1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-or-later */
2*4882a593Smuzhiyun /* SCTP kernel implementation
3*4882a593Smuzhiyun * (C) Copyright IBM Corp. 2001, 2004
4*4882a593Smuzhiyun * Copyright (c) 1999-2000 Cisco, Inc.
5*4882a593Smuzhiyun * Copyright (c) 1999-2001 Motorola, Inc.
6*4882a593Smuzhiyun * Copyright (c) 2001 Intel Corp.
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * This file is part of the SCTP kernel implementation
9*4882a593Smuzhiyun *
10*4882a593Smuzhiyun * These are the definitions needed for the tsnmap type. The tsnmap is used
11*4882a593Smuzhiyun * to track out of order TSNs received.
12*4882a593Smuzhiyun *
13*4882a593Smuzhiyun * Please send any bug reports or fixes you make to the
14*4882a593Smuzhiyun * email address(es):
15*4882a593Smuzhiyun * lksctp developers <linux-sctp@vger.kernel.org>
16*4882a593Smuzhiyun *
17*4882a593Smuzhiyun * Written or modified by:
18*4882a593Smuzhiyun * Jon Grimm <jgrimm@us.ibm.com>
19*4882a593Smuzhiyun * La Monte H.P. Yarroll <piggy@acm.org>
20*4882a593Smuzhiyun * Karl Knutson <karl@athena.chicago.il.us>
21*4882a593Smuzhiyun * Sridhar Samudrala <sri@us.ibm.com>
22*4882a593Smuzhiyun */
23*4882a593Smuzhiyun #include <net/sctp/constants.h>
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun #ifndef __sctp_tsnmap_h__
26*4882a593Smuzhiyun #define __sctp_tsnmap_h__
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun /* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
29*4882a593Smuzhiyun * Mapping An array of bits or bytes indicating which out of
30*4882a593Smuzhiyun * Array order TSN's have been received (relative to the
31*4882a593Smuzhiyun * Last Rcvd TSN). If no gaps exist, i.e. no out of
32*4882a593Smuzhiyun * order packets have been received, this array
33*4882a593Smuzhiyun * will be set to all zero. This structure may be
34*4882a593Smuzhiyun * in the form of a circular buffer or bit array.
35*4882a593Smuzhiyun */
36*4882a593Smuzhiyun struct sctp_tsnmap {
37*4882a593Smuzhiyun /* This array counts the number of chunks with each TSN.
38*4882a593Smuzhiyun * It points at one of the two buffers with which we will
39*4882a593Smuzhiyun * ping-pong between.
40*4882a593Smuzhiyun */
41*4882a593Smuzhiyun unsigned long *tsn_map;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun /* This is the TSN at tsn_map[0]. */
44*4882a593Smuzhiyun __u32 base_tsn;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun /* Last Rcvd : This is the last TSN received in
47*4882a593Smuzhiyun * TSN : sequence. This value is set initially by
48*4882a593Smuzhiyun * : taking the peer's Initial TSN, received in
49*4882a593Smuzhiyun * : the INIT or INIT ACK chunk, and subtracting
50*4882a593Smuzhiyun * : one from it.
51*4882a593Smuzhiyun *
52*4882a593Smuzhiyun * Throughout most of the specification this is called the
53*4882a593Smuzhiyun * "Cumulative TSN ACK Point". In this case, we
54*4882a593Smuzhiyun * ignore the advice in 12.2 in favour of the term
55*4882a593Smuzhiyun * used in the bulk of the text.
56*4882a593Smuzhiyun */
57*4882a593Smuzhiyun __u32 cumulative_tsn_ack_point;
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun /* This is the highest TSN we've marked. */
60*4882a593Smuzhiyun __u32 max_tsn_seen;
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun /* This is the minimum number of TSNs we can track. This corresponds
63*4882a593Smuzhiyun * to the size of tsn_map. Note: the overflow_map allows us to
64*4882a593Smuzhiyun * potentially track more than this quantity.
65*4882a593Smuzhiyun */
66*4882a593Smuzhiyun __u16 len;
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun /* Data chunks pending receipt. used by SCTP_STATUS sockopt */
69*4882a593Smuzhiyun __u16 pending_data;
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun /* Record duplicate TSNs here. We clear this after
72*4882a593Smuzhiyun * every SACK. Store up to SCTP_MAX_DUP_TSNS worth of
73*4882a593Smuzhiyun * information.
74*4882a593Smuzhiyun */
75*4882a593Smuzhiyun __u16 num_dup_tsns;
76*4882a593Smuzhiyun __be32 dup_tsns[SCTP_MAX_DUP_TSNS];
77*4882a593Smuzhiyun };
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun struct sctp_tsnmap_iter {
80*4882a593Smuzhiyun __u32 start;
81*4882a593Smuzhiyun };
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun /* Initialize a block of memory as a tsnmap. */
84*4882a593Smuzhiyun struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
85*4882a593Smuzhiyun __u32 initial_tsn, gfp_t gfp);
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun void sctp_tsnmap_free(struct sctp_tsnmap *map);
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun /* Test the tracking state of this TSN.
90*4882a593Smuzhiyun * Returns:
91*4882a593Smuzhiyun * 0 if the TSN has not yet been seen
92*4882a593Smuzhiyun * >0 if the TSN has been seen (duplicate)
93*4882a593Smuzhiyun * <0 if the TSN is invalid (too large to track)
94*4882a593Smuzhiyun */
95*4882a593Smuzhiyun int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun /* Mark this TSN as seen. */
98*4882a593Smuzhiyun int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn,
99*4882a593Smuzhiyun struct sctp_transport *trans);
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun /* Mark this TSN and all lower as seen. */
102*4882a593Smuzhiyun void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
103*4882a593Smuzhiyun
104*4882a593Smuzhiyun /* Retrieve the Cumulative TSN ACK Point. */
sctp_tsnmap_get_ctsn(const struct sctp_tsnmap * map)105*4882a593Smuzhiyun static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
106*4882a593Smuzhiyun {
107*4882a593Smuzhiyun return map->cumulative_tsn_ack_point;
108*4882a593Smuzhiyun }
109*4882a593Smuzhiyun
110*4882a593Smuzhiyun /* Retrieve the highest TSN we've seen. */
sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap * map)111*4882a593Smuzhiyun static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
112*4882a593Smuzhiyun {
113*4882a593Smuzhiyun return map->max_tsn_seen;
114*4882a593Smuzhiyun }
115*4882a593Smuzhiyun
116*4882a593Smuzhiyun /* How many duplicate TSNs are stored? */
sctp_tsnmap_num_dups(struct sctp_tsnmap * map)117*4882a593Smuzhiyun static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
118*4882a593Smuzhiyun {
119*4882a593Smuzhiyun return map->num_dup_tsns;
120*4882a593Smuzhiyun }
121*4882a593Smuzhiyun
122*4882a593Smuzhiyun /* Return pointer to duplicate tsn array as needed by SACK. */
sctp_tsnmap_get_dups(struct sctp_tsnmap * map)123*4882a593Smuzhiyun static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
124*4882a593Smuzhiyun {
125*4882a593Smuzhiyun map->num_dup_tsns = 0;
126*4882a593Smuzhiyun return map->dup_tsns;
127*4882a593Smuzhiyun }
128*4882a593Smuzhiyun
129*4882a593Smuzhiyun /* How many gap ack blocks do we have recorded? */
130*4882a593Smuzhiyun __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
131*4882a593Smuzhiyun struct sctp_gap_ack_block *gabs);
132*4882a593Smuzhiyun
133*4882a593Smuzhiyun /* Refresh the count on pending data. */
134*4882a593Smuzhiyun __u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
135*4882a593Smuzhiyun
136*4882a593Smuzhiyun /* Is there a gap in the TSN map? */
sctp_tsnmap_has_gap(const struct sctp_tsnmap * map)137*4882a593Smuzhiyun static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
138*4882a593Smuzhiyun {
139*4882a593Smuzhiyun return map->cumulative_tsn_ack_point != map->max_tsn_seen;
140*4882a593Smuzhiyun }
141*4882a593Smuzhiyun
142*4882a593Smuzhiyun /* Mark a duplicate TSN. Note: limit the storage of duplicate TSN
143*4882a593Smuzhiyun * information.
144*4882a593Smuzhiyun */
sctp_tsnmap_mark_dup(struct sctp_tsnmap * map,__u32 tsn)145*4882a593Smuzhiyun static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
146*4882a593Smuzhiyun {
147*4882a593Smuzhiyun if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
148*4882a593Smuzhiyun map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
149*4882a593Smuzhiyun }
150*4882a593Smuzhiyun
151*4882a593Smuzhiyun /* Renege a TSN that was seen. */
152*4882a593Smuzhiyun void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
153*4882a593Smuzhiyun
154*4882a593Smuzhiyun /* Is there a gap in the TSN map? */
155*4882a593Smuzhiyun int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
156*4882a593Smuzhiyun
157*4882a593Smuzhiyun #endif /* __sctp_tsnmap_h__ */
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