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_TYPES_H
29#include <sys/types.h>
30#endif
31#ifdef HAVE_ERRNO_H
32#include <errno.h>
33#endif
34#ifdef HAVE_UNISTD_H
35#include <unistd.h>
36#endif
37
38#include "archive.h"
39#include "archive_private.h"
40
41/* Maximum amount of data to write at one time. */
42#define	MAX_WRITE	(1024 * 1024)
43
44/*
45 * This implementation minimizes copying of data and is sparse-file aware.
46 */
47static int
48pad_to(struct archive *a, int fd, int can_lseek,
49    size_t nulls_size, const char *nulls,
50    int64_t target_offset, int64_t actual_offset)
51{
52	size_t to_write;
53	ssize_t bytes_written;
54
55	if (can_lseek) {
56		actual_offset = lseek(fd,
57		    target_offset - actual_offset, SEEK_CUR);
58		if (actual_offset != target_offset) {
59			archive_set_error(a, errno, "Seek error");
60			return (ARCHIVE_FATAL);
61		}
62		return (ARCHIVE_OK);
63	}
64	while (target_offset > actual_offset) {
65		to_write = nulls_size;
66		if (target_offset < actual_offset + (int64_t)nulls_size)
67			to_write = (size_t)(target_offset - actual_offset);
68		bytes_written = write(fd, nulls, to_write);
69		if (bytes_written < 0) {
70			archive_set_error(a, errno, "Write error");
71			return (ARCHIVE_FATAL);
72		}
73		actual_offset += bytes_written;
74	}
75	return (ARCHIVE_OK);
76}
77
78
79int
80archive_read_data_into_fd(struct archive *a, int fd)
81{
82	struct stat st;
83	int r, r2;
84	const void *buff;
85	size_t size, bytes_to_write;
86	ssize_t bytes_written;
87	int64_t target_offset;
88	int64_t actual_offset = 0;
89	int can_lseek;
90	char *nulls = NULL;
91	size_t nulls_size = 16384;
92
93	archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA,
94	    "archive_read_data_into_fd");
95
96	can_lseek = (fstat(fd, &st) == 0) && S_ISREG(st.st_mode);
97	if (!can_lseek) {
98		nulls = calloc(1, nulls_size);
99		if (!nulls) {
100			r = ARCHIVE_FATAL;
101			goto cleanup;
102		}
103	}
104
105	while ((r = archive_read_data_block(a, &buff, &size, &target_offset)) ==
106	    ARCHIVE_OK) {
107		const char *p = buff;
108		if (target_offset > actual_offset) {
109			r = pad_to(a, fd, can_lseek, nulls_size, nulls,
110			    target_offset, actual_offset);
111			if (r != ARCHIVE_OK)
112				break;
113			actual_offset = target_offset;
114		}
115		while (size > 0) {
116			bytes_to_write = size;
117			if (bytes_to_write > MAX_WRITE)
118				bytes_to_write = MAX_WRITE;
119			bytes_written = write(fd, p, bytes_to_write);
120			if (bytes_written < 0) {
121				archive_set_error(a, errno, "Write error");
122				r = ARCHIVE_FATAL;
123				goto cleanup;
124			}
125			actual_offset += bytes_written;
126			p += bytes_written;
127			size -= bytes_written;
128		}
129	}
130
131	if (r == ARCHIVE_EOF && target_offset > actual_offset) {
132		r2 = pad_to(a, fd, can_lseek, nulls_size, nulls,
133		    target_offset, actual_offset);
134		if (r2 != ARCHIVE_OK)
135			r = r2;
136	}
137
138cleanup:
139	free(nulls);
140	if (r != ARCHIVE_EOF)
141		return (r);
142	return (ARCHIVE_OK);
143}
144