321 lines
9.1 KiB
C
321 lines
9.1 KiB
C
/***
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This file is part of systemd.
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Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <stdio.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <unistd.h>
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#include <errno.h>
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#include <string.h>
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#include <dirent.h>
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#include <ctype.h>
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#include <fcntl.h>
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#include <time.h>
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#include <pwd.h>
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#include <grp.h>
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#include <sys/stat.h>
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#include <sys/param.h>
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#include "device-nodes.h"
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#include "libudev.h"
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#include "libudev-private.h"
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#include "utf8.h"
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#include "MurmurHash2.h"
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/**
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* SECTION:libudev-util
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* @short_description: utils
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*
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* Utilities useful when dealing with devices and device node names.
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*/
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/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
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int util_resolve_subsys_kernel(struct udev *udev, const char *string,
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char *result, size_t maxsize, int read_value)
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{
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char temp[UTIL_PATH_SIZE];
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char *subsys;
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char *sysname;
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struct udev_device *dev;
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char *attr;
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if (string[0] != '[')
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return -1;
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strscpy(temp, sizeof(temp), string);
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subsys = &temp[1];
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sysname = strchr(subsys, '/');
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if (sysname == NULL)
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return -1;
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sysname[0] = '\0';
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sysname = &sysname[1];
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attr = strchr(sysname, ']');
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if (attr == NULL)
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return -1;
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attr[0] = '\0';
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attr = &attr[1];
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if (attr[0] == '/')
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attr = &attr[1];
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if (attr[0] == '\0')
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attr = NULL;
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if (read_value && attr == NULL)
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return -1;
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dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
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if (dev == NULL)
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return -1;
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if (read_value) {
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const char *val;
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val = udev_device_get_sysattr_value(dev, attr);
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if (val != NULL)
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strscpy(result, maxsize, val);
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else
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result[0] = '\0';
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log_debug("value '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
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} else {
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size_t l;
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char *s;
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s = result;
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l = strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
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if (attr != NULL)
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strpcpyl(&s, l, "/", attr, NULL);
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log_debug("path '[%s/%s]%s' is '%s'\n", subsys, sysname, attr, result);
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}
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udev_device_unref(dev);
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return 0;
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}
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ssize_t util_get_sys_core_link_value(struct udev *udev, const char *slink, const char *syspath, char *value, size_t size)
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{
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char path[UTIL_PATH_SIZE];
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char target[UTIL_PATH_SIZE];
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ssize_t len;
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const char *pos;
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strscpyl(path, sizeof(path), syspath, "/", slink, NULL);
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len = readlink(path, target, sizeof(target));
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if (len <= 0 || len == (ssize_t)sizeof(target))
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return -1;
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target[len] = '\0';
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pos = strrchr(target, '/');
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if (pos == NULL)
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return -1;
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pos = &pos[1];
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return strscpy(value, size, pos);
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}
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int util_resolve_sys_link(struct udev *udev, char *syspath, size_t size)
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{
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char link_target[UTIL_PATH_SIZE];
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ssize_t len;
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int i;
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int back;
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char *base = NULL;
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len = readlink(syspath, link_target, sizeof(link_target));
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if (len <= 0 || len == (ssize_t)sizeof(link_target))
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return -1;
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link_target[len] = '\0';
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for (back = 0; startswith(&link_target[back * 3], "../"); back++)
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;
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for (i = 0; i <= back; i++) {
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base = strrchr(syspath, '/');
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if (base == NULL)
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return -EINVAL;
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base[0] = '\0';
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}
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strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL);
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return 0;
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}
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int util_log_priority(const char *priority)
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{
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char *endptr;
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int prio;
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prio = strtoul(priority, &endptr, 10);
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if (endptr[0] == '\0' || isspace(endptr[0])) {
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if (prio >= 0 && prio <= 7)
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return prio;
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else
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return -ERANGE;
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}
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return log_level_from_string(priority);
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}
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size_t util_path_encode(const char *src, char *dest, size_t size)
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{
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size_t i, j;
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for (i = 0, j = 0; src[i] != '\0'; i++) {
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if (src[i] == '/') {
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if (j+4 >= size) {
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j = 0;
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break;
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}
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memcpy(&dest[j], "\\x2f", 4);
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j += 4;
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} else if (src[i] == '\\') {
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if (j+4 >= size) {
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j = 0;
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break;
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}
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memcpy(&dest[j], "\\x5c", 4);
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j += 4;
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} else {
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if (j+1 >= size) {
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j = 0;
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break;
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}
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dest[j] = src[i];
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j++;
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}
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}
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dest[j] = '\0';
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return j;
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}
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void util_remove_trailing_chars(char *path, char c)
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{
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size_t len;
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if (path == NULL)
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return;
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len = strlen(path);
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while (len > 0 && path[len-1] == c)
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path[--len] = '\0';
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}
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int util_replace_whitespace(const char *str, char *to, size_t len)
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{
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size_t i, j;
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/* strip trailing whitespace */
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len = strnlen(str, len);
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while (len && isspace(str[len-1]))
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len--;
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/* strip leading whitespace */
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i = 0;
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while (isspace(str[i]) && (i < len))
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i++;
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j = 0;
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while (i < len) {
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/* substitute multiple whitespace with a single '_' */
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if (isspace(str[i])) {
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while (isspace(str[i]))
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i++;
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to[j++] = '_';
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}
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to[j++] = str[i++];
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}
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to[j] = '\0';
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return 0;
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}
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/* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */
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int util_replace_chars(char *str, const char *white)
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{
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size_t i = 0;
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int replaced = 0;
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while (str[i] != '\0') {
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int len;
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if (whitelisted_char_for_devnode(str[i], white)) {
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i++;
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continue;
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}
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/* accept hex encoding */
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if (str[i] == '\\' && str[i+1] == 'x') {
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i += 2;
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continue;
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}
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/* accept valid utf8 */
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len = utf8_encoded_valid_unichar(&str[i]);
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if (len > 1) {
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i += len;
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continue;
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}
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/* if space is allowed, replace whitespace with ordinary space */
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if (isspace(str[i]) && white != NULL && strchr(white, ' ') != NULL) {
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str[i] = ' ';
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i++;
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replaced++;
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continue;
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}
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/* everything else is replaced with '_' */
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str[i] = '_';
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i++;
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replaced++;
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}
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return replaced;
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}
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/**
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* udev_util_encode_string:
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* @str: input string to be encoded
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* @str_enc: output string to store the encoded input string
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* @len: maximum size of the output string, which may be
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* four times as long as the input string
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*
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* Encode all potentially unsafe characters of a string to the
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* corresponding 2 char hex value prefixed by '\x'.
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*
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* Returns: 0 if the entire string was copied, non-zero otherwise.
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**/
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_public_ int udev_util_encode_string(const char *str, char *str_enc, size_t len)
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{
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return encode_devnode_name(str, str_enc, len);
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}
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unsigned int util_string_hash32(const char *str)
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{
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return MurmurHash2(str, strlen(str), 0);
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}
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/* get a bunch of bit numbers out of the hash, and set the bits in our bit field */
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uint64_t util_string_bloom64(const char *str)
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{
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uint64_t bits = 0;
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unsigned int hash = util_string_hash32(str);
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bits |= 1LLU << (hash & 63);
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bits |= 1LLU << ((hash >> 6) & 63);
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bits |= 1LLU << ((hash >> 12) & 63);
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bits |= 1LLU << ((hash >> 18) & 63);
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return bits;
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}
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