xref: /openbmc/qemu/block/parallels.c (revision 1529ae1b)
1 /*
2  * Block driver for Parallels disk image format
3  *
4  * Copyright (c) 2007 Alex Beregszaszi
5  *
6  * This code is based on comparing different disk images created by Parallels.
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 #include "qemu-common.h"
27 #include "block_int.h"
28 #include "module.h"
29 
30 /**************************************************************/
31 
32 #define HEADER_MAGIC "WithoutFreeSpace"
33 #define HEADER_VERSION 2
34 #define HEADER_SIZE 64
35 
36 // always little-endian
37 struct parallels_header {
38     char magic[16]; // "WithoutFreeSpace"
39     uint32_t version;
40     uint32_t heads;
41     uint32_t cylinders;
42     uint32_t tracks;
43     uint32_t catalog_entries;
44     uint32_t nb_sectors;
45     char padding[24];
46 } QEMU_PACKED;
47 
48 typedef struct BDRVParallelsState {
49     CoMutex lock;
50 
51     uint32_t *catalog_bitmap;
52     int catalog_size;
53 
54     int tracks;
55 } BDRVParallelsState;
56 
57 static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
58 {
59     const struct parallels_header *ph = (const void *)buf;
60 
61     if (buf_size < HEADER_SIZE)
62 	return 0;
63 
64     if (!memcmp(ph->magic, HEADER_MAGIC, 16) &&
65 	(le32_to_cpu(ph->version) == HEADER_VERSION))
66 	return 100;
67 
68     return 0;
69 }
70 
71 static int parallels_open(BlockDriverState *bs, int flags)
72 {
73     BDRVParallelsState *s = bs->opaque;
74     int i;
75     struct parallels_header ph;
76 
77     bs->read_only = 1; // no write support yet
78 
79     if (bdrv_pread(bs->file, 0, &ph, sizeof(ph)) != sizeof(ph))
80         goto fail;
81 
82     if (memcmp(ph.magic, HEADER_MAGIC, 16) ||
83 	(le32_to_cpu(ph.version) != HEADER_VERSION)) {
84         goto fail;
85     }
86 
87     bs->total_sectors = le32_to_cpu(ph.nb_sectors);
88 
89     s->tracks = le32_to_cpu(ph.tracks);
90 
91     s->catalog_size = le32_to_cpu(ph.catalog_entries);
92     s->catalog_bitmap = g_malloc(s->catalog_size * 4);
93     if (bdrv_pread(bs->file, 64, s->catalog_bitmap, s->catalog_size * 4) !=
94 	s->catalog_size * 4)
95 	goto fail;
96     for (i = 0; i < s->catalog_size; i++)
97 	le32_to_cpus(&s->catalog_bitmap[i]);
98 
99     qemu_co_mutex_init(&s->lock);
100     return 0;
101 fail:
102     if (s->catalog_bitmap)
103 	g_free(s->catalog_bitmap);
104     return -1;
105 }
106 
107 static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
108 {
109     BDRVParallelsState *s = bs->opaque;
110     uint32_t index, offset;
111 
112     index = sector_num / s->tracks;
113     offset = sector_num % s->tracks;
114 
115     /* not allocated */
116     if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0))
117 	return -1;
118     return (uint64_t)(s->catalog_bitmap[index] + offset) * 512;
119 }
120 
121 static int parallels_read(BlockDriverState *bs, int64_t sector_num,
122                     uint8_t *buf, int nb_sectors)
123 {
124     while (nb_sectors > 0) {
125         int64_t position = seek_to_sector(bs, sector_num);
126         if (position >= 0) {
127             if (bdrv_pread(bs->file, position, buf, 512) != 512)
128                 return -1;
129         } else {
130             memset(buf, 0, 512);
131         }
132         nb_sectors--;
133         sector_num++;
134         buf += 512;
135     }
136     return 0;
137 }
138 
139 static coroutine_fn int parallels_co_read(BlockDriverState *bs, int64_t sector_num,
140                                           uint8_t *buf, int nb_sectors)
141 {
142     int ret;
143     BDRVParallelsState *s = bs->opaque;
144     qemu_co_mutex_lock(&s->lock);
145     ret = parallels_read(bs, sector_num, buf, nb_sectors);
146     qemu_co_mutex_unlock(&s->lock);
147     return ret;
148 }
149 
150 static void parallels_close(BlockDriverState *bs)
151 {
152     BDRVParallelsState *s = bs->opaque;
153     g_free(s->catalog_bitmap);
154 }
155 
156 static BlockDriver bdrv_parallels = {
157     .format_name	= "parallels",
158     .instance_size	= sizeof(BDRVParallelsState),
159     .bdrv_probe		= parallels_probe,
160     .bdrv_open		= parallels_open,
161     .bdrv_read          = parallels_co_read,
162     .bdrv_close		= parallels_close,
163 };
164 
165 static void bdrv_parallels_init(void)
166 {
167     bdrv_register(&bdrv_parallels);
168 }
169 
170 block_init(bdrv_parallels_init);
171