| /* SCTP kernel implementation |
| * (C) Copyright IBM Corp. 2001, 2004 |
| * Copyright (c) 1999-2000 Cisco, Inc. |
| * Copyright (c) 1999-2001 Motorola, Inc. |
| * Copyright (c) 2001 Intel Corp. |
| * |
| * This file is part of the SCTP kernel implementation |
| * |
| * These are the definitions needed for the tsnmap type. The tsnmap is used |
| * to track out of order TSNs received. |
| * |
| * This SCTP implementation is free software; |
| * you can redistribute it and/or modify it under the terms of |
| * the GNU General Public License as published by |
| * the Free Software Foundation; either version 2, or (at your option) |
| * any later version. |
| * |
| * This SCTP implementation is distributed in the hope that it |
| * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| * ************************ |
| * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| * See the GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with GNU CC; see the file COPYING. If not, write to |
| * the Free Software Foundation, 59 Temple Place - Suite 330, |
| * Boston, MA 02111-1307, USA. |
| * |
| * Please send any bug reports or fixes you make to the |
| * email address(es): |
| * lksctp developers <lksctp-developers@lists.sourceforge.net> |
| * |
| * Or submit a bug report through the following website: |
| * http://www.sf.net/projects/lksctp |
| * |
| * Written or modified by: |
| * Jon Grimm <jgrimm@us.ibm.com> |
| * La Monte H.P. Yarroll <piggy@acm.org> |
| * Karl Knutson <karl@athena.chicago.il.us> |
| * Sridhar Samudrala <sri@us.ibm.com> |
| * |
| * Any bugs reported given to us we will try to fix... any fixes shared will |
| * be incorporated into the next SCTP release. |
| */ |
| #include <net/sctp/constants.h> |
| |
| #ifndef __sctp_tsnmap_h__ |
| #define __sctp_tsnmap_h__ |
| |
| /* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB) |
| * Mapping An array of bits or bytes indicating which out of |
| * Array order TSN's have been received (relative to the |
| * Last Rcvd TSN). If no gaps exist, i.e. no out of |
| * order packets have been received, this array |
| * will be set to all zero. This structure may be |
| * in the form of a circular buffer or bit array. |
| */ |
| struct sctp_tsnmap { |
| /* This array counts the number of chunks with each TSN. |
| * It points at one of the two buffers with which we will |
| * ping-pong between. |
| */ |
| unsigned long *tsn_map; |
| |
| /* This is the TSN at tsn_map[0]. */ |
| __u32 base_tsn; |
| |
| /* Last Rcvd : This is the last TSN received in |
| * TSN : sequence. This value is set initially by |
| * : taking the peer's Initial TSN, received in |
| * : the INIT or INIT ACK chunk, and subtracting |
| * : one from it. |
| * |
| * Throughout most of the specification this is called the |
| * "Cumulative TSN ACK Point". In this case, we |
| * ignore the advice in 12.2 in favour of the term |
| * used in the bulk of the text. |
| */ |
| __u32 cumulative_tsn_ack_point; |
| |
| /* This is the highest TSN we've marked. */ |
| __u32 max_tsn_seen; |
| |
| /* This is the minimum number of TSNs we can track. This corresponds |
| * to the size of tsn_map. Note: the overflow_map allows us to |
| * potentially track more than this quantity. |
| */ |
| __u16 len; |
| |
| /* Data chunks pending receipt. used by SCTP_STATUS sockopt */ |
| __u16 pending_data; |
| |
| /* Record duplicate TSNs here. We clear this after |
| * every SACK. Store up to SCTP_MAX_DUP_TSNS worth of |
| * information. |
| */ |
| __be32 dup_tsns[SCTP_MAX_DUP_TSNS]; |
| __u16 num_dup_tsns; |
| |
| /* Record gap ack block information here. */ |
| struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; |
| }; |
| |
| struct sctp_tsnmap_iter { |
| __u32 start; |
| }; |
| |
| /* Initialize a block of memory as a tsnmap. */ |
| struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len, |
| __u32 initial_tsn, gfp_t gfp); |
| |
| void sctp_tsnmap_free(struct sctp_tsnmap *map); |
| |
| /* Test the tracking state of this TSN. |
| * Returns: |
| * 0 if the TSN has not yet been seen |
| * >0 if the TSN has been seen (duplicate) |
| * <0 if the TSN is invalid (too large to track) |
| */ |
| int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn); |
| |
| /* Mark this TSN as seen. */ |
| int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn); |
| |
| /* Mark this TSN and all lower as seen. */ |
| void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn); |
| |
| /* Retrieve the Cumulative TSN ACK Point. */ |
| static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map) |
| { |
| return map->cumulative_tsn_ack_point; |
| } |
| |
| /* Retrieve the highest TSN we've seen. */ |
| static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map) |
| { |
| return map->max_tsn_seen; |
| } |
| |
| /* How many duplicate TSNs are stored? */ |
| static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map) |
| { |
| return map->num_dup_tsns; |
| } |
| |
| /* Return pointer to duplicate tsn array as needed by SACK. */ |
| static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map) |
| { |
| map->num_dup_tsns = 0; |
| return map->dup_tsns; |
| } |
| |
| /* How many gap ack blocks do we have recorded? */ |
| __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map); |
| |
| /* Refresh the count on pending data. */ |
| __u16 sctp_tsnmap_pending(struct sctp_tsnmap *map); |
| |
| /* Return pointer to gap ack blocks as needed by SACK. */ |
| static inline struct sctp_gap_ack_block *sctp_tsnmap_get_gabs(struct sctp_tsnmap *map) |
| { |
| return map->gabs; |
| } |
| |
| /* Is there a gap in the TSN map? */ |
| static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map) |
| { |
| return (map->cumulative_tsn_ack_point != map->max_tsn_seen); |
| } |
| |
| /* Mark a duplicate TSN. Note: limit the storage of duplicate TSN |
| * information. |
| */ |
| static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn) |
| { |
| if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS) |
| map->dup_tsns[map->num_dup_tsns++] = htonl(tsn); |
| } |
| |
| /* Renege a TSN that was seen. */ |
| void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn); |
| |
| /* Is there a gap in the TSN map? */ |
| int sctp_tsnmap_has_gap(const struct sctp_tsnmap *); |
| |
| #endif /* __sctp_tsnmap_h__ */ |