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60c778b2 | 1 | /* SCTP kernel implementation |
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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 |
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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; |
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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 |
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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]; |
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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) |
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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__ */ |