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: src/lib/libarchive/archive_write_open_memory.c,v 1.3 2007/01/09 08:05:56 kientzle Exp $");
28 
29 #include <errno.h>
30 #include <stdlib.h>
31 #include <string.h>
32 
33 #include "archive.h"
34 
35 struct write_memory_data {
36 	size_t	used;
37 	size_t  size;
38 	size_t * client_size;
39 	unsigned char * buff;
40 };
41 
42 static int	memory_write_close(struct archive *, void *);
43 static int	memory_write_open(struct archive *, void *);
44 static ssize_t	memory_write(struct archive *, void *, const void *buff, size_t);
45 
46 /*
47  * Client provides a pointer to a block of memory to receive
48  * the data.  The 'size' param both tells us the size of the
49  * client buffer and lets us tell the client the final size.
50  */
51 int
52 archive_write_open_memory(struct archive *a, void *buff, size_t buffSize, size_t *used)
53 {
54 	struct write_memory_data *mine;
55 
56 	mine = (struct write_memory_data *)malloc(sizeof(*mine));
57 	if (mine == NULL) {
58 		archive_set_error(a, ENOMEM, "No memory");
59 		return (ARCHIVE_FATAL);
60 	}
61 	memset(mine, 0, sizeof(*mine));
62 	mine->buff = buff;
63 	mine->size = buffSize;
64 	mine->client_size = used;
65 	return (archive_write_open(a, mine,
66 		    memory_write_open, memory_write, memory_write_close));
67 }
68 
69 static int
70 memory_write_open(struct archive *a, void *client_data)
71 {
72 	struct write_memory_data *mine;
73 	mine = client_data;
74 	mine->used = 0;
75 	if (mine->client_size != NULL)
76 		*mine->client_size = mine->used;
77 	/* Disable padding if it hasn't been set explicitly. */
78 	if (-1 == archive_write_get_bytes_in_last_block(a))
79 		archive_write_set_bytes_in_last_block(a, 1);
80 	return (ARCHIVE_OK);
81 }
82 
83 /*
84  * Copy the data into the client buffer.
85  * Note that we update mine->client_size on every write.
86  * In particular, this means the client can follow exactly
87  * how much has been written into their buffer at any time.
88  */
89 static ssize_t
90 memory_write(struct archive *a, void *client_data, const void *buff, size_t length)
91 {
92 	struct write_memory_data *mine;
93 	mine = client_data;
94 
95 	if (mine->used + length > mine->size) {
96 		archive_set_error(a, ENOMEM, "Buffer exhausted");
97 		return (ARCHIVE_FATAL);
98 	}
99 	memcpy(mine->buff + mine->used, buff, length);
100 	mine->used += length;
101 	if (mine->client_size != NULL)
102 		*mine->client_size = mine->used;
103 	return (length);
104 }
105 
106 static int
107 memory_write_close(struct archive *a, void *client_data)
108 {
109 	struct write_memory_data *mine;
110 	(void)a; /* UNUSED */
111 	mine = client_data;
112 	free(mine);
113 	return (ARCHIVE_OK);
114 }
115