read_open_memory.c revision 328827 
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 328827 2018-02-03 02:17:04Z mm $");
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		__LA_FALLTHROUGH;
95	case 2:
96		archive_read_set_open_callback(a, memory_read_open);
97		archive_read_set_skip_callback(a, memory_read_skip);
98		__LA_FALLTHROUGH;
99	case 1:
100		mine = malloc(sizeof(*mine));
101		if (mine == NULL) {
102			archive_set_error(a, ENOMEM, "No memory");
103			return (ARCHIVE_FATAL);
104		}
105		memset(mine, 0, sizeof(*mine));
106		mine->start = mine->p = (const unsigned char *)buff;
107		mine->end = mine->start + size;
108		mine->read_size = read_size;
109		mine->copy_buff_offset = 32;
110		mine->copy_buff_size = read_size + mine->copy_buff_offset * 2;
111		mine->copy_buff = malloc(mine->copy_buff_size);
112		memset(mine->copy_buff, 0xA5, mine->copy_buff_size);
113
114		archive_read_set_read_callback(a, memory_read);
115		archive_read_set_close_callback(a, memory_read_close);
116		archive_read_set_callback_data(a, mine);
117	}
118	return archive_read_open1(a);
119}
120
121/*
122 * There's nothing to open.
123 */
124static int
125memory_read_open(struct archive *a, void *client_data)
126{
127	(void)a; /* UNUSED */
128	(void)client_data; /* UNUSED */
129	return (ARCHIVE_OK);
130}
131
132/*
133 * In order to exercise libarchive's internal read-combining logic,
134 * we deliberately copy data for each read to a separate buffer.
135 * That way, code that runs off the end of the provided data
136 * will screw up.
137 */
138static ssize_t
139memory_read(struct archive *a, void *client_data, const void **buff)
140{
141	struct read_memory_data *mine = (struct read_memory_data *)client_data;
142	ssize_t size;
143
144	(void)a; /* UNUSED */
145	size = mine->end - mine->p;
146	if (size < 0) {
147		buff = NULL;
148		return 0;
149	}
150	if ((size_t)size > mine->read_size)
151		size = mine->read_size;
152	else
153		memset(mine->copy_buff, 0xA5, mine->copy_buff_size);
154	memcpy(mine->copy_buff + mine->copy_buff_offset, mine->p, size);
155	*buff = mine->copy_buff + mine->copy_buff_offset;
156
157        mine->p += size;
158	return ((ssize_t)size);
159}
160
161/*
162 * How mean can a skip() routine be?  Let's try to find out.
163 */
164static int64_t
165memory_read_skip(struct archive *a, void *client_data, int64_t skip)
166{
167	struct read_memory_data *mine = (struct read_memory_data *)client_data;
168
169	(void)a; /* UNUSED */
170	/* We can't skip by more than is available. */
171	if ((off_t)skip > (off_t)(mine->end - mine->p))
172		skip = mine->end - mine->p;
173	/* Always do small skips by prime amounts. */
174	if (skip > 71)
175		skip = 71;
176	mine->p += skip;
177	return (skip);
178}
179
180/*
181 */
182static int64_t
183memory_read_seek(struct archive *a, void *client_data, int64_t offset, int whence)
184{
185	struct read_memory_data *mine = (struct read_memory_data *)client_data;
186
187	(void)a; /* UNUSED */
188	switch (whence) {
189	case SEEK_SET:
190		mine->p = mine->start + offset;
191		break;
192	case SEEK_END:
193		mine->p = mine->end + offset;
194		break;
195	case SEEK_CUR:
196		mine->p += offset;
197		break;
198	}
199	if (mine->p < mine->start) {
200		mine->p = mine->start;
201		return ARCHIVE_FAILED;
202	}
203	if (mine->p > mine->end) {
204		mine->p = mine->end;
205		return ARCHIVE_FAILED;
206	}
207	return (mine->p - mine->start);
208}
209
210/*
211 * Close is just cleaning up our one small bit of data.
212 */
213static int
214memory_read_close(struct archive *a, void *client_data)
215{
216	struct read_memory_data *mine = (struct read_memory_data *)client_data;
217	(void)a; /* UNUSED */
218	if (mine != NULL)
219		free(mine->copy_buff);
220	free(mine);
221	return (ARCHIVE_OK);
222}
223