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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 | |
4b2f13a2 JK |
25 | * along with GNU CC; see the file COPYING. If not, see |
26 | * <http://www.gnu.org/licenses/>. | |
1da177e4 LT |
27 | * |
28 | * Please send any bug reports or fixes you make to the | |
29 | * email address(es): | |
91705c61 | 30 | * lksctp developers <linux-sctp@vger.kernel.org> |
1da177e4 | 31 | * |
1da177e4 LT |
32 | * 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> | |
1da177e4 LT |
37 | */ |
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 | */ | |
51 | struct 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 | */ | |
8e1ee18c | 56 | unsigned long *tsn_map; |
1da177e4 LT |
57 | |
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 | ||
8e1ee18c VY |
74 | /* This is the highest TSN we've marked. */ |
75 | __u32 max_tsn_seen; | |
76 | ||
1da177e4 LT |
77 | /* 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 | ||
1da177e4 LT |
83 | /* 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 | */ | |
1da177e4 | 90 | __u16 num_dup_tsns; |
02015180 | 91 | __be32 dup_tsns[SCTP_MAX_DUP_TSNS]; |
1da177e4 LT |
92 | }; |
93 | ||
94 | struct sctp_tsnmap_iter { | |
95 | __u32 start; | |
96 | }; | |
97 | ||
1da177e4 LT |
98 | /* Initialize a block of memory as a tsnmap. */ |
99 | struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len, | |
8e1ee18c VY |
100 | __u32 initial_tsn, gfp_t gfp); |
101 | ||
102 | void sctp_tsnmap_free(struct sctp_tsnmap *map); | |
1da177e4 LT |
103 | |
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 | */ | |
110 | int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn); | |
111 | ||
112 | /* Mark this TSN as seen. */ | |
4244854d NH |
113 | int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn, |
114 | struct sctp_transport *trans); | |
1da177e4 LT |
115 | |
116 | /* Mark this TSN and all lower as seen. */ | |
117 | void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn); | |
118 | ||
119 | /* Retrieve the Cumulative TSN ACK Point. */ | |
120 | static 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. */ | |
126 | static 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? */ | |
132 | static 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. */ | |
72f17e1c | 138 | static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map) |
1da177e4 LT |
139 | { |
140 | map->num_dup_tsns = 0; | |
141 | return map->dup_tsns; | |
142 | } | |
143 | ||
144 | /* How many gap ack blocks do we have recorded? */ | |
02015180 VY |
145 | __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map, |
146 | struct sctp_gap_ack_block *gabs); | |
1da177e4 LT |
147 | |
148 | /* Refresh the count on pending data. */ | |
149 | __u16 sctp_tsnmap_pending(struct sctp_tsnmap *map); | |
150 | ||
1da177e4 LT |
151 | /* Is there a gap in the TSN map? */ |
152 | static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map) | |
153 | { | |
a02cec21 | 154 | return map->cumulative_tsn_ack_point != map->max_tsn_seen; |
1da177e4 LT |
155 | } |
156 | ||
157 | /* Mark a duplicate TSN. Note: limit the storage of duplicate TSN | |
158 | * information. | |
159 | */ | |
160 | static 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. */ | |
167 | void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn); | |
168 | ||
169 | /* Is there a gap in the TSN map? */ | |
170 | int sctp_tsnmap_has_gap(const struct sctp_tsnmap *); | |
171 | ||
172 | #endif /* __sctp_tsnmap_h__ */ |