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("$FreeBSD$");
28
29#ifdef HAVE_SYS_TYPES_H
30#include <sys/types.h>
31#endif
32#ifdef HAVE_ERRNO_H
33#include <errno.h>
34#endif
35#ifdef HAVE_UNISTD_H
36#include <unistd.h>
37#endif
38
39#include "archive.h"
40#include "archive_private.h"
41
42/* Maximum amount of data to write at one time. */
43#define	MAX_WRITE	(1024 * 1024)
44
45/*
46 * This implementation minimizes copying of data and is sparse-file aware.
47 */
48static int
49pad_to(struct archive *a, int fd, int can_lseek,
50    size_t nulls_size, const char *nulls,
51    int64_t target_offset, int64_t actual_offset)
52{
53	size_t to_write;
54	ssize_t bytes_written;
55
56	if (can_lseek) {
57		actual_offset = lseek(fd,
58		    target_offset - actual_offset, SEEK_CUR);
59		if (actual_offset != target_offset) {
60			archive_set_error(a, errno, "Seek error");
61			return (ARCHIVE_FATAL);
62		}
63		return (ARCHIVE_OK);
64	}
65	while (target_offset > actual_offset) {
66		to_write = nulls_size;
67		if (target_offset < actual_offset + (int64_t)nulls_size)
68			to_write = (size_t)(target_offset - actual_offset);
69		bytes_written = write(fd, nulls, to_write);
70		if (bytes_written < 0) {
71			archive_set_error(a, errno, "Write error");
72			return (ARCHIVE_FATAL);
73		}
74		actual_offset += bytes_written;
75	}
76	return (ARCHIVE_OK);
77}
78
79
80int
81archive_read_data_into_fd(struct archive *a, int fd)
82{
83	struct stat st;
84	int r, r2;
85	const void *buff;
86	size_t size, bytes_to_write;
87	ssize_t bytes_written;
88	int64_t target_offset;
89	int64_t actual_offset = 0;
90	int can_lseek;
91	char *nulls = NULL;
92	size_t nulls_size = 16384;
93
94	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA,
95	    "archive_read_data_into_fd");
96
97	can_lseek = (fstat(fd, &st) == 0) && S_ISREG(st.st_mode);
98	if (!can_lseek)
99		nulls = calloc(1, nulls_size);
100
101	while ((r = archive_read_data_block(a, &buff, &size, &target_offset)) ==
102	    ARCHIVE_OK) {
103		const char *p = buff;
104		if (target_offset > actual_offset) {
105			r = pad_to(a, fd, can_lseek, nulls_size, nulls,
106			    target_offset, actual_offset);
107			if (r != ARCHIVE_OK)
108				break;
109			actual_offset = target_offset;
110		}
111		while (size > 0) {
112			bytes_to_write = size;
113			if (bytes_to_write > MAX_WRITE)
114				bytes_to_write = MAX_WRITE;
115			bytes_written = write(fd, p, bytes_to_write);
116			if (bytes_written < 0) {
117				archive_set_error(a, errno, "Write error");
118				r = ARCHIVE_FATAL;
119				goto cleanup;
120			}
121			actual_offset += bytes_written;
122			p += bytes_written;
123			size -= bytes_written;
124		}
125	}
126
127	if (r == ARCHIVE_EOF && target_offset > actual_offset) {
128		r2 = pad_to(a, fd, can_lseek, nulls_size, nulls,
129		    target_offset, actual_offset);
130		if (r2 != ARCHIVE_OK)
131			r = r2;
132	}
133
134cleanup:
135	free(nulls);
136	if (r != ARCHIVE_EOF)
137		return (r);
138	return (ARCHIVE_OK);
139}
140