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 int util_delete_path(struct udev *udev, const char *path)
50 char p[UTIL_PATH_SIZE];
57 strscpy(p, sizeof(p), path);
58 pos = strrchr(p, '/');
59 if (pos == p || pos == NULL)
64 pos = strrchr(p, '/');
66 /* don't remove the last one */
67 if ((pos == p) || (pos == NULL))
80 uid_t util_lookup_user(struct udev *udev, const char *user)
86 size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
87 char *buf = alloca(buflen);
89 if (streq(user, "root"))
91 uid = strtoul(user, &endptr, 10);
92 if (endptr[0] == '\0')
95 errno = getpwnam_r(user, &pwbuf, buf, buflen, &pw);
98 if (errno == 0 || errno == ENOENT || errno == ESRCH)
99 udev_err(udev, "specified user '%s' unknown\n", user);
101 udev_err(udev, "error resolving user '%s': %m\n", user);
105 gid_t util_lookup_group(struct udev *udev, const char *group)
111 size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
114 if (streq(group, "root"))
116 gid = strtoul(group, &endptr, 10);
117 if (endptr[0] == '\0')
123 newbuf = realloc(buf, buflen);
127 errno = getgrnam_r(group, &grbuf, buf, buflen, &gr);
130 } else if (errno == ERANGE) {
133 } else if (errno == 0 || errno == ENOENT || errno == ESRCH) {
134 udev_err(udev, "specified group '%s' unknown\n", group);
136 udev_err(udev, "error resolving group '%s': %m\n", group);
144 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
145 int util_resolve_subsys_kernel(struct udev *udev, const char *string,
146 char *result, size_t maxsize, int read_value)
148 char temp[UTIL_PATH_SIZE];
151 struct udev_device *dev;
154 if (string[0] != '[')
157 strscpy(temp, sizeof(temp), string);
161 sysname = strchr(subsys, '/');
165 sysname = &sysname[1];
167 attr = strchr(sysname, ']');
177 if (read_value && attr == NULL)
180 dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
187 val = udev_device_get_sysattr_value(dev, attr);
189 strscpy(result, maxsize, val);
192 udev_dbg(udev, "value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
198 l = strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
200 strpcpyl(&s, l, "/", attr, NULL);
201 udev_dbg(udev, "path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
203 udev_device_unref(dev);
207 ssize_t util_get_sys_core_link_value(struct udev *udev, const char *slink, const char *syspath, char *value, size_t size)
209 char path[UTIL_PATH_SIZE];
210 char target[UTIL_PATH_SIZE];
214 strscpyl(path, sizeof(path), syspath, "/", slink, NULL);
215 len = readlink(path, target, sizeof(target));
216 if (len <= 0 || len == (ssize_t)sizeof(target))
219 pos = strrchr(target, '/');
223 return strscpy(value, size, pos);
226 int util_resolve_sys_link(struct udev *udev, char *syspath, size_t size)
228 char link_target[UTIL_PATH_SIZE];
235 len = readlink(syspath, link_target, sizeof(link_target));
236 if (len <= 0 || len == (ssize_t)sizeof(link_target))
238 link_target[len] = '\0';
240 for (back = 0; startswith(&link_target[back * 3], "../"); back++)
242 for (i = 0; i <= back; i++) {
243 base = strrchr(syspath, '/');
249 strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL);
253 int util_log_priority(const char *priority)
258 prio = strtol(priority, &endptr, 10);
259 if (endptr[0] == '\0' || isspace(endptr[0]))
261 if (startswith(priority, "err"))
263 if (startswith(priority, "info"))
265 if (startswith(priority, "debug"))
270 size_t util_path_encode(const char *src, char *dest, size_t size)
274 for (i = 0, j = 0; src[i] != '\0'; i++) {
280 memcpy(&dest[j], "\\x2f", 4);
282 } else if (src[i] == '\\') {
287 memcpy(&dest[j], "\\x5c", 4);
302 void util_remove_trailing_chars(char *path, char c)
309 while (len > 0 && path[len-1] == c)
313 int util_replace_whitespace(const char *str, char *to, size_t len)
317 /* strip trailing whitespace */
318 len = strnlen(str, len);
319 while (len && isspace(str[len-1]))
322 /* strip leading whitespace */
324 while (isspace(str[i]) && (i < len))
329 /* substitute multiple whitespace with a single '_' */
330 if (isspace(str[i])) {
331 while (isspace(str[i]))
341 /* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */
342 int util_replace_chars(char *str, const char *white)
347 while (str[i] != '\0') {
350 if (whitelisted_char_for_devnode(str[i], white)) {
355 /* accept hex encoding */
356 if (str[i] == '\\' && str[i+1] == 'x') {
361 /* accept valid utf8 */
362 len = utf8_encoded_valid_unichar(&str[i]);
368 /* if space is allowed, replace whitespace with ordinary space */
369 if (isspace(str[i]) && white != NULL && strchr(white, ' ') != NULL) {
376 /* everything else is replaced with '_' */
385 * udev_util_encode_string:
386 * @str: input string to be encoded
387 * @str_enc: output string to store the encoded input string
388 * @len: maximum size of the output string, which may be
389 * four times as long as the input string
391 * Encode all potentially unsafe characters of a string to the
392 * corresponding 2 char hex value prefixed by '\x'.
394 * Returns: 0 if the entire string was copied, non-zero otherwise.
396 _public_ int udev_util_encode_string(const char *str, char *str_enc, size_t len)
398 return encode_devnode_name(str, str_enc, len);
401 unsigned int util_string_hash32(const char *str)
403 return MurmurHash2(str, strlen(str), 0);
406 /* get a bunch of bit numbers out of the hash, and set the bits in our bit field */
407 uint64_t util_string_bloom64(const char *str)
410 unsigned int hash = util_string_hash32(str);
412 bits |= 1LLU << (hash & 63);
413 bits |= 1LLU << ((hash >> 6) & 63);
414 bits |= 1LLU << ((hash >> 12) & 63);
415 bits |= 1LLU << ((hash >> 18) & 63);
419 ssize_t print_kmsg(const char *fmt, ...)
421 _cleanup_close_ int fd = -1;
427 fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC);
431 len = snprintf(text, sizeof(text), "<30>systemd-udevd[%u]: ", getpid());
434 len += vsnprintf(text + len, sizeof(text) - len, fmt, ap);
437 ret = write(fd, text, len);