archive_read_support_format_raw.c revision 302408 
1/*-
2 * Copyright (c) 2003-2009 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#include "archive_platform.h"
26__FBSDID("$FreeBSD: stable/11/contrib/libarchive/libarchive/archive_read_support_format_raw.c 299529 2016-05-12 10:16:16Z mm $");
27
28#ifdef HAVE_ERRNO_H
29#include <errno.h>
30#endif
31#include <stdio.h>
32#ifdef HAVE_STDLIB_H
33#include <stdlib.h>
34#endif
35
36#include "archive.h"
37#include "archive_entry.h"
38#include "archive_private.h"
39#include "archive_read_private.h"
40
41struct raw_info {
42	int64_t offset; /* Current position in the file. */
43	int64_t unconsumed;
44	int     end_of_file;
45};
46
47static int	archive_read_format_raw_bid(struct archive_read *, int);
48static int	archive_read_format_raw_cleanup(struct archive_read *);
49static int	archive_read_format_raw_read_data(struct archive_read *,
50		    const void **, size_t *, int64_t *);
51static int	archive_read_format_raw_read_data_skip(struct archive_read *);
52static int	archive_read_format_raw_read_header(struct archive_read *,
53		    struct archive_entry *);
54
55int
56archive_read_support_format_raw(struct archive *_a)
57{
58	struct raw_info *info;
59	struct archive_read *a = (struct archive_read *)_a;
60	int r;
61
62	archive_check_magic(_a, ARCHIVE_READ_MAGIC,
63	    ARCHIVE_STATE_NEW, "archive_read_support_format_raw");
64
65	info = (struct raw_info *)calloc(1, sizeof(*info));
66	if (info == NULL) {
67		archive_set_error(&a->archive, ENOMEM,
68		    "Can't allocate raw_info data");
69		return (ARCHIVE_FATAL);
70	}
71
72	r = __archive_read_register_format(a,
73	    info,
74	    "raw",
75	    archive_read_format_raw_bid,
76	    NULL,
77	    archive_read_format_raw_read_header,
78	    archive_read_format_raw_read_data,
79	    archive_read_format_raw_read_data_skip,
80	    NULL,
81	    archive_read_format_raw_cleanup,
82	    NULL,
83	    NULL);
84	if (r != ARCHIVE_OK)
85		free(info);
86	return (r);
87}
88
89/*
90 * Bid 1 if this is a non-empty file.  Anyone who can really support
91 * this should outbid us, so it should generally be safe to use "raw"
92 * in conjunction with other formats.  But, this could really confuse
93 * folks if there are bid errors or minor file damage, so we don't
94 * include "raw" as part of support_format_all().
95 */
96static int
97archive_read_format_raw_bid(struct archive_read *a, int best_bid)
98{
99	if (best_bid < 1 && __archive_read_ahead(a, 1, NULL) != NULL)
100		return (1);
101	return (-1);
102}
103
104/*
105 * Mock up a fake header.
106 */
107static int
108archive_read_format_raw_read_header(struct archive_read *a,
109    struct archive_entry *entry)
110{
111	struct raw_info *info;
112
113	info = (struct raw_info *)(a->format->data);
114	if (info->end_of_file)
115		return (ARCHIVE_EOF);
116
117	a->archive.archive_format = ARCHIVE_FORMAT_RAW;
118	a->archive.archive_format_name = "raw";
119	archive_entry_set_pathname(entry, "data");
120	archive_entry_set_filetype(entry, AE_IFREG);
121	archive_entry_set_perm(entry, 0644);
122	/* I'm deliberately leaving most fields unset here. */
123	return (ARCHIVE_OK);
124}
125
126static int
127archive_read_format_raw_read_data(struct archive_read *a,
128    const void **buff, size_t *size, int64_t *offset)
129{
130	struct raw_info *info;
131	ssize_t avail;
132
133	info = (struct raw_info *)(a->format->data);
134
135	/* Consume the bytes we read last time. */
136	if (info->unconsumed) {
137		__archive_read_consume(a, info->unconsumed);
138		info->unconsumed = 0;
139	}
140
141	if (info->end_of_file)
142		return (ARCHIVE_EOF);
143
144	/* Get whatever bytes are immediately available. */
145	*buff = __archive_read_ahead(a, 1, &avail);
146	if (avail > 0) {
147		/* Return the bytes we just read */
148		*size = avail;
149		*offset = info->offset;
150		info->offset += *size;
151		info->unconsumed = avail;
152		return (ARCHIVE_OK);
153	} else if (0 == avail) {
154		/* Record and return end-of-file. */
155		info->end_of_file = 1;
156		*size = 0;
157		*offset = info->offset;
158		return (ARCHIVE_EOF);
159	} else {
160		/* Record and return an error. */
161		*size = 0;
162		*offset = info->offset;
163		return ((int)avail);
164	}
165}
166
167static int
168archive_read_format_raw_read_data_skip(struct archive_read *a)
169{
170	struct raw_info *info = (struct raw_info *)(a->format->data);
171
172	/* Consume the bytes we read last time. */
173	if (info->unconsumed) {
174		__archive_read_consume(a, info->unconsumed);
175		info->unconsumed = 0;
176	}
177	info->end_of_file = 1;
178	return (ARCHIVE_OK);
179}
180
181static int
182archive_read_format_raw_cleanup(struct archive_read *a)
183{
184	struct raw_info *info;
185
186	info = (struct raw_info *)(a->format->data);
187	free(info);
188	a->format->data = NULL;
189	return (ARCHIVE_OK);
190}
191