read_open_memory.c revision 310569 
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 "test.h"
27__FBSDID("$FreeBSD: stable/11/contrib/libarchive/libarchive/test/read_open_memory.c 310569 2016-12-26 06:16:27Z ngie $");
28
29#include <errno.h>
30#include <stdlib.h>
31#include <string.h>
32
33/*
34 * Read an archive from a block of memory.
35 *
36 * This is identical to archive_read_open_memory(), except
37 * that it goes out of its way to be a little bit unpleasant,
38 * in order to better test the libarchive internals.
39 */
40
41struct read_memory_data {
42	const unsigned char	*start;
43	const unsigned char	*p;
44	const unsigned char	*end;
45	size_t	 read_size;
46	size_t copy_buff_size;
47	size_t copy_buff_offset;
48	char *copy_buff;
49};
50
51static int	memory_read_close(struct archive *, void *);
52static int	memory_read_open(struct archive *, void *);
53static int64_t	memory_read_seek(struct archive *, void *, int64_t request, int whence);
54static int64_t	memory_read_skip(struct archive *, void *, int64_t request);
55static ssize_t	memory_read(struct archive *, void *, const void **buff);
56static int	read_open_memory_internal(struct archive *a, const void *buff,
57    size_t size, size_t read_size, int fullapi);
58
59
60int
61read_open_memory(struct archive *a, const void *buff, size_t size, size_t read_size)
62{
63	return read_open_memory_internal(a, buff, size, read_size, 2);
64}
65
66/*
67 * As above, but don't register any optional part of the API, to verify
68 * that internals work correctly with just the minimal entry points.
69 */
70int
71read_open_memory_minimal(struct archive *a, const void *buff, size_t size, size_t read_size)
72{
73	return read_open_memory_internal(a, buff, size, read_size, 1);
74}
75
76/*
77 * Include a seek callback as well.
78 */
79int
80read_open_memory_seek(struct archive *a, const void *buff, size_t size, size_t read_size)
81{
82	return read_open_memory_internal(a, buff, size, read_size, 3);
83}
84
85static int
86read_open_memory_internal(struct archive *a, const void *buff,
87    size_t size, size_t read_size, int level)
88{
89	struct read_memory_data *mine = NULL;
90
91	switch (level) {
92	case 3:
93		archive_read_set_seek_callback(a, memory_read_seek);
94	case 2:
95		archive_read_set_open_callback(a, memory_read_open);
96		archive_read_set_skip_callback(a, memory_read_skip);
97	case 1:
98		mine = malloc(sizeof(*mine));
99		if (mine == NULL) {
100			archive_set_error(a, ENOMEM, "No memory");
101			return (ARCHIVE_FATAL);
102		}
103		memset(mine, 0, sizeof(*mine));
104		mine->start = mine->p = (const unsigned char *)buff;
105		mine->end = mine->start + size;
106		mine->read_size = read_size;
107		mine->copy_buff_offset = 32;
108		mine->copy_buff_size = read_size + mine->copy_buff_offset * 2;
109		mine->copy_buff = malloc(mine->copy_buff_size);
110		memset(mine->copy_buff, 0xA5, mine->copy_buff_size);
111
112		archive_read_set_read_callback(a, memory_read);
113		archive_read_set_close_callback(a, memory_read_close);
114		archive_read_set_callback_data(a, mine);
115	}
116	return archive_read_open1(a);
117}
118
119/*
120 * There's nothing to open.
121 */
122static int
123memory_read_open(struct archive *a, void *client_data)
124{
125	(void)a; /* UNUSED */
126	(void)client_data; /* UNUSED */
127	return (ARCHIVE_OK);
128}
129
130/*
131 * In order to exercise libarchive's internal read-combining logic,
132 * we deliberately copy data for each read to a separate buffer.
133 * That way, code that runs off the end of the provided data
134 * will screw up.
135 */
136static ssize_t
137memory_read(struct archive *a, void *client_data, const void **buff)
138{
139	struct read_memory_data *mine = (struct read_memory_data *)client_data;
140	ssize_t size;
141
142	(void)a; /* UNUSED */
143	size = mine->end - mine->p;
144	if (size < 0) {
145		buff = NULL;
146		return 0;
147	}
148	if ((size_t)size > mine->read_size)
149		size = mine->read_size;
150	else
151		memset(mine->copy_buff, 0xA5, mine->copy_buff_size);
152	memcpy(mine->copy_buff + mine->copy_buff_offset, mine->p, size);
153	*buff = mine->copy_buff + mine->copy_buff_offset;
154
155        mine->p += size;
156	return ((ssize_t)size);
157}
158
159/*
160 * How mean can a skip() routine be?  Let's try to find out.
161 */
162static int64_t
163memory_read_skip(struct archive *a, void *client_data, int64_t skip)
164{
165	struct read_memory_data *mine = (struct read_memory_data *)client_data;
166
167	(void)a; /* UNUSED */
168	/* We can't skip by more than is available. */
169	if ((off_t)skip > (off_t)(mine->end - mine->p))
170		skip = mine->end - mine->p;
171	/* Always do small skips by prime amounts. */
172	if (skip > 71)
173		skip = 71;
174	mine->p += skip;
175	return (skip);
176}
177
178/*
179 */
180static int64_t
181memory_read_seek(struct archive *a, void *client_data, int64_t offset, int whence)
182{
183	struct read_memory_data *mine = (struct read_memory_data *)client_data;
184
185	(void)a; /* UNUSED */
186	switch (whence) {
187	case SEEK_SET:
188		mine->p = mine->start + offset;
189		break;
190	case SEEK_END:
191		mine->p = mine->end + offset;
192		break;
193	case SEEK_CUR:
194		mine->p += offset;
195		break;
196	}
197	if (mine->p < mine->start) {
198		mine->p = mine->start;
199		return ARCHIVE_FAILED;
200	}
201	if (mine->p > mine->end) {
202		mine->p = mine->end;
203		return ARCHIVE_FAILED;
204	}
205	return (mine->p - mine->start);
206}
207
208/*
209 * Close is just cleaning up our one small bit of data.
210 */
211static int
212memory_read_close(struct archive *a, void *client_data)
213{
214	struct read_memory_data *mine = (struct read_memory_data *)client_data;
215	(void)a; /* UNUSED */
216	if (mine != NULL)
217		free(mine->copy_buff);
218	free(mine);
219	return (ARCHIVE_OK);
220}
221