cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tsnmap.h (4846B)

      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/* SCTP kernel implementation
      3 * (C) Copyright IBM Corp. 2001, 2004
      4 * Copyright (c) 1999-2000 Cisco, Inc.
      5 * Copyright (c) 1999-2001 Motorola, Inc.
      6 * Copyright (c) 2001 Intel Corp.
      7 *
      8 * This file is part of the SCTP kernel implementation
      9 *
     10 * These are the definitions needed for the tsnmap type.  The tsnmap is used
     11 * to track out of order TSNs received.
     12 *
     13 * Please send any bug reports or fixes you make to the
     14 * email address(es):
     15 *    lksctp developers <linux-sctp@vger.kernel.org>
     16 *
     17 * Written or modified by:
     18 *   Jon Grimm             <jgrimm@us.ibm.com>
     19 *   La Monte H.P. Yarroll <piggy@acm.org>
     20 *   Karl Knutson          <karl@athena.chicago.il.us>
     21 *   Sridhar Samudrala     <sri@us.ibm.com>
     22 */
     23#include <net/sctp/constants.h>
     24
     25#ifndef __sctp_tsnmap_h__
     26#define __sctp_tsnmap_h__
     27
     28/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB)
     29 * Mapping  An array of bits or bytes indicating which out of
     30 * Array    order TSN's have been received (relative to the
     31 *          Last Rcvd TSN). If no gaps exist, i.e. no out of
     32 *          order packets have been received, this array
     33 *          will be set to all zero. This structure may be
     34 *          in the form of a circular buffer or bit array.
     35 */
     36struct sctp_tsnmap {
     37	/* This array counts the number of chunks with each TSN.
     38	 * It points at one of the two buffers with which we will
     39	 * ping-pong between.
     40	 */
     41	unsigned long *tsn_map;
     42
     43	/* This is the TSN at tsn_map[0].  */
     44	__u32 base_tsn;
     45
     46	/* Last Rcvd   : This is the last TSN received in
     47	 * TSN	       : sequence. This value is set initially by
     48	 *             : taking the peer's Initial TSN, received in
     49	 *             : the INIT or INIT ACK chunk, and subtracting
     50	 *             : one from it.
     51	 *
     52	 * Throughout most of the specification this is called the
     53	 * "Cumulative TSN ACK Point".  In this case, we
     54	 * ignore the advice in 12.2 in favour of the term
     55	 * used in the bulk of the text.
     56	 */
     57	__u32 cumulative_tsn_ack_point;
     58
     59	/* This is the highest TSN we've marked.  */
     60	__u32 max_tsn_seen;
     61
     62	/* This is the minimum number of TSNs we can track.  This corresponds
     63	 * to the size of tsn_map.   Note: the overflow_map allows us to
     64	 * potentially track more than this quantity.
     65	 */
     66	__u16 len;
     67
     68	/* Data chunks pending receipt. used by SCTP_STATUS sockopt */
     69	__u16 pending_data;
     70
     71	/* Record duplicate TSNs here.  We clear this after
     72	 * every SACK.  Store up to SCTP_MAX_DUP_TSNS worth of
     73	 * information.
     74	 */
     75	__u16 num_dup_tsns;
     76	__be32 dup_tsns[SCTP_MAX_DUP_TSNS];
     77};
     78
     79struct sctp_tsnmap_iter {
     80	__u32 start;
     81};
     82
     83/* Initialize a block of memory as a tsnmap.  */
     84struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len,
     85				     __u32 initial_tsn, gfp_t gfp);
     86
     87void sctp_tsnmap_free(struct sctp_tsnmap *map);
     88
     89/* Test the tracking state of this TSN.
     90 * Returns:
     91 *   0 if the TSN has not yet been seen
     92 *  >0 if the TSN has been seen (duplicate)
     93 *  <0 if the TSN is invalid (too large to track)
     94 */
     95int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn);
     96
     97/* Mark this TSN as seen.  */
     98int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn,
     99		     struct sctp_transport *trans);
    100
    101/* Mark this TSN and all lower as seen. */
    102void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn);
    103
    104/* Retrieve the Cumulative TSN ACK Point.  */
    105static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map)
    106{
    107	return map->cumulative_tsn_ack_point;
    108}
    109
    110/* Retrieve the highest TSN we've seen.  */
    111static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map)
    112{
    113	return map->max_tsn_seen;
    114}
    115
    116/* How many duplicate TSNs are stored? */
    117static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map)
    118{
    119	return map->num_dup_tsns;
    120}
    121
    122/* Return pointer to duplicate tsn array as needed by SACK. */
    123static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map)
    124{
    125	map->num_dup_tsns = 0;
    126	return map->dup_tsns;
    127}
    128
    129/* How many gap ack blocks do we have recorded? */
    130__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
    131			   struct sctp_gap_ack_block *gabs);
    132
    133/* Refresh the count on pending data. */
    134__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map);
    135
    136/* Is there a gap in the TSN map?  */
    137static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map)
    138{
    139	return map->cumulative_tsn_ack_point != map->max_tsn_seen;
    140}
    141
    142/* Mark a duplicate TSN.  Note:  limit the storage of duplicate TSN
    143 * information.
    144 */
    145static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn)
    146{
    147	if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS)
    148		map->dup_tsns[map->num_dup_tsns++] = htonl(tsn);
    149}
    150
    151/* Renege a TSN that was seen.  */
    152void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn);
    153
    154/* Is there a gap in the TSN map? */
    155int sctp_tsnmap_has_gap(const struct sctp_tsnmap *);
    156
    157#endif /* __sctp_tsnmap_h__ */