1 /* Copyright (c) 2008, XenSource Inc.
2 * All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 * * Redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer.
8 * * Redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution.
11 * * Neither the name of XenSource Inc. nor the names of its contributors
12 * may be used to endorse or promote products derived from this software
13 * without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
19 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
23 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
24 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Altering operations:
28 *
29 * 1. Change the parent pointer to another file.
30 * 2. Change the size of the file containing the VHD image. This does NOT
31 * affect the VHD disk capacity, only the physical size of the file containing
32 * the VHD. Naturally, it is not possible to set the file size to be less than
33 * the what VHD utilizes.
34 * The operation doesn't actually change the file size, but it writes the
35 * footer in the right location such that resizing the file (manually, as a
36 * separate step) will produce the correct results. If the new file size is
37 * greater than the current file size, the file must first be expanded and then
38 * altered with this operation. If the new size is smaller than the current
39 * size, the VHD must first be altered with this operation and then the file
40 * must be shrunk. Failing to resize the file will result in a corrupted VHD.
41 */
42
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48
49 #include "libvhd.h"
50
51 TEST_FAIL_EXTERN_VARS;
52
53 int
vhd_util_modify(int argc,char ** argv)54 vhd_util_modify(int argc, char **argv)
55 {
56 char *name;
57 vhd_context_t vhd;
58 int err, c, size, parent, parent_raw;
59 off_t newsize = 0;
60 char *newparent = NULL;
61
62 name = NULL;
63 size = 0;
64 parent = 0;
65 parent_raw = 0;
66
67 optind = 0;
68 while ((c = getopt(argc, argv, "n:s:p:mh")) != -1) {
69 switch (c) {
70 case 'n':
71 name = optarg;
72 break;
73 case 's':
74 size = 1;
75 errno = 0;
76 newsize = strtoll(optarg, NULL, 10);
77 if (errno) {
78 fprintf(stderr, "Invalid size '%s'\n", optarg);
79 goto usage;
80 }
81 break;
82 case 'p':
83 parent = 1;
84 newparent = optarg;
85 break;
86 case 'm':
87 parent_raw = 1;
88 break;
89
90 case 'h':
91 default:
92 goto usage;
93 }
94 }
95
96 if (!name || optind != argc)
97 goto usage;
98
99 err = vhd_open(&vhd, name, VHD_OPEN_RDWR);
100 if (err) {
101 printf("error opening %s: %d\n", name, err);
102 return err;
103 }
104
105 if (size) {
106 err = vhd_set_phys_size(&vhd, newsize);
107 if (err)
108 printf("failed to set physical size to %"PRIu64":"
109 " %d\n", newsize, err);
110 }
111
112 if (parent) {
113 TEST_FAIL_AT(FAIL_REPARENT_BEGIN);
114 err = vhd_change_parent(&vhd, newparent, parent_raw);
115 if (err) {
116 printf("failed to set parent to '%s': %d\n",
117 newparent, err);
118 goto done;
119 }
120 TEST_FAIL_AT(FAIL_REPARENT_END);
121 }
122
123 done:
124 vhd_close(&vhd);
125 return err;
126
127 usage:
128 printf("*** Dangerous operations, use with care ***\n");
129 printf("options: <-n name> [-p NEW_PARENT set parent [-m raw]] "
130 "[-s NEW_SIZE set size] [-h help]\n");
131 return -EINVAL;
132 }
133