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
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <ctype.h>
#include <errno.h>
#include "sd-device.h"
#include "device-nodes.h"
#include "libudev-util.h"
#include "string-util.h"
#include "strxcpyx.h"
#include "utf8.h"
/**
* SECTION:libudev-util
* @short_description: utils
*
* Utilities useful when dealing with devices and device node names.
*/
/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
int util_resolve_subsys_kernel(const char *string, char *result, size_t maxsize, bool read_value) {
char temp[UTIL_PATH_SIZE], *subsys, *sysname, *attr;
_cleanup_(sd_device_unrefp) sd_device *dev = NULL;
const char *val;
int r;
if (string[0] != '[')
return -EINVAL;
strscpy(temp, sizeof(temp), string);
subsys = &temp[1];
sysname = strchr(subsys, '/');
if (!sysname)
return -EINVAL;
sysname[0] = '\0';
sysname = &sysname[1];
attr = strchr(sysname, ']');
if (!attr)
return -EINVAL;
attr[0] = '\0';
attr = &attr[1];
if (attr[0] == '/')
attr = &attr[1];
if (attr[0] == '\0')
attr = NULL;
if (read_value && !attr)
return -EINVAL;
r = sd_device_new_from_subsystem_sysname(&dev, subsys, sysname);
if (r < 0)
return r;
if (read_value) {
r = sd_device_get_sysattr_value(dev, attr, &val);
if (r < 0 && r != -ENOENT)
return r;
if (r == -ENOENT)
result[0] = '\0';
else
strscpy(result, maxsize, val);
log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
} else {
r = sd_device_get_syspath(dev, &val);
if (r < 0)
return r;
strscpyl(result, maxsize, val, attr ? "/" : NULL, attr ?: NULL, NULL);
log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, strempty(attr), result);
}
return 0;
}
/**
* udev_util_encode_string:
* @str: input string to be encoded
* @str_enc: output string to store the encoded input string
* @len: maximum size of the output string, which may be
* four times as long as the input string
*
* Encode all potentially unsafe characters of a string to the
* corresponding 2 char hex value prefixed by '\x'.
*
* Returns: 0 if the entire string was copied, non-zero otherwise.
**/
_public_ int udev_util_encode_string(const char *str, char *str_enc, size_t len) {
return encode_devnode_name(str, str_enc, len);
}
|
