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-rw-r--r--remote_cmds/telnet.tproj/ring.c322
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diff --git a/remote_cmds/telnet.tproj/ring.c b/remote_cmds/telnet.tproj/ring.c
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+/*
+ * Copyright (c) 1988, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if 0
+#ifndef lint
+static const char sccsid[] = "@(#)ring.c 8.2 (Berkeley) 5/30/95";
+#endif
+#endif
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: src/contrib/telnet/telnet/ring.c,v 1.7 2003/05/04 02:54:48 obrien Exp $");
+
+/*
+ * This defines a structure for a ring buffer.
+ *
+ * The circular buffer has two parts:
+ *(((
+ * full: [consume, supply)
+ * empty: [supply, consume)
+ *]]]
+ *
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifdef size_t
+#undef size_t
+#endif
+
+#include <sys/types.h>
+#ifndef FILIO_H
+#include <sys/ioctl.h>
+#endif
+#include <sys/socket.h>
+
+#include "ring.h"
+#include "general.h"
+
+/* Internal macros */
+
+#if !defined(MIN)
+#define MIN(a,b) (((a)<(b))? (a):(b))
+#endif /* !defined(MIN) */
+
+#define ring_subtract(d,a,b) (((a)-(b) >= 0)? \
+ (a)-(b): (((a)-(b))+(d)->size))
+
+#define ring_increment(d,a,c) (((a)+(c) < (d)->top)? \
+ (a)+(c) : (((a)+(c))-(d)->size))
+
+#define ring_decrement(d,a,c) (((a)-(c) >= (d)->bottom)? \
+ (a)-(c) : (((a)-(c))-(d)->size))
+
+
+/*
+ * The following is a clock, used to determine full, empty, etc.
+ *
+ * There is some trickiness here. Since the ring buffers are initialized
+ * to ZERO on allocation, we need to make sure, when interpreting the
+ * clock, that when the times are EQUAL, then the buffer is FULL.
+ */
+static u_long ring_clock = 0;
+
+
+#define ring_empty(d) (((d)->consume == (d)->supply) && \
+ ((d)->consumetime >= (d)->supplytime))
+#define ring_full(d) (((d)->supply == (d)->consume) && \
+ ((d)->supplytime > (d)->consumetime))
+
+/* Buffer state transition routines */
+
+int
+ring_init(Ring *ring, unsigned char *buffer, int count)
+{
+ memset((char *)ring, 0, sizeof *ring);
+
+ ring->size = count;
+
+ ring->supply = ring->consume = ring->bottom = buffer;
+
+ ring->top = ring->bottom+ring->size;
+
+#ifdef ENCRYPTION
+ ring->clearto = 0;
+#endif /* ENCRYPTION */
+
+ return 1;
+}
+
+/* Mark routines */
+
+/*
+ * Mark the most recently supplied byte.
+ */
+
+void
+ring_mark(Ring *ring)
+{
+ ring->mark = ring_decrement(ring, ring->supply, 1);
+}
+
+/*
+ * Is the ring pointing to the mark?
+ */
+
+int
+ring_at_mark(Ring *ring)
+{
+ if (ring->mark == ring->consume) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Clear any mark set on the ring.
+ */
+
+void
+ring_clear_mark(Ring *ring)
+{
+ ring->mark = 0;
+}
+
+/*
+ * Add characters from current segment to ring buffer.
+ */
+void
+ring_supplied(Ring *ring, int count)
+{
+ ring->supply = ring_increment(ring, ring->supply, count);
+ ring->supplytime = ++ring_clock;
+}
+
+/*
+ * We have just consumed "c" bytes.
+ */
+void
+ring_consumed(Ring *ring, int count)
+{
+ if (count == 0) /* don't update anything */
+ return;
+
+ if (ring->mark &&
+ (ring_subtract(ring, ring->mark, ring->consume) < count)) {
+ ring->mark = 0;
+ }
+#ifdef ENCRYPTION
+ if (ring->consume < ring->clearto &&
+ ring->clearto <= ring->consume + count)
+ ring->clearto = 0;
+ else if (ring->consume + count > ring->top &&
+ ring->bottom <= ring->clearto &&
+ ring->bottom + ((ring->consume + count) - ring->top))
+ ring->clearto = 0;
+#endif /* ENCRYPTION */
+ ring->consume = ring_increment(ring, ring->consume, count);
+ ring->consumetime = ++ring_clock;
+ /*
+ * Try to encourage "ring_empty_consecutive()" to be large.
+ */
+ if (ring_empty(ring)) {
+ ring->consume = ring->supply = ring->bottom;
+ }
+}
+
+
+
+/* Buffer state query routines */
+
+
+/* Number of bytes that may be supplied */
+int
+ring_empty_count(Ring *ring)
+{
+ if (ring_empty(ring)) { /* if empty */
+ return ring->size;
+ } else {
+ return ring_subtract(ring, ring->consume, ring->supply);
+ }
+}
+
+/* number of CONSECUTIVE bytes that may be supplied */
+int
+ring_empty_consecutive(Ring *ring)
+{
+ if ((ring->consume < ring->supply) || ring_empty(ring)) {
+ /*
+ * if consume is "below" supply, or empty, then
+ * return distance to the top
+ */
+ return ring_subtract(ring, ring->top, ring->supply);
+ } else {
+ /*
+ * else, return what we may.
+ */
+ return ring_subtract(ring, ring->consume, ring->supply);
+ }
+}
+
+/* Return the number of bytes that are available for consuming
+ * (but don't give more than enough to get to cross over set mark)
+ */
+
+int
+ring_full_count(Ring *ring)
+{
+ if ((ring->mark == 0) || (ring->mark == ring->consume)) {
+ if (ring_full(ring)) {
+ return ring->size; /* nothing consumed, but full */
+ } else {
+ return ring_subtract(ring, ring->supply, ring->consume);
+ }
+ } else {
+ return ring_subtract(ring, ring->mark, ring->consume);
+ }
+}
+
+/*
+ * Return the number of CONSECUTIVE bytes available for consuming.
+ * However, don't return more than enough to cross over set mark.
+ */
+int
+ring_full_consecutive(Ring *ring)
+{
+ if ((ring->mark == 0) || (ring->mark == ring->consume)) {
+ if ((ring->supply < ring->consume) || ring_full(ring)) {
+ return ring_subtract(ring, ring->top, ring->consume);
+ } else {
+ return ring_subtract(ring, ring->supply, ring->consume);
+ }
+ } else {
+ if (ring->mark < ring->consume) {
+ return ring_subtract(ring, ring->top, ring->consume);
+ } else { /* Else, distance to mark */
+ return ring_subtract(ring, ring->mark, ring->consume);
+ }
+ }
+}
+
+/*
+ * Move data into the "supply" portion of of the ring buffer.
+ */
+void
+ring_supply_data(Ring *ring, unsigned char *buffer, int count)
+{
+ int i;
+
+ while (count) {
+ i = MIN(count, ring_empty_consecutive(ring));
+ memcpy(ring->supply, buffer, i);
+ ring_supplied(ring, i);
+ count -= i;
+ buffer += i;
+ }
+}
+
+#ifdef ENCRYPTION
+void
+ring_encrypt(Ring *ring, void (*encryptor)(unsigned char *, int))
+{
+ unsigned char *s, *c;
+
+ if (ring_empty(ring) || ring->clearto == ring->supply)
+ return;
+
+ if (!(c = ring->clearto))
+ c = ring->consume;
+
+ s = ring->supply;
+
+ if (s <= c) {
+ (*encryptor)(c, ring->top - c);
+ (*encryptor)(ring->bottom, s - ring->bottom);
+ } else
+ (*encryptor)(c, s - c);
+
+ ring->clearto = ring->supply;
+}
+
+ void
+ring_clearto(ring)
+ Ring *ring;
+{
+ if (!ring_empty(ring))
+ ring->clearto = ring->supply;
+ else
+ ring->clearto = 0;
+}
+#endif /* ENCRYPTION */