archive_read_open_file.c revision 302001 
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__FBSDID("$FreeBSD: stable/10/contrib/libarchive/libarchive/archive_read_open_file.c 302001 2016-06-17 22:40:10Z mm $");
28
29#ifdef HAVE_SYS_STAT_H
30#include <sys/stat.h>
31#endif
32#ifdef HAVE_ERRNO_H
33#include <errno.h>
34#endif
35#ifdef HAVE_FCNTL_H
36#include <fcntl.h>
37#endif
38#ifdef HAVE_IO_H
39#include <io.h>
40#endif
41#ifdef HAVE_STDLIB_H
42#include <stdlib.h>
43#endif
44#ifdef HAVE_STRING_H
45#include <string.h>
46#endif
47#ifdef HAVE_UNISTD_H
48#include <unistd.h>
49#endif
50
51#include "archive.h"
52
53struct read_FILE_data {
54	FILE    *f;
55	size_t	 block_size;
56	void	*buffer;
57	char	 can_skip;
58};
59
60static int	file_close(struct archive *, void *);
61static ssize_t	file_read(struct archive *, void *, const void **buff);
62static int64_t	file_skip(struct archive *, void *, int64_t request);
63
64int
65archive_read_open_FILE(struct archive *a, FILE *f)
66{
67	struct stat st;
68	struct read_FILE_data *mine;
69	size_t block_size = 128 * 1024;
70	void *b;
71
72	archive_clear_error(a);
73	mine = (struct read_FILE_data *)malloc(sizeof(*mine));
74	b = malloc(block_size);
75	if (mine == NULL || b == NULL) {
76		archive_set_error(a, ENOMEM, "No memory");
77		free(mine);
78		free(b);
79		return (ARCHIVE_FATAL);
80	}
81	mine->block_size = block_size;
82	mine->buffer = b;
83	mine->f = f;
84	/*
85	 * If we can't fstat() the file, it may just be that it's not
86	 * a file.  (On some platforms, FILE * objects can wrap I/O
87	 * streams that don't support fileno()).  As a result, fileno()
88	 * should be used cautiously.)
89	 */
90	if (fstat(fileno(mine->f), &st) == 0 && S_ISREG(st.st_mode)) {
91		archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
92		/* Enable the seek optimization only for regular files. */
93		mine->can_skip = 1;
94	} else
95		mine->can_skip = 0;
96
97#if defined(__CYGWIN__) || defined(_WIN32)
98	setmode(fileno(mine->f), O_BINARY);
99#endif
100
101	archive_read_set_read_callback(a, file_read);
102	archive_read_set_skip_callback(a, file_skip);
103	archive_read_set_close_callback(a, file_close);
104	archive_read_set_callback_data(a, mine);
105	return (archive_read_open1(a));
106}
107
108static ssize_t
109file_read(struct archive *a, void *client_data, const void **buff)
110{
111	struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
112	size_t bytes_read;
113
114	*buff = mine->buffer;
115	bytes_read = fread(mine->buffer, 1, mine->block_size, mine->f);
116	if (bytes_read < mine->block_size && ferror(mine->f)) {
117		archive_set_error(a, errno, "Error reading file");
118	}
119	return (bytes_read);
120}
121
122static int64_t
123file_skip(struct archive *a, void *client_data, int64_t request)
124{
125	struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
126#if HAVE_FSEEKO
127	off_t skip = (off_t)request;
128#elif HAVE__FSEEKI64
129	int64_t skip = request;
130#else
131	long skip = (long)request;
132#endif
133	int skip_bits = sizeof(skip) * 8 - 1;
134
135	(void)a; /* UNUSED */
136
137	/*
138	 * If we can't skip, return 0 as the amount we did step and
139	 * the caller will work around by reading and discarding.
140	 */
141	if (!mine->can_skip)
142		return (0);
143	if (request == 0)
144		return (0);
145
146	/* If request is too big for a long or an off_t, reduce it. */
147	if (sizeof(request) > sizeof(skip)) {
148		int64_t max_skip =
149		    (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1;
150		if (request > max_skip)
151			skip = max_skip;
152	}
153
154#ifdef __ANDROID__
155        /* fileno() isn't safe on all platforms ... see above. */
156	if (lseek(fileno(mine->f), skip, SEEK_CUR) < 0)
157#elif HAVE_FSEEKO
158	if (fseeko(mine->f, skip, SEEK_CUR) != 0)
159#elif HAVE__FSEEKI64
160	if (_fseeki64(mine->f, skip, SEEK_CUR) != 0)
161#else
162	if (fseek(mine->f, skip, SEEK_CUR) != 0)
163#endif
164	{
165		mine->can_skip = 0;
166		return (0);
167	}
168	return (request);
169}
170
171static int
172file_close(struct archive *a, void *client_data)
173{
174	struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
175
176	(void)a; /* UNUSED */
177	if (mine->buffer != NULL)
178		free(mine->buffer);
179	free(mine);
180	return (ARCHIVE_OK);
181}
182