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#include <errno.h>
30#include <stdlib.h>
31#include <string.h>
32
33#include "archive.h"
34
35/*
36 * This is a little tricky.  I used to allow the
37 * compression handling layer to fork the compressor,
38 * which means this write function gets invoked in
39 * a separate process.  That would, of course, make it impossible
40 * to actually use the data stored into memory here.
41 * Fortunately, none of the compressors fork today and
42 * I'm reluctant to use that route in the future but, if
43 * forking compressors ever do reappear, this will have
44 * to get a lot more complicated.
45 */
46
47struct write_memory_data {
48	size_t	used;
49	size_t  size;
50	size_t * client_size;
51	unsigned char * buff;
52};
53
54static int	memory_write_close(struct archive *, void *);
55static int	memory_write_open(struct archive *, void *);
56static ssize_t	memory_write(struct archive *, void *, const void *buff, size_t);
57
58/*
59 * Client provides a pointer to a block of memory to receive
60 * the data.  The 'size' param both tells us the size of the
61 * client buffer and lets us tell the client the final size.
62 */
63int
64archive_write_open_memory(struct archive *a, void *buff, size_t buffSize, size_t *used)
65{
66	struct write_memory_data *mine;
67
68	mine = (struct write_memory_data *)malloc(sizeof(*mine));
69	if (mine == NULL) {
70		archive_set_error(a, ENOMEM, "No memory");
71		return (ARCHIVE_FATAL);
72	}
73	memset(mine, 0, sizeof(*mine));
74	mine->buff = buff;
75	mine->size = buffSize;
76	mine->client_size = used;
77	return (archive_write_open(a, mine,
78		    memory_write_open, memory_write, memory_write_close));
79}
80
81static int
82memory_write_open(struct archive *a, void *client_data)
83{
84	struct write_memory_data *mine;
85	mine = client_data;
86	mine->used = 0;
87	if (mine->client_size != NULL)
88		*mine->client_size = mine->used;
89	/* Disable padding if it hasn't been set explicitly. */
90	if (-1 == archive_write_get_bytes_in_last_block(a))
91		archive_write_set_bytes_in_last_block(a, 1);
92	return (ARCHIVE_OK);
93}
94
95/*
96 * Copy the data into the client buffer.
97 * Note that we update mine->client_size on every write.
98 * In particular, this means the client can follow exactly
99 * how much has been written into their buffer at any time.
100 */
101static ssize_t
102memory_write(struct archive *a, void *client_data, const void *buff, size_t length)
103{
104	struct write_memory_data *mine;
105	mine = client_data;
106
107	if (mine->used + length > mine->size) {
108		archive_set_error(a, ENOMEM, "Buffer exhausted");
109		return (ARCHIVE_FATAL);
110	}
111	memcpy(mine->buff + mine->used, buff, length);
112	mine->used += length;
113	if (mine->client_size != NULL)
114		*mine->client_size = mine->used;
115	return (length);
116}
117
118static int
119memory_write_close(struct archive *a, void *client_data)
120{
121	struct write_memory_data *mine;
122	(void)a; /* UNUSED */
123	mine = client_data;
124	free(mine);
125	return (ARCHIVE_OK);
126}
127