path: root/src/include/gnunet_ats_service.h

/*
     This file is part of GNUnet.
     (C) 2010,2011 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 include/gnunet_ats_service.h
 * @brief automatic transport selection and outbound bandwidth determination
 * @author Christian Grothoff
 * @author Matthias Wachs
 */
#ifndef GNUNET_ATS_SERVICE_H
#define GNUNET_ATS_SERVICE_H

#include "gnunet_constants.h"
#include "gnunet_util_lib.h"
#include "gnunet_hello_lib.h"

/**
 * Number of network types supported by ATS
 */
#define GNUNET_ATS_NetworkTypeCount 5

/**
 * ATS network types as array initializer
 */
#define GNUNET_ATS_NetworkType {GNUNET_ATS_NET_UNSPECIFIED, GNUNET_ATS_NET_LOOPBACK, GNUNET_ATS_NET_LAN, GNUNET_ATS_NET_WAN, GNUNET_ATS_NET_WLAN}

/**
 * ATS network types as string array initializer
 */
#define GNUNET_ATS_NetworkTypeString {"UNSPECIFIED", "LOOPBACK", "LAN", "WAN", "WLAN"}

enum GNUNET_ATS_Network_Type
{
  GNUNET_ATS_NET_UNSPECIFIED = 0,
  GNUNET_ATS_NET_LOOPBACK = 1,
  GNUNET_ATS_NET_LAN = 2,
  GNUNET_ATS_NET_WAN = 3,
  GNUNET_ATS_NET_WLAN = 4,
};

/**
 * Default bandwidth assigned to a network : 64 KB/s
 */
#define GNUNET_ATS_DefaultBandwidth 65536

/**
 * Maximum bandwidth assigned to a network : 4095 MB/s
 */
#define GNUNET_ATS_MaxBandwidth UINT32_MAX

/**
 * Number of property types supported by ATS
 */
#define GNUNET_ATS_PropertyCount 9

/**
 * ATS properties types as string array initializer
 */
#define GNUNET_ATS_PropertyStrings {"Terminator", "Utilization up", "Utilization down", "Network type", "Delay", "Distance", "Cost WAN", "Cost LAN", "Cost WLAN"}

/**
 * Enum defining all known property types for ATS Enum values are used
 * in the GNUNET_ATS_Information struct as
 * (key,value)-pairs.
 *
 * Cost are always stored in uint32_t, so all units used to define costs
 * have to be normalized to fit in uint32_t [0 .. 4.294.967.295]
 */
enum GNUNET_ATS_Property
{

  /**
   * End of the array.
   * @deprecated
   */
  GNUNET_ATS_ARRAY_TERMINATOR = 0,

  /**
   * Actual traffic on this connection from the other peer to this peer.
   *
   * Unit: [bytes/second]
   */
  GNUNET_ATS_UTILIZATION_UP,

  /**
   * Actual traffic on this connection from this peer to the other peer.
   *
   * Unit: [bytes/second]
   */
  GNUNET_ATS_UTILIZATION_DOWN,

  /**
   * Is this address located in WAN, LAN or a loopback address
   * Value is element of GNUNET_ATS_Network_Type
   */
  GNUNET_ATS_NETWORK_TYPE,

  /**
   * Delay
   * Time between when the time packet is sent and the packet arrives
   *
   * Unit: [ms]
   *
   * Examples:
   *
   * LAN   :    1
   * WLAN  :    2
   * Dialup:  500
   */
  GNUNET_ATS_QUALITY_NET_DELAY,

  /**
   * Distance on network layer (required for distance-vector routing).
   *
   * Unit: [DV-hops]
   */
  GNUNET_ATS_QUALITY_NET_DISTANCE,

  /**
   * Network overhead on WAN (Wide-Area Network)
   *
   * How many bytes are sent on the WAN when 1 kilobyte (1024 bytes)
   * of application data is transmitted?
   * A factor used with connect cost, bandwidth cost and energy cost
   * to describe the overhead produced by the transport protocol
   *
   * Unit: [bytes/kb]
   *
   * Interpretation: less is better
   *
   * Examples:
   *
   * TCP/IPv4 over Ethernet: 1024 + 38 + 20 + 20 = 1102 [bytes/kb]
   * TCP/IPv6 over Ethernet: 1024 + 38 + 20 + 40 = 1122 [bytes/kb]
   * UDP/IPv4 over Ethernet: 1024 + 38 + 20 + 8  = 1090 [bytes/kb]
   * UDP/IPv6 over Ethernet: 1024 + 38 + 40 + 8  = 1110 [bytes/kb]
   */
  GNUNET_ATS_COST_WAN,

  /**
   * Network overhead on LAN (Local-Area Network)
   *
   * How many bytes are sent on the LAN when 1 kilobyte (1024 bytes)
   * of application data is transmitted?
   * A factor used with connect cost, bandwidth cost and energy cost
   * to describe the overhead produced by the transport protocol
   *
   * Unit: [bytes/kb]
   *
   * Interpretation: less is better
   *
   * Examples:
   *
   * TCP/IPv4 over Ethernet: 1024 + 38 + 20 + 20 = 1102 [bytes/kb]
   * TCP/IPv6 over Ethernet: 1024 + 38 + 20 + 40 = 1122 [bytes/kb]
   * UDP/IPv4 over Ethernet: 1024 + 38 + 20 + 8  = 1090 [bytes/kb]
   * UDP/IPv6 over Ethernet: 1024 + 38 + 40 + 8  = 1110 [bytes/kb]
   */
  GNUNET_ATS_COST_LAN,

  /**
   * Network overhead on WLAN (Wireless Local Area Network)
   *
   * How many bytes are sent on the LAN when 1 kilobyte (1024 bytes)
   * of application data is transmitted?
   * A factor used with connect cost, bandwidth cost and energy cost
   * to describe the overhead produced by the transport protocol
   *
   * Unit: [bytes/kb]
   *
   * Interpretation: less is better
   *
   * Examples:
   *
   * TCP/IPv4 over Ethernet: 1024 + 38 + 20 + 20 = 1102 [bytes/kb]
   * TCP/IPv6 over Ethernet: 1024 + 38 + 20 + 40 = 1122 [bytes/kb]
   * UDP/IPv4 over Ethernet: 1024 + 38 + 20 + 8  = 1090 [bytes/kb]
   * UDP/IPv6 over Ethernet: 1024 + 38 + 40 + 8  = 1110 [bytes/kb]
   */
  GNUNET_ATS_COST_WLAN
      /* Cost related values */
      /* =================== */
  /**
   * Volume based cost in financial units to transmit data
   *
   * Note: This value is not bound to a specific currency or unit and only
   * used locally.
   * "cent" just refers the smallest amount of money in the respective
   * currency.
   *
   * Unit: [cent/MB]
   *
   * Interpretation: less is better
   *
   * Examples:
   * LAN:  0 [cent/MB]
   * 2G : 10 [cent/MB]
   */
      // GNUNET_ATS_COST_FINANCIAL_PER_VOLUME = 1,
  /**
   * Time based cost in financial units to transmit data
   *
   * Note: This value is not bound to a specific currency or unit and only
   * used locally.
   * "cent" just refers the smallest amount of money in the respective
   * currency.
   *
   * Unit: [cent/h]
   *
   * Interpretation: less is better
   *
   * Examples:
   * LAN   :  0 [cent/h]
   * Dialup: 10 [cent/h]
   */
      // GNUNET_ATS_COST_FINANCIAL_PER_TIME = 2,
  /**
   * Computational costs
   *
   * Effort of preparing data to be sent with this transport
   * Includes encoding, encryption and conversion of data
   * Partial values can be summed up: c_sum = c_enc + c_enc + c_conv
   * Resulting values depend on local system properties, e.g. CPU
   *
   * Unit: [ms/GB]
   *
   * Interpretation: less is better
   *
   * Examples:
   *
   * HTTPS with AES CBC-256: 	7,382
   * HTTPS with AES CBC-128: 	5,279
   * HTTPS with RC4-1024: 	2,652
   */
      // GNUNET_ATS_COST_COMPUTATIONAL = 3,
  /**
   * Energy consumption
   *
   * Energy consumption using this transport when sending with a certain
   * power at a certain bitrate. This is only an approximation based on:
   * Energy consumption E = P / D
   *
   * with:
   * Power P in Watt (J/s)
   * Datarate D in MBit/s
   *
   * Conversion between power P and dBm used by WLAN in radiotap's dBm TX power:
   *
   * Lp(dbm) = 10 log10 (P/ 1mW)
   *
   * => P = 1 mW  * 10^(Lp(dbm)/10)
   *
   * Unit: [mJ/MB]
   *
   * Interpretation: less is better
   *
   * Examples:
   *
   * LAN:       0
   * WLAN:      89 (600 mW @ 802.11g /w 54 MBit/s)
   * Bluetooth: 267 (100 mW @ BT2.0 EDR /w 3 MBit/s)
   */
      // GNUNET_ATS_COST_ENERGY_CONSUMPTION = 4,
  /**
   * Connect cost
   * How many bytes are transmitted to initiate a new connection using
   * this transport?
   *
   * Unit: [bytes]
   *
   * Interpretation: less is better
   *
   * Examples:
   *
   * UDP (No connection)      :
   *     0 bytes
   * TCP (TCP 3-Way handshake):
   *   220 bytes Ethernet,  172 bytes TCP/IP,  122 bytes TCP
   * HTTP (TCP + Header)      :
   *   477 bytes Ethernet,  429 bytes TCP/IP,  374 bytes TCP,  278 bytes HTTP
   * HTTPS  HTTP+TLS Handshake:
   *  2129 bytes Ethernet, 1975 bytes TCP/IP, 1755 bytes TCP, 1403 bytes HTTPS
   *
   * */
      // GNUNET_ATS_COST_CONNECT = 5,
  /**
   * Bandwidth cost
   *
   * How many bandwidth is available to consume?
   * Used to calculate which impact sending data with this transport has
   *
   * Unit: [kB/s]
   *
   * Interpretation: more is better
   *
   * Examples:
   * LAN:     12,800  (100 MBit/s)
   * WLAN:    6,912   (54 MBit/s)
   * Dial-up: 8       (64 Kbit/s)
   *
   */
      // GNUNET_ATS_COST_BANDWITH_AVAILABLE = 6,
  /**
   *  Network overhead
   *
   * How many bytes are sent over the wire when 1 kilobyte (1024 bytes)
   * of application data is transmitted?
   * A factor used with connect cost, bandwidth cost and energy cost
   * to describe the overhead produced by the transport protocol
   *
   * Unit: [bytes/kb]
   *
   * Interpretation: less is better
   *
   * Examples:
   *
   * TCP/IPv4 over Ethernet: 1024 + 38 + 20 + 20 = 1102 [bytes/kb]
   * TCP/IPv6 over Ethernet: 1024 + 38 + 20 + 40 = 1122 [bytes/kb]
   * UDP/IPv4 over Ethernet: 1024 + 38 + 20 + 8  = 1090 [bytes/kb]
   * UDP/IPv6 over Ethernet: 1024 + 38 + 40 + 8  = 1110 [bytes/kb]
   */
      // GNUNET_ATS_COST_NETWORK_OVERHEAD = 7,
      /* Quality related values */
      /* ====================== */
      /* Physical layer quality properties */
  /**
   * Signal strength on physical layer
   *
   * Unit: [dBm]
   */
      // GNUNET_ATS_QUALITY_PHY_SIGNAL_STRENGTH = 1025,
  /**
   * Collision rate on physical layer
   *
   * Unit: [B/s]
   */
      // GNUNET_ATS_QUALITY_PHY_COLLISION_RATE = 1026,
  /**
   * Error rate on physical layer
   *
   * Unit: [B/s]
   */
      // GNUNET_ATS_QUALITY_PHY_ERROR_RATE = 1027,
  /**
   * Jitter
   * Time variations of the delay
   * 1st derivative of a delay function
   *
   * Unit: [ms]
   */
      // GNUNET_ATS_QUALITY_NET_JITTER = 1029,
  /**
   * Error rate on network layer
   *
   * Unit: [B/s]
   *
   * Examples:
   *
   * LAN       :    0
   * WLAN      :  400
   * Bluetooth :  100
   * Note: This numbers are just assumptions as an example, not
   * measured or somehow determined
   */
      // GNUNET_ATS_QUALITY_NET_ERRORRATE = 1030,
  /**
   * Drop rate on network layer
   * Bytes actively dismissed by a network component during transmission
   * Reasons for dropped data can be full queues, congestion, quota violations...
   *
   * Unit: [B/s]
   *
   * Examples:
   *
   * LAN       :    0
   * WLAN      :  400
   * Bluetooth :  100
   * Note: This numbers are just assumptions as an example, not
   * measured or somehow determined
   */
      // GNUNET_ATS_QUALITY_NET_DROPRATE = 1031,
  /**
   * Loss rate on network layer
   * Bytes lost during transmission
   * Reasons can be collisions, ...
   *
   * Unit: [B/s]
   *
   * Examples:
   *
   * LAN       :    0
   * WLAN      :   40
   * Bluetooth :   10
   * Note: This numbers are just assumptions as an example, not measured
   * or somehow determined
   */
      // GNUNET_ATS_QUALITY_NET_LOSSRATE = 1032,
  /**
   * Throughput on network layer
   *
   * Unit: [kB/s]
   *
   * Examples:
   *
   * LAN   : 3400
   * WLAN  : 1200
   * Dialup: 	  4
   *
   */
      // GNUNET_ATS_QUALITY_NET_THROUGHPUT = 1033,
      /* Availability related values */
      /* =========================== */
  /**
   * Is a peer reachable?
   */
      // GNUNET_ATS_AVAILABILITY_REACHABLE = 2048,
  /**
   * Is there a connection established to a peer using this transport
   */
      // GNUNET_ATS_AVAILABILITY_CONNECTED = 2049
};

/**
 * Number of ATS quality properties
 */
#define GNUNET_ATS_QualityPropertiesCount 2

/**
 * ATS quality properties as array initializer
 */
#define GNUNET_ATS_QualityProperties {GNUNET_ATS_QUALITY_NET_DELAY, GNUNET_ATS_QUALITY_NET_DISTANCE}

/**
 * ATS quality properties as string array initializer
 */
#define GNUNET_ATS_QualityPropertiesString {"Delay", "Distance"}


GNUNET_NETWORK_STRUCT_BEGIN

/**
 * struct used to communicate the transport's properties like cost and
 * quality of service as well as high-level constraints on resource
 * consumption.
 *
 *                             +---+
 *  +-----------+ Constraints  |   |  Plugin properties +---------+
 *  | Highlevel |------------> |ATS| <------------------|Transport|
 *  | Component | ATS struct   |   |    ATS struct      | Plugin  |
 *  +-----------+              |   |                    +---------+
 *                             +---+
 *
 * This structure will be used by transport plugins to communicate
 * costs to ATS or by higher level components to tell ATS their
 * constraints.  Always a pair of (GNUNET_ATS_Property,
 * uint32_t value).  Value is always uint32_t, so all units used to
 * define costs have to be normalized to fit uint32_t.
 */
struct GNUNET_ATS_Information
{
  /**
   * ATS property type, in network byte order.
   */
  uint32_t type GNUNET_PACKED;

  /**
   * ATS property value, in network byte order.
   */
  uint32_t value GNUNET_PACKED;
};
GNUNET_NETWORK_STRUCT_END


/* ******************************** Scheduling API ***************************** */

/**
 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
 */
struct GNUNET_ATS_SchedulingHandle;

/**
 * Handle for address suggestion requests
 *
 */
struct GNUNET_ATS_SuggestHandle;



/**
 * Opaque session handle, defined by plugins.  Contents not known to ATS.
 */
struct Session;



/**
 * Signature of a function called by ATS with the current bandwidth
 * and address preferences as determined by ATS.
 *
 * @param cls closure
 * @param address suggested address (including peer identity of the peer)
 * @param session session to use
 * @param bandwidth_out assigned outbound bandwidth for the connection
 * @param bandwidth_in assigned inbound bandwidth for the connection
 * @param ats performance data for the address (as far as known)
 * @param ats_count number of performance records in 'ats'
 */
typedef void (*GNUNET_ATS_AddressSuggestionCallback) (void *cls,
                                                      const struct
                                                      GNUNET_HELLO_Address *
                                                      address,
                                                      struct Session * session,
                                                      struct
                                                      GNUNET_BANDWIDTH_Value32NBO
                                                      bandwidth_out,
                                                      struct
                                                      GNUNET_BANDWIDTH_Value32NBO
                                                      bandwidth_in,
                                                      const struct
                                                      GNUNET_ATS_Information *
                                                      ats, uint32_t ats_count);


/**
 * Initialize the ATS subsystem.
 *
 * @param cfg configuration to use
 * @param suggest_cb notification to call whenever the suggestation changed
 * @param suggest_cb_cls closure for 'suggest_cb'
 * @return ats context
 */
struct GNUNET_ATS_SchedulingHandle *
GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
                            GNUNET_ATS_AddressSuggestionCallback suggest_cb,
                            void *suggest_cb_cls);


/**
 * Client is done with ATS scheduling, release resources.
 *
 * @param sh handle to release
 */
void
GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh);


/**
 * We would like to reset the address suggestion block time for this
 * peer
 *
 * @param sh handle
 * @param peer identity of the peer we want to reset
 */
void
GNUNET_ATS_reset_backoff (struct GNUNET_ATS_SchedulingHandle *sh,
                          const struct GNUNET_PeerIdentity *peer);

/**
 * We would like to establish a new connection with a peer.  ATS
 * should suggest a good address to begin with.
 *
 * @param sh handle
 * @param peer identity of the peer we need an address for
 * @return suggestion handle
 */
struct GNUNET_ATS_SuggestHandle *
GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
                            const struct GNUNET_PeerIdentity *peer);


/**
 * We want to cancel ATS suggesting addresses for a peer.
 *
 * @param sh handle
 * @param peer identity of the peer
 */
void
GNUNET_ATS_suggest_address_cancel (struct GNUNET_ATS_SchedulingHandle *sh,
                                   const struct GNUNET_PeerIdentity *peer);


/**
 * Convert a GNUNET_ATS_NetworkType to a string
 *
 * @param net the network type
 * @return a string or NULL if invalid
 */
const char *
GNUNET_ATS_print_network_type (uint32_t net);

/**
 * Returns where the address is located: LAN or WAN or ...
 * @param sh the GNUNET_ATS_SchedulingHandle handle
 * @param addr address
 * @param addrlen address length
 * @return location as GNUNET_ATS_Information
 */
struct GNUNET_ATS_Information
GNUNET_ATS_address_get_type (struct GNUNET_ATS_SchedulingHandle *sh,
                             const struct sockaddr * addr,
                             socklen_t addrlen);

/**
 * We have a new address ATS should know. Addresses have to be added with this
 * function before they can be: updated, set in use and destroyed
 *
 * @param sh handle
 * @param address the address
 * @param session session handle (if available)
 * @param ats performance data for the address
 * @param ats_count number of performance records in 'ats'
 */
int
GNUNET_ATS_address_add (struct GNUNET_ATS_SchedulingHandle *sh,
                        const struct GNUNET_HELLO_Address *address,
                        struct Session *session,
                        const struct GNUNET_ATS_Information *ats,
                        uint32_t ats_count);


/**
 * We have updated performance statistics for a given address.  Note
 * that this function can be called for addresses that are currently
 * in use as well as addresses that are valid but not actively in use.
 * Furthermore, the peer may not even be connected to us right now (in
 * which case the call may be ignored or the information may be stored
 * for later use).  Update bandwidth assignments.
 *
 * @param sh handle
 * @param address updated address
 * @param session session handle (if available)
 * @param ats performance data for the address
 * @param ats_count number of performance records in 'ats'
 */
void
GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
                           const struct GNUNET_HELLO_Address *address,
                           struct Session *session,
                           const struct GNUNET_ATS_Information *ats,
                           uint32_t ats_count);


/**
 * An address is now in use or not used any more.
 *
 * @param sh handle
 * @param address the address
 * @param session session handle
 * @param in_use GNUNET_YES if this address is now used, GNUNET_NO
 * if address is not used any more
 */
void
GNUNET_ATS_address_in_use (struct GNUNET_ATS_SchedulingHandle *sh,
                           const struct GNUNET_HELLO_Address *address,
                           struct Session *session, int in_use);


/**
 * A session got destroyed, stop including it as a valid address.
 *
 * @param sh handle
 * @param address the address
 * @param session session handle that is no longer valid (if available)
 */
void
GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
                              const struct GNUNET_HELLO_Address *address,
                              struct Session *session);


/* ******************************** Performance API ***************************** */

/**
 * ATS Handle to obtain and/or modify performance information.
 */
struct GNUNET_ATS_PerformanceHandle;


/**
 * Signature of a function that is called with QoS information about a peer.
 *
 * @param cls closure
 * @param address the address
 * @param bandwidth_out assigned outbound bandwidth for the connection
 * @param bandwidth_in assigned inbound bandwidth for the connection
 * @param ats performance data for the address (as far as known)
 * @param ats_count number of performance records in 'ats'
 */
typedef void (*GNUNET_ATS_PeerInformationCallback) (void *cls,
                                                    const struct
                                                    GNUNET_HELLO_Address *
                                                    address,
                                                    struct
                                                    GNUNET_BANDWIDTH_Value32NBO
                                                    bandwidth_out,
                                                    struct
                                                    GNUNET_BANDWIDTH_Value32NBO
                                                    bandwidth_in,
                                                    const struct
                                                    GNUNET_ATS_Information *
                                                    ats, uint32_t ats_count);

/**
 * Handle for an address listing operation
 */
struct GNUNET_ATS_AddressListHandle;


/**
 * Get handle to access performance API of the ATS subsystem.
 *
 * @param cfg configuration to use
 * @param infocb function to call on performance changes, can be NULL
 * @param infocb_cls closure for infocb
 * @return ats performance context
 */
struct GNUNET_ATS_PerformanceHandle *
GNUNET_ATS_performance_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
                             GNUNET_ATS_PeerInformationCallback infocb,
                             void *infocb_cls);


/**
 * Get information about addresses known to the ATS subsystem.
 *
 * @param handle the performance handle to use
 * @param peer peer idm can be NULL for all peers
 * @param all GNUNET_YES to get information about all addresses or GNUNET_NO to
 *        get only address currently used
 * @param infocb callback to call with the addresses,
 *        will callback with address == NULL when done
 * @param infocb_cls closure for infocb
 * @return ats performance context
 */
struct GNUNET_ATS_AddressListHandle *
GNUNET_ATS_performance_list_addresses (struct GNUNET_ATS_PerformanceHandle *handle,
                                       const struct GNUNET_PeerIdentity *peer,
                                       int all,
                                       GNUNET_ATS_PeerInformationCallback infocb,
                                       void *infocb_cls);


/**
 * Cancel a pending address listing operation
 *
 * @param handle the GNUNET_ATS_AddressListHandle handle to cancel
 */
void
GNUNET_ATS_performance_list_addresses_cancel (struct GNUNET_ATS_AddressListHandle *handle);


/**
 * Client is done using the ATS performance subsystem, release resources.
 *
 * @param ph handle
 */
void
GNUNET_ATS_performance_done (struct GNUNET_ATS_PerformanceHandle *ph);


/**
 * Function called with reservation result.
 *
 * @param cls closure
 * @param peer identifies the peer
 * @param amount set to the amount that was actually reserved or unreserved;
 *               either the full requested amount or zero (no partial reservations)
 * @param res_delay if the reservation could not be satisfied (amount was 0), how
 *        long should the client wait until re-trying?
 */
typedef void (*GNUNET_ATS_ReservationCallback) (void *cls,
                                                const struct GNUNET_PeerIdentity
                                                * peer, int32_t amount,
                                                struct GNUNET_TIME_Relative
                                                res_delay);



/**
 * Context that can be used to cancel a peer information request.
 */
struct GNUNET_ATS_ReservationContext;


/**
 * Reserve inbound bandwidth from the given peer.  ATS will look at
 * the current amount of traffic we receive from the peer and ensure
 * that the peer could add 'amount' of data to its stream.
 *
 * @param ph performance handle
 * @param peer identifies the peer
 * @param amount reserve N bytes for receiving, negative
 *                amounts can be used to undo a (recent) reservation;
 * @param rcb function to call with the resulting reservation information
 * @param rcb_cls closure for info
 * @return NULL on error
 * @deprecated will be replaced soon
 */
struct GNUNET_ATS_ReservationContext *
GNUNET_ATS_reserve_bandwidth (struct GNUNET_ATS_PerformanceHandle *ph,
                              const struct GNUNET_PeerIdentity *peer,
                              int32_t amount,
                              GNUNET_ATS_ReservationCallback rcb,
                              void *rcb_cls);


/**
 * Cancel request for reserving bandwidth.
 *
 * @param rc context returned by the original GNUNET_ATS_reserve_bandwidth call
 */
void
GNUNET_ATS_reserve_bandwidth_cancel (struct GNUNET_ATS_ReservationContext *rc);


/**
 * Number of preference types supported by ATS
 */
#define GNUNET_ATS_PreferenceCount 3

/**
 * ATS preference types as array initializer
 */
#define GNUNET_ATS_PreferenceType {GNUNET_ATS_PREFERENCE_END, GNUNET_ATS_PREFERENCE_BANDWIDTH, GNUNET_ATS_PREFERENCE_LATENCY}

/**
 * ATS preference types as string array initializer
 */
#define GNUNET_ATS_PreferenceTypeString {"END", "BANDWIDTH", "LATENCY"}


/**
 * Enum defining all known preference categories.
 */
enum GNUNET_ATS_PreferenceKind
{

  /**
   * End of preference list.
   */
  GNUNET_ATS_PREFERENCE_END = 0,

  /**
   * Change the peer's bandwidth value (value per byte of bandwidth in
   * the goal function) to the given amount.  The argument is followed
   * by a double value giving the desired value (can be negative).
   * Preference changes are forgotten if peers disconnect.
   */
  GNUNET_ATS_PREFERENCE_BANDWIDTH,

  /**
   * Change the peer's latency value to the given amount.  The
   * argument is followed by a double value giving the desired value
   * (can be negative).  The absolute score in the goal function is
   * the inverse of the latency in ms (minimum: 1 ms) multiplied by
   * the latency preferences.
   */
  GNUNET_ATS_PREFERENCE_LATENCY
};

/**
 * Convert a GNUNET_ATS_PreferenceType to a string
 *
 * @param type the preference type
 * @return a string or NULL if invalid
 */
const char *
GNUNET_ATS_print_preference_type (uint32_t type);

/**
 * Change preferences for the given peer. Preference changes are forgotten if peers
 * disconnect.
 *
 * @param ph performance handle
 * @param peer identifies the peer
 * @param ... 0-terminated specification of the desired changes
 */
void
GNUNET_ATS_change_preference (struct GNUNET_ATS_PerformanceHandle *ph,
                              const struct GNUNET_PeerIdentity *peer, ...);



#endif
/* end of file gnunet-service-transport_ats.h */