1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/* guestfish - the filesystem interactive shell
* Copyright (C) 2010 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libintl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "fish.h"
#define MAX_DOWNLOAD_SIZE (16 * 1024 * 1024)
#define MAX_DOWNLOAD_SIZE_TEXT "16MB"
static off_t get_size (const char *filename);
int
run_hexedit (const char *cmd, size_t argc, char *argv[])
{
if (argc < 1 || argc > 3) {
fprintf (stderr, _("hexedit (device|filename) [max | start max]\n"));
return -1;
}
const char *filename = argv[0];
off_t size = get_size (filename);
if (size == -1)
return -1;
if (size == 0) {
fprintf (stderr,
_("hexedit: %s is a zero length file or device\n"), filename);
return -1;
}
off_t start;
off_t max;
if (argc == 1) { /* hexedit device */
/* Check we're not going to download a huge file. */
if (size > MAX_DOWNLOAD_SIZE) {
fprintf (stderr,
_("hexedit: %s is larger than %s. You must supply a limit using\n"
" 'hexedit %s <max>' (eg. 'hexedit %s 1M') or a range using\n"
" 'hexedit %s <start> <max>'.\n"),
filename, MAX_DOWNLOAD_SIZE_TEXT,
filename, filename,
filename);
return -1;
}
start = 0;
max = size;
}
else {
if (argc == 3) { /* hexedit device start max */
if (parse_size (argv[1], &start) == -1)
return -1;
if (parse_size (argv[2], &max) == -1)
return -1;
} else { /* hexedit device max */
start = 0;
if (parse_size (argv[1], &max) == -1)
return -1;
}
if (start + max > size)
max = size - start;
}
if (max <= 0) {
fprintf (stderr, _("hexedit: invalid range\n"));
return -1;
}
/* Download the requested range from the remote file|device into a
* local temporary file.
*/
const char *editor;
int r;
struct stat oldstat, newstat;
char buf[BUFSIZ];
TMP_TEMPLATE_ON_STACK (tmp);
int fd = mkstemp (tmp);
if (fd == -1) {
perror ("mkstemp");
return -1;
}
/* Choose an editor. */
editor = getenv ("HEXEDITOR");
if (editor == NULL)
editor = "hexedit";
snprintf (buf, sizeof buf, "/dev/fd/%d", fd);
if (guestfs_download_offset (g, filename, buf, start, max) == -1) {
unlink (tmp);
close (fd);
return -1;
}
if (close (fd) == -1) {
unlink (tmp);
return -1;
}
/* Get the old stat. */
if (stat (tmp, &oldstat) == -1) {
perror (tmp);
unlink (tmp);
return -1;
}
/* Edit it. */
snprintf (buf, sizeof buf, "%s %s", editor, tmp);
r = system (buf);
if (r != 0) {
perror (buf);
unlink (tmp);
return -1;
}
/* Get the new stat. */
if (stat (tmp, &newstat) == -1) {
perror (tmp);
unlink (tmp);
return -1;
}
/* Changed? */
if (oldstat.st_ctime == newstat.st_ctime &&
oldstat.st_size == newstat.st_size) {
unlink (tmp);
return 0;
}
/* Write new content. */
if (guestfs_upload_offset (g, tmp, filename, start) == -1) {
unlink (tmp);
return -1;
}
unlink (tmp);
return 0;
}
/* Get the size of the file or block device. */
static off_t
get_size (const char *filename)
{
int64_t size;
if (STRPREFIX (filename, "/dev/")) {
size = guestfs_blockdev_getsize64 (g, filename);
if (size == -1)
return -1;
}
else {
size = guestfs_filesize (g, filename);
if (size == -1)
return -1;
}
/* This case should be safe because we always compile with
* 64 bit file offsets.
*/
return (off_t) size;
}
|
