path: root/src/ats/gnunet-service-ats_addresses.c

/*
     This file is part of GNUnet.
     (C) 2011 Christian Grothoff (and other contributing authors)

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, 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
     General Public License for more details.

     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.
*/

/**
 * @file ats/gnunet-service-ats_addresses.c
 * @brief ats service address management
 * @author Matthias Wachs
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_ats_service.h"
#include "gnunet-service-ats.h"
#include "gnunet-service-ats_addresses.h"
#include "gnunet-service-ats_performance.h"
#include "gnunet-service-ats_scheduling.h"
#include "gnunet-service-ats_reservations.h"
#if HAVE_LIBGLPK
#include "gnunet-service-ats_addresses_mlp.h"
#endif
#include "gnunet-service-ats_addresses_simplistic.h"

/**
 * ATS address management
 *
 * Adding addresses:
 *
 * - If you add a new address without a session, a new address will be added
 * - If you add this address again now with a session a, the existing address
 *   will be updated with this session
 * - If you add this address again now with a session b, a new address object
 *   with this session will be added

 * Destroying addresses:
 *
 * - If you destroy an address without a session, the address itself and all
 *   address instances with an session will be removed
 * - If you destroy an address with a session, the session for this address
 *   will be removed
 *
 * Conclusion
 * Addresses without a session will be updated with a new session and if the
 * the session is destroyed the session is removed and address itself still
 * exists for suggestion
 *
 */


/**
 * Available ressource assignment modes
 */
enum ATS_Mode
{
  /*
   * Simplistic mode:
   *
   * Assign each peer an equal amount of bandwidth (bw)
   *
   * bw_per_peer = bw_total / #active addresses
   */
  MODE_SIMPLISTIC,

  /*
   * MLP mode:
   *
   * Solve ressource assignment as an optimization problem
   * Uses an mixed integer programming solver
   */
  MODE_MLP
};

/**
 * Pending Address suggestion requests
 */
struct GAS_Addresses_Suggestion_Requests
{
  /**
   * Next in DLL
   */
  struct GAS_Addresses_Suggestion_Requests *next;

  /**
   * Previous in DLL
   */
  struct GAS_Addresses_Suggestion_Requests *prev;

  /**
   * Peer ID
   */
  struct GNUNET_PeerIdentity id;
};

/**
 * Handle for ATS address component
 */
struct GAS_Addresses_Handle
{
  /**
   *
   */
  struct GNUNET_STATISTICS_Handle *stat;

  /**
   * A multihashmap to store all addresses
   */
  struct GNUNET_CONTAINER_MultiHashMap *addresses;

  /**
   * Configure WAN quota in
   */
  unsigned long long wan_quota_in;

  /**
   * Configure WAN quota out
   */
  unsigned long long wan_quota_out;

  /**
   * Is ATS addresses running
   */
  int running;

  /**
   * Configured ATS solver
   */
  int ats_mode;

  /**
   *  Solver handle
   */
  void *solver;

  /**
   * Address suggestion requests DLL head
   */
  struct GAS_Addresses_Suggestion_Requests *r_head;

  /**
   * Address suggestion requests DLL tail
   */
  struct GAS_Addresses_Suggestion_Requests *r_tail;

  /* Solver functions */

  /**
   * Initialize solver
   */
  GAS_solver_init s_init;

  /**
   * Add an address to the solver
   */
  GAS_solver_address_add s_add;

  /**
   * Update address in solver
   */
  GAS_solver_address_update s_update;

  /**
   * Get address from solver
   */
  GAS_solver_get_preferred_address s_get;

  /**
   * Delete address in solver
   */
  GAS_solver_address_delete s_del;

  /**
   * Change preference for quality in solver
   */
  GAS_solver_address_change_preference s_pref;

  /**
   * Shutdown solver
   */
  GAS_solver_done s_done;
};


static unsigned int
assemble_ats_information (const struct ATS_Address *aa,  struct GNUNET_ATS_Information **dest)
{
  unsigned int ats_count = GNUNET_ATS_PropertyCount - 1;
  struct GNUNET_ATS_Information *ats = GNUNET_malloc (ats_count * sizeof (struct GNUNET_ATS_Information));
  (*dest) = ats;

  ats[0].type = ntohl(GNUNET_ATS_UTILIZATION_UP);
  ats[0].value = aa->atsp_utilization_out.value__;
  ats[1].type = ntohl(GNUNET_ATS_UTILIZATION_DOWN);
  ats[1].value = aa->atsp_utilization_in.value__;
  ats[2].type = ntohl(GNUNET_ATS_NETWORK_TYPE);
  ats[2].value = ntohl(aa->atsp_network_type);
  ats[3].type = ntohl(GNUNET_ATS_QUALITY_NET_DELAY);
  ats[3].value = ntohl(aa->atsp_latency.rel_value);
  ats[4].type = ntohl(GNUNET_ATS_QUALITY_NET_DISTANCE);
  ats[4].value = ntohl(aa->atsp_distance);
  ats[5].type = ntohl(GNUNET_ATS_COST_WAN);
  ats[5].value = ntohl (aa->atsp_cost_wan);
  ats[6].type = ntohl(GNUNET_ATS_COST_LAN);
  ats[6].value = ntohl (aa->atsp_cost_lan);
  ats[7].type = ntohl(GNUNET_ATS_COST_WLAN);
  ats[7].value = ntohl (aa->atsp_cost_wlan);
  return ats_count;
}

static unsigned int
disassemble_ats_information (const struct GNUNET_ATS_Information *src,
                             uint32_t ats_count,
                             struct ATS_Address *dest)
{
  int i;
  int res = 0;
  for (i = 0; i < ats_count; i++)
    switch (ntohl (src[i].type))
    {
    case GNUNET_ATS_UTILIZATION_UP:
      dest->atsp_utilization_out.value__ = src[i].value;
      res ++;
      break;
    case GNUNET_ATS_UTILIZATION_DOWN:
      dest->atsp_utilization_in.value__ = src[i].value;
      res ++;
      break;
    case GNUNET_ATS_QUALITY_NET_DELAY:
      dest->atsp_latency.rel_value = ntohl (src[i].value);
      res ++;
      break;
    case GNUNET_ATS_QUALITY_NET_DISTANCE:
      dest->atsp_distance = ntohl (src[i].value);
      res ++;
      break;
    case GNUNET_ATS_COST_WAN:
      dest->atsp_cost_wan = ntohl (src[i].value);
      res ++;
      break;
    case GNUNET_ATS_COST_LAN:
      dest->atsp_cost_lan = ntohl (src[i].value);
      res ++;
      break;
    case GNUNET_ATS_COST_WLAN:
      dest->atsp_cost_wlan = ntohl (src[i].value);
      res ++;
      break;
    case GNUNET_ATS_NETWORK_TYPE:
      dest->atsp_network_type = ntohl (src[i].value);
      res ++;
      break;
    case GNUNET_ATS_ARRAY_TERMINATOR:
      break;
    default:
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "Received unsupported ATS type %u\n", ntohl (src[i].type));
      GNUNET_break (0);
      break;
    }
  return res;
}

/**
 * Free the given address
 * @param addr address to destroy
 */
static void
free_address (struct ATS_Address *addr)
{
  GNUNET_free (addr->plugin);
  GNUNET_free (addr);
}

/**
 * Create a ATS_address with the given information
 * @param peer peer
 * @param plugin_name plugin
 * @param plugin_addr address
 * @param plugin_addr_len address length
 * @param session_id session
 * @return the ATS_Address
 */
static struct ATS_Address *
create_address (const struct GNUNET_PeerIdentity *peer,
                const char *plugin_name,
                const void *plugin_addr, size_t plugin_addr_len,
                uint32_t session_id)
{
  struct ATS_Address *aa = NULL;

  aa = GNUNET_malloc (sizeof (struct ATS_Address) + plugin_addr_len);
  aa->peer = *peer;
  aa->addr_len = plugin_addr_len;
  aa->addr = &aa[1];
  memcpy (&aa[1], plugin_addr, plugin_addr_len);
  aa->plugin = GNUNET_strdup (plugin_name);
  aa->session_id = session_id;
  aa->active = GNUNET_NO;
  aa->used = GNUNET_NO;
  aa->solver_information = NULL;
  aa->assigned_bw_in = GNUNET_BANDWIDTH_value_init(0);
  aa->assigned_bw_out = GNUNET_BANDWIDTH_value_init(0);
  return aa;
}


/**
 * Destroy the given address.
 *
 * @param handle the address handle
 * @param addr address to destroy
 * @return GNUNET_YES if bandwidth allocations should be recalcualted
 */
static int
destroy_address (struct GAS_Addresses_Handle *handle, struct ATS_Address *addr)
{
  int ret;

  ret = GNUNET_NO;
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove (handle->addresses,
                                                       &addr->peer.hashPubKey,
                                                       addr));
  free_address (addr);
  return ret;
}


struct CompareAddressContext
{
  const struct ATS_Address *search;

  /* exact_address != NULL if address and session is equal */
  struct ATS_Address *exact_address;
  /* exact_address != NULL if address and session is 0 */
  struct ATS_Address *base_address;
};


static int
compare_address_it (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct CompareAddressContext *cac = cls;
  struct ATS_Address *aa = value;

  /* Find an matching exact address:
   *
   * Compare by:
   * aa->addr_len == cac->search->addr_len
   * aa->plugin == cac->search->plugin
   * aa->addr == cac->search->addr
   * aa->session == cac->search->session
   *
   * return as exact address
   */
  if ((aa->addr_len == cac->search->addr_len) && (0 == strcmp (aa->plugin, cac->search->plugin)))
  {
      if ((0 == memcmp (aa->addr, cac->search->addr, aa->addr_len)) && (aa->session_id == cac->search->session_id))
        cac->exact_address = aa;
  }

  /* Find an matching base address:
   *
   * Properties:
   *
   * aa->session_id == 0
   *
   * Compare by:
   * aa->addr_len == cac->search->addr_len
   * aa->plugin == cac->search->plugin
   * aa->addr == cac->search->addr
   *
   * return as base address
   */
  if ((aa->addr_len == cac->search->addr_len) && (0 == strcmp (aa->plugin, cac->search->plugin)))
  {
      if ((0 == memcmp (aa->addr, cac->search->addr, aa->addr_len)) && (aa->session_id == 0))
        cac->base_address = aa;
  }

  /* Find an matching exact address based on session:
   *
   * Properties:
   *
   * cac->search->addr_len == 0
   *
   * Compare by:
   * aa->plugin == cac->search->plugin
   * aa->session_id == cac->search->session_id
   *
   * return as exact address
   */
  if (0 == cac->search->addr_len)
  {
      if ((0 == strcmp (aa->plugin, cac->search->plugin)) && (aa->session_id == cac->search->session_id))
        cac->exact_address = aa;
  }

  if (cac->exact_address == NULL)
    return GNUNET_YES; /* Continue iteration to find exact address */
  else
    return GNUNET_NO; /* Stop iteration since we have an exact address */
}


/**
 * Find an existing equivalent address record.
 * Compares by peer identity and network address OR by session ID
 * (one of the two must match).
 *
 * @param handle the address handle
 * @param peer peer to lookup addresses for
 * @param addr existing address record
 * @return existing address record, NULL for none
 */
struct ATS_Address *
find_equivalent_address (struct GAS_Addresses_Handle *handle,
                         const struct GNUNET_PeerIdentity *peer,
                         const struct ATS_Address *addr)
{
  struct CompareAddressContext cac;

  cac.exact_address = NULL;
  cac.base_address = NULL;
  cac.search = addr;
  GNUNET_CONTAINER_multihashmap_get_multiple (handle->addresses, &peer->hashPubKey,
                                              &compare_address_it, &cac);

  if (cac.exact_address == NULL)
    return cac.base_address;
  return cac.exact_address;
}


static struct ATS_Address *
lookup_address (struct GAS_Addresses_Handle *handle,
                const struct GNUNET_PeerIdentity *peer,
                const char *plugin_name,
                const void *plugin_addr,
                size_t plugin_addr_len,
                uint32_t session_id,
                const struct GNUNET_ATS_Information *atsi,
                uint32_t atsi_count)
{
  struct ATS_Address *aa;
  struct ATS_Address *ea;

  aa = create_address (peer,
                       plugin_name,
                       plugin_addr, plugin_addr_len,
                       session_id);

  /* Get existing address or address with session == 0 */
  ea = find_equivalent_address (handle, peer, aa);
  free_address (aa);
  if (ea == NULL)
  {
    return NULL;
  }
  else if (ea->session_id != session_id)
  {
    return NULL;
  }
  return ea;
}


void
GAS_addresses_add (struct GAS_Addresses_Handle *handle,
                   const struct GNUNET_PeerIdentity *peer,
                   const char *plugin_name, const void *plugin_addr,
                   size_t plugin_addr_len, uint32_t session_id,
                   const struct GNUNET_ATS_Information *atsi,
                   uint32_t atsi_count)
{
  struct ATS_Address *aa;
  struct ATS_Address *ea;
  unsigned int ats_res;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received `%s' for peer `%s'\n",
              "ADDRESS ADD",
              GNUNET_i2s (peer));

  if (GNUNET_NO == handle->running)
    return;

  GNUNET_assert (NULL != handle->addresses);

  aa = create_address (peer, plugin_name, plugin_addr, plugin_addr_len,
                       session_id);
  if (atsi_count != (ats_res = disassemble_ats_information(atsi, atsi_count, aa)))
  {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "While adding address: had %u ATS elements to add, could only add %u\n",
                atsi_count, ats_res);
  }

  /* Get existing address or address with session == 0 */
  ea = find_equivalent_address (handle, peer, aa);
  if (ea == NULL)
  {
    /* We have a new address */
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_CONTAINER_multihashmap_put (handle->addresses,
                                                      &peer->hashPubKey, aa,
                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Added new address for peer `%s' session id %u, %p\n",
                GNUNET_i2s (peer), session_id, aa);
    /* Tell solver about new address */
    handle->s_add (handle->solver, handle->addresses, aa);
    return;
  }
  GNUNET_free (aa->plugin);
  GNUNET_free (aa);

  if (ea->session_id != 0)
  {
      /* This address with the same session is already existing
       * Should not happen */
      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Added already existing address for peer `%s' `%s' %p with new session %u\n",
                GNUNET_i2s (peer), plugin_name, session_id);
      GNUNET_break (0);
      return;
  }

  /* We have an address without an session, update this address */

  /* Notify solver about update with atsi information and session */
  handle->s_update (handle->solver, handle->addresses, ea, session_id, ea->used, atsi, atsi_count);

  /* Do the update */
  ea->session_id = session_id;
  if (atsi_count != (ats_res = disassemble_ats_information(atsi, atsi_count, ea)))
  {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "While updating address: had %u ATS elements to add, could only add %u\n",
                  atsi_count, ats_res);
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
           "Updated existing address for peer `%s' %p with new session %u\n",
           GNUNET_i2s (peer), ea, session_id);
}


void
GAS_addresses_update (struct GAS_Addresses_Handle *handle,
                      const struct GNUNET_PeerIdentity *peer,
                      const char *plugin_name, const void *plugin_addr,
                      size_t plugin_addr_len, uint32_t session_id,
                      const struct GNUNET_ATS_Information *atsi,
                      uint32_t atsi_count)
{
  struct ATS_Address *aa;
  uint32_t ats_res;

  if (GNUNET_NO == handle->running)
    return;

  GNUNET_assert (NULL != handle->addresses);

  /* Get existing address */
  aa = lookup_address (handle, peer, plugin_name, plugin_addr, plugin_addr_len,
                       session_id, atsi, atsi_count);
  if (aa == NULL)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Tried to update unknown address for peer `%s' `%s' session id %u\n",
                GNUNET_i2s (peer), plugin_name, session_id);
    GNUNET_break (0);
    return;
  }

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Received `%s' for peer `%s' address \n",
                "ADDRESS UPDATE",
                GNUNET_i2s (peer), aa);

  /* Tell solver about update */
  handle->s_update (handle->solver, handle->addresses, aa, session_id, aa->used, atsi, atsi_count);

  /* Update address */
  if (atsi_count != (ats_res = disassemble_ats_information (atsi, atsi_count, aa)))
  {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "While adding address: had %u ATS elements to add, could only add %u\n",
                atsi_count, ats_res);
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
            "Updated %u ATS elements for address %p\n",
            ats_res, aa);
}


struct DestroyContext
{
  struct ATS_Address *aa;

  struct GAS_Addresses_Handle *handle;

  /**
   * GNUNET_NO  : full address
   * GNUNET_YES : just session
   */
  int result;
};


/**
 * Delete an address
 *
 * If session != 0, just the session is deleted, the address itself still exists
 * If session == 0, remove full address
 * If session == 0 and addrlen == 0, destroy inbound address
 *
 * @param cls unused
 * @param key unused
 * @param value the 'struct ATS_Address'
 * @return GNUNET_OK (continue to iterate)
 */
static int
destroy_by_session_id (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct DestroyContext *dc = cls;
  struct GAS_Addresses_Handle *handle = dc->handle;
  const struct ATS_Address *des = dc->aa;
  struct ATS_Address *aa = value;

  GNUNET_assert (0 == memcmp (&aa->peer, &des->peer,
                              sizeof (struct GNUNET_PeerIdentity)));


  if (des->session_id == 0)
  {
    /* Session == 0, remove full address  */
    if ((0 == strcmp (des->plugin, aa->plugin)) &&
        (aa->addr_len == des->addr_len) &&
        (0 == memcmp (des->addr, aa->addr, aa->addr_len)))
    {

      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Deleting full address for peer `%s' session %u %p\n",
                  GNUNET_i2s (&aa->peer), aa->session_id, aa);

      /* Notify solver about deletion */
      handle->s_del (handle->solver, handle->addresses, aa, GNUNET_NO);
      destroy_address (handle, aa);
      dc->result = GNUNET_NO;
      return GNUNET_OK; /* Continue iteration */
    }
  }
  else
  {
    /* Session != 0, just remove session */
    if (aa->session_id != des->session_id)
      return GNUNET_OK; /* irrelevant */

    if ((aa->session_id != 0) &&
        (0 != strcmp (des->plugin, aa->plugin)))
    {
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "Different plugins during removal: `%s' vs `%s' \n",
                    des->plugin, aa->plugin);
        GNUNET_break (0);
        return GNUNET_OK;
    }

    if (aa->addr_len == 0)
    {
        /* Inbound connection died, delete full address */
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "Deleting inbound address for peer `%s': `%s' session %u\n",
                    GNUNET_i2s (&aa->peer), aa->plugin, aa->session_id);

        /* Notify solver about deletion */
        handle->s_del (handle->solver, handle->addresses, aa, GNUNET_NO);
        destroy_address (handle, aa);
        dc->result = GNUNET_NO;
        return GNUNET_OK; /* Continue iteration */
    }
    else
    {
        /* Session died */
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "Deleting session for peer `%s': `%s' %u\n",
                    GNUNET_i2s (&aa->peer), aa->plugin, aa->session_id);
        /* Notify solver to delete session */
        handle->s_del (handle->solver, handle->addresses, aa, GNUNET_YES);
        aa->session_id = 0;
        return GNUNET_OK;
    }
  }
  return GNUNET_OK;
}

void
GAS_addresses_destroy (struct GAS_Addresses_Handle *handle,
                       const struct GNUNET_PeerIdentity *peer,
                       const char *plugin_name, const void *plugin_addr,
                       size_t plugin_addr_len, uint32_t session_id)
{
  struct ATS_Address *ea;
  struct DestroyContext dc;

  if (GNUNET_NO == handle->running)
    return;

  /* Get existing address */
  ea = lookup_address (handle, peer, plugin_name, plugin_addr, plugin_addr_len,
                       session_id, NULL, 0);

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received `%s' for peer `%s' address %p session %u\n",
              "ADDRESS DESTROY",
              GNUNET_i2s (peer), ea, session_id);

  if (ea == NULL)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Tried to destroy unknown address for peer `%s' `%s' session id %u\n",
                GNUNET_i2s (peer), plugin_name, session_id);
    return;
  }

  GNUNET_break (0 < strlen (plugin_name));
  dc.handle = handle;
  dc.aa = create_address (peer, plugin_name, plugin_addr, plugin_addr_len, session_id);

  GNUNET_CONTAINER_multihashmap_get_multiple (handle->addresses, &peer->hashPubKey,
                                              &destroy_by_session_id, &dc);
  free_address (dc.aa);
}


int
GAS_addresses_in_use (struct GAS_Addresses_Handle *handle,
                      const struct GNUNET_PeerIdentity *peer,
                      const char *plugin_name, const void *plugin_addr,
                      size_t plugin_addr_len, uint32_t session_id, int in_use)
{
  struct ATS_Address *ea;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Received `%s' for peer `%s'\n",
                "ADDRESS IN USE",
                GNUNET_i2s (peer));

  if (GNUNET_NO == handle->running)
    return GNUNET_SYSERR;

  ea = lookup_address (handle, peer, plugin_name,
                        plugin_addr, plugin_addr_len,
                        session_id, NULL, 0);
  if (NULL == ea)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Trying to set unknown address `%s', %s %u %s \n",
                GNUNET_i2s (peer),
                plugin_name, session_id,
                (GNUNET_NO == in_use) ? "NO" : "YES");
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if (ea->used == in_use)
  {
    GNUNET_break (0);
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Address in use called multiple times for peer `%s': %s -> %s \n",
                GNUNET_i2s (peer),
                (GNUNET_NO == ea->used) ? "NO" : "YES",
                (GNUNET_NO == in_use) ? "NO" : "YES");
    return GNUNET_SYSERR;
  }

  /* Tell solver about update */
  handle->s_update (handle->solver, handle->addresses, ea, session_id, in_use, NULL, 0);
  ea->used = in_use;

  return GNUNET_OK;
}


/**
 * Cancel address suggestions for a peer
 *
 * @param handle the address handle
 * @param peer the respective peer
 */
void
GAS_addresses_request_address_cancel (struct GAS_Addresses_Handle *handle,
                                      const struct GNUNET_PeerIdentity *peer)
{
  struct GAS_Addresses_Suggestion_Requests *cur = handle->r_head;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received request: `%s' for peer %s\n", "request_address_cancel", GNUNET_i2s (peer));

  while (NULL != cur)
  {
      if (0 == memcmp (peer, &cur->id, sizeof (cur->id)))
        break; /* found */
      cur = cur->next;
  }

  if (NULL == cur)
  {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "No address requests pending for peer `%s', cannot remove!\n", GNUNET_i2s (peer));
      return;
  }
  GAS_addresses_handle_backoff_reset (handle, peer);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Removed request pending for peer `%s\n", GNUNET_i2s (peer));
  GNUNET_CONTAINER_DLL_remove (handle->r_head, handle->r_tail, cur);
  GNUNET_free (cur);
}


/**
 * Add an address suggestions for a peer
 *
 * @param handle the address handle
 * @param peer the respective peer
 */
void
GAS_addresses_request_address (struct GAS_Addresses_Handle *handle,
                               const struct GNUNET_PeerIdentity *peer)
{
  struct GAS_Addresses_Suggestion_Requests *cur = handle->r_head;
  struct ATS_Address *aa;
  struct GNUNET_ATS_Information *ats;
  unsigned int ats_count;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received `%s' for peer `%s'\n",
              "REQUEST ADDRESS",
              GNUNET_i2s (peer));

  if (GNUNET_NO == handle->running)
    return;
  while (NULL != cur)
  {
      if (0 == memcmp (peer, &cur->id, sizeof (cur->id)))
        break; /* already suggesting */
      cur = cur->next;
  }
  if (NULL == cur)
  {
      cur = GNUNET_malloc (sizeof (struct GAS_Addresses_Suggestion_Requests));
      cur->id = (*peer);
      GNUNET_CONTAINER_DLL_insert (handle->r_head, handle->r_tail, cur);
  }

  /* Get prefered address from solver */
  aa = (struct ATS_Address *) handle->s_get (handle->solver, handle->addresses, peer);
  if (NULL == aa)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Cannot suggest address for peer `%s'\n", GNUNET_i2s (peer));
    return;
  }

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Suggesting address %p for peer `%s'\n", aa, GNUNET_i2s (peer));

  ats_count = assemble_ats_information (aa, &ats);
  GAS_scheduling_transmit_address_suggestion (peer,
                                              aa->plugin,
                                              aa->addr, aa->addr_len,
                                              aa->session_id,
                                              ats, ats_count,
                                              aa->assigned_bw_out,
                                              aa->assigned_bw_in);

  aa->block_interval = GNUNET_TIME_relative_add (aa->block_interval, ATS_BLOCKING_DELTA);
  aa->blocked_until = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(), aa->block_interval);

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
       "Address %p ready for suggestion, block interval now %llu \n",
       aa, aa->block_interval);

  GNUNET_free (ats);
}


static int
reset_address_it (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct ATS_Address *aa = value;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Resetting interval for peer `%s' address %p from %llu to 0\n",
              GNUNET_i2s (&aa->peer), aa, aa->block_interval);

  aa->blocked_until = GNUNET_TIME_UNIT_ZERO_ABS;
  aa->block_interval = GNUNET_TIME_UNIT_ZERO;
  return GNUNET_OK;
}


void
GAS_addresses_handle_backoff_reset (struct GAS_Addresses_Handle *handle,
                                    const struct GNUNET_PeerIdentity *peer)
{
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received `%s' for peer `%s'\n",
              "RESET BACKOFF",
              GNUNET_i2s (peer));

  GNUNET_break (GNUNET_SYSERR != GNUNET_CONTAINER_multihashmap_get_multiple (handle->addresses,
                                              &peer->hashPubKey,
                                              &reset_address_it,
                                              NULL));
}


void
GAS_addresses_change_preference (struct GAS_Addresses_Handle *handle,
                                 void *client,
                                 const struct GNUNET_PeerIdentity *peer,
                                 enum GNUNET_ATS_PreferenceKind kind,
                                 float score)
{
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received `%s' for peer `%s' for client %p\n",
              "CHANGE PREFERENCE",
              GNUNET_i2s (peer), client);

  if (GNUNET_NO == handle->running)
    return;

  if (GNUNET_NO == GNUNET_CONTAINER_multihashmap_contains (handle->addresses,
                                                          &peer->hashPubKey))
  {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "Received `%s' for unknown peer `%s' from client %p\n",
                  "CHANGE PREFERENCE",
                  GNUNET_i2s (peer), client);
      return;
  }

  /* Tell solver about update */
  handle->s_pref (handle->solver, client, peer, kind, score);
}

static unsigned int
load_quotas (const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned long long *out_dest, unsigned long long *in_dest, int dest_length)
{
  char *network_str[GNUNET_ATS_NetworkTypeCount] = GNUNET_ATS_NetworkTypeString;
  char * entry_in = NULL;
  char * entry_out = NULL;
  char * quota_out_str;
  char * quota_in_str;
  int c;
  int res;

  for (c = 0; (c < GNUNET_ATS_NetworkTypeCount) && (c < dest_length); c++)
  {
    in_dest[c] = 0;
    out_dest[c] = 0;
    GNUNET_asprintf (&entry_out, "%s_QUOTA_OUT", network_str[c]);
    GNUNET_asprintf (&entry_in, "%s_QUOTA_IN", network_str[c]);

    /* quota out */
    if (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "ats", entry_out, &quota_out_str))
    {
      res = GNUNET_NO;
      if (0 == strcmp(quota_out_str, BIG_M_STRING))
      {
        out_dest[c] = GNUNET_ATS_MaxBandwidth;
        res = GNUNET_YES;
      }
      if ((GNUNET_NO == res) && (GNUNET_OK == GNUNET_STRINGS_fancy_size_to_bytes (quota_out_str, &out_dest[c])))
        res = GNUNET_YES;
      if ((GNUNET_NO == res) && (GNUNET_OK == GNUNET_CONFIGURATION_get_value_number (cfg, "ats", entry_out,  &out_dest[c])))
         res = GNUNET_YES;

      if (GNUNET_NO == res)
      {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not load quota for network `%s':  `%s', assigning default bandwidth %llu\n"),
              network_str[c], quota_out_str, GNUNET_ATS_DefaultBandwidth);
          out_dest[c] = GNUNET_ATS_DefaultBandwidth;
      }
      else
      {
          GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Outbound quota configure for network `%s' is %llu\n"),
              network_str[c], out_dest[c]);
      }
      GNUNET_free (quota_out_str);
    }
    else
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("No outbound quota configured for network `%s', assigning default bandwidth %llu\n"),
          network_str[c], GNUNET_ATS_DefaultBandwidth);
      out_dest[c] = GNUNET_ATS_DefaultBandwidth;
    }

    /* quota in */
    if (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "ats", entry_in, &quota_in_str))
    {
      res = GNUNET_NO;
      if (0 == strcmp(quota_in_str, BIG_M_STRING))
      {
        in_dest[c] = GNUNET_ATS_MaxBandwidth;
        res = GNUNET_YES;
      }
      if ((GNUNET_NO == res) && (GNUNET_OK == GNUNET_STRINGS_fancy_size_to_bytes (quota_in_str, &in_dest[c])))
        res = GNUNET_YES;
      if ((GNUNET_NO == res) && (GNUNET_OK == GNUNET_CONFIGURATION_get_value_number (cfg, "ats", entry_in,  &in_dest[c])))
         res = GNUNET_YES;

      if (GNUNET_NO == res)
      {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not load quota for network `%s':  `%s', assigning default bandwidth %llu\n"),
              network_str[c], quota_in_str, GNUNET_ATS_DefaultBandwidth);
          in_dest[c] = GNUNET_ATS_DefaultBandwidth;
      }
      else
      {
          GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Inbound quota configured for network `%s' is %llu\n"),
              network_str[c], in_dest[c]);
      }
      GNUNET_free (quota_in_str);
    }
    else
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("No outbound quota configure for network `%s', assigning default bandwidth %llu\n"),
          network_str[c], GNUNET_ATS_DefaultBandwidth);
      out_dest[c] = GNUNET_ATS_DefaultBandwidth;
    }
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Loaded quota for network `%s' (in/out): %llu %llu\n", network_str[c], in_dest[c], out_dest[c]);
    GNUNET_free (entry_out);
    GNUNET_free (entry_in);
  }
  return GNUNET_ATS_NetworkTypeCount;
}


static void
bandwidth_changed_cb (void *cls, struct ATS_Address *address)
{
  struct GAS_Addresses_Handle *handle = cls;
  struct GAS_Addresses_Suggestion_Requests *cur;

  GNUNET_assert (handle != NULL);
  GNUNET_assert (address != NULL);

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Bandwidth assignment changed for peer %s \n", GNUNET_i2s(&address->peer));
  struct GNUNET_ATS_Information *ats;
  unsigned int ats_count;

  cur = handle->r_head;
  while (NULL != cur)
  {
      if (0 == memcmp (&address->peer, &cur->id, sizeof (cur->id)))
        break; /* we have an address request pending*/
      cur = cur->next;
  }
  if (NULL == cur)
  {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Nobody is interested in peer `%s' :(\n",GNUNET_i2s (&address->peer));
      return;
  }

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Sending bandwidth update for peer `%s'\n",GNUNET_i2s (&address->peer));

  ats_count = assemble_ats_information (address, &ats);
  GAS_scheduling_transmit_address_suggestion (&address->peer,
                                              address->plugin,
                                              address->addr, address->addr_len,
                                              address->session_id,
                                              ats, ats_count,
                                              address->assigned_bw_out,
                                              address->assigned_bw_in);
  GNUNET_free (ats);
}


/**
 * Initialize address subsystem.
 *
 * @param cfg configuration to use
 * @param stats the statistics handle to use
 */
struct GAS_Addresses_Handle *
GAS_addresses_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
                    const struct GNUNET_STATISTICS_Handle *stats)
{
  struct GAS_Addresses_Handle *ah;
  int quotas[GNUNET_ATS_NetworkTypeCount] = GNUNET_ATS_NetworkType;
  unsigned long long  quotas_in[GNUNET_ATS_NetworkTypeCount];
  unsigned long long  quotas_out[GNUNET_ATS_NetworkTypeCount];
  int quota_count;
  char *mode_str;
  int c;

  ah = GNUNET_malloc (sizeof (struct GAS_Addresses_Handle));
  ah->running = GNUNET_NO;

  ah->stat = (struct GNUNET_STATISTICS_Handle *) stats;
  /* Initialize the addresses database */
  ah->addresses = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_NO);
  GNUNET_assert (NULL != ah->addresses);

  /* Figure out configured solution method */
  if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string (cfg, "ats", "MODE", &mode_str))
  {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "No ressource assignment method configured, using simplistic approch\n");
      ah->ats_mode = MODE_SIMPLISTIC;
  }
  else
  {
      for (c = 0; c < strlen (mode_str); c++)
        mode_str[c] = toupper (mode_str[c]);
      if (0 == strcmp (mode_str, "SIMPLISTIC"))
      {
          ah->ats_mode = MODE_SIMPLISTIC;
      }
      else if (0 == strcmp (mode_str, "MLP"))
      {
          ah->ats_mode = MODE_MLP;
#if !HAVE_LIBGLPK
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Assignment method `%s' configured, but GLPK is not availabe, please install \n", mode_str);
          ah->ats_mode = MODE_SIMPLISTIC;
#endif
      }
      else
      {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Invalid ressource assignment method `%s' configured, using simplistic approch\n", mode_str);
          ah->ats_mode = MODE_SIMPLISTIC;
      }
      GNUNET_free (mode_str);
  }
  /* Start configured solution method */
  switch (ah->ats_mode)
  {
    case MODE_MLP:
      /* Init the MLP solver with default values */
#if HAVE_LIBGLPK
      ah->ats_mode = MODE_MLP;
      ah->s_init = &GAS_mlp_init;
      ah->s_add = &GAS_mlp_address_add;
      ah->s_update = &GAS_mlp_address_update;
      ah->s_get = &GAS_mlp_get_preferred_address;
      ah->s_pref = &GAS_mlp_address_change_preference;
      ah->s_del =  &GAS_mlp_address_delete;
      ah->s_done = &GAS_mlp_done;
#else
      GNUNET_free (ah);
      return NULL;
#endif
      break;
    case MODE_SIMPLISTIC:
      /* Init the simplistic solver with default values */
      ah->ats_mode = MODE_SIMPLISTIC;
      ah->s_init = &GAS_simplistic_init;
      ah->s_add = &GAS_simplistic_address_add;
      ah->s_update = &GAS_simplistic_address_update;
      ah->s_get = &GAS_simplistic_get_preferred_address;
      ah->s_pref = &GAS_simplistic_address_change_preference;
      ah->s_del  = &GAS_simplistic_address_delete;
      ah->s_done = &GAS_simplistic_done;
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "ATS started in %s mode\n", "SIMPLISTIC");
      break;
    default:
      return NULL;
      break;
  }

  GNUNET_assert (NULL != ah->s_init);
  GNUNET_assert (NULL != ah->s_add);
  GNUNET_assert (NULL != ah->s_update);
  GNUNET_assert (NULL != ah->s_get);
  GNUNET_assert (NULL != ah->s_pref);
  GNUNET_assert (NULL != ah->s_del);
  GNUNET_assert (NULL != ah->s_done);

  quota_count = load_quotas(cfg, quotas_in, quotas_out, GNUNET_ATS_NetworkTypeCount);

  ah->solver = ah->s_init (cfg, stats, quotas, quotas_in, quotas_out, quota_count, &bandwidth_changed_cb, ah);
  if (NULL == ah->solver)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to initialize solver!\n");
    GNUNET_free (ah);
    return NULL;
  }

  /* up and running */
  ah->running = GNUNET_YES;
  return ah;
}


/**
 * Free memory of address.
 *
 * @param cls NULL
 * @param key peer identity (unused)
 * @param value the 'struct ATS_Address' to free
 * @return GNUNET_OK (continue to iterate)
 */
static int
free_address_it (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct GAS_Addresses_Handle *handle = cls;
  struct ATS_Address *aa = value;
  handle->s_del (handle->solver, handle->addresses, aa, GNUNET_NO);
  destroy_address (handle, aa);
  return GNUNET_OK;
}


void
GAS_addresses_destroy_all (struct GAS_Addresses_Handle *handle)
{
  if (GNUNET_NO == handle->running)
    return;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received `%s'\n",
              "DESTROY ALL");

  if (handle->addresses != NULL)
    GNUNET_CONTAINER_multihashmap_iterate (handle->addresses, &free_address_it, handle);
}


/**
 * Shutdown address subsystem.
 */
void
GAS_addresses_done (struct GAS_Addresses_Handle *handle)
{
  struct GAS_Addresses_Suggestion_Requests *cur;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Shutting down addresses\n");
  GNUNET_assert (NULL != handle);
  GAS_addresses_destroy_all (handle);
  handle->running = GNUNET_NO;
  GNUNET_CONTAINER_multihashmap_destroy (handle->addresses);
  handle->addresses = NULL;
  while (NULL != (cur = handle->r_head))
  {
      GNUNET_CONTAINER_DLL_remove (handle->r_head, handle->r_tail, cur);
      GNUNET_free (cur);
  }
  handle->s_done (handle->solver);
  GNUNET_free (handle);
  /* Stop configured solution method */

}

struct PeerIteratorContext
{
  GNUNET_ATS_Peer_Iterator it;
  void *it_cls;
  struct GNUNET_CONTAINER_MultiHashMap *peers_returned;
};

static int
peer_it (void *cls,
         const struct GNUNET_HashCode * key,
         void *value)
{
  struct PeerIteratorContext *ip_ctx = cls;
  struct GNUNET_PeerIdentity tmp;

  if (GNUNET_NO == GNUNET_CONTAINER_multihashmap_contains(ip_ctx->peers_returned, key))
  {
      GNUNET_CONTAINER_multihashmap_put(ip_ctx->peers_returned, key, NULL, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
      tmp.hashPubKey = (*key);
      ip_ctx->it (ip_ctx->it_cls, &tmp);
  }

  return GNUNET_OK;
}

/**
 * Return all peers currently known to ATS
 *
 * @param handle the address handle
 * @param p_it the iterator to call for every peer, callbach with id == NULL
 *        when done
 * @param p_it_cls the closure for the iterator
 */
void
GAS_addresses_iterate_peers (struct GAS_Addresses_Handle *handle, GNUNET_ATS_Peer_Iterator p_it, void *p_it_cls)
{
  struct PeerIteratorContext ip_ctx;
  unsigned int size;

  if (NULL == p_it)
      return;
  GNUNET_assert (NULL != handle->addresses);

  size = GNUNET_CONTAINER_multihashmap_size(handle->addresses);
  if (0 != size)
  {
    ip_ctx.it = p_it;
    ip_ctx.it_cls = p_it_cls;
    ip_ctx.peers_returned = GNUNET_CONTAINER_multihashmap_create (size, GNUNET_NO);
    GNUNET_CONTAINER_multihashmap_iterate (handle->addresses, &peer_it, &ip_ctx);
    GNUNET_CONTAINER_multihashmap_destroy (ip_ctx.peers_returned);
  }
  p_it (p_it_cls, NULL);
}

struct PeerInfoIteratorContext
{
  GNUNET_ATS_PeerInfo_Iterator it;
  void *it_cls;
};


static int 
peerinfo_it (void *cls,
	     const struct GNUNET_HashCode * key,
	     void *value)
{
  struct PeerInfoIteratorContext *pi_ctx = cls;
  struct ATS_Address *addr = (struct ATS_Address *)  value;
  struct GNUNET_ATS_Information *ats;
  uint32_t ats_count;

  if (NULL != pi_ctx->it)
  {
    ats_count = assemble_ats_information (addr, &ats);

    pi_ctx->it (pi_ctx->it_cls,
                &addr->peer,
                addr->plugin,
                addr->addr, addr->addr_len,
                addr->active,
                ats, ats_count,
                addr->assigned_bw_out,
                addr->assigned_bw_in);
    GNUNET_free (ats);
  }
  return GNUNET_YES;
}


/**
 * Return all peers currently known to ATS
 *
 * @param handle the address handle
 * @param peer the respective peer
 * @param pi_it the iterator to call for every peer
 * @param pi_it_cls the closure for the iterator
 */
void
GAS_addresses_get_peer_info (struct GAS_Addresses_Handle *handle,
                             const struct GNUNET_PeerIdentity *peer,
                             GNUNET_ATS_PeerInfo_Iterator pi_it,
                             void *pi_it_cls)
{
  struct PeerInfoIteratorContext pi_ctx;
  struct GNUNET_BANDWIDTH_Value32NBO zero_bw;
  GNUNET_assert (NULL != peer);
  GNUNET_assert (NULL != handle->addresses);
  if (NULL == pi_it)
    return; /* does not make sense without callback */

  zero_bw = GNUNET_BANDWIDTH_value_init (0);
  pi_ctx.it = pi_it;
  pi_ctx.it_cls = pi_it_cls;

  GNUNET_CONTAINER_multihashmap_get_multiple (handle->addresses, &peer->hashPubKey, &peerinfo_it, &pi_ctx);

  if (NULL != pi_it)
    pi_it (pi_it_cls, NULL, NULL, NULL, 0, GNUNET_NO, NULL, 0, zero_bw, zero_bw);

}


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