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/*
* Dropbear SSH
*
* Copyright (c) 2002-2004 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
#include "includes.h"
#include "dbutil.h"
#include "circbuffer.h"
#define MAX_CBUF_SIZE 100000000
circbuffer * cbuf_new(unsigned int size) {
circbuffer *cbuf = NULL;
if (size > MAX_CBUF_SIZE) {
dropbear_exit("Bad cbuf size");
}
cbuf = (circbuffer*)m_malloc(sizeof(circbuffer));
/* data is malloced on first write */
cbuf->data = NULL;
cbuf->used = 0;
cbuf->readpos = 0;
cbuf->writepos = 0;
cbuf->size = size;
return cbuf;
}
void cbuf_free(circbuffer * cbuf) {
if (cbuf->data) {
m_burn(cbuf->data, cbuf->size);
m_free(cbuf->data);
}
m_free(cbuf);
}
unsigned int cbuf_getused(const circbuffer * cbuf) {
return cbuf->used;
}
unsigned int cbuf_getavail(const circbuffer * cbuf) {
return cbuf->size - cbuf->used;
}
unsigned int cbuf_writelen(const circbuffer *cbuf) {
dropbear_assert(cbuf->used <= cbuf->size);
dropbear_assert(((2*cbuf->size)+cbuf->writepos-cbuf->readpos)%cbuf->size == cbuf->used%cbuf->size);
dropbear_assert(((2*cbuf->size)+cbuf->readpos-cbuf->writepos)%cbuf->size == (cbuf->size-cbuf->used)%cbuf->size);
if (cbuf->used == cbuf->size) {
TRACE(("cbuf_writelen: full buffer"))
return 0; /* full */
}
if (cbuf->writepos < cbuf->readpos) {
return cbuf->readpos - cbuf->writepos;
}
return cbuf->size - cbuf->writepos;
}
void cbuf_readptrs(const circbuffer *cbuf,
unsigned char **p1, unsigned int *len1,
unsigned char **p2, unsigned int *len2) {
*p1 = &cbuf->data[cbuf->readpos];
*len1 = MIN(cbuf->used, cbuf->size - cbuf->readpos);
if (*len1 < cbuf->used) {
*p2 = cbuf->data;
*len2 = cbuf->used - *len1;
} else {
*p2 = NULL;
*len2 = 0;
}
}
unsigned char* cbuf_writeptr(circbuffer *cbuf, unsigned int len) {
if (len > cbuf_writelen(cbuf)) {
dropbear_exit("Bad cbuf write");
}
if (!cbuf->data) {
/* lazy allocation */
cbuf->data = (unsigned char*)m_malloc(cbuf->size);
}
return &cbuf->data[cbuf->writepos];
}
void cbuf_incrwrite(circbuffer *cbuf, unsigned int len) {
if (len > cbuf_writelen(cbuf)) {
dropbear_exit("Bad cbuf write");
}
cbuf->used += len;
dropbear_assert(cbuf->used <= cbuf->size);
cbuf->writepos = (cbuf->writepos + len) % cbuf->size;
}
void cbuf_incrread(circbuffer *cbuf, unsigned int len) {
dropbear_assert(cbuf->used >= len);
cbuf->used -= len;
cbuf->readpos = (cbuf->readpos + len) % cbuf->size;
}
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