1/* SCTP kernel implementation 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 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These are the definitions needed for the tsnmap type. The tsnmap is used 10 * to track out of order TSNs received. 11 * 12 * This SCTP implementation is free software; 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 * 18 * This SCTP implementation is distributed in the hope that it 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 */ 58struct 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 unsigned long *tsn_map; 64 65 /* This is the TSN at tsn_map[0]. */ 66 __u32 base_tsn; 67 68 /* Last Rcvd : This is the last TSN received in 69 * TSN : sequence. This value is set initially by 70 * : taking the peer's Initial TSN, received in 71 * : the INIT or INIT ACK chunk, and subtracting 72 * : one from it. 73 * 74 * Throughout most of the specification this is called the 75 * "Cumulative TSN ACK Point". In this case, we 76 * ignore the advice in 12.2 in favour of the term 77 * used in the bulk of the text. 78 */ 79 __u32 cumulative_tsn_ack_point; 80 81 /* This is the highest TSN we've marked. */ 82 __u32 max_tsn_seen; 83 84 /* This is the minimum number of TSNs we can track. This corresponds 85 * to the size of tsn_map. Note: the overflow_map allows us to 86 * potentially track more than this quantity. 87 */ 88 __u16 len; 89 90 /* Data chunks pending receipt. used by SCTP_STATUS sockopt */ 91 __u16 pending_data; 92 93 /* Record duplicate TSNs here. We clear this after 94 * every SACK. Store up to SCTP_MAX_DUP_TSNS worth of 95 * information. 96 */ 97 __u16 num_dup_tsns; 98 __be32 dup_tsns[SCTP_MAX_DUP_TSNS]; 99}; 100 101struct sctp_tsnmap_iter { 102 __u32 start; 103}; 104 105/* Initialize a block of memory as a tsnmap. */ 106struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len, 107 __u32 initial_tsn, gfp_t gfp); 108 109void sctp_tsnmap_free(struct sctp_tsnmap *map); 110 111/* Test the tracking state of this TSN. 112 * Returns: 113 * 0 if the TSN has not yet been seen 114 * >0 if the TSN has been seen (duplicate) 115 * <0 if the TSN is invalid (too large to track) 116 */ 117int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn); 118 119/* Mark this TSN as seen. */ 120int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn); 121 122/* Mark this TSN and all lower as seen. */ 123void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn); 124 125/* Retrieve the Cumulative TSN ACK Point. */ 126static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map) 127{ 128 return map->cumulative_tsn_ack_point; 129} 130 131/* Retrieve the highest TSN we've seen. */ 132static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map) 133{ 134 return map->max_tsn_seen; 135} 136 137/* How many duplicate TSNs are stored? */ 138static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map) 139{ 140 return map->num_dup_tsns; 141} 142 143/* Return pointer to duplicate tsn array as needed by SACK. */ 144static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map) 145{ 146 map->num_dup_tsns = 0; 147 return map->dup_tsns; 148} 149 150/* How many gap ack blocks do we have recorded? */ 151__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map, 152 struct sctp_gap_ack_block *gabs); 153 154/* Refresh the count on pending data. */ 155__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map); 156 157/* Is there a gap in the TSN map? */ 158static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map) 159{ 160 return (map->cumulative_tsn_ack_point != map->max_tsn_seen); 161} 162 163/* Mark a duplicate TSN. Note: limit the storage of duplicate TSN 164 * information. 165 */ 166static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn) 167{ 168 if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS) 169 map->dup_tsns[map->num_dup_tsns++] = htonl(tsn); 170} 171 172/* Renege a TSN that was seen. */ 173void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn); 174 175/* Is there a gap in the TSN map? */ 176int sctp_tsnmap_has_gap(const struct sctp_tsnmap *); 177 178#endif /* __sctp_tsnmap_h__ */ 179