blob: 31b8dbaad45a62f438f89069f0d22ec4fef19deb [file] [log] [blame]
Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05007 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
9 * These are the definitions needed for the tsnmap type. The tsnmap is used
10 * to track out of order TSNs received.
11 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050012 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * 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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050018 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * 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
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080025 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020030 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 * Written or modified by:
33 * Jon Grimm <jgrimm@us.ibm.com>
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * Sridhar Samudrala <sri@us.ibm.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 */
38#include <net/sctp/constants.h>
39
40#ifndef __sctp_tsnmap_h__
41#define __sctp_tsnmap_h__
42
43/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
44 * Mapping An array of bits or bytes indicating which out of
45 * Array order TSN's have been received (relative to the
46 * Last Rcvd TSN). If no gaps exist, i.e. no out of
47 * order packets have been received, this array
48 * will be set to all zero. This structure may be
49 * in the form of a circular buffer or bit array.
50 */
51struct sctp_tsnmap {
52 /* This array counts the number of chunks with each TSN.
53 * It points at one of the two buffers with which we will
54 * ping-pong between.
55 */
Vlad Yasevich8e1ee182008-10-08 14:18:39 -070056 unsigned long *tsn_map;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58 /* This is the TSN at tsn_map[0]. */
59 __u32 base_tsn;
60
61 /* Last Rcvd : This is the last TSN received in
62 * TSN : sequence. This value is set initially by
63 * : taking the peer's Initial TSN, received in
64 * : the INIT or INIT ACK chunk, and subtracting
65 * : one from it.
66 *
67 * Throughout most of the specification this is called the
68 * "Cumulative TSN ACK Point". In this case, we
69 * ignore the advice in 12.2 in favour of the term
70 * used in the bulk of the text.
71 */
72 __u32 cumulative_tsn_ack_point;
73
Vlad Yasevich8e1ee182008-10-08 14:18:39 -070074 /* This is the highest TSN we've marked. */
75 __u32 max_tsn_seen;
76
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 /* This is the minimum number of TSNs we can track. This corresponds
78 * to the size of tsn_map. Note: the overflow_map allows us to
79 * potentially track more than this quantity.
80 */
81 __u16 len;
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 /* Data chunks pending receipt. used by SCTP_STATUS sockopt */
84 __u16 pending_data;
85
86 /* Record duplicate TSNs here. We clear this after
87 * every SACK. Store up to SCTP_MAX_DUP_TSNS worth of
88 * information.
89 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 __u16 num_dup_tsns;
Vlad Yasevich02015182008-10-08 14:19:01 -070091 __be32 dup_tsns[SCTP_MAX_DUP_TSNS];
Linus Torvalds1da177e2005-04-16 15:20:36 -070092};
93
94struct sctp_tsnmap_iter {
95 __u32 start;
96};
97
Linus Torvalds1da177e2005-04-16 15:20:36 -070098/* Initialize a block of memory as a tsnmap. */
99struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
Vlad Yasevich8e1ee182008-10-08 14:18:39 -0700100 __u32 initial_tsn, gfp_t gfp);
101
102void sctp_tsnmap_free(struct sctp_tsnmap *map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
104/* Test the tracking state of this TSN.
105 * Returns:
106 * 0 if the TSN has not yet been seen
107 * >0 if the TSN has been seen (duplicate)
108 * <0 if the TSN is invalid (too large to track)
109 */
110int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
111
112/* Mark this TSN as seen. */
Neil Horman42448542012-06-30 03:04:26 +0000113int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn,
114 struct sctp_transport *trans);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
116/* Mark this TSN and all lower as seen. */
117void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
118
119/* Retrieve the Cumulative TSN ACK Point. */
120static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
121{
122 return map->cumulative_tsn_ack_point;
123}
124
125/* Retrieve the highest TSN we've seen. */
126static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
127{
128 return map->max_tsn_seen;
129}
130
131/* How many duplicate TSNs are stored? */
132static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
133{
134 return map->num_dup_tsns;
135}
136
137/* Return pointer to duplicate tsn array as needed by SACK. */
Al Viro72f17e12006-11-20 17:01:23 -0800138static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 map->num_dup_tsns = 0;
141 return map->dup_tsns;
142}
143
144/* How many gap ack blocks do we have recorded? */
Vlad Yasevich02015182008-10-08 14:19:01 -0700145__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
146 struct sctp_gap_ack_block *gabs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
148/* Refresh the count on pending data. */
149__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151/* Is there a gap in the TSN map? */
152static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
153{
Eric Dumazeta02cec22010-09-22 20:43:57 +0000154 return map->cumulative_tsn_ack_point != map->max_tsn_seen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
157/* Mark a duplicate TSN. Note: limit the storage of duplicate TSN
158 * information.
159 */
160static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
161{
162 if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
163 map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
164}
165
166/* Renege a TSN that was seen. */
167void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
168
169/* Is there a gap in the TSN map? */
170int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
171
172#endif /* __sctp_tsnmap_h__ */