8e1ee18c33
The tsn map currently use is 4K large and is stuck inside the sctp_association structure making memory references REALLY expensive. What we really need is at most 4K worth of bits so the biggest map we would have is 512 bytes. Also, the map is only really usefull when we have gaps to store and report. As such, starting with minimal map of say 32 TSNs (bits) should be enough for normal low-loss operations. We can grow the map by some multiple of 32 along with some extra room any time we receive the TSN which would put us outside of the map boundry. As we close gaps, we can shift the map to rebase it on the latest TSN we've seen. This saves 4088 bytes per association just in the map alone along savings from the now unnecessary structure members. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
187 lines
5.9 KiB
C
187 lines
5.9 KiB
C
/* SCTP kernel implementation
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* (C) Copyright IBM Corp. 2001, 2004
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* Copyright (c) 1999-2000 Cisco, Inc.
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* Copyright (c) 1999-2001 Motorola, Inc.
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* Copyright (c) 2001 Intel Corp.
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*
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* This file is part of the SCTP kernel implementation
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*
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* These are the definitions needed for the tsnmap type. The tsnmap is used
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* to track out of order TSNs received.
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*
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* This SCTP implementation is free software;
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* you can redistribute it and/or modify it under the terms of
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* the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This SCTP implementation is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* ************************
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU CC; see the file COPYING. If not, write to
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* the Free Software Foundation, 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*
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* Please send any bug reports or fixes you make to the
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* email address(es):
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* lksctp developers <lksctp-developers@lists.sourceforge.net>
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*
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* Or submit a bug report through the following website:
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* http://www.sf.net/projects/lksctp
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*
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* Written or modified by:
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* Jon Grimm <jgrimm@us.ibm.com>
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* La Monte H.P. Yarroll <piggy@acm.org>
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* Karl Knutson <karl@athena.chicago.il.us>
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* Sridhar Samudrala <sri@us.ibm.com>
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*
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* Any bugs reported given to us we will try to fix... any fixes shared will
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* be incorporated into the next SCTP release.
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*/
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#include <net/sctp/constants.h>
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#ifndef __sctp_tsnmap_h__
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#define __sctp_tsnmap_h__
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/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
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* Mapping An array of bits or bytes indicating which out of
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* Array order TSN's have been received (relative to the
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* Last Rcvd TSN). If no gaps exist, i.e. no out of
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* order packets have been received, this array
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* will be set to all zero. This structure may be
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* in the form of a circular buffer or bit array.
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*/
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struct sctp_tsnmap {
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/* This array counts the number of chunks with each TSN.
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* It points at one of the two buffers with which we will
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* ping-pong between.
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*/
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unsigned long *tsn_map;
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/* This is the TSN at tsn_map[0]. */
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__u32 base_tsn;
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/* Last Rcvd : This is the last TSN received in
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* TSN : sequence. This value is set initially by
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* : taking the peer's Initial TSN, received in
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* : the INIT or INIT ACK chunk, and subtracting
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* : one from it.
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*
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* Throughout most of the specification this is called the
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* "Cumulative TSN ACK Point". In this case, we
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* ignore the advice in 12.2 in favour of the term
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* used in the bulk of the text.
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*/
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__u32 cumulative_tsn_ack_point;
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/* This is the highest TSN we've marked. */
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__u32 max_tsn_seen;
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/* This is the minimum number of TSNs we can track. This corresponds
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* to the size of tsn_map. Note: the overflow_map allows us to
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* potentially track more than this quantity.
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*/
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__u16 len;
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/* Data chunks pending receipt. used by SCTP_STATUS sockopt */
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__u16 pending_data;
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/* Record duplicate TSNs here. We clear this after
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* every SACK. Store up to SCTP_MAX_DUP_TSNS worth of
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* information.
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*/
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__be32 dup_tsns[SCTP_MAX_DUP_TSNS];
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__u16 num_dup_tsns;
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/* Record gap ack block information here. */
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struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
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};
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struct sctp_tsnmap_iter {
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__u32 start;
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};
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/* Initialize a block of memory as a tsnmap. */
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struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
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__u32 initial_tsn, gfp_t gfp);
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void sctp_tsnmap_free(struct sctp_tsnmap *map);
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/* Test the tracking state of this TSN.
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* Returns:
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* 0 if the TSN has not yet been seen
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* >0 if the TSN has been seen (duplicate)
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* <0 if the TSN is invalid (too large to track)
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*/
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int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
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/* Mark this TSN as seen. */
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int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn);
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/* Mark this TSN and all lower as seen. */
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void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
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/* Retrieve the Cumulative TSN ACK Point. */
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static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
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{
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return map->cumulative_tsn_ack_point;
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}
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/* Retrieve the highest TSN we've seen. */
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static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
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{
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return map->max_tsn_seen;
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}
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/* How many duplicate TSNs are stored? */
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static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
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{
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return map->num_dup_tsns;
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}
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/* Return pointer to duplicate tsn array as needed by SACK. */
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static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
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{
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map->num_dup_tsns = 0;
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return map->dup_tsns;
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}
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/* How many gap ack blocks do we have recorded? */
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__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map);
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/* Refresh the count on pending data. */
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__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
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/* Return pointer to gap ack blocks as needed by SACK. */
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static inline struct sctp_gap_ack_block *sctp_tsnmap_get_gabs(struct sctp_tsnmap *map)
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{
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return map->gabs;
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}
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/* Is there a gap in the TSN map? */
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static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
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{
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return (map->cumulative_tsn_ack_point != map->max_tsn_seen);
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}
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/* Mark a duplicate TSN. Note: limit the storage of duplicate TSN
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* information.
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*/
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static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
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{
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if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
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map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
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}
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/* Renege a TSN that was seen. */
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void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
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/* Is there a gap in the TSN map? */
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int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
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#endif /* __sctp_tsnmap_h__ */
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