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/*-
* Copyright (c) 2003-2007 Tim Kientzle
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD: src/lib/libarchive/archive_read_open_memory.c,v 1.6 2007/07/06 15:51:59 kientzle Exp $");
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "archive.h"
/*
* Glue to read an archive from a block of memory.
*
* This is mostly a huge help in building test harnesses;
* test programs can build archives in memory and read them
* back again without having to mess with files on disk.
*/
struct read_memory_data {
const unsigned char *start;
const unsigned char *p;
const unsigned char *end;
ssize_t read_size;
};
static int memory_read_close(struct archive *, void *);
static int memory_read_open(struct archive *, void *);
static int64_t memory_read_seek(struct archive *, void *, int64_t offset, int whence);
static int64_t memory_read_skip(struct archive *, void *, int64_t request);
static ssize_t memory_read(struct archive *, void *, const void **buff);
int
archive_read_open_memory(struct archive *a, const void *buff, size_t size)
{
return archive_read_open_memory2(a, buff, size, size);
}
/*
* Don't use _open_memory2() in production code; the archive_read_open_memory()
* version is the one you really want. This is just here so that
* test harnesses can exercise block operations inside the library.
*/
int
archive_read_open_memory2(struct archive *a, const void *buff,
size_t size, size_t read_size)
{
struct read_memory_data *mine;
mine = (struct read_memory_data *)calloc(1, sizeof(*mine));
if (mine == NULL) {
archive_set_error(a, ENOMEM, "No memory");
return (ARCHIVE_FATAL);
}
mine->start = mine->p = (const unsigned char *)buff;
mine->end = mine->start + size;
mine->read_size = read_size;
archive_read_set_open_callback(a, memory_read_open);
archive_read_set_read_callback(a, memory_read);
archive_read_set_seek_callback(a, memory_read_seek);
archive_read_set_skip_callback(a, memory_read_skip);
archive_read_set_close_callback(a, memory_read_close);
archive_read_set_callback_data(a, mine);
return (archive_read_open1(a));
}
/*
* There's nothing to open.
*/
static int
memory_read_open(struct archive *a, void *client_data)
{
(void)a; /* UNUSED */
(void)client_data; /* UNUSED */
return (ARCHIVE_OK);
}
/*
* This is scary simple: Just advance a pointer. Limiting
* to read_size is not technically necessary, but it exercises
* more of the internal logic when used with a small block size
* in a test harness. Production use should not specify a block
* size; then this is much faster.
*/
static ssize_t
memory_read(struct archive *a, void *client_data, const void **buff)
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
ssize_t size;
(void)a; /* UNUSED */
*buff = mine->p;
size = mine->end - mine->p;
if (size > mine->read_size)
size = mine->read_size;
mine->p += size;
return (size);
}
/*
* Advancing is just as simple. Again, this is doing more than
* necessary in order to better exercise internal code when used
* as a test harness.
*/
static int64_t
memory_read_skip(struct archive *a, void *client_data, int64_t skip)
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
(void)a; /* UNUSED */
if ((int64_t)skip > (int64_t)(mine->end - mine->p))
skip = mine->end - mine->p;
/* Round down to block size. */
skip /= mine->read_size;
skip *= mine->read_size;
mine->p += skip;
return (skip);
}
/*
* Seeking.
*/
static int64_t
memory_read_seek(struct archive *a, void *client_data, int64_t offset, int whence)
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
(void)a; /* UNUSED */
switch (whence) {
case SEEK_SET:
mine->p = mine->start + offset;
break;
case SEEK_CUR:
mine->p += offset;
break;
case SEEK_END:
mine->p = mine->end + offset;
break;
default:
return ARCHIVE_FATAL;
}
if (mine->p < mine->start) {
mine->p = mine->start;
return ARCHIVE_FAILED;
}
if (mine->p > mine->end) {
mine->p = mine->end;
return ARCHIVE_FAILED;
}
return (mine->p - mine->start);
}
/*
* Close is just cleaning up our one small bit of data.
*/
static int
memory_read_close(struct archive *a, void *client_data)
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
(void)a; /* UNUSED */
free(mine);
return (ARCHIVE_OK);
}