usr.bin/telnet/ring.h

   1 /*      $NetBSD: ring.h,v 1.10 2003/08/07 11:16:10 agc Exp $    */
   2
   3 /*
   4  * Copyright (c) 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      from: @(#)ring.h        8.1 (Berkeley) 6/6/93
  32  */
  33
  34 #include <sys/cdefs.h>
  35
  36 /*
  37  * This defines a structure for a ring buffer.
  38  *
  39  * The circular buffer has two parts:
  40  *(((
  41  *      full:   [consume, supply)
  42  *      empty:  [supply, consume)
  43  *]]]
  44  *
  45  */
  46 typedef struct {
  47     unsigned char       *consume,       /* where data comes out of */
  48                         *supply,        /* where data comes in to */
  49                         *bottom,        /* lowest address in buffer */
  50                         *top,           /* highest address+1 in buffer */
  51                         *mark;          /* marker (user defined) */
  52 #ifdef  ENCRYPTION
  53     unsigned char       *clearto;       /* Data to this point is clear text */
  54     unsigned char       *encryyptedto;  /* Data is encrypted to here */
  55 #endif  /* ENCRYPTION */
  56     int         size;           /* size in bytes of buffer */
  57     u_long      consumetime,    /* help us keep straight full, empty, etc. */
  58                 supplytime;
  59 } Ring;
  60
  61 /* Ring buffer structures which are shared */
  62
  63 extern Ring
  64     netoring,
  65     netiring,
  66     ttyoring,
  67     ttyiring;
  68
  69 /* Here are some functions and macros to deal with the ring buffer */
  70
  71 /* Initialization routine */
  72 extern int
  73         ring_init(Ring *ring, unsigned char *buffer, int count);
  74
  75 /* Data movement routines */
  76 extern void
  77         ring_supply_data(Ring *ring, unsigned char *buffer, int count);
  78 #ifdef notdef
  79 extern void
  80         ring_consume_data(Ring *ring, unsigned char *buffer, int count);
  81 #endif
  82
  83 /* Buffer state transition routines */
  84 extern void
  85         ring_supplied(Ring *ring, int count),
  86         ring_consumed(Ring *ring, int count);
  87
  88 /* Buffer state query routines */
  89 extern int
  90         ring_empty_count(Ring *ring),
  91         ring_empty_consecutive(Ring *ring),
  92         ring_full_count(Ring *ring),
  93         ring_full_consecutive(Ring *ring),
  94         ring_at_mark(Ring *ring);
  95
  96 #ifdef  ENCRYPTION
  97 extern void
  98         ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)),
  99         ring_clearto(Ring *ring);
 100 #endif  /* ENCRYPTION */
 101
 102 extern void
 103         ring_clear_mark(Ring *ring),
 104         ring_mark(Ring *ring);