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/>.
27 #include "device-nodes.h"
29 #include "libudev-private.h"
31 #include "MurmurHash2.h"
34 * SECTION:libudev-util
35 * @short_description: utils
37 * Utilities useful when dealing with devices and device node names.
40 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
41 int util_resolve_subsys_kernel(struct udev *udev, const char *string,
42 char *result, size_t maxsize, int read_value)
44 char temp[UTIL_PATH_SIZE];
47 struct udev_device *dev;
53 strscpy(temp, sizeof(temp), string);
57 sysname = strchr(subsys, '/');
61 sysname = &sysname[1];
63 attr = strchr(sysname, ']');
73 if (read_value && attr == NULL)
76 dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
83 val = udev_device_get_sysattr_value(dev, attr);
85 strscpy(result, maxsize, val);
88 log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
94 l = strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
96 strpcpyl(&s, l, "/", attr, NULL);
97 log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
99 udev_device_unref(dev);
103 ssize_t util_get_sys_core_link_value(struct udev *udev, const char *slink, const char *syspath, char *value, size_t size)
105 char path[UTIL_PATH_SIZE];
106 char target[UTIL_PATH_SIZE];
110 strscpyl(path, sizeof(path), syspath, "/", slink, NULL);
111 len = readlink(path, target, sizeof(target));
112 if (len <= 0 || len == (ssize_t)sizeof(target))
115 pos = strrchr(target, '/');
119 return strscpy(value, size, pos);
122 int util_resolve_sys_link(struct udev *udev, char *syspath, size_t size)
124 char link_target[UTIL_PATH_SIZE];
131 len = readlink(syspath, link_target, sizeof(link_target));
132 if (len <= 0 || len == (ssize_t)sizeof(link_target))
134 link_target[len] = '\0';
136 for (back = 0; startswith(&link_target[back * 3], "../"); back++)
138 for (i = 0; i <= back; i++) {
139 base = strrchr(syspath, '/');
145 strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL);
149 int util_log_priority(const char *priority)
154 prio = strtoul(priority, &endptr, 10);
155 if (endptr[0] == '\0' || isspace(endptr[0])) {
156 if (prio >= 0 && prio <= 7)
162 return log_level_from_string(priority);
165 size_t util_path_encode(const char *src, char *dest, size_t size)
169 for (i = 0, j = 0; src[i] != '\0'; i++) {
175 memcpy(&dest[j], "\\x2f", 4);
177 } else if (src[i] == '\\') {
182 memcpy(&dest[j], "\\x5c", 4);
197 void util_remove_trailing_chars(char *path, char c)
204 while (len > 0 && path[len-1] == c)
208 int util_replace_whitespace(const char *str, char *to, size_t len)
212 /* strip trailing whitespace */
213 len = strnlen(str, len);
214 while (len && isspace(str[len-1]))
217 /* strip leading whitespace */
219 while (isspace(str[i]) && (i < len))
224 /* substitute multiple whitespace with a single '_' */
225 if (isspace(str[i])) {
226 while (isspace(str[i]))
236 /* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */
237 int util_replace_chars(char *str, const char *white)
242 while (str[i] != '\0') {
245 if (whitelisted_char_for_devnode(str[i], white)) {
250 /* accept hex encoding */
251 if (str[i] == '\\' && str[i+1] == 'x') {
256 /* accept valid utf8 */
257 len = utf8_encoded_valid_unichar(&str[i]);
263 /* if space is allowed, replace whitespace with ordinary space */
264 if (isspace(str[i]) && white != NULL && strchr(white, ' ') != NULL) {
271 /* everything else is replaced with '_' */
280 * udev_util_encode_string:
281 * @str: input string to be encoded
282 * @str_enc: output string to store the encoded input string
283 * @len: maximum size of the output string, which may be
284 * four times as long as the input string
286 * Encode all potentially unsafe characters of a string to the
287 * corresponding 2 char hex value prefixed by '\x'.
289 * Returns: 0 if the entire string was copied, non-zero otherwise.
291 _public_ int udev_util_encode_string(const char *str, char *str_enc, size_t len)
293 return encode_devnode_name(str, str_enc, len);
296 unsigned int util_string_hash32(const char *str)
298 return MurmurHash2(str, strlen(str), 0);
301 /* get a bunch of bit numbers out of the hash, and set the bits in our bit field */
302 uint64_t util_string_bloom64(const char *str)
305 unsigned int hash = util_string_hash32(str);
307 bits |= 1LLU << (hash & 63);
308 bits |= 1LLU << ((hash >> 6) & 63);
309 bits |= 1LLU << ((hash >> 12) & 63);
310 bits |= 1LLU << ((hash >> 18) & 63);