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 #include <errno.h>
29 #include <stdlib.h>
30 #include <string.h>
31
32 #include "archive.h"
33
34 /*
35 * Glue to read an archive from a block of memory.
36 *
37 * This is mostly a huge help in building test harnesses;
38 * test programs can build archives in memory and read them
39 * back again without having to mess with files on disk.
40 */
41
42 struct read_memory_data {
43 const unsigned char *start;
44 const unsigned char *p;
45 const unsigned char *end;
46 ssize_t read_size;
47 };
48
49 static int memory_read_close(struct archive *, void *);
50 static int memory_read_open(struct archive *, void *);
51 static int64_t memory_read_seek(struct archive *, void *, int64_t offset, int whence);
52 static int64_t memory_read_skip(struct archive *, void *, int64_t request);
53 static ssize_t memory_read(struct archive *, void *, const void **buff);
54
55 int
archive_read_open_memory(struct archive * a,const void * buff,size_t size)56 archive_read_open_memory(struct archive *a, const void *buff, size_t size)
57 {
58 return archive_read_open_memory2(a, buff, size, size);
59 }
60
61 /*
62 * Don't use _open_memory2() in production code; the archive_read_open_memory()
63 * version is the one you really want. This is just here so that
64 * test harnesses can exercise block operations inside the library.
65 */
66 int
archive_read_open_memory2(struct archive * a,const void * buff,size_t size,size_t read_size)67 archive_read_open_memory2(struct archive *a, const void *buff,
68 size_t size, size_t read_size)
69 {
70 struct read_memory_data *mine;
71
72 mine = (struct read_memory_data *)calloc(1, sizeof(*mine));
73 if (mine == NULL) {
74 archive_set_error(a, ENOMEM, "No memory");
75 return (ARCHIVE_FATAL);
76 }
77 mine->start = mine->p = (const unsigned char *)buff;
78 mine->end = mine->start + size;
79 mine->read_size = read_size;
80 archive_read_set_open_callback(a, memory_read_open);
81 archive_read_set_read_callback(a, memory_read);
82 archive_read_set_seek_callback(a, memory_read_seek);
83 archive_read_set_skip_callback(a, memory_read_skip);
84 archive_read_set_close_callback(a, memory_read_close);
85 archive_read_set_callback_data(a, mine);
86 return (archive_read_open1(a));
87 }
88
89 /*
90 * There's nothing to open.
91 */
92 static int
memory_read_open(struct archive * a,void * client_data)93 memory_read_open(struct archive *a, void *client_data)
94 {
95 (void)a; /* UNUSED */
96 (void)client_data; /* UNUSED */
97 return (ARCHIVE_OK);
98 }
99
100 /*
101 * This is scary simple: Just advance a pointer. Limiting
102 * to read_size is not technically necessary, but it exercises
103 * more of the internal logic when used with a small block size
104 * in a test harness. Production use should not specify a block
105 * size; then this is much faster.
106 */
107 static ssize_t
memory_read(struct archive * a,void * client_data,const void ** buff)108 memory_read(struct archive *a, void *client_data, const void **buff)
109 {
110 struct read_memory_data *mine = (struct read_memory_data *)client_data;
111 ssize_t size;
112
113 (void)a; /* UNUSED */
114 *buff = mine->p;
115 size = mine->end - mine->p;
116 if (size > mine->read_size)
117 size = mine->read_size;
118 mine->p += size;
119 return (size);
120 }
121
122 /*
123 * Advancing is just as simple. Again, this is doing more than
124 * necessary in order to better exercise internal code when used
125 * as a test harness.
126 */
127 static int64_t
memory_read_skip(struct archive * a,void * client_data,int64_t skip)128 memory_read_skip(struct archive *a, void *client_data, int64_t skip)
129 {
130 struct read_memory_data *mine = (struct read_memory_data *)client_data;
131
132 (void)a; /* UNUSED */
133 if ((int64_t)skip > (int64_t)(mine->end - mine->p))
134 skip = mine->end - mine->p;
135 /* Round down to block size. */
136 skip /= mine->read_size;
137 skip *= mine->read_size;
138 mine->p += skip;
139 return (skip);
140 }
141
142 /*
143 * Seeking.
144 */
145 static int64_t
memory_read_seek(struct archive * a,void * client_data,int64_t offset,int whence)146 memory_read_seek(struct archive *a, void *client_data, int64_t offset, int whence)
147 {
148 struct read_memory_data *mine = (struct read_memory_data *)client_data;
149
150 (void)a; /* UNUSED */
151 switch (whence) {
152 case SEEK_SET:
153 mine->p = mine->start + offset;
154 break;
155 case SEEK_CUR:
156 mine->p += offset;
157 break;
158 case SEEK_END:
159 mine->p = mine->end + offset;
160 break;
161 default:
162 return ARCHIVE_FATAL;
163 }
164 if (mine->p < mine->start) {
165 mine->p = mine->start;
166 return ARCHIVE_FAILED;
167 }
168 if (mine->p > mine->end) {
169 mine->p = mine->end;
170 return ARCHIVE_FAILED;
171 }
172 return (mine->p - mine->start);
173 }
174
175 /*
176 * Close is just cleaning up our one small bit of data.
177 */
178 static int
memory_read_close(struct archive * a,void * client_data)179 memory_read_close(struct archive *a, void *client_data)
180 {
181 struct read_memory_data *mine = (struct read_memory_data *)client_data;
182 (void)a; /* UNUSED */
183 free(mine);
184 return (ARCHIVE_OK);
185 }
186