of_client));
    GNUNET_SERVICE_client_continue (c->client);
    return;
  }
  payload_size = ntohs (msg->header.size) - sizeof(*msg);
  GNUNET_STATISTICS_update (stats,
                            "# payload received from clients",
                            payload_size,
                            GNUNET_NO);
  buf = (const char *) &msg[1];
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Received %u bytes payload from %s for %s\n",
       (unsigned int) payload_size,
       GSC_2s (c),
       GCCH_2s (ch));
  if (GNUNET_OK !=
      GCCH_handle_local_data (ch,
                              msg->ccn,
                              buf,
                              payload_size))
  {
    GNUNET_break (0);
    GNUNET_SERVICE_client_drop (c->client);
    return;
  }
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static void
handle_local_ack (void *cls,
                  const struct GNUNET_CADET_LocalAck *msg)
{
  struct CadetClient *c = cls;
  struct CadetChannel *ch;
 
  ch = lookup_channel (c,
                       msg->ccn);
  if (NULL == ch)
  {
    /* Channel does not exist (anymore) */
    LOG (GNUNET_ERROR_TYPE_WARNING,
         "Ignoring local ACK for channel %u from client (channel unknown, other endpoint may have disconnected)\n",
         (unsigned int) ntohl (msg->ccn.channel_of_client));
    GNUNET_SERVICE_client_continue (c->client);
    return;
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Got a local ACK from %s for %s\n",
       GSC_2s (c),
       GCCH_2s (ch));
  GCCH_handle_local_ack (ch,
                         msg->ccn);
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static int
get_all_peers_iterator (void *cls,
                        const struct GNUNET_PeerIdentity *peer,
                        void *value)
{
  struct CadetClient *c = cls;
  struct CadetPeer *p = value;
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_CADET_LocalInfoPeers *msg;
 
  env = GNUNET_MQ_msg (msg,
                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PEERS);
  msg->destination = *peer;
  msg->paths = htons (GCP_count_paths (p));
  msg->tunnel = htons (NULL != GCP_get_tunnel (p,
                                               GNUNET_NO));
  msg->best_path_length = htonl (0);  // FIXME: get length of shortest known path!
  GNUNET_MQ_send (c->mq,
                  env);
  return GNUNET_YES;
}
 
 
static void
handle_get_peers (void *cls,
                  const struct GNUNET_MessageHeader *message)
{
  struct CadetClient *c = cls;
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_MessageHeader *reply;
 
  GCP_iterate_all (&get_all_peers_iterator,
                   c);
  env = GNUNET_MQ_msg (reply,
                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PEERS_END);
  GNUNET_MQ_send (c->mq,
                  env);
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static int
path_info_iterator (void *cls,
                    struct CadetPeerPath *path,
                    unsigned int off)
{
  struct GNUNET_MQ_Handle *mq = cls;
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_CADET_LocalInfoPath *resp;
  struct GNUNET_PeerIdentity *id;
  size_t path_size;
  unsigned int path_length;
 
  path_length = GCPP_get_length (path);
  path_size = sizeof(struct GNUNET_PeerIdentity) * path_length;
  if (sizeof(*resp) + path_size > UINT16_MAX)
  {
    /* try just giving the relevant path */
    path_length = GNUNET_MIN ((UINT16_MAX - sizeof(*resp)) / sizeof(struct
                                                                    GNUNET_PeerIdentity),
                              off);
    path_size = sizeof(struct GNUNET_PeerIdentity) * path_length;
  }
  if (sizeof(*resp) + path_size > UINT16_MAX)
  {
    LOG (GNUNET_ERROR_TYPE_WARNING,
         "Path of %u entries is too long for info message\n",
         path_length);
    return GNUNET_YES;
  }
  env = GNUNET_MQ_msg_extra (resp,
                             path_size,
                             GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PATH);
  id = (struct GNUNET_PeerIdentity *) &resp[1];
 
  /* Don't copy first peer.  First peer is always the local one.  Last
   * peer is always the destination (leave as 0, EOL).
   */
  for (unsigned int i = 0; i < path_length; i++)
    id[i] = *GCP_get_id (GCPP_get_peer_at_offset (path,
                                                  i));
  resp->off = htonl (off);
  GNUNET_MQ_send (mq,
                  env);
  return GNUNET_YES;
}
 
 
static void
handle_show_path (void *cls,
                  const struct GNUNET_CADET_RequestPathInfoMessage *msg)
{
  struct CadetClient *c = cls;
  struct CadetPeer *p;
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_MessageHeader *resp;
 
  p = GCP_get (&msg->peer,
               GNUNET_NO);
  if (NULL != p)
    GCP_iterate_indirect_paths (p,
                                &path_info_iterator,
                                c->mq);
  env = GNUNET_MQ_msg (resp,
                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PATH_END);
  GNUNET_MQ_send (c->mq,
                  env);
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static int
get_all_tunnels_iterator (void *cls,
                          const struct GNUNET_PeerIdentity *peer,
                          void *value)
{
  struct CadetClient *c = cls;
  struct CadetPeer *p = value;
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_CADET_LocalInfoTunnel *msg;
  struct CadetTunnel *t;
 
  t = GCP_get_tunnel (p,
                      GNUNET_NO);
  if (NULL == t)
    return GNUNET_YES;
  env = GNUNET_MQ_msg (msg,
                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_TUNNELS);
  msg->destination = *peer;
  msg->channels = htonl (GCT_count_channels (t));
  msg->connections = htonl (GCT_count_any_connections (t));
  msg->cstate = htons (0);
  msg->estate = htons (GCT_get_estate (t));
  GNUNET_MQ_send (c->mq,
                  env);
  return GNUNET_YES;
}
 
 
static void
handle_info_tunnels (void *cls,
                     const struct GNUNET_MessageHeader *message)
{
  struct CadetClient *c = cls;
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_MessageHeader *reply;
 
  GCP_iterate_all (&get_all_tunnels_iterator,
                   c);
  env = GNUNET_MQ_msg (reply,
                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_TUNNELS_END);
  GNUNET_MQ_send (c->mq,
                  env);
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static void
handle_drop_message (void *cls,
                     const struct GNUNET_CADET_RequestDropCadetMessage *message)
{
  struct CadetClient *c = cls;
  struct CadetChannel *ch;
 
  ch = lookup_channel (c,
                       message->ccn);
 
  if (NULL != ch)
    GCCH_assign_type_to_drop (ch, message);
 
  GNUNET_SERVICE_client_continue (c->client);
}
 
 
static void *
client_connect_cb (void *cls,
                   struct GNUNET_SERVICE_Client *client,
                   struct GNUNET_MQ_Handle *mq)
{
  struct CadetClient *c;
 
  c = GNUNET_new (struct CadetClient);
  c->client = client;
  c->mq = mq;
  c->id = next_client_id++; /* overflow not important: just for debug */
  c->channels
    = GNUNET_CONTAINER_multihashmap32_create (32);
  GNUNET_CONTAINER_DLL_insert (clients_head,
                               clients_tail,
                               c);
  GNUNET_STATISTICS_update (stats,
                            "# clients",
                            +1,
                            GNUNET_NO);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "%s connected\n",
       GSC_2s (c));
  return c;
}
 
 
void
GSC_handle_remote_channel_destroy (struct CadetClient *c,
                                   struct GNUNET_CADET_ClientChannelNumber ccn,
                                   struct CadetChannel *ch)
{
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_CADET_LocalChannelDestroyMessage *tdm;
 
  env = GNUNET_MQ_msg (tdm,
                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_DESTROY);
  tdm->ccn = ccn;
  GSC_send_to_client (c,
                      env);
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap32_remove (c->channels,
                                                         ntohl (
                                                           ccn.channel_of_client),
                                                         ch));
}
 
 
void
GSC_drop_loose_channel (const struct GNUNET_HashCode *h_port,
                        struct CadetChannel *ch)
{
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (loose_channels,
                                                       h_port,
                                                       ch));
}
 
 
static int
channel_destroy_iterator (void *cls,
                          uint32_t key,
                          void *value)
{
  struct CadetClient *c = cls;
  struct GNUNET_CADET_ClientChannelNumber ccn;
  struct CadetChannel *ch = value;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Destroying %s, due to %s disconnecting.\n",
       GCCH_2s (ch),
       GSC_2s (c));
  ccn.channel_of_client = htonl (key);
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap32_remove (c->channels,
                                                         key,
                                                         ch));
  GCCH_channel_local_destroy (ch,
                              c,
                              ccn);
  return GNUNET_OK;
}
 
 
static int
client_release_ports (void *cls,
                      const struct GNUNET_HashCode *port,
                      void *value)
{
  struct CadetClient *c = cls;
  struct OpenPort *op = value;
 
  GNUNET_assert (c == op->c);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Closing port %s due to %s disconnect.\n",
       GNUNET_h2s (port),
       GSC_2s (c));
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (open_ports,
                                                       &op->h_port,
                                                       op));
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (c->ports,
                                                       port,
                                                       op));
  GNUNET_free (op);
  return GNUNET_OK;
}
 
 
static void
client_disconnect_cb (void *cls,
                      struct GNUNET_SERVICE_Client *client,
                      void *internal_cls)
{
  struct CadetClient *c = internal_cls;
 
  GNUNET_assert (c->client == client);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "%s is disconnecting.\n",
       GSC_2s (c));
  if (NULL != c->channels)
  {
    GNUNET_CONTAINER_multihashmap32_iterate (c->channels,
                                             &channel_destroy_iterator,
                                             c);
    GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap32_size (c->channels));
    GNUNET_CONTAINER_multihashmap32_destroy (c->channels);
  }
  if (NULL != c->ports)
  {
    GNUNET_CONTAINER_multihashmap_iterate (c->ports,
                                           &client_release_ports,
                                           c);
    GNUNET_CONTAINER_multihashmap_destroy (c->ports);
  }
  GNUNET_CONTAINER_DLL_remove (clients_head,
                               clients_tail,
                               c);
  GNUNET_STATISTICS_update (stats,
                            "# clients",
                            -1,
                            GNUNET_NO);
  GNUNET_free (c);
  if ((NULL == clients_head) &&
      (GNUNET_YES == shutting_down))
    shutdown_rest ();
}
 
 
static void
run (void *cls,
     const struct GNUNET_CONFIGURATION_Handle *c,
     struct GNUNET_SERVICE_Handle *service)
{
  cfg = c;
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_number (c,
                                             "CADET",
                                             "RATCHET_MESSAGES",
                                             &ratchet_messages))
  {
    GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
                               "CADET",
                               "RATCHET_MESSAGES",
                               "needs to be a number");
    ratchet_messages = 64;
  }
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_time (c,
                                           "CADET",
                                           "RATCHET_TIME",
                                           &ratchet_time))
  {
    GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
                               "CADET",
                               "RATCHET_TIME",
                               "need delay value");
    ratchet_time = GNUNET_TIME_UNIT_HOURS;
  }
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_time (c,
                                           "CADET",
                                           "REFRESH_CONNECTION_TIME",
                                           &keepalive_period))
  {
    GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
                               "CADET",
                               "REFRESH_CONNECTION_TIME",
                               "need delay value");
    keepalive_period = GNUNET_TIME_UNIT_MINUTES;
  }
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_number (c,
                                             "CADET",
                                             "DROP_PERCENT",
                                             &drop_percent))
  {
    drop_percent = 0;
  }
  else
  {
    LOG (GNUNET_ERROR_TYPE_WARNING, "**************************************\n");
    LOG (GNUNET_ERROR_TYPE_WARNING, "Cadet is running with DROP enabled.\n");
    LOG (GNUNET_ERROR_TYPE_WARNING, "This is NOT a good idea!\n");
    LOG (GNUNET_ERROR_TYPE_WARNING, "Remove DROP_PERCENT from config file.\n");
    LOG (GNUNET_ERROR_TYPE_WARNING, "**************************************\n");
  }
  my_private_key = GNUNET_CRYPTO_eddsa_key_create_from_configuration (c);
  if (NULL == my_private_key)
  {
    GNUNET_break (0);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  GNUNET_CRYPTO_eddsa_key_get_public (my_private_key,
                                      &my_full_id.public_key);
  stats = GNUNET_STATISTICS_create ("cadet",
                                    c);
  GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
                                 NULL);
  transport = GNUNET_TRANSPORT_application_init (c);
  /* FIXME: optimize code to allow GNUNET_YES here! */
  open_ports = GNUNET_CONTAINER_multihashmap_create (16,
                                                     GNUNET_NO);
  loose_channels = GNUNET_CONTAINER_multihashmap_create (16,
                                                         GNUNET_NO);
  peers = GNUNET_CONTAINER_multipeermap_create (16,
                                                GNUNET_YES);
  connections = GNUNET_CONTAINER_multishortmap_create (256,
                                                       GNUNET_YES);
  GCH_init (c);
  GCD_init (c);
  GCO_init (c);
  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
              "CADET started for peer %s\n",
              GNUNET_i2s (&my_full_id));
}
 
 
GNUNET_SERVICE_MAIN
(GNUNET_OS_project_data_gnunet(),
 "cadet",
  GNUNET_SERVICE_OPTION_NONE,
  &run,
  &client_connect_cb,
  &client_disconnect_cb,
  NULL,
  GNUNET_MQ_hd_fixed_size (port_open,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_PORT_OPEN,
                           struct GNUNET_CADET_PortMessage,
                           NULL),
  GNUNET_MQ_hd_fixed_size (port_close,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_PORT_CLOSE,
                           struct GNUNET_CADET_PortMessage,
                           NULL),
  GNUNET_MQ_hd_fixed_size (channel_create,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_CREATE,
                           struct GNUNET_CADET_LocalChannelCreateMessage,
                           NULL),
  GNUNET_MQ_hd_fixed_size (channel_destroy,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_CHANNEL_DESTROY,
                           struct GNUNET_CADET_LocalChannelDestroyMessage,
                           NULL),
  GNUNET_MQ_hd_var_size (local_data,
                         GNUNET_MESSAGE_TYPE_CADET_LOCAL_DATA,
                         struct GNUNET_CADET_LocalData,
                         NULL),
  GNUNET_MQ_hd_fixed_size (local_ack,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_ACK,
                           struct GNUNET_CADET_LocalAck,
                           NULL),
  GNUNET_MQ_hd_fixed_size (get_peers,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_REQUEST_INFO_PEERS,
                           struct GNUNET_MessageHeader,
                           NULL),
  GNUNET_MQ_hd_fixed_size (show_path,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_REQUEST_INFO_PATH,
                           struct GNUNET_CADET_RequestPathInfoMessage,
                           NULL),
  GNUNET_MQ_hd_fixed_size (info_tunnels,
                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_REQUEST_INFO_TUNNELS,
                           struct GNUNET_MessageHeader,
                           NULL),
  GNUNET_MQ_hd_fixed_size (drop_message,
                           GNUNET_MESSAGE_TYPE_CADET_DROP_CADET_MESSAGE,
                           struct GNUNET_CADET_RequestDropCadetMessage,
                           NULL),
  GNUNET_MQ_handler_end ());
 
/* end of gnunet-service-cadet-new.c */