2 * Copyright (c) 2003-2007 Tim Kientzle
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
26 #include "archive_platform.h"
27 __FBSDID("$FreeBSD: head/lib/libarchive/archive_read_open_fd.c 201103 2009-12-28 03:13:49Z kientzle $");
29 #ifdef HAVE_SYS_STAT_H
60 static int file_close(struct archive *, void *);
61 static ssize_t file_read(struct archive *, void *, const void **buff);
62 static int64_t file_skip(struct archive *, void *, int64_t request);
65 archive_read_open_fd(struct archive *a, int fd, size_t block_size)
68 struct read_fd_data *mine;
71 archive_clear_error(a);
72 if (fstat(fd, &st) != 0) {
73 archive_set_error(a, errno, "Can't stat fd %d", fd);
74 return (ARCHIVE_FATAL);
77 mine = (struct read_fd_data *)calloc(1, sizeof(*mine));
78 b = malloc(block_size);
79 if (mine == NULL || b == NULL) {
80 archive_set_error(a, ENOMEM, "No memory");
83 return (ARCHIVE_FATAL);
85 mine->block_size = block_size;
89 * Skip support is a performance optimization for anything
90 * that supports lseek(). On FreeBSD, only regular files and
91 * raw disk devices support lseek() and there's no portable
92 * way to determine if a device is a raw disk device, so we
93 * only enable this optimization for regular files.
95 if (S_ISREG(st.st_mode)) {
96 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
99 #if defined(__CYGWIN__) || defined(_WIN32)
100 setmode(mine->fd, O_BINARY);
103 archive_read_set_read_callback(a, file_read);
104 archive_read_set_skip_callback(a, file_skip);
105 archive_read_set_close_callback(a, file_close);
106 archive_read_set_callback_data(a, mine);
107 return (archive_read_open1(a));
111 file_read(struct archive *a, void *client_data, const void **buff)
113 struct read_fd_data *mine = (struct read_fd_data *)client_data;
116 *buff = mine->buffer;
118 bytes_read = read(mine->fd, mine->buffer, mine->block_size);
119 if (bytes_read < 0) {
122 archive_set_error(a, errno, "Error reading fd %d",
130 file_skip(struct archive *a, void *client_data, int64_t request)
132 struct read_fd_data *mine = (struct read_fd_data *)client_data;
133 int64_t skip = request;
134 int64_t old_offset, new_offset;
135 int skip_bits = sizeof(skip) * 8 - 1; /* off_t is a signed type. */
137 if (!mine->use_lseek)
140 /* Reduce a request that would overflow the 'skip' variable. */
141 if (sizeof(request) > sizeof(skip)) {
143 (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1;
144 if (request > max_skip)
148 /* Reduce request to the next smallest multiple of block_size */
149 request = (request / mine->block_size) * mine->block_size;
153 if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) >= 0) &&
154 ((new_offset = lseek(mine->fd, skip, SEEK_CUR)) >= 0))
155 return (new_offset - old_offset);
157 /* If seek failed once, it will probably fail again. */
160 /* Let libarchive recover with read+discard. */
165 * There's been an error other than ESPIPE. This is most
166 * likely caused by a programmer error (too large request)
167 * or a corrupted archive file.
169 archive_set_error(a, errno, "Error seeking");
174 file_close(struct archive *a, void *client_data)
176 struct read_fd_data *mine = (struct read_fd_data *)client_data;
178 (void)a; /* UNUSED */