/* SCTP kernel implementation
   * (C) Copyright IBM Corp. 2001, 2004
   * Copyright (c) 1999-2000 Cisco, Inc.
   * Copyright (c) 1999-2001 Motorola, Inc.
   * Copyright (c) 2002 Intel Corp.
   *
   * This file is part of the SCTP kernel implementation
   *
   * This header represents the structures and constants needed to support
   * the SCTP Extension to the Sockets API.
   *
   * This SCTP implementation 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 2, or (at your option)
   * any later version.
   *
   * This SCTP implementation 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 GNU CC; see the file COPYING.  If not, see
   * <http://www.gnu.org/licenses/>.
   *
   * Please send any bug reports or fixes you make to the
   * email address(es):
   *    lksctp developers <linux-sctp@vger.kernel.org>
   *
   * Or submit a bug report through the following website:
   *    http://www.sf.net/projects/lksctp
   *
   * Written or modified by:
   *    La Monte H.P. Yarroll    <piggy@acm.org>
   *    R. Stewart               <randall@sctp.chicago.il.us>
   *    K. Morneau               <kmorneau@cisco.com>
   *    Q. Xie                   <qxie1@email.mot.com>
   *    Karl Knutson             <karl@athena.chicago.il.us>
   *    Jon Grimm                <jgrimm@us.ibm.com>
   *    Daisy Chang              <daisyc@us.ibm.com>
   *    Ryan Layer               <rmlayer@us.ibm.com>
   *    Ardelle Fan              <ardelle.fan@intel.com>
   *    Sridhar Samudrala        <sri@us.ibm.com>
   *    Inaky Perez-Gonzalez     <inaky.gonzalez@intel.com>
   *    Vlad Yasevich            <vladislav.yasevich@hp.com>
   *
   * Any bugs reported given to us we will try to fix... any fixes shared will
   * be incorporated into the next SCTP release.
   */
  
  #ifndef _UAPI_SCTP_H
  #define _UAPI_SCTP_H
  
  #include <linux/types.h>
  #include <linux/socket.h>
  
  typedef __s32 sctp_assoc_t;
  
  /* The following symbols come from the Sockets API Extensions for
   * SCTP <draft-ietf-tsvwg-sctpsocket-07.txt>.
   */
  #define SCTP_RTOINFO	0
  #define SCTP_ASSOCINFO  1
  #define SCTP_INITMSG	2
  #define SCTP_NODELAY	3		/* Get/set nodelay option. */
  #define SCTP_AUTOCLOSE	4
  #define SCTP_SET_PEER_PRIMARY_ADDR 5
  #define SCTP_PRIMARY_ADDR	6
  #define SCTP_ADAPTATION_LAYER	7
  #define SCTP_DISABLE_FRAGMENTS	8
  #define SCTP_PEER_ADDR_PARAMS	9
  #define SCTP_DEFAULT_SEND_PARAM	10
  #define SCTP_EVENTS	11
  #define SCTP_I_WANT_MAPPED_V4_ADDR 12	/* Turn on/off mapped v4 addresses  */
  #define SCTP_MAXSEG	13		/* Get/set maximum fragment. */
  #define SCTP_STATUS	14
  #define SCTP_GET_PEER_ADDR_INFO	15
  #define SCTP_DELAYED_ACK_TIME	16
  #define SCTP_DELAYED_ACK SCTP_DELAYED_ACK_TIME
  #define SCTP_DELAYED_SACK SCTP_DELAYED_ACK_TIME
  #define SCTP_CONTEXT	17
  #define SCTP_FRAGMENT_INTERLEAVE	18
  #define SCTP_PARTIAL_DELIVERY_POINT	19 /* Set/Get partial delivery point */
  #define SCTP_MAX_BURST	20		/* Set/Get max burst */
  #define SCTP_AUTH_CHUNK	21	/* Set only: add a chunk type to authenticate */
  #define SCTP_HMAC_IDENT	22
  #define SCTP_AUTH_KEY	23
  #define SCTP_AUTH_ACTIVE_KEY	24
  #define SCTP_AUTH_DELETE_KEY	25
  #define SCTP_PEER_AUTH_CHUNKS	26	/* Read only */
  #define SCTP_LOCAL_AUTH_CHUNKS	27	/* Read only */
  #define SCTP_GET_ASSOC_NUMBER	28	/* Read only */
  #define SCTP_GET_ASSOC_ID_LIST	29	/* Read only */
  #define SCTP_AUTO_ASCONF       30
  #define SCTP_PEER_ADDR_THLDS	31
  
  /* Internal Socket Options. Some of the sctp library functions are
   * implemented using these socket options.
   */
  #define SCTP_SOCKOPT_BINDX_ADD	100	/* BINDX requests for adding addrs */
  #define SCTP_SOCKOPT_BINDX_REM	101	/* BINDX requests for removing addrs. */
  #define SCTP_SOCKOPT_PEELOFF	102	/* peel off association. */
  /* Options 104-106 are deprecated and removed. Do not use this space */
  #define SCTP_SOCKOPT_CONNECTX_OLD	107	/* CONNECTX old requests. */
  #define SCTP_GET_PEER_ADDRS	108		/* Get all peer address. */
  #define SCTP_GET_LOCAL_ADDRS	109		/* Get all local address. */
  #define SCTP_SOCKOPT_CONNECTX	110		/* CONNECTX requests. */
  #define SCTP_SOCKOPT_CONNECTX3	111	/* CONNECTX requests (updated) */
  #define SCTP_GET_ASSOC_STATS	112	/* Read only */
  
  /*
   * 5.2.1 SCTP Initiation Structure (SCTP_INIT)
   *
   *   This cmsghdr structure provides information for initializing new
   *   SCTP associations with sendmsg().  The SCTP_INITMSG socket option
   *   uses this same data structure.  This structure is not used for
   *   recvmsg().
   *
   *   cmsg_level    cmsg_type      cmsg_data[]
   *   ------------  ------------   ----------------------
   *   IPPROTO_SCTP  SCTP_INIT      struct sctp_initmsg
   *
   */
  struct sctp_initmsg {
  	__u16 sinit_num_ostreams;
  	__u16 sinit_max_instreams;
  	__u16 sinit_max_attempts;
  	__u16 sinit_max_init_timeo;
  };
  
  /*
   * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
   *
   *   This cmsghdr structure specifies SCTP options for sendmsg() and
   *   describes SCTP header information about a received message through
   *   recvmsg().
   *
   *   cmsg_level    cmsg_type      cmsg_data[]
   *   ------------  ------------   ----------------------
   *   IPPROTO_SCTP  SCTP_SNDRCV    struct sctp_sndrcvinfo
   *
   */
  struct sctp_sndrcvinfo {
  	__u16 sinfo_stream;
  	__u16 sinfo_ssn;
  	__u16 sinfo_flags;
  	__u32 sinfo_ppid;
  	__u32 sinfo_context;
  	__u32 sinfo_timetolive;
  	__u32 sinfo_tsn;
  	__u32 sinfo_cumtsn;
  	sctp_assoc_t sinfo_assoc_id;
  };
  
  /*
   *  sinfo_flags: 16 bits (unsigned integer)
   *
   *   This field may contain any of the following flags and is composed of
   *   a bitwise OR of these values.
   */
  
  enum sctp_sinfo_flags {
  	SCTP_UNORDERED = 1,  /* Send/receive message unordered. */
  	SCTP_ADDR_OVER = 2,  /* Override the primary destination. */
  	SCTP_ABORT=4,        /* Send an ABORT message to the peer. */
  	SCTP_SACK_IMMEDIATELY = 8,	/* SACK should be sent without delay */
  	SCTP_EOF=MSG_FIN,    /* Initiate graceful shutdown process. */
  };
  
  typedef union {
  	__u8   			raw;
  	struct sctp_initmsg	init;
  	struct sctp_sndrcvinfo	sndrcv;
  } sctp_cmsg_data_t;
  
  /* These are cmsg_types.  */
  typedef enum sctp_cmsg_type {
  	SCTP_INIT,              /* 5.2.1 SCTP Initiation Structure */
  #define SCTP_INIT	SCTP_INIT
  	SCTP_SNDRCV,            /* 5.2.2 SCTP Header Information Structure */
  #define SCTP_SNDRCV	SCTP_SNDRCV
  } sctp_cmsg_t;
  
  /*
   * 5.3.1.1 SCTP_ASSOC_CHANGE
   *
   *   Communication notifications inform the ULP that an SCTP association
   *   has either begun or ended. The identifier for a new association is
   *   provided by this notificaion. The notification information has the
   *   following format:
   *
   */
  struct sctp_assoc_change {
  	__u16 sac_type;
  	__u16 sac_flags;
  	__u32 sac_length;
  	__u16 sac_state;
  	__u16 sac_error;
  	__u16 sac_outbound_streams;
  	__u16 sac_inbound_streams;
  	sctp_assoc_t sac_assoc_id;
  	__u8 sac_info[0];
  };
  
  /*
   *   sac_state: 32 bits (signed integer)
   *
   *   This field holds one of a number of values that communicate the
   *   event that happened to the association.  They include:
   *
   *   Note:  The following state names deviate from the API draft as
   *   the names clash too easily with other kernel symbols.
   */
  enum sctp_sac_state {
  	SCTP_COMM_UP,
  	SCTP_COMM_LOST,
  	SCTP_RESTART,
  	SCTP_SHUTDOWN_COMP,
  	SCTP_CANT_STR_ASSOC,
  };
  
  /*
   * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
   *
   *   When a destination address on a multi-homed peer encounters a change
   *   an interface details event is sent.  The information has the
   *   following structure:
   */
  struct sctp_paddr_change {
  	__u16 spc_type;
  	__u16 spc_flags;
  	__u32 spc_length;
  	struct sockaddr_storage spc_aaddr;
  	int spc_state;
  	int spc_error;
  	sctp_assoc_t spc_assoc_id;
  } __attribute__((packed, aligned(4)));
  
  /*
   *    spc_state:  32 bits (signed integer)
   *
   *   This field holds one of a number of values that communicate the
   *   event that happened to the address.  They include:
   */
  enum sctp_spc_state {
  	SCTP_ADDR_AVAILABLE,
  	SCTP_ADDR_UNREACHABLE,
  	SCTP_ADDR_REMOVED,
  	SCTP_ADDR_ADDED,
  	SCTP_ADDR_MADE_PRIM,
  	SCTP_ADDR_CONFIRMED,
  };
  
  
  /*
   * 5.3.1.3 SCTP_REMOTE_ERROR
   *
   *   A remote peer may send an Operational Error message to its peer.
   *   This message indicates a variety of error conditions on an
   *   association. The entire error TLV as it appears on the wire is
   *   included in a SCTP_REMOTE_ERROR event.  Please refer to the SCTP
   *   specification [SCTP] and any extensions for a list of possible
   *   error formats. SCTP error TLVs have the format:
   */
  struct sctp_remote_error {
  	__u16 sre_type;
  	__u16 sre_flags;
  	__u32 sre_length;
  	__u16 sre_error;
  	sctp_assoc_t sre_assoc_id;
  	__u8 sre_data[0];
  };
  
  
  /*
   * 5.3.1.4 SCTP_SEND_FAILED
   *
   *   If SCTP cannot deliver a message it may return the message as a
   *   notification.
   */
  struct sctp_send_failed {
  	__u16 ssf_type;
  	__u16 ssf_flags;
  	__u32 ssf_length;
  	__u32 ssf_error;
  	struct sctp_sndrcvinfo ssf_info;
  	sctp_assoc_t ssf_assoc_id;
  	__u8 ssf_data[0];
  };
  
  /*
   *   ssf_flags: 16 bits (unsigned integer)
   *
   *   The flag value will take one of the following values
   *
   *   SCTP_DATA_UNSENT  - Indicates that the data was never put on
   *                       the wire.
   *
   *   SCTP_DATA_SENT    - Indicates that the data was put on the wire.
   *                       Note that this does not necessarily mean that the
   *                       data was (or was not) successfully delivered.
   */
  enum sctp_ssf_flags {
  	SCTP_DATA_UNSENT,
  	SCTP_DATA_SENT,
  };
  
  /*
   * 5.3.1.5 SCTP_SHUTDOWN_EVENT
   *
   *   When a peer sends a SHUTDOWN, SCTP delivers this notification to
   *   inform the application that it should cease sending data.
   */
  struct sctp_shutdown_event {
  	__u16 sse_type;
  	__u16 sse_flags;
  	__u32 sse_length;
  	sctp_assoc_t sse_assoc_id;
  };
  
  /*
   * 5.3.1.6 SCTP_ADAPTATION_INDICATION
   *
   *   When a peer sends a Adaptation Layer Indication parameter , SCTP
   *   delivers this notification to inform the application
   *   that of the peers requested adaptation layer.
   */
  struct sctp_adaptation_event {
  	__u16 sai_type;
  	__u16 sai_flags;
  	__u32 sai_length;
  	__u32 sai_adaptation_ind;
  	sctp_assoc_t sai_assoc_id;
  };
  
  /*
   * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
   *
   *   When a receiver is engaged in a partial delivery of a
   *   message this notification will be used to indicate
   *   various events.
   */
  struct sctp_pdapi_event {
  	__u16 pdapi_type;
  	__u16 pdapi_flags;
  	__u32 pdapi_length;
  	__u32 pdapi_indication;
  	sctp_assoc_t pdapi_assoc_id;
  };
  
  enum { SCTP_PARTIAL_DELIVERY_ABORTED=0, };
  
  /*
   * 5.3.1.8.  SCTP_AUTHENTICATION_EVENT
   *
   *  When a receiver is using authentication this message will provide
   *  notifications regarding new keys being made active as well as errors.
   */
  struct sctp_authkey_event {
  	__u16 auth_type;
  	__u16 auth_flags;
  	__u32 auth_length;
  	__u16 auth_keynumber;
  	__u16 auth_altkeynumber;
  	__u32 auth_indication;
  	sctp_assoc_t auth_assoc_id;
  };
  
  enum { SCTP_AUTH_NEWKEY = 0, };
  
  /*
   * 6.1.9. SCTP_SENDER_DRY_EVENT
   *
   * When the SCTP stack has no more user data to send or retransmit, this
   * notification is given to the user. Also, at the time when a user app
   * subscribes to this event, if there is no data to be sent or
   * retransmit, the stack will immediately send up this notification.
   */
  struct sctp_sender_dry_event {
  	__u16 sender_dry_type;
  	__u16 sender_dry_flags;
  	__u32 sender_dry_length;
  	sctp_assoc_t sender_dry_assoc_id;
  };
  
  /*
   * Described in Section 7.3
   *   Ancillary Data and Notification Interest Options
   */
  struct sctp_event_subscribe {
  	__u8 sctp_data_io_event;
  	__u8 sctp_association_event;
  	__u8 sctp_address_event;
  	__u8 sctp_send_failure_event;
  	__u8 sctp_peer_error_event;
  	__u8 sctp_shutdown_event;
  	__u8 sctp_partial_delivery_event;
  	__u8 sctp_adaptation_layer_event;
  	__u8 sctp_authentication_event;
  	__u8 sctp_sender_dry_event;
  };
  
  /*
   * 5.3.1 SCTP Notification Structure
   *
   *   The notification structure is defined as the union of all
   *   notification types.
   *
   */
  union sctp_notification {
  	struct {
  		__u16 sn_type;             /* Notification type. */
  		__u16 sn_flags;
  		__u32 sn_length;
  	} sn_header;
  	struct sctp_assoc_change sn_assoc_change;
  	struct sctp_paddr_change sn_paddr_change;
  	struct sctp_remote_error sn_remote_error;
  	struct sctp_send_failed sn_send_failed;
  	struct sctp_shutdown_event sn_shutdown_event;
  	struct sctp_adaptation_event sn_adaptation_event;
  	struct sctp_pdapi_event sn_pdapi_event;
  	struct sctp_authkey_event sn_authkey_event;
  	struct sctp_sender_dry_event sn_sender_dry_event;
  };
  
  /* Section 5.3.1
   * All standard values for sn_type flags are greater than 2^15.
   * Values from 2^15 and down are reserved.
   */
  
  enum sctp_sn_type {
  	SCTP_SN_TYPE_BASE     = (1<<15),
  	SCTP_ASSOC_CHANGE,
  #define SCTP_ASSOC_CHANGE		SCTP_ASSOC_CHANGE
  	SCTP_PEER_ADDR_CHANGE,
  #define SCTP_PEER_ADDR_CHANGE		SCTP_PEER_ADDR_CHANGE
  	SCTP_SEND_FAILED,
  #define SCTP_SEND_FAILED		SCTP_SEND_FAILED
  	SCTP_REMOTE_ERROR,
  #define SCTP_REMOTE_ERROR		SCTP_REMOTE_ERROR
  	SCTP_SHUTDOWN_EVENT,
  #define SCTP_SHUTDOWN_EVENT		SCTP_SHUTDOWN_EVENT
  	SCTP_PARTIAL_DELIVERY_EVENT,
  #define SCTP_PARTIAL_DELIVERY_EVENT	SCTP_PARTIAL_DELIVERY_EVENT
  	SCTP_ADAPTATION_INDICATION,
  #define SCTP_ADAPTATION_INDICATION	SCTP_ADAPTATION_INDICATION
  	SCTP_AUTHENTICATION_EVENT,
  #define SCTP_AUTHENTICATION_INDICATION	SCTP_AUTHENTICATION_EVENT
  	SCTP_SENDER_DRY_EVENT,
  #define SCTP_SENDER_DRY_EVENT		SCTP_SENDER_DRY_EVENT
  };
  
  /* Notification error codes used to fill up the error fields in some
   * notifications.
   * SCTP_PEER_ADDRESS_CHAGE 	: spc_error
   * SCTP_ASSOC_CHANGE		: sac_error
   * These names should be potentially included in the draft 04 of the SCTP
   * sockets API specification.
   */
  typedef enum sctp_sn_error {
  	SCTP_FAILED_THRESHOLD,
  	SCTP_RECEIVED_SACK,
  	SCTP_HEARTBEAT_SUCCESS,
  	SCTP_RESPONSE_TO_USER_REQ,
  	SCTP_INTERNAL_ERROR,
  	SCTP_SHUTDOWN_GUARD_EXPIRES,
  	SCTP_PEER_FAULTY,
  } sctp_sn_error_t;
  
  /*
   * 7.1.1 Retransmission Timeout Parameters (SCTP_RTOINFO)
   *
   *   The protocol parameters used to initialize and bound retransmission
   *   timeout (RTO) are tunable.  See [SCTP] for more information on how
   *   these parameters are used in RTO calculation.
   */
  struct sctp_rtoinfo {
  	sctp_assoc_t	srto_assoc_id;
  	__u32		srto_initial;
  	__u32		srto_max;
  	__u32		srto_min;
  };
  
  /*
   * 7.1.2 Association Parameters (SCTP_ASSOCINFO)
   *
   *   This option is used to both examine and set various association and
   *   endpoint parameters.
   */
  struct sctp_assocparams {
  	sctp_assoc_t	sasoc_assoc_id;
  	__u16		sasoc_asocmaxrxt;
  	__u16		sasoc_number_peer_destinations;
  	__u32		sasoc_peer_rwnd;
  	__u32		sasoc_local_rwnd;
  	__u32		sasoc_cookie_life;
  };
  
  /*
   * 7.1.9 Set Peer Primary Address (SCTP_SET_PEER_PRIMARY_ADDR)
   *
   *  Requests that the peer mark the enclosed address as the association
   *  primary. The enclosed address must be one of the association's
   *  locally bound addresses. The following structure is used to make a
   *   set primary request:
   */
  struct sctp_setpeerprim {
  	sctp_assoc_t            sspp_assoc_id;
  	struct sockaddr_storage sspp_addr;
  } __attribute__((packed, aligned(4)));
  
  /*
   * 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
   *
   *  Requests that the local SCTP stack use the enclosed peer address as
   *  the association primary. The enclosed address must be one of the
   *  association peer's addresses. The following structure is used to
   *  make a set peer primary request:
   */
  struct sctp_prim {
  	sctp_assoc_t            ssp_assoc_id;
  	struct sockaddr_storage ssp_addr;
  } __attribute__((packed, aligned(4)));
  
  /* For backward compatibility use, define the old name too */
  #define sctp_setprim	sctp_prim
  
  /*
   * 7.1.11 Set Adaptation Layer Indicator (SCTP_ADAPTATION_LAYER)
   *
   * Requests that the local endpoint set the specified Adaptation Layer
   * Indication parameter for all future INIT and INIT-ACK exchanges.
   */
  struct sctp_setadaptation {
  	__u32	ssb_adaptation_ind;
  };
  
  /*
   * 7.1.13 Peer Address Parameters  (SCTP_PEER_ADDR_PARAMS)
   *
   *   Applications can enable or disable heartbeats for any peer address
   *   of an association, modify an address's heartbeat interval, force a
   *   heartbeat to be sent immediately, and adjust the address's maximum
   *   number of retransmissions sent before an address is considered
   *   unreachable. The following structure is used to access and modify an
   *   address's parameters:
   */
  enum  sctp_spp_flags {
  	SPP_HB_ENABLE = 1<<0,		/*Enable heartbeats*/
  	SPP_HB_DISABLE = 1<<1,		/*Disable heartbeats*/
  	SPP_HB = SPP_HB_ENABLE | SPP_HB_DISABLE,
  	SPP_HB_DEMAND = 1<<2,		/*Send heartbeat immediately*/
  	SPP_PMTUD_ENABLE = 1<<3,	/*Enable PMTU discovery*/
  	SPP_PMTUD_DISABLE = 1<<4,	/*Disable PMTU discovery*/
  	SPP_PMTUD = SPP_PMTUD_ENABLE | SPP_PMTUD_DISABLE,
  	SPP_SACKDELAY_ENABLE = 1<<5,	/*Enable SACK*/
  	SPP_SACKDELAY_DISABLE = 1<<6,	/*Disable SACK*/
  	SPP_SACKDELAY = SPP_SACKDELAY_ENABLE | SPP_SACKDELAY_DISABLE,
  	SPP_HB_TIME_IS_ZERO = 1<<7,	/* Set HB delay to 0 */
  };
  
  struct sctp_paddrparams {
  	sctp_assoc_t		spp_assoc_id;
  	struct sockaddr_storage	spp_address;
  	__u32			spp_hbinterval;
  	__u16			spp_pathmaxrxt;
  	__u32			spp_pathmtu;
  	__u32			spp_sackdelay;
  	__u32			spp_flags;
  } __attribute__((packed, aligned(4)));
  
  /*
   * 7.1.18.  Add a chunk that must be authenticated (SCTP_AUTH_CHUNK)
   *
   * This set option adds a chunk type that the user is requesting to be
   * received only in an authenticated way.  Changes to the list of chunks
   * will only effect future associations on the socket.
   */
  struct sctp_authchunk {
  	__u8		sauth_chunk;
  };
  
  /*
   * 7.1.19.  Get or set the list of supported HMAC Identifiers (SCTP_HMAC_IDENT)
   *
   * This option gets or sets the list of HMAC algorithms that the local
   * endpoint requires the peer to use.
   */
  #ifndef __KERNEL__
  /* This here is only used by user space as is. It might not be a good idea
   * to export/reveal the whole structure with reserved fields etc.
   */
  enum {
  	SCTP_AUTH_HMAC_ID_SHA1 = 1,
  	SCTP_AUTH_HMAC_ID_SHA256 = 3,
  };
  #endif
  
  struct sctp_hmacalgo {
  	__u32		shmac_num_idents;
  	__u16		shmac_idents[];
  };
  
  /* Sadly, user and kernel space have different names for
   * this structure member, so this is to not break anything.
   */
  #define shmac_number_of_idents	shmac_num_idents
  
  /*
   * 7.1.20.  Set a shared key (SCTP_AUTH_KEY)
   *
   * This option will set a shared secret key which is used to build an
   * association shared key.
   */
  struct sctp_authkey {
  	sctp_assoc_t	sca_assoc_id;
  	__u16		sca_keynumber;
  	__u16		sca_keylength;
  	__u8		sca_key[];
  };
  
  /*
   * 7.1.21.  Get or set the active shared key (SCTP_AUTH_ACTIVE_KEY)
   *
   * This option will get or set the active shared key to be used to build
   * the association shared key.
   */
  
  struct sctp_authkeyid {
  	sctp_assoc_t	scact_assoc_id;
  	__u16		scact_keynumber;
  };
  
  
  /*
   * 7.1.23.  Get or set delayed ack timer (SCTP_DELAYED_SACK)
   *
   * This option will effect the way delayed acks are performed.  This
   * option allows you to get or set the delayed ack time, in
   * milliseconds.  It also allows changing the delayed ack frequency.
   * Changing the frequency to 1 disables the delayed sack algorithm.  If
   * the assoc_id is 0, then this sets or gets the endpoints default
   * values.  If the assoc_id field is non-zero, then the set or get
   * effects the specified association for the one to many model (the
   * assoc_id field is ignored by the one to one model).  Note that if
   * sack_delay or sack_freq are 0 when setting this option, then the
   * current values will remain unchanged.
   */
  struct sctp_sack_info {
  	sctp_assoc_t	sack_assoc_id;
  	uint32_t	sack_delay;
  	uint32_t	sack_freq;
  };
  
  struct sctp_assoc_value {
      sctp_assoc_t            assoc_id;
      uint32_t                assoc_value;
  };
  
  /*
   * 7.2.2 Peer Address Information
   *
   *   Applications can retrieve information about a specific peer address
   *   of an association, including its reachability state, congestion
   *   window, and retransmission timer values.  This information is
   *   read-only. The following structure is used to access this
   *   information:
   */
  struct sctp_paddrinfo {
  	sctp_assoc_t		spinfo_assoc_id;
  	struct sockaddr_storage	spinfo_address;
  	__s32			spinfo_state;
  	__u32			spinfo_cwnd;
  	__u32			spinfo_srtt;
  	__u32			spinfo_rto;
  	__u32			spinfo_mtu;
  } __attribute__((packed, aligned(4)));
  
  /* Peer addresses's state. */
  /* UNKNOWN: Peer address passed by the upper layer in sendmsg or connect[x]
   * calls.
   * UNCONFIRMED: Peer address received in INIT/INIT-ACK address parameters.
   *              Not yet confirmed by a heartbeat and not available for data
   *		transfers.
   * ACTIVE : Peer address confirmed, active and available for data transfers.
   * INACTIVE: Peer address inactive and not available for data transfers.
   */
  enum sctp_spinfo_state {
  	SCTP_INACTIVE,
  	SCTP_PF,
  	SCTP_ACTIVE,
  	SCTP_UNCONFIRMED,
  	SCTP_UNKNOWN = 0xffff  /* Value used for transport state unknown */
  };
  
  /*
   * 7.2.1 Association Status (SCTP_STATUS)
   *
   *   Applications can retrieve current status information about an
   *   association, including association state, peer receiver window size,
   *   number of unacked data chunks, and number of data chunks pending
   *   receipt.  This information is read-only.  The following structure is
   *   used to access this information:
   */
  struct sctp_status {
  	sctp_assoc_t		sstat_assoc_id;
  	__s32			sstat_state;
  	__u32			sstat_rwnd;
  	__u16			sstat_unackdata;
  	__u16			sstat_penddata;
  	__u16			sstat_instrms;
  	__u16			sstat_outstrms;
  	__u32			sstat_fragmentation_point;
  	struct sctp_paddrinfo	sstat_primary;
  };
  
  /*
   * 7.2.3.  Get the list of chunks the peer requires to be authenticated
   *         (SCTP_PEER_AUTH_CHUNKS)
   *
   * This option gets a list of chunks for a specified association that
   * the peer requires to be received authenticated only.
   */
  struct sctp_authchunks {
  	sctp_assoc_t	gauth_assoc_id;
  	__u32		gauth_number_of_chunks;
  	uint8_t		gauth_chunks[];
  };
  
  /* The broken spelling has been released already in lksctp-tools header,
   * so don't break anyone, now that it's fixed.
   */
  #define guth_number_of_chunks	gauth_number_of_chunks
  
  /* Association states.  */
  enum sctp_sstat_state {
  	SCTP_EMPTY                = 0,
  	SCTP_CLOSED               = 1,
  	SCTP_COOKIE_WAIT          = 2,
  	SCTP_COOKIE_ECHOED        = 3,
  	SCTP_ESTABLISHED          = 4,
  	SCTP_SHUTDOWN_PENDING     = 5,
  	SCTP_SHUTDOWN_SENT        = 6,
  	SCTP_SHUTDOWN_RECEIVED    = 7,
  	SCTP_SHUTDOWN_ACK_SENT    = 8,
  };
  
  /*
   * 8.2.6. Get the Current Identifiers of Associations
   *        (SCTP_GET_ASSOC_ID_LIST)
   *
   * This option gets the current list of SCTP association identifiers of
   * the SCTP associations handled by a one-to-many style socket.
   */
  struct sctp_assoc_ids {
  	__u32		gaids_number_of_ids;
  	sctp_assoc_t	gaids_assoc_id[];
  };
  
  /*
   * 8.3, 8.5 get all peer/local addresses in an association.
   * This parameter struct is used by SCTP_GET_PEER_ADDRS and
   * SCTP_GET_LOCAL_ADDRS socket options used internally to implement
   * sctp_getpaddrs() and sctp_getladdrs() API.
   */
  struct sctp_getaddrs_old {
  	sctp_assoc_t            assoc_id;
  	int			addr_num;
  #ifdef __KERNEL__
  	struct sockaddr		__user *addrs;
  #else
  	struct sockaddr		*addrs;
  #endif
  };
  
  struct sctp_getaddrs {
  	sctp_assoc_t		assoc_id; /*input*/
  	__u32			addr_num; /*output*/
  	__u8			addrs[0]; /*output, variable size*/
  };
  
  /* A socket user request obtained via SCTP_GET_ASSOC_STATS that retrieves
   * association stats. All stats are counts except sas_maxrto and
   * sas_obs_rto_ipaddr. maxrto is the max observed rto + transport since
   * the last call. Will return 0 when RTO was not update since last call
   */
  struct sctp_assoc_stats {
  	sctp_assoc_t	sas_assoc_id;    /* Input */
  					 /* Transport of observed max RTO */
  	struct sockaddr_storage sas_obs_rto_ipaddr;
  	__u64		sas_maxrto;      /* Maximum Observed RTO for period */
  	__u64		sas_isacks;	 /* SACKs received */
  	__u64		sas_osacks;	 /* SACKs sent */
  	__u64		sas_opackets;	 /* Packets sent */
  	__u64		sas_ipackets;	 /* Packets received */
  	__u64		sas_rtxchunks;   /* Retransmitted Chunks */
  	__u64		sas_outofseqtsns;/* TSN received > next expected */
  	__u64		sas_idupchunks;  /* Dups received (ordered+unordered) */
  	__u64		sas_gapcnt;      /* Gap Acknowledgements Received */
  	__u64		sas_ouodchunks;  /* Unordered data chunks sent */
  	__u64		sas_iuodchunks;  /* Unordered data chunks received */
  	__u64		sas_oodchunks;	 /* Ordered data chunks sent */
  	__u64		sas_iodchunks;	 /* Ordered data chunks received */
  	__u64		sas_octrlchunks; /* Control chunks sent */
  	__u64		sas_ictrlchunks; /* Control chunks received */
  };
  
  /* These are bit fields for msghdr->msg_flags.  See section 5.1.  */
  /* On user space Linux, these live in <bits/socket.h> as an enum.  */
  enum sctp_msg_flags {
  	MSG_NOTIFICATION = 0x8000,
  #define MSG_NOTIFICATION MSG_NOTIFICATION
  };
  
  /*
   * 8.1 sctp_bindx()
   *
   * The flags parameter is formed from the bitwise OR of zero or more of the
   * following currently defined flags:
   */
  #define SCTP_BINDX_ADD_ADDR 0x01
  #define SCTP_BINDX_REM_ADDR 0x02
  
  /* This is the structure that is passed as an argument(optval) to
   * getsockopt(SCTP_SOCKOPT_PEELOFF).
   */
  typedef struct {
  	sctp_assoc_t associd;
  	int sd;
  } sctp_peeloff_arg_t;
  
  /*
   *  Peer Address Thresholds socket option
   */
  struct sctp_paddrthlds {
  	sctp_assoc_t spt_assoc_id;
  	struct sockaddr_storage spt_address;
  	__u16 spt_pathmaxrxt;
  	__u16 spt_pathpfthld;
  };
  
  #endif /* _UAPI_SCTP_H */