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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)ring.h 8.1 (Berkeley) 6/6/93 30 * $FreeBSD: src/crypto/telnet/telnet/ring.h,v 1.1.1.1.8.1 2002/04/13 10:59:08 markm Exp $ 31 * $DragonFly: src/crypto/telnet/telnet/ring.h,v 1.2 2003/06/17 04:24:37 dillon Exp $ 32 */ 33 34 /* 35 * This defines a structure for a ring buffer. 36 * 37 * The circular buffer has two parts: 38 *((( 39 * full: [consume, supply) 40 * empty: [supply, consume) 41 *]]] 42 * 43 */ 44 typedef struct { 45 unsigned char *consume, /* where data comes out of */ 46 *supply, /* where data comes in to */ 47 *bottom, /* lowest address in buffer */ 48 *top, /* highest address+1 in buffer */ 49 *mark; /* marker (user defined) */ 50 #ifdef ENCRYPTION 51 unsigned char *clearto; /* Data to this point is clear text */ 52 unsigned char *encryyptedto; /* Data is encrypted to here */ 53 #endif /* ENCRYPTION */ 54 int size; /* size in bytes of buffer */ 55 u_long consumetime, /* help us keep straight full, empty, etc. */ 56 supplytime; 57 } Ring; 58 59 /* Here are some functions and macros to deal with the ring buffer */ 60 61 /* Initialization routine */ 62 extern int 63 ring_init(Ring *ring, unsigned char *buffer, int count); 64 65 /* Data movement routines */ 66 extern void 67 ring_supply_data(Ring *ring, unsigned char *buffer, int count); 68 #ifdef notdef 69 extern void 70 ring_consume_data(Ring *ring, unsigned char *buffer, int count); 71 #endif 72 73 /* Buffer state transition routines */ 74 extern void 75 ring_supplied(Ring *ring, int count), 76 ring_consumed(Ring *ring, int count); 77 78 /* Buffer state query routines */ 79 extern int 80 ring_at_mark(Ring *), 81 ring_empty_count(Ring *ring), 82 ring_empty_consecutive(Ring *ring), 83 ring_full_count(Ring *ring), 84 ring_full_consecutive(Ring *ring); 85 86 #ifdef ENCRYPTION 87 extern void 88 ring_encrypt(Ring *ring, void (*func)(unsigned char *, int)), 89 ring_clearto(Ring *ring); 90 #endif /* ENCRYPTION */ 91 92 extern void 93 ring_clear_mark(Ring *), 94 ring_mark(Ring *); 95