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SGI Developer Toolbox 6.1
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SGI Developer Toolbox 6.1 - Disc 4.iso
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HDLCFrame.c++
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1994-08-01
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/* $Header: /usr/people/sam/fax/faxd/RCS/HDLCFrame.c++,v 1.11 1994/02/28 14:15:26 sam Rel $ */
/*
* Copyright (c) 1990, 1991, 1992, 1993, 1994 Sam Leffler
* Copyright (c) 1991, 1992, 1993, 1994 Silicon Graphics, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software and
* its documentation for any purpose is hereby granted without fee, provided
* that (i) the above copyright notices and this permission notice appear in
* all copies of the software and related documentation, and (ii) the names of
* Sam Leffler and Silicon Graphics may not be used in any advertising or
* publicity relating to the software without the specific, prior written
* permission of Sam Leffler and Silicon Graphics.
*
* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
/*
* Raw HDLC Frame Interface.
*/
#include "HDLCFrame.h"
#include <string.h>
#include <stdlib.h>
HDLCFrame::HDLCFrame(u_int fo)
{
frameOverhead = fo;
base = next = buf;
end = &buf[sizeof(buf)];
amountToGrowBy = 1024;
ok = FALSE;
}
HDLCFrame::~HDLCFrame()
{
if (base != buf) delete base;
}
HDLCFrame::HDLCFrame(const HDLCFrame& other)
{
u_int size = other.end - other.base;
u_int len = other.getLength();
if (size > sizeof(buf)) {
base = (u_char*) malloc(size);
} else {
base = &buf[0];
}
end = base + size;
next = base + len;
memcpy(base, other.base, len);
ok = other.ok;
frameOverhead = other.frameOverhead;
}
void
HDLCFrame::addc(u_char c)
{
if (next >= end)
grow(amountToGrowBy);
*next++ = c;
}
void
HDLCFrame::grow(u_int amount)
{
// insure an acceptable amount of growth
if (amount < amountToGrowBy) amount = amountToGrowBy;
// move data into larger piece of memory
u_int size = end - base;
u_int len = getLength();
u_int newSize = size + amount;
if (base == buf) {
base = (u_char*) malloc(newSize);
memcpy(base, buf, sizeof(buf));
} else {
base = (u_char*) realloc(base, newSize);
}
// update position pointers
end = base + newSize;
next = base + len;
}
void
HDLCFrame::put(const u_char* c, u_int len)
{
u_int remainingSpace = end - next;
if (len > remainingSpace)
grow(len - remainingSpace);
memcpy(next, c, len);
next += len;
}
u_int
HDLCFrame::getDataWord() const
{
u_int n = getFrameDataLength();
u_int w = (n > 1) ? (*this)[3] : 0;
if (n > 2) w = (w<<8)|(*this)[4];
if (n > 3) w = (w<<8)|(*this)[5];
if (n > 4) w = (w<<8)|(*this)[6];
return w;
}
u_int
HDLCFrame::getDIS() const
{
u_int n = getFrameDataLength();
u_int dis = (n > 1) ? (*this)[3] : 0;
dis <<= 8; if (n > 2) dis |= (*this)[4];
dis <<= 8; if (n > 3) dis |= (*this)[5];
return dis;
}
u_int
HDLCFrame::getXINFO() const
{
return (getFrameDataLength() > 4 && ((*this)[5] & 0x1)) ? (*this)[6] : 0;
}