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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <ctype.h>
#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "device-nodes.h"
#include "libudev-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, int read_value) {
char temp[UTIL_PATH_SIZE];
char *subsys;
char *sysname;
struct udev_device *dev;
char *attr;
if (string[0] != '[')
return -1;
strscpy(temp, sizeof(temp), string);
subsys = &temp[1];
sysname = strchr(subsys, '/');
if (sysname == NULL)
return -1;
sysname[0] = '\0';
sysname = &sysname[1];
attr = strchr(sysname, ']');
if (attr == NULL)
return -1;
attr[0] = '\0';
attr = &attr[1];
if (attr[0] == '/')
attr = &attr[1];
if (attr[0] == '\0')
attr = NULL;
if (read_value && attr == NULL)
return -1;
dev = udev_device_new_from_subsystem_sysname(NULL, subsys, sysname);
if (dev == NULL)
return -1;
if (read_value) {
const char *val;
val = udev_device_get_sysattr_value(dev, attr);
if (val != NULL)
strscpy(result, maxsize, val);
else
result[0] = '\0';
log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
} else {
size_t l;
char *s;
s = result;
l = strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
if (attr != NULL)
strpcpyl(&s, l, "/", attr, NULL);
log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
}
udev_device_unref(dev);
return 0;
}
size_t util_path_encode(const char *src, char *dest, size_t size) {
size_t i, j;
for (i = 0, j = 0; src[i] != '\0'; i++) {
if (src[i] == '/') {
if (j+4 >= size) {
j = 0;
break;
}
memcpy(&dest[j], "\\x2f", 4);
j += 4;
} else if (src[i] == '\\') {
if (j+4 >= size) {
j = 0;
break;
}
memcpy(&dest[j], "\\x5c", 4);
j += 4;
} else {
if (j+1 >= size) {
j = 0;
break;
}
dest[j] = src[i];
j++;
}
}
dest[j] = '\0';
return j;
}
/*
* Copy from 'str' to 'to', while removing all leading and trailing whitespace,
* and replacing each run of consecutive whitespace with a single underscore.
* The chars from 'str' are copied up to the \0 at the end of the string, or
* at most 'len' chars. This appends \0 to 'to', at the end of the copied
* characters.
*
* If 'len' chars are copied into 'to', the final \0 is placed at len+1
* (i.e. 'to[len] = \0'), so the 'to' buffer must have at least len+1
* chars available.
*
* Note this may be called with 'str' == 'to', i.e. to replace whitespace
* in-place in a buffer. This function can handle that situation.
*/
int util_replace_whitespace(const char *str, char *to, size_t len) {
size_t i, j;
/* strip trailing whitespace */
len = strnlen(str, len);
while (len && isspace(str[len-1]))
len--;
/* strip leading whitespace */
i = 0;
while ((i < len) && isspace(str[i]))
i++;
j = 0;
while (i < len) {
/* substitute multiple whitespace with a single '_' */
if (isspace(str[i])) {
while (isspace(str[i]))
i++;
to[j++] = '_';
}
to[j++] = str[i++];
}
to[j] = '\0';
return j;
}
/* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */
int util_replace_chars(char *str, const char *white) {
size_t i = 0;
int replaced = 0;
while (str[i] != '\0') {
int len;
if (whitelisted_char_for_devnode(str[i], white)) {
i++;
continue;
}
/* accept hex encoding */
if (str[i] == '\\' && str[i+1] == 'x') {
i += 2;
continue;
}
/* accept valid utf8 */
len = utf8_encoded_valid_unichar(&str[i]);
if (len > 1) {
i += len;
continue;
}
/* if space is allowed, replace whitespace with ordinary space */
if (isspace(str[i]) && white != NULL && strchr(white, ' ') != NULL) {
str[i] = ' ';
i++;
replaced++;
continue;
}
/* everything else is replaced with '_' */
str[i] = '_';
i++;
replaced++;
}
return replaced;
}
/**
* 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);
}
|
