1 /*-
2  * Copyright (c) 2003-2007 Tim Kientzle
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "archive_platform.h"
27 
28 __FBSDID("$FreeBSD$");
29 
30 
31 #ifdef HAVE_ERRNO_H
32 #include <errno.h>
33 #endif
34 #ifdef HAVE_STDLIB_H
35 #include <stdlib.h>
36 #endif
37 #ifdef HAVE_STRING_H
38 #include <string.h>
39 #endif
40 #ifdef HAVE_UNISTD_H
41 #include <unistd.h>
42 #endif
43 
44 #include "archive.h"
45 #include "archive_private.h"
46 #include "archive_read_private.h"
47 
48 #define LRZIP_HEADER_MAGIC "LRZI"
49 #define LRZIP_HEADER_MAGIC_LEN 4
50 
51 static int	lrzip_bidder_bid(struct archive_read_filter_bidder *,
52 		    struct archive_read_filter *);
53 static int	lrzip_bidder_init(struct archive_read_filter *);
54 
55 
56 static const struct archive_read_filter_bidder_vtable
57 lrzip_bidder_vtable = {
58 	.bid = lrzip_bidder_bid,
59 	.init = lrzip_bidder_init,
60 };
61 
62 int
63 archive_read_support_filter_lrzip(struct archive *_a)
64 {
65 	struct archive_read *a = (struct archive_read *)_a;
66 
67 	if (__archive_read_register_bidder(a, NULL, "lrzip",
68 				&lrzip_bidder_vtable) != ARCHIVE_OK)
69 		return (ARCHIVE_FATAL);
70 
71 	/* This filter always uses an external program. */
72 	archive_set_error(_a, ARCHIVE_ERRNO_MISC,
73 	    "Using external lrzip program for lrzip decompression");
74 	return (ARCHIVE_WARN);
75 }
76 
77 /*
78  * Bidder just verifies the header and returns the number of verified bits.
79  */
80 static int
81 lrzip_bidder_bid(struct archive_read_filter_bidder *self,
82     struct archive_read_filter *filter)
83 {
84 	const unsigned char *p;
85 	ssize_t avail, len;
86 	int i;
87 
88 	(void)self; /* UNUSED */
89 	/* Start by looking at the first six bytes of the header, which
90 	 * is all fixed layout. */
91 	len = 6;
92 	p = __archive_read_filter_ahead(filter, len, &avail);
93 	if (p == NULL || avail == 0)
94 		return (0);
95 
96 	if (memcmp(p, LRZIP_HEADER_MAGIC, LRZIP_HEADER_MAGIC_LEN))
97 		return (0);
98 
99 	/* current major version is always 0, verify this */
100 	if (p[LRZIP_HEADER_MAGIC_LEN])
101 		return 0;
102 	/* support only v0.6+ lrzip for sanity */
103 	i = p[LRZIP_HEADER_MAGIC_LEN + 1];
104 	if ((i < 6) || (i > 10))
105 		return 0;
106 
107 	return (int)len;
108 }
109 
110 static int
111 lrzip_bidder_init(struct archive_read_filter *self)
112 {
113 	int r;
114 
115 	r = __archive_read_program(self, "lrzip -d -q");
116 	/* Note: We set the format here even if __archive_read_program()
117 	 * above fails.  We do, after all, know what the format is
118 	 * even if we weren't able to read it. */
119 	self->code = ARCHIVE_FILTER_LRZIP;
120 	self->name = "lrzip";
121 	return (r);
122 }
123