/*-

 * 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("$FreeBSD$");

#ifdef HAVE_ERRNO_H

#include <errno.h>

#endif

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#endif

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#include "archive.h"

#include "archive_private.h"

#include "archive_read_private.h"

#define LRZIP_HEADER_MAGIC "LRZI"

#define LRZIP_HEADER_MAGIC_LEN 4

static int	lrzip_bidder_bid(struct archive_read_filter_bidder *,

		    struct archive_read_filter *);

static int	lrzip_bidder_init(struct archive_read_filter *);

static int

lrzip_reader_free(struct archive_read_filter_bidder *self)

{

	(void)self; /* UNUSED */

	return (ARCHIVE_OK);

}

int

archive_read_support_filter_lrzip(struct archive *_a)

{

	struct archive_read *a = (struct archive_read *)_a;

	struct archive_read_filter_bidder *reader;

	archive_check_magic(_a, ARCHIVE_READ_MAGIC,

	    ARCHIVE_STATE_NEW, "archive_read_support_filter_lrzip");

	if (__archive_read_get_bidder(a, &reader) != ARCHIVE_OK)

		return (ARCHIVE_FATAL);

	reader->data = NULL;

	reader->name = "lrzip";

	reader->bid = lrzip_bidder_bid;

	reader->init = lrzip_bidder_init;

	reader->options = NULL;

	reader->free = lrzip_reader_free;

	/* This filter always uses an external program. */

	archive_set_error(_a, ARCHIVE_ERRNO_MISC,

	    "Using external lrzip program for lrzip decompression");

	return (ARCHIVE_WARN);

}

/*

 * Bidder just verifies the header and returns the number of verified bits.

 */

static int

lrzip_bidder_bid(struct archive_read_filter_bidder *self,

    struct archive_read_filter *filter)

{

	const unsigned char *p;

	ssize_t avail, len;

	int i;

	(void)self; /* UNUSED */

	/* Start by looking at the first six bytes of the header, which

	 * is all fixed layout. */

	len = 6;

	p = __archive_read_filter_ahead(filter, len, &avail);

	if (p == NULL || avail == 0)

		return (0);

	if (memcmp(p, LRZIP_HEADER_MAGIC, LRZIP_HEADER_MAGIC_LEN))

		return (0);

	/* current major version is always 0, verify this */

	if (p[LRZIP_HEADER_MAGIC_LEN])

		return 0;

	/* support only v0.6+ lrzip for sanity */

	i = p[LRZIP_HEADER_MAGIC_LEN + 1];

	if ((i < 6) || (i > 10))

		return 0;

	return (int)len;

}

static int

lrzip_bidder_init(struct archive_read_filter *self)

{

	int r;

	r = __archive_read_program(self, "lrzip -d -q");

	/* Note: We set the format here even if __archive_read_program()

	 * above fails.  We do, after all, know what the format is

	 * even if we weren't able to read it. */

	self->code = ARCHIVE_FILTER_LRZIP;

	self->name = "lrzip";

	return (r);

}