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v5.14.15
  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/* SCTP kernel implementation
  3 * (C) Copyright IBM Corp. 2001, 2004
  4 * Copyright (c) 1999-2000 Cisco, Inc.
  5 * Copyright (c) 1999-2001 Motorola, Inc.
  6 * Copyright (c) 2001 Intel Corp.
  7 *
  8 * This file is part of the SCTP kernel implementation
  9 *
 10 * These are the definitions needed for the tsnmap type.  The tsnmap is used
 11 * to track out of order TSNs received.
 12 *
 13 * Please send any bug reports or fixes you make to the
 14 * email address(es):
 15 *    lksctp developers <linux-sctp@vger.kernel.org>
 16 *
 17 * Written or modified by:
 18 *   Jon Grimm             <jgrimm@us.ibm.com>
 19 *   La Monte H.P. Yarroll <piggy@acm.org>
 20 *   Karl Knutson          <karl@athena.chicago.il.us>
 21 *   Sridhar Samudrala     <sri@us.ibm.com>
 22 */
 23#include <net/sctp/constants.h>
 24
 25#ifndef __sctp_tsnmap_h__
 26#define __sctp_tsnmap_h__
 27
 28/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
 29 * Mapping  An array of bits or bytes indicating which out of
 30 * Array    order TSN's have been received (relative to the
 31 *          Last Rcvd TSN). If no gaps exist, i.e. no out of
 32 *          order packets have been received, this array
 33 *          will be set to all zero. This structure may be
 34 *          in the form of a circular buffer or bit array.
 35 */
 36struct sctp_tsnmap {
 37	/* This array counts the number of chunks with each TSN.
 38	 * It points at one of the two buffers with which we will
 39	 * ping-pong between.
 40	 */
 41	unsigned long *tsn_map;
 42
 43	/* This is the TSN at tsn_map[0].  */
 44	__u32 base_tsn;
 45
 46	/* Last Rcvd   : This is the last TSN received in
 47	 * TSN	       : sequence. This value is set initially by
 48	 *             : taking the peer's Initial TSN, received in
 49	 *             : the INIT or INIT ACK chunk, and subtracting
 50	 *             : one from it.
 51	 *
 52	 * Throughout most of the specification this is called the
 53	 * "Cumulative TSN ACK Point".  In this case, we
 54	 * ignore the advice in 12.2 in favour of the term
 55	 * used in the bulk of the text.
 56	 */
 57	__u32 cumulative_tsn_ack_point;
 58
 59	/* This is the highest TSN we've marked.  */
 60	__u32 max_tsn_seen;
 61
 62	/* This is the minimum number of TSNs we can track.  This corresponds
 63	 * to the size of tsn_map.   Note: the overflow_map allows us to
 64	 * potentially track more than this quantity.
 65	 */
 66	__u16 len;
 67
 68	/* Data chunks pending receipt. used by SCTP_STATUS sockopt */
 69	__u16 pending_data;
 70
 71	/* Record duplicate TSNs here.  We clear this after
 72	 * every SACK.  Store up to SCTP_MAX_DUP_TSNS worth of
 73	 * information.
 74	 */
 75	__u16 num_dup_tsns;
 76	__be32 dup_tsns[SCTP_MAX_DUP_TSNS];
 77};
 78
 79struct sctp_tsnmap_iter {
 80	__u32 start;
 81};
 82
 83/* Initialize a block of memory as a tsnmap.  */
 84struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
 85				     __u32 initial_tsn, gfp_t gfp);
 86
 87void sctp_tsnmap_free(struct sctp_tsnmap *map);
 88
 89/* Test the tracking state of this TSN.
 90 * Returns:
 91 *   0 if the TSN has not yet been seen
 92 *  >0 if the TSN has been seen (duplicate)
 93 *  <0 if the TSN is invalid (too large to track)
 94 */
 95int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
 96
 97/* Mark this TSN as seen.  */
 98int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn,
 99		     struct sctp_transport *trans);
100
101/* Mark this TSN and all lower as seen. */
102void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
103
104/* Retrieve the Cumulative TSN ACK Point.  */
105static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
106{
107	return map->cumulative_tsn_ack_point;
108}
109
110/* Retrieve the highest TSN we've seen.  */
111static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
112{
113	return map->max_tsn_seen;
114}
115
116/* How many duplicate TSNs are stored? */
117static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
118{
119	return map->num_dup_tsns;
120}
121
122/* Return pointer to duplicate tsn array as needed by SACK. */
123static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
124{
125	map->num_dup_tsns = 0;
126	return map->dup_tsns;
127}
128
129/* How many gap ack blocks do we have recorded? */
130__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
131			   struct sctp_gap_ack_block *gabs);
132
133/* Refresh the count on pending data. */
134__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
135
136/* Is there a gap in the TSN map?  */
137static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
138{
139	return map->cumulative_tsn_ack_point != map->max_tsn_seen;
140}
141
142/* Mark a duplicate TSN.  Note:  limit the storage of duplicate TSN
143 * information.
144 */
145static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
146{
147	if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
148		map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
149}
150
151/* Renege a TSN that was seen.  */
152void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
153
154/* Is there a gap in the TSN map? */
155int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
156
157#endif /* __sctp_tsnmap_h__ */
v6.9.4
  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/* SCTP kernel implementation
  3 * (C) Copyright IBM Corp. 2001, 2004
  4 * Copyright (c) 1999-2000 Cisco, Inc.
  5 * Copyright (c) 1999-2001 Motorola, Inc.
  6 * Copyright (c) 2001 Intel Corp.
  7 *
  8 * This file is part of the SCTP kernel implementation
  9 *
 10 * These are the definitions needed for the tsnmap type.  The tsnmap is used
 11 * to track out of order TSNs received.
 12 *
 13 * Please send any bug reports or fixes you make to the
 14 * email address(es):
 15 *    lksctp developers <linux-sctp@vger.kernel.org>
 16 *
 17 * Written or modified by:
 18 *   Jon Grimm             <jgrimm@us.ibm.com>
 19 *   La Monte H.P. Yarroll <piggy@acm.org>
 20 *   Karl Knutson          <karl@athena.chicago.il.us>
 21 *   Sridhar Samudrala     <sri@us.ibm.com>
 22 */
 23#include <net/sctp/constants.h>
 24
 25#ifndef __sctp_tsnmap_h__
 26#define __sctp_tsnmap_h__
 27
 28/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
 29 * Mapping  An array of bits or bytes indicating which out of
 30 * Array    order TSN's have been received (relative to the
 31 *          Last Rcvd TSN). If no gaps exist, i.e. no out of
 32 *          order packets have been received, this array
 33 *          will be set to all zero. This structure may be
 34 *          in the form of a circular buffer or bit array.
 35 */
 36struct sctp_tsnmap {
 37	/* This array counts the number of chunks with each TSN.
 38	 * It points at one of the two buffers with which we will
 39	 * ping-pong between.
 40	 */
 41	unsigned long *tsn_map;
 42
 43	/* This is the TSN at tsn_map[0].  */
 44	__u32 base_tsn;
 45
 46	/* Last Rcvd   : This is the last TSN received in
 47	 * TSN	       : sequence. This value is set initially by
 48	 *             : taking the peer's Initial TSN, received in
 49	 *             : the INIT or INIT ACK chunk, and subtracting
 50	 *             : one from it.
 51	 *
 52	 * Throughout most of the specification this is called the
 53	 * "Cumulative TSN ACK Point".  In this case, we
 54	 * ignore the advice in 12.2 in favour of the term
 55	 * used in the bulk of the text.
 56	 */
 57	__u32 cumulative_tsn_ack_point;
 58
 59	/* This is the highest TSN we've marked.  */
 60	__u32 max_tsn_seen;
 61
 62	/* This is the minimum number of TSNs we can track.  This corresponds
 63	 * to the size of tsn_map.   Note: the overflow_map allows us to
 64	 * potentially track more than this quantity.
 65	 */
 66	__u16 len;
 67
 68	/* Data chunks pending receipt. used by SCTP_STATUS sockopt */
 69	__u16 pending_data;
 70
 71	/* Record duplicate TSNs here.  We clear this after
 72	 * every SACK.  Store up to SCTP_MAX_DUP_TSNS worth of
 73	 * information.
 74	 */
 75	__u16 num_dup_tsns;
 76	__be32 dup_tsns[SCTP_MAX_DUP_TSNS];
 77};
 78
 79struct sctp_tsnmap_iter {
 80	__u32 start;
 81};
 82
 83/* Initialize a block of memory as a tsnmap.  */
 84struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
 85				     __u32 initial_tsn, gfp_t gfp);
 86
 87void sctp_tsnmap_free(struct sctp_tsnmap *map);
 88
 89/* Test the tracking state of this TSN.
 90 * Returns:
 91 *   0 if the TSN has not yet been seen
 92 *  >0 if the TSN has been seen (duplicate)
 93 *  <0 if the TSN is invalid (too large to track)
 94 */
 95int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
 96
 97/* Mark this TSN as seen.  */
 98int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn,
 99		     struct sctp_transport *trans);
100
101/* Mark this TSN and all lower as seen. */
102void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
103
104/* Retrieve the Cumulative TSN ACK Point.  */
105static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
106{
107	return map->cumulative_tsn_ack_point;
108}
109
110/* Retrieve the highest TSN we've seen.  */
111static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
112{
113	return map->max_tsn_seen;
114}
115
116/* How many duplicate TSNs are stored? */
117static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
118{
119	return map->num_dup_tsns;
120}
121
122/* Return pointer to duplicate tsn array as needed by SACK. */
123static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
124{
125	map->num_dup_tsns = 0;
126	return map->dup_tsns;
127}
128
129/* How many gap ack blocks do we have recorded? */
130__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
131			   struct sctp_gap_ack_block *gabs);
132
133/* Refresh the count on pending data. */
134__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
135
136/* Is there a gap in the TSN map?  */
137static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
138{
139	return map->cumulative_tsn_ack_point != map->max_tsn_seen;
140}
141
142/* Mark a duplicate TSN.  Note:  limit the storage of duplicate TSN
143 * information.
144 */
145static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
146{
147	if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
148		map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
149}
150
151/* Renege a TSN that was seen.  */
152void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
153
154/* Is there a gap in the TSN map? */
155int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
156
157#endif /* __sctp_tsnmap_h__ */