core-admin/qrexec/buffer.c
2011-03-04 16:32:58 +01:00

94 lines
2.1 KiB
C

/*
* The Qubes OS Project, http://www.qubes-os.org
*
* Copyright (C) 2010 Rafal Wojtczuk <rafal@invisiblethingslab.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "buffer.h"
#define BUFFER_LIMIT 50000000
static int total_mem;
static char *limited_malloc(int len)
{
char *ret;
total_mem += len;
if (total_mem > BUFFER_LIMIT) {
fprintf(stderr, "attempt to allocate >BUFFER_LIMIT\n");
exit(1);
}
ret = malloc(len);
if (!ret) {
perror("malloc");
exit(1);
}
return ret;
}
static void limited_free(char *ptr, int len)
{
free(ptr);
total_mem -= len;
}
void buffer_init(struct buffer *b)
{
b->buflen = 0;
b->data = NULL;
}
void buffer_free(struct buffer *b)
{
if (b->buflen)
limited_free(b->data, b->buflen);
buffer_init(b);
}
void buffer_append(struct buffer *b, char *data, int len)
{
int newsize = len + b->buflen;
char *qdata = limited_malloc(len + b->buflen);
memcpy(qdata, b->data, b->buflen);
memcpy(qdata + b->buflen, data, len);
buffer_free(b);
b->buflen = newsize;
b->data = qdata;
}
void buffer_remove(struct buffer *b, int len)
{
int newsize = b->buflen - len;
char *qdata = limited_malloc(newsize);
memcpy(qdata, b->data + len, newsize);
buffer_free(b);
b->buflen = newsize;
b->data = qdata;
}
int buffer_len(struct buffer *b)
{
return b->buflen;
}
void *buffer_data(struct buffer *b)
{
return b->data;
}