726 lines
20 KiB
C
726 lines
20 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 "libudev.h"
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#include "libudev-private.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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int util_delete_path(struct udev *udev, const char *path)
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{
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char p[UTIL_PATH_SIZE];
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char *pos;
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int err = 0;
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if (path[0] == '/')
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while(path[1] == '/')
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path++;
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util_strscpy(p, sizeof(p), path);
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pos = strrchr(p, '/');
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if (pos == p || pos == NULL)
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return 0;
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for (;;) {
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*pos = '\0';
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pos = strrchr(p, '/');
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/* don't remove the last one */
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if ((pos == p) || (pos == NULL))
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break;
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err = rmdir(p);
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if (err < 0) {
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if (errno == ENOENT)
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err = 0;
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break;
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}
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}
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return err;
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}
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uid_t util_lookup_user(struct udev *udev, const char *user)
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{
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char *endptr;
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struct passwd pwbuf;
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struct passwd *pw;
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uid_t uid;
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size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
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char *buf = alloca(buflen);
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if (strcmp(user, "root") == 0)
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return 0;
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uid = strtoul(user, &endptr, 10);
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if (endptr[0] == '\0')
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return uid;
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errno = getpwnam_r(user, &pwbuf, buf, buflen, &pw);
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if (pw != NULL)
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return pw->pw_uid;
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if (errno == 0 || errno == ENOENT || errno == ESRCH)
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udev_err(udev, "specified user '%s' unknown\n", user);
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else
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udev_err(udev, "error resolving user '%s': %m\n", user);
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return 0;
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}
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gid_t util_lookup_group(struct udev *udev, const char *group)
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{
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char *endptr;
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struct group grbuf;
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struct group *gr;
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gid_t gid = 0;
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size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
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char *buf = NULL;
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if (strcmp(group, "root") == 0)
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return 0;
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gid = strtoul(group, &endptr, 10);
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if (endptr[0] == '\0')
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return gid;
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gid = 0;
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for (;;) {
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char *newbuf;
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newbuf = realloc(buf, buflen);
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if (!newbuf)
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break;
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buf = newbuf;
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errno = getgrnam_r(group, &grbuf, buf, buflen, &gr);
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if (gr != NULL) {
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gid = gr->gr_gid;
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} else if (errno == ERANGE) {
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buflen *= 2;
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continue;
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} else if (errno == 0 || errno == ENOENT || errno == ESRCH) {
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udev_err(udev, "specified group '%s' unknown\n", group);
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} else {
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udev_err(udev, "error resolving group '%s': %m\n", group);
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}
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break;
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}
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free(buf);
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return gid;
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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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util_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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util_strscpy(result, maxsize, val);
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else
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result[0] = '\0';
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udev_dbg(udev, "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 = util_strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
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if (attr != NULL)
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util_strpcpyl(&s, l, "/", attr, NULL);
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udev_dbg(udev, "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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util_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 util_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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if (base == NULL)
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return -EINVAL;
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util_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 = strtol(priority, &endptr, 10);
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if (endptr[0] == '\0' || isspace(endptr[0]))
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return prio;
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if (startswith(priority, "err"))
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return LOG_ERR;
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if (startswith(priority, "info"))
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return LOG_INFO;
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if (startswith(priority, "debug"))
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return LOG_DEBUG;
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return 0;
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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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/*
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* Concatenates strings. In any case, terminates in _all_ cases with '\0'
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* and moves the @dest pointer forward to the added '\0'. Returns the
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* remaining size, and 0 if the string was truncated.
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*/
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size_t util_strpcpy(char **dest, size_t size, const char *src)
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{
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size_t len;
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len = strlen(src);
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if (len >= size) {
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if (size > 1)
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*dest = mempcpy(*dest, src, size-1);
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size = 0;
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*dest[0] = '\0';
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} else {
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if (len > 0) {
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*dest = mempcpy(*dest, src, len);
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size -= len;
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}
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*dest[0] = '\0';
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}
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return size;
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}
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/* concatenates list of strings, moves dest forward */
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size_t util_strpcpyl(char **dest, size_t size, const char *src, ...)
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{
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va_list va;
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va_start(va, src);
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do {
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size = util_strpcpy(dest, size, src);
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src = va_arg(va, char *);
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} while (src != NULL);
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va_end(va);
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return size;
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}
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/* copies string */
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size_t util_strscpy(char *dest, size_t size, const char *src)
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{
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char *s;
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s = dest;
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return util_strpcpy(&s, size, src);
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}
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/* concatenates list of strings */
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size_t util_strscpyl(char *dest, size_t size, const char *src, ...)
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{
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va_list va;
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char *s;
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va_start(va, src);
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s = dest;
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do {
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size = util_strpcpy(&s, size, src);
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src = va_arg(va, char *);
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} while (src != NULL);
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va_end(va);
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return size;
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}
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/* count of characters used to encode one unicode char */
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static int utf8_encoded_expected_len(const char *str)
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{
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unsigned char c = (unsigned char)str[0];
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if (c < 0x80)
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return 1;
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if ((c & 0xe0) == 0xc0)
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return 2;
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if ((c & 0xf0) == 0xe0)
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return 3;
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if ((c & 0xf8) == 0xf0)
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return 4;
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if ((c & 0xfc) == 0xf8)
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return 5;
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if ((c & 0xfe) == 0xfc)
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return 6;
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return 0;
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}
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/* decode one unicode char */
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static int utf8_encoded_to_unichar(const char *str)
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{
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int unichar;
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int len;
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int i;
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len = utf8_encoded_expected_len(str);
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switch (len) {
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case 1:
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return (int)str[0];
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case 2:
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unichar = str[0] & 0x1f;
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break;
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case 3:
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unichar = (int)str[0] & 0x0f;
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break;
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case 4:
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unichar = (int)str[0] & 0x07;
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break;
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case 5:
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unichar = (int)str[0] & 0x03;
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break;
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case 6:
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unichar = (int)str[0] & 0x01;
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break;
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default:
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return -1;
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}
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for (i = 1; i < len; i++) {
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if (((int)str[i] & 0xc0) != 0x80)
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return -1;
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unichar <<= 6;
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unichar |= (int)str[i] & 0x3f;
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}
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return unichar;
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}
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/* expected size used to encode one unicode char */
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static int utf8_unichar_to_encoded_len(int unichar)
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{
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if (unichar < 0x80)
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return 1;
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if (unichar < 0x800)
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return 2;
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if (unichar < 0x10000)
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return 3;
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if (unichar < 0x200000)
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return 4;
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if (unichar < 0x4000000)
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return 5;
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return 6;
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}
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/* check if unicode char has a valid numeric range */
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static int utf8_unichar_valid_range(int unichar)
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{
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if (unichar > 0x10ffff)
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return 0;
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if ((unichar & 0xfffff800) == 0xd800)
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return 0;
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if ((unichar > 0xfdcf) && (unichar < 0xfdf0))
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return 0;
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if ((unichar & 0xffff) == 0xffff)
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return 0;
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return 1;
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}
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/* validate one encoded unicode char and return its length */
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static int utf8_encoded_valid_unichar(const char *str)
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{
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int len;
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int unichar;
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int i;
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len = utf8_encoded_expected_len(str);
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if (len == 0)
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return -1;
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/* ascii is valid */
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if (len == 1)
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return 1;
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/* check if expected encoded chars are available */
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for (i = 0; i < len; i++)
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if ((str[i] & 0x80) != 0x80)
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return -1;
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unichar = utf8_encoded_to_unichar(str);
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/* check if encoded length matches encoded value */
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if (utf8_unichar_to_encoded_len(unichar) != len)
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return -1;
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/* check if value has valid range */
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if (!utf8_unichar_valid_range(unichar))
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return -1;
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return len;
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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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static int is_whitelisted(char c, const char *white)
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{
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if ((c >= '0' && c <= '9') ||
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(c >= 'A' && c <= 'Z') ||
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(c >= 'a' && c <= 'z') ||
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strchr("#+-.:=@_", c) != NULL ||
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(white != NULL && strchr(white, c) != NULL))
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return 1;
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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 (is_whitelisted(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 */
|
|
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)
|
|
{
|
|
size_t i, j;
|
|
|
|
if (str == NULL || str_enc == NULL)
|
|
return -1;
|
|
|
|
for (i = 0, j = 0; str[i] != '\0'; i++) {
|
|
int seqlen;
|
|
|
|
seqlen = utf8_encoded_valid_unichar(&str[i]);
|
|
if (seqlen > 1) {
|
|
if (len-j < (size_t)seqlen)
|
|
goto err;
|
|
memcpy(&str_enc[j], &str[i], seqlen);
|
|
j += seqlen;
|
|
i += (seqlen-1);
|
|
} else if (str[i] == '\\' || !is_whitelisted(str[i], NULL)) {
|
|
if (len-j < 4)
|
|
goto err;
|
|
sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
|
|
j += 4;
|
|
} else {
|
|
if (len-j < 1)
|
|
goto err;
|
|
str_enc[j] = str[i];
|
|
j++;
|
|
}
|
|
}
|
|
if (len-j < 1)
|
|
goto err;
|
|
str_enc[j] = '\0';
|
|
return 0;
|
|
err:
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* http://sites.google.com/site/murmurhash/
|
|
*
|
|
* All code is released to the public domain. For business purposes,
|
|
* Murmurhash is under the MIT license.
|
|
*
|
|
*/
|
|
static unsigned int murmur_hash2(const char *key, int len, unsigned int seed)
|
|
{
|
|
/*
|
|
* 'm' and 'r' are mixing constants generated offline.
|
|
* They're not really 'magic', they just happen to work well.
|
|
*/
|
|
const unsigned int m = 0x5bd1e995;
|
|
const int r = 24;
|
|
|
|
/* initialize the hash to a 'random' value */
|
|
unsigned int h = seed ^ len;
|
|
|
|
/* mix 4 bytes at a time into the hash */
|
|
const unsigned char * data = (const unsigned char *)key;
|
|
|
|
while(len >= 4) {
|
|
unsigned int k = *(unsigned int *)data;
|
|
|
|
k *= m;
|
|
k ^= k >> r;
|
|
k *= m;
|
|
h *= m;
|
|
h ^= k;
|
|
|
|
data += 4;
|
|
len -= 4;
|
|
}
|
|
|
|
/* handle the last few bytes of the input array */
|
|
switch(len) {
|
|
case 3:
|
|
h ^= data[2] << 16;
|
|
case 2:
|
|
h ^= data[1] << 8;
|
|
case 1:
|
|
h ^= data[0];
|
|
h *= m;
|
|
};
|
|
|
|
/* do a few final mixes of the hash to ensure the last few bytes are well-incorporated */
|
|
h ^= h >> 13;
|
|
h *= m;
|
|
h ^= h >> 15;
|
|
|
|
return h;
|
|
}
|
|
|
|
unsigned int util_string_hash32(const char *str)
|
|
{
|
|
return murmur_hash2(str, strlen(str), 0);
|
|
}
|
|
|
|
/* get a bunch of bit numbers out of the hash, and set the bits in our bit field */
|
|
uint64_t util_string_bloom64(const char *str)
|
|
{
|
|
uint64_t bits = 0;
|
|
unsigned int hash = util_string_hash32(str);
|
|
|
|
bits |= 1LLU << (hash & 63);
|
|
bits |= 1LLU << ((hash >> 6) & 63);
|
|
bits |= 1LLU << ((hash >> 12) & 63);
|
|
bits |= 1LLU << ((hash >> 18) & 63);
|
|
return bits;
|
|
}
|
|
|
|
ssize_t print_kmsg(const char *fmt, ...)
|
|
{
|
|
int fd;
|
|
va_list ap;
|
|
char text[1024];
|
|
ssize_t len;
|
|
ssize_t ret;
|
|
|
|
fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
len = snprintf(text, sizeof(text), "<30>systemd-udevd[%u]: ", getpid());
|
|
|
|
va_start(ap, fmt);
|
|
len += vsnprintf(text + len, sizeof(text) - len, fmt, ap);
|
|
va_end(ap);
|
|
|
|
ret = write(fd, text, len);
|
|
if (ret < 0)
|
|
ret = -errno;
|
|
close(fd);
|
|
return ret;
|
|
}
|