[deliverable/linux.git] / include / net / sctp / tsnmap.h

/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001 Intel Corp.
 *
 * This file is part of the SCTP kernel implementation
 *
 * These are the definitions needed for the tsnmap type.  The tsnmap is used
 * to track out of order TSNs received.
 *
 * 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, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 *
 * Or submit a bug report through the following website:
 *    http://www.sf.net/projects/lksctp
 *
 * Written or modified by:
 *   Jon Grimm             <jgrimm@us.ibm.com>
 *   La Monte H.P. Yarroll <piggy@acm.org>
 *   Karl Knutson          <karl@athena.chicago.il.us>
 *   Sridhar Samudrala     <sri@us.ibm.com>
 *
 * Any bugs reported given to us we will try to fix... any fixes shared will
 * be incorporated into the next SCTP release.
 */
#include <net/sctp/constants.h>

#ifndef __sctp_tsnmap_h__
#define __sctp_tsnmap_h__

/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
 * Mapping  An array of bits or bytes indicating which out of
 * Array    order TSN's have been received (relative to the
 *          Last Rcvd TSN). If no gaps exist, i.e. no out of
 *          order packets have been received, this array
 *          will be set to all zero. This structure may be
 *          in the form of a circular buffer or bit array.
 */
struct sctp_tsnmap {
	/* This array counts the number of chunks with each TSN.
	 * It points at one of the two buffers with which we will
	 * ping-pong between.
	 */
	__u8 *tsn_map;

	/* This marks the tsn which overflows the tsn_map, when the
	 * cumulative ack point reaches this point we know we can switch
	 * maps (tsn_map and overflow_map swap).
	 */
	__u32 overflow_tsn;

	/* This is the overflow array for tsn_map.
	 * It points at one of the other ping-pong buffers.
	 */
	__u8 *overflow_map;

	/* This is the TSN at tsn_map[0].  */
	__u32 base_tsn;

	/* Last Rcvd   : This is the last TSN received in
	 * TSN	       : sequence. This value is set initially by
	 *             : taking the peer's Initial TSN, received in
	 *             : the INIT or INIT ACK chunk, and subtracting
	 *             : one from it.
	 *
	 * Throughout most of the specification this is called the
	 * "Cumulative TSN ACK Point".  In this case, we
	 * ignore the advice in 12.2 in favour of the term
	 * used in the bulk of the text.
	 */
	__u32 cumulative_tsn_ack_point;

	/* This is the minimum number of TSNs we can track.  This corresponds
	 * to the size of tsn_map.   Note: the overflow_map allows us to
	 * potentially track more than this quantity.
	 */
	__u16 len;

	/* This is the highest TSN we've marked.  */
	__u32 max_tsn_seen;

	/* Data chunks pending receipt. used by SCTP_STATUS sockopt */
	__u16 pending_data;

	/* Record duplicate TSNs here.  We clear this after
	 * every SACK.  Store up to SCTP_MAX_DUP_TSNS worth of
	 * information.
	 */
	__be32 dup_tsns[SCTP_MAX_DUP_TSNS];
	__u16 num_dup_tsns;

	/* Record gap ack block information here.  */
	struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];

	int malloced;

	__u8 raw_map[0];
};

struct sctp_tsnmap_iter {
	__u32 start;
};

/* This macro assists in creation of external storage for variable length
 * internal buffers.  We double allocate so the overflow map works.
 */
#define sctp_tsnmap_storage_size(count) (sizeof(__u8) * (count) * 2)

/* Initialize a block of memory as a tsnmap.  */
struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
				     __u32 initial_tsn);

/* Test the tracking state of this TSN.
 * Returns:
 *   0 if the TSN has not yet been seen
 *  >0 if the TSN has been seen (duplicate)
 *  <0 if the TSN is invalid (too large to track)
 */
int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);

/* Mark this TSN as seen.  */
void sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn);

/* Mark this TSN and all lower as seen. */
void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);

/* Retrieve the Cumulative TSN ACK Point.  */
static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
{
	return map->cumulative_tsn_ack_point;
}

/* Retrieve the highest TSN we've seen.  */
static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
{
	return map->max_tsn_seen;
}

/* How many duplicate TSNs are stored? */
static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
{
	return map->num_dup_tsns;
}

/* Return pointer to duplicate tsn array as needed by SACK. */
static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
{
	map->num_dup_tsns = 0;
	return map->dup_tsns;
}

/* How many gap ack blocks do we have recorded? */
__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map);

/* Refresh the count on pending data. */
__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);

/* Return pointer to gap ack blocks as needed by SACK. */
static inline struct sctp_gap_ack_block *sctp_tsnmap_get_gabs(struct sctp_tsnmap *map)
{
	return map->gabs;
}

/* Is there a gap in the TSN map?  */
static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
{
	int has_gap;

	has_gap = (map->cumulative_tsn_ack_point != map->max_tsn_seen);
	return has_gap;
}

/* Mark a duplicate TSN.  Note:  limit the storage of duplicate TSN
 * information.
 */
static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
{
	if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
		map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
}

/* Renege a TSN that was seen.  */
void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);

/* Is there a gap in the TSN map? */
int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);

#endif /* __sctp_tsnmap_h__ */
Commit	Line	Data
60c778b2	1	/* SCTP kernel implementation
1da177e4 LT	2	* (C) Copyright IBM Corp. 2001, 2004
	3	* Copyright (c) 1999-2000 Cisco, Inc.
	4	* Copyright (c) 1999-2001 Motorola, Inc.
	5	* Copyright (c) 2001 Intel Corp.
	6	*
60c778b2	7	* This file is part of the SCTP kernel implementation
1da177e4 LT	8	*
	9	* These are the definitions needed for the tsnmap type. The tsnmap is used
	10	* to track out of order TSNs received.
	11	*
60c778b2	12	* This SCTP implementation is free software;
1da177e4 LT	13	* you can redistribute it and/or modify it under the terms of
	14	* the GNU General Public License as published by
	15	* the Free Software Foundation; either version 2, or (at your option)
	16	* any later version.
	17	*
60c778b2	18	* This SCTP implementation is distributed in the hope that it
1da177e4 LT	19	* will be useful, but WITHOUT ANY WARRANTY; without even the implied
	20	* ************************
	21	* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	22	* See the GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with GNU CC; see the file COPYING. If not, write to
	26	* the Free Software Foundation, 59 Temple Place - Suite 330,
	27	* Boston, MA 02111-1307, USA.
	28	*
	29	* Please send any bug reports or fixes you make to the
	30	* email address(es):
	31	* lksctp developers <lksctp-developers@lists.sourceforge.net>
	32	*
	33	* Or submit a bug report through the following website:
	34	* http://www.sf.net/projects/lksctp
	35	*
	36	* Written or modified by:
	37	* Jon Grimm <jgrimm@us.ibm.com>
	38	* La Monte H.P. Yarroll <piggy@acm.org>
	39	* Karl Knutson <karl@athena.chicago.il.us>
	40	* Sridhar Samudrala <sri@us.ibm.com>
	41	*
	42	* Any bugs reported given to us we will try to fix... any fixes shared will
	43	* be incorporated into the next SCTP release.
	44	*/
	45	#include <net/sctp/constants.h>
	46
	47	#ifndef __sctp_tsnmap_h__
	48	#define __sctp_tsnmap_h__
	49
	50	/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
	51	* Mapping An array of bits or bytes indicating which out of
	52	* Array order TSN's have been received (relative to the
	53	* Last Rcvd TSN). If no gaps exist, i.e. no out of
	54	* order packets have been received, this array
	55	* will be set to all zero. This structure may be
	56	* in the form of a circular buffer or bit array.
	57	*/
	58	struct sctp_tsnmap {
	59	/* This array counts the number of chunks with each TSN.
	60	* It points at one of the two buffers with which we will
	61	* ping-pong between.
	62	*/
	63	__u8 *tsn_map;
	64
	65	/* This marks the tsn which overflows the tsn_map, when the
	66	* cumulative ack point reaches this point we know we can switch
	67	* maps (tsn_map and overflow_map swap).
	68	*/
	69	__u32 overflow_tsn;
	70
	71	/* This is the overflow array for tsn_map.
	72	* It points at one of the other ping-pong buffers.
	73	*/
	74	__u8 *overflow_map;
	75
	76	/* This is the TSN at tsn_map[0]. */
	77	__u32 base_tsn;
	78
	79	/* Last Rcvd : This is the last TSN received in
	80	* TSN : sequence. This value is set initially by
	81	* : taking the peer's Initial TSN, received in
	82	* : the INIT or INIT ACK chunk, and subtracting
83	* : one from it.
84	*
85	* Throughout most of the specification this is called the
86	* "Cumulative TSN ACK Point". In this case, we
87	* ignore the advice in 12.2 in favour of the term
88	* used in the bulk of the text.
89	*/
90	__u32 cumulative_tsn_ack_point;
91
92	/* This is the minimum number of TSNs we can track. This corresponds
93	* to the size of tsn_map. Note: the overflow_map allows us to
94	* potentially track more than this quantity.
95	*/
96	__u16 len;
97
98	/* This is the highest TSN we've marked. */
99	__u32 max_tsn_seen;
100
101	/* Data chunks pending receipt. used by SCTP_STATUS sockopt */
102	__u16 pending_data;
103
104	/* Record duplicate TSNs here. We clear this after
105	* every SACK. Store up to SCTP_MAX_DUP_TSNS worth of
106	* information.
107	*/
72f17e1c	108	__be32 dup_tsns[SCTP_MAX_DUP_TSNS];
1da177e4 LT	109	__u16 num_dup_tsns;
	110
	111	/* Record gap ack block information here. */
	112	struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
	113
	114	int malloced;
	115
	116	__u8 raw_map[0];
	117	};
	118
	119	struct sctp_tsnmap_iter {
	120	__u32 start;
	121	};
	122
	123	/* This macro assists in creation of external storage for variable length
	124	* internal buffers. We double allocate so the overflow map works.
	125	*/
	126	#define sctp_tsnmap_storage_size(count) (sizeof(__u8) * (count) * 2)
	127
	128	/* Initialize a block of memory as a tsnmap. */
	129	struct sctp_tsnmap sctp_tsnmap_init(struct sctp_tsnmap , __u16 len,
	130	__u32 initial_tsn);
	131
	132	/* Test the tracking state of this TSN.
	133	* Returns:
	134	* 0 if the TSN has not yet been seen
	135	* >0 if the TSN has been seen (duplicate)
	136	* <0 if the TSN is invalid (too large to track)
	137	*/
	138	int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
	139
	140	/* Mark this TSN as seen. */
	141	void sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn);
	142
	143	/* Mark this TSN and all lower as seen. */
	144	void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
	145
	146	/* Retrieve the Cumulative TSN ACK Point. */
	147	static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
	148	{
	149	return map->cumulative_tsn_ack_point;
	150	}
	151
	152	/* Retrieve the highest TSN we've seen. */
	153	static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
	154	{
	155	return map->max_tsn_seen;
	156	}
	157
	158	/* How many duplicate TSNs are stored? */
	159	static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
	160	{
	161	return map->num_dup_tsns;
	162	}
	163
	164	/* Return pointer to duplicate tsn array as needed by SACK. */
72f17e1c	165	static inline __be32 sctp_tsnmap_get_dups(struct sctp_tsnmap map)
1da177e4 LT	166	{
	167	map->num_dup_tsns = 0;
	168	return map->dup_tsns;
	169	}
	170
	171	/* How many gap ack blocks do we have recorded? */
	172	__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map);
	173
	174	/* Refresh the count on pending data. */
	175	__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
	176
	177	/* Return pointer to gap ack blocks as needed by SACK. */
	178	static inline struct sctp_gap_ack_block sctp_tsnmap_get_gabs(struct sctp_tsnmap map)
	179	{
	180	return map->gabs;
	181	}
	182
	183	/* Is there a gap in the TSN map? */
	184	static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
	185	{
	186	int has_gap;
	187
	188	has_gap = (map->cumulative_tsn_ack_point != map->max_tsn_seen);
	189	return has_gap;
	190	}
	191
	192	/* Mark a duplicate TSN. Note: limit the storage of duplicate TSN
	193	* information.
	194	*/
	195	static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
	196	{
	197	if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
	198	map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
	199	}
	200
	201	/* Renege a TSN that was seen. */
	202	void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
	203
	204	/* Is there a gap in the TSN map? */
	205	int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
	206
	207	#endif /* __sctp_tsnmap_h__ */