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#ifdef HAVE_SYS_STAT_H
29#include <sys/stat.h>
30#endif
31#ifdef HAVE_ERRNO_H
32#include <errno.h>
33#endif
34#ifdef HAVE_FCNTL_H
35#include <fcntl.h>
36#endif
37#ifdef HAVE_IO_H
38#include <io.h>
39#endif
40#ifdef HAVE_STDLIB_H
41#include <stdlib.h>
42#endif
43#ifdef HAVE_STRING_H
44#include <string.h>
45#endif
46#ifdef HAVE_UNISTD_H
47#include <unistd.h>
48#endif
49
50#include "archive.h"
51
52struct read_FILE_data {
53	FILE    *f;
54	size_t	 block_size;
55	void	*buffer;
56	char	 can_skip;
57};
58
59static int	file_close(struct archive *, void *);
60static ssize_t	file_read(struct archive *, void *, const void **buff);
61static int64_t	file_skip(struct archive *, void *, int64_t request);
62
63int
64archive_read_open_FILE(struct archive *a, FILE *f)
65{
66	struct stat st;
67	struct read_FILE_data *mine;
68	size_t block_size = 128 * 1024;
69	void *b;
70
71	archive_clear_error(a);
72	mine = (struct read_FILE_data *)malloc(sizeof(*mine));
73	b = malloc(block_size);
74	if (mine == NULL || b == NULL) {
75		archive_set_error(a, ENOMEM, "No memory");
76		free(mine);
77		free(b);
78		return (ARCHIVE_FATAL);
79	}
80	mine->block_size = block_size;
81	mine->buffer = b;
82	mine->f = f;
83	/*
84	 * If we can't fstat() the file, it may just be that it's not
85	 * a file.  (On some platforms, FILE * objects can wrap I/O
86	 * streams that don't support fileno()).  As a result, fileno()
87	 * should be used cautiously.)
88	 */
89	if (fstat(fileno(mine->f), &st) == 0 && S_ISREG(st.st_mode)) {
90		archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
91		/* Enable the seek optimization only for regular files. */
92		mine->can_skip = 1;
93	} else
94		mine->can_skip = 0;
95
96#if defined(__CYGWIN__) || defined(_WIN32)
97	setmode(fileno(mine->f), O_BINARY);
98#endif
99
100	archive_read_set_read_callback(a, file_read);
101	archive_read_set_skip_callback(a, file_skip);
102	archive_read_set_close_callback(a, file_close);
103	archive_read_set_callback_data(a, mine);
104	return (archive_read_open1(a));
105}
106
107static ssize_t
108file_read(struct archive *a, void *client_data, const void **buff)
109{
110	struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
111	size_t bytes_read;
112
113	*buff = mine->buffer;
114	bytes_read = fread(mine->buffer, 1, mine->block_size, mine->f);
115	if (bytes_read < mine->block_size && ferror(mine->f)) {
116		archive_set_error(a, errno, "Error reading file");
117	}
118	return (bytes_read);
119}
120
121static int64_t
122file_skip(struct archive *a, void *client_data, int64_t request)
123{
124	struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
125#if HAVE_FSEEKO
126	off_t skip = (off_t)request;
127#elif HAVE__FSEEKI64
128	int64_t skip = request;
129#else
130	long skip = (long)request;
131#endif
132	int skip_bits = sizeof(skip) * 8 - 1;
133
134	(void)a; /* UNUSED */
135
136	/*
137	 * If we can't skip, return 0 as the amount we did step and
138	 * the caller will work around by reading and discarding.
139	 */
140	if (!mine->can_skip)
141		return (0);
142	if (request == 0)
143		return (0);
144
145	/* If request is too big for a long or an off_t, reduce it. */
146	if (sizeof(request) > sizeof(skip)) {
147		int64_t max_skip =
148		    (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1;
149		if (request > max_skip)
150			skip = max_skip;
151	}
152
153#ifdef __ANDROID__
154        /* fileno() isn't safe on all platforms ... see above. */
155	if (lseek(fileno(mine->f), skip, SEEK_CUR) < 0)
156#elif HAVE__FSEEKI64
157	if (_fseeki64(mine->f, skip, SEEK_CUR) != 0)
158#elif HAVE_FSEEKO
159	if (fseeko(mine->f, skip, SEEK_CUR) != 0)
160#else
161	if (fseek(mine->f, skip, SEEK_CUR) != 0)
162#endif
163	{
164		mine->can_skip = 0;
165		return (0);
166	}
167	return (request);
168}
169
170static int
171file_close(struct archive *a, void *client_data)
172{
173	struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
174
175	(void)a; /* UNUSED */
176	free(mine->buffer);
177	free(mine);
178	return (ARCHIVE_OK);
179}
180