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: src/lib/libarchive/archive_read_open_fd.c,v 1.13 2007/06/26 03:06:48 kientzle Exp $");
29 #ifdef HAVE_SYS_STAT_H
54 static int file_close(struct archive *, void *);
55 static ssize_t file_read(struct archive *, void *, const void **buff);
56 #if ARCHIVE_API_VERSION < 2
57 static ssize_t file_skip(struct archive *, void *, size_t request);
59 static off_t file_skip(struct archive *, void *, off_t request);
63 archive_read_open_fd(struct archive *a, int fd, size_t block_size)
66 struct read_fd_data *mine;
69 if (fstat(fd, &st) != 0) {
70 archive_set_error(a, errno, "Can't stat fd %d", fd);
71 return (ARCHIVE_FATAL);
74 mine = (struct read_fd_data *)malloc(sizeof(*mine));
75 b = malloc(block_size);
76 if (mine == NULL || b == NULL) {
77 archive_set_error(a, ENOMEM, "No memory");
80 return (ARCHIVE_FATAL);
82 mine->block_size = block_size;
86 * Skip support is a performance optimization for anything
87 * that supports lseek(). On FreeBSD, only regular files and
88 * raw disk devices support lseek() and there's no portable
89 * way to determine if a device is a raw disk device, so we
90 * only enable this optimization for regular files.
92 if (S_ISREG(st.st_mode)) {
93 archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
98 return (archive_read_open2(a, mine,
99 NULL, file_read, file_skip, file_close));
103 file_read(struct archive *a, void *client_data, const void **buff)
105 struct read_fd_data *mine = (struct read_fd_data *)client_data;
108 *buff = mine->buffer;
109 bytes_read = read(mine->fd, mine->buffer, mine->block_size);
110 if (bytes_read < 0) {
111 archive_set_error(a, errno, "Error reading fd %d", mine->fd);
116 #if ARCHIVE_API_VERSION < 2
118 file_skip(struct archive *a, void *client_data, size_t request)
121 file_skip(struct archive *a, void *client_data, off_t request)
124 struct read_fd_data *mine = (struct read_fd_data *)client_data;
125 off_t old_offset, new_offset;
130 /* Reduce request to the next smallest multiple of block_size */
131 request = (request / mine->block_size) * mine->block_size;
136 * Hurray for lazy evaluation: if the first lseek fails, the second
137 * one will not be executed.
139 if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) ||
140 ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0))
142 /* If seek failed once, it will probably fail again. */
148 * Failure to lseek() can be caused by the file
149 * descriptor pointing to a pipe, socket or FIFO.
150 * Return 0 here, so the compression layer will use
151 * read()s instead to advance the file descriptor.
152 * It's slower of course, but works as well.
157 * There's been an error other than ESPIPE. This is most
158 * likely caused by a programmer error (too large request)
159 * or a corrupted archive file.
161 archive_set_error(a, errno, "Error seeking");
164 return (new_offset - old_offset);
168 file_close(struct archive *a, void *client_data)
170 struct read_fd_data *mine = (struct read_fd_data *)client_data;
172 (void)a; /* UNUSED */