src/bin/network/telnet/ring.h

   1 /*
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)ring.h      8.1 (Berkeley) 6/6/93
  34  * $FreeBSD: src/contrib/telnet/telnet/ring.h,v 1.4 2001/11/30 22:28:07 markm Exp $
  35  */
  36
  37 #if defined(P)
  38 # undef P
  39 #endif
  40
  41 #if defined(__STDC__) || defined(LINT_ARGS)
  42 # define        P(x)    x
  43 #else
  44 # define        P(x)    ()
  45 #endif
  46
  47 /*
  48  * This defines a structure for a ring buffer.
  49  *
  50  * The circular buffer has two parts:
  51  *(((
  52  *      full:   [consume, supply)
  53  *      empty:  [supply, consume)
  54  *]]]
  55  *
  56  */
  57 typedef struct {
  58     unsigned char       *consume,       /* where data comes out of */
  59                         *supply,        /* where data comes in to */
  60                         *bottom,        /* lowest address in buffer */
  61                         *top,           /* highest address+1 in buffer */
  62                         *mark;          /* marker (user defined) */
  63 #ifdef  ENCRYPTION
  64     unsigned char       *clearto;       /* Data to this point is clear text */
  65     unsigned char       *encryyptedto;  /* Data is encrypted to here */
  66 #endif  /* ENCRYPTION */
  67     int         size;           /* size in bytes of buffer */
  68     u_long      consumetime,    /* help us keep straight full, empty, etc. */
  69                 supplytime;
  70 } Ring;
  71
  72 /* Here are some functions and macros to deal with the ring buffer */
  73
  74 /* Initialization routine */
  75 extern int
  76         ring_init(Ring *ring, unsigned char *buffer, int count);
  77
  78 /* Data movement routines */
  79 extern void
  80         ring_supply_data(Ring *ring, unsigned char *buffer, int count);
  81 #ifdef notdef
  82 extern void
  83         ring_consume_data(Ring *ring, unsigned char *buffer, int count);
  84 #endif
  85
  86 /* Buffer state transition routines */
  87 extern void
  88         ring_supplied(Ring *ring, int count),
  89         ring_consumed(Ring *ring, int count);
  90
  91 /* Buffer state query routines */
  92 extern int
  93         ring_at_mark(Ring *),
  94         ring_empty_count(Ring *ring),
  95         ring_empty_consecutive(Ring *ring),
  96         ring_full_count(Ring *ring),
  97         ring_full_consecutive(Ring *ring);
  98
  99 #ifdef  ENCRYPTION
 100 extern void
 101         ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)),
 102         ring_clearto(Ring *ring);
 103 #endif  /* ENCRYPTION */
 104
 105 extern void
 106         ring_clear_mark(Ring *),
 107         ring_mark(Ring *);