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
|
/*
* udev-remove.c
*
* Userspace devfs
*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
*
*
* 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 version 2 of the License.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include "udev.h"
#include "udev_lib.h"
#include "udev_version.h"
#include "logging.h"
#include "namedev.h"
#include "udevdb.h"
static int delete_path(char *path)
{
char *pos;
int retval;
pos = strrchr(path, '/');
while (1) {
*pos = '\0';
pos = strrchr(path, '/');
/* don't remove the last one */
if ((pos == path) || (pos == NULL))
break;
/* remove if empty */
retval = rmdir(path);
if (errno == ENOENT)
retval = 0;
if (retval) {
if (errno == ENOTEMPTY)
return 0;
dbg("rmdir(%s) failed with error '%s'",
path, strerror(errno));
break;
}
dbg("removed '%s'", path);
}
return 0;
}
/** Remove all permissions on the device node, before
* unlinking it. This fixes a security issue.
* If the user created a hard-link to the device node,
* he can't use it any longer, because he lost permission
* to do so.
*/
static int secure_unlink(const char *filename)
{
int retval;
retval = chown(filename, 0, 0);
if (retval) {
dbg("chown(%s, 0, 0) failed with error '%s'",
filename, strerror(errno));
/* We continue nevertheless.
* I think it's very unlikely for chown
* to fail here, if the file exists.
*/
}
retval = chmod(filename, 0000);
if (retval) {
dbg("chmod(%s, 0000) failed with error '%s'",
filename, strerror(errno));
/* We continue nevertheless. */
}
retval = unlink(filename);
if (errno == ENOENT)
retval = 0;
if (retval) {
dbg("unlink(%s) failed with error '%s'",
filename, strerror(errno));
}
return retval;
}
static int delete_node(struct udevice *dev)
{
char filename[NAME_SIZE];
char linkname[NAME_SIZE];
char partitionname[NAME_SIZE];
int retval;
int i;
char *pos;
int len;
strfieldcpy(filename, udev_root);
strfieldcat(filename, dev->name);
info("removing device node '%s'", filename);
retval = secure_unlink(filename);
if (retval)
return retval;
/* remove partition nodes */
if (dev->partitions > 0) {
info("removing partitions '%s[1-%i]'", filename, dev->partitions);
for (i = 1; i <= dev->partitions; i++) {
strfieldcpy(partitionname, filename);
strintcat(partitionname, i);
secure_unlink(partitionname);
}
}
/* remove subdirectories */
if (strchr(dev->name, '/'))
delete_path(filename);
foreach_strpart(dev->symlink, " ", pos, len) {
strfieldcpymax(linkname, pos, len+1);
strfieldcpy(filename, udev_root);
strfieldcat(filename, linkname);
dbg("unlinking symlink '%s'", filename);
retval = unlink(filename);
if (errno == ENOENT)
retval = 0;
if (retval) {
dbg("unlink(%s) failed with error '%s'",
filename, strerror(errno));
return retval;
}
if (strchr(dev->symlink, '/')) {
delete_path(filename);
}
}
return retval;
}
/*
* Look up the sysfs path in the database to see if we have named this device
* something different from the kernel name. If we have, us it. If not, use
* the default kernel name for lack of anything else to know to do.
*/
int udev_remove_device(const char *path, const char *subsystem)
{
struct udevice dev;
char *temp;
int retval;
memset(&dev, 0x00, sizeof(dev));
retval = udevdb_get_dev(path, &dev);
if (retval != 0) {
dbg("'%s' not found in database, falling back on default name", path);
temp = strrchr(path, '/');
if (temp == NULL)
return -ENODEV;
strfieldcpy(dev.name, &temp[1]);
}
dbg("name='%s'", dev.name);
dev.type = get_device_type(path, subsystem);
dev_d_send(&dev, subsystem, path);
udevdb_delete_dev(path);
if (dev.type == 'b' || dev.type == 'c')
retval = delete_node(&dev);
else if (dev.type == 'n')
retval = 0;
return retval;
}
|
