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git.proxmox.com Git - systemd.git/blob - src/libudev/libudev-util.c
2 This file is part of systemd.
4 Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
33 #include <sys/param.h>
35 #include "device-nodes.h"
37 #include "libudev-private.h"
39 #include "MurmurHash2.h"
42 * SECTION:libudev-util
43 * @short_description: utils
45 * Utilities useful when dealing with devices and device node names.
48 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
49 int util_resolve_subsys_kernel(struct udev
*udev
, const char *string
,
50 char *result
, size_t maxsize
, int read_value
)
52 char temp
[UTIL_PATH_SIZE
];
55 struct udev_device
*dev
;
61 strscpy(temp
, sizeof(temp
), string
);
65 sysname
= strchr(subsys
, '/');
69 sysname
= &sysname
[1];
71 attr
= strchr(sysname
, ']');
81 if (read_value
&& attr
== NULL
)
84 dev
= udev_device_new_from_subsystem_sysname(udev
, subsys
, sysname
);
91 val
= udev_device_get_sysattr_value(dev
, attr
);
93 strscpy(result
, maxsize
, val
);
96 log_debug("value '[%s/%s]%s' is '%s'", subsys
, sysname
, attr
, result
);
102 l
= strpcpyl(&s
, maxsize
, udev_device_get_syspath(dev
), NULL
);
104 strpcpyl(&s
, l
, "/", attr
, NULL
);
105 log_debug("path '[%s/%s]%s' is '%s'", subsys
, sysname
, attr
, result
);
107 udev_device_unref(dev
);
111 ssize_t
util_get_sys_core_link_value(struct udev
*udev
, const char *slink
, const char *syspath
, char *value
, size_t size
)
113 char path
[UTIL_PATH_SIZE
];
114 char target
[UTIL_PATH_SIZE
];
118 strscpyl(path
, sizeof(path
), syspath
, "/", slink
, NULL
);
119 len
= readlink(path
, target
, sizeof(target
));
120 if (len
<= 0 || len
== (ssize_t
)sizeof(target
))
123 pos
= strrchr(target
, '/');
127 return strscpy(value
, size
, pos
);
130 int util_resolve_sys_link(struct udev
*udev
, char *syspath
, size_t size
)
132 char link_target
[UTIL_PATH_SIZE
];
139 len
= readlink(syspath
, link_target
, sizeof(link_target
));
140 if (len
<= 0 || len
== (ssize_t
)sizeof(link_target
))
142 link_target
[len
] = '\0';
144 for (back
= 0; startswith(&link_target
[back
* 3], "../"); back
++)
146 for (i
= 0; i
<= back
; i
++) {
147 base
= strrchr(syspath
, '/');
153 strscpyl(base
, size
- (base
- syspath
), "/", &link_target
[back
* 3], NULL
);
157 int util_log_priority(const char *priority
)
162 prio
= strtoul(priority
, &endptr
, 10);
163 if (endptr
[0] == '\0' || isspace(endptr
[0])) {
164 if (prio
>= 0 && prio
<= 7)
170 return log_level_from_string(priority
);
173 size_t util_path_encode(const char *src
, char *dest
, size_t size
)
177 for (i
= 0, j
= 0; src
[i
] != '\0'; i
++) {
183 memcpy(&dest
[j
], "\\x2f", 4);
185 } else if (src
[i
] == '\\') {
190 memcpy(&dest
[j
], "\\x5c", 4);
205 void util_remove_trailing_chars(char *path
, char c
)
212 while (len
> 0 && path
[len
-1] == c
)
216 int util_replace_whitespace(const char *str
, char *to
, size_t len
)
220 /* strip trailing whitespace */
221 len
= strnlen(str
, len
);
222 while (len
&& isspace(str
[len
-1]))
225 /* strip leading whitespace */
227 while (isspace(str
[i
]) && (i
< len
))
232 /* substitute multiple whitespace with a single '_' */
233 if (isspace(str
[i
])) {
234 while (isspace(str
[i
]))
244 /* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */
245 int util_replace_chars(char *str
, const char *white
)
250 while (str
[i
] != '\0') {
253 if (whitelisted_char_for_devnode(str
[i
], white
)) {
258 /* accept hex encoding */
259 if (str
[i
] == '\\' && str
[i
+1] == 'x') {
264 /* accept valid utf8 */
265 len
= utf8_encoded_valid_unichar(&str
[i
]);
271 /* if space is allowed, replace whitespace with ordinary space */
272 if (isspace(str
[i
]) && white
!= NULL
&& strchr(white
, ' ') != NULL
) {
279 /* everything else is replaced with '_' */
288 * udev_util_encode_string:
289 * @str: input string to be encoded
290 * @str_enc: output string to store the encoded input string
291 * @len: maximum size of the output string, which may be
292 * four times as long as the input string
294 * Encode all potentially unsafe characters of a string to the
295 * corresponding 2 char hex value prefixed by '\x'.
297 * Returns: 0 if the entire string was copied, non-zero otherwise.
299 _public_
int udev_util_encode_string(const char *str
, char *str_enc
, size_t len
)
301 return encode_devnode_name(str
, str_enc
, len
);
304 unsigned int util_string_hash32(const char *str
)
306 return MurmurHash2(str
, strlen(str
), 0);
309 /* get a bunch of bit numbers out of the hash, and set the bits in our bit field */
310 uint64_t util_string_bloom64(const char *str
)
313 unsigned int hash
= util_string_hash32(str
);
315 bits
|= 1LLU << (hash
& 63);
316 bits
|= 1LLU << ((hash
>> 6) & 63);
317 bits
|= 1LLU << ((hash
>> 12) & 63);
318 bits
|= 1LLU << ((hash
>> 18) & 63);