libudev-util.c revision b250ea2fd6fe35242a7d161a3b37bb756ae87be0
/***
This file is part of systemd.
Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include "device-nodes.h"
#include "libudev.h"
#include "libudev-private.h"
#include "utf8.h"
#include "MurmurHash2.h"
/**
* SECTION:libudev-util
* @short_description: utils
*
* Utilities useful when dealing with devices and device node names.
*/
/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
int util_resolve_subsys_kernel(struct udev *udev, const char *string,
char *result, size_t maxsize, int read_value)
{
char temp[UTIL_PATH_SIZE];
char *subsys;
char *sysname;
struct udev_device *dev;
char *attr;
if (string[0] != '[')
return -1;
strscpy(temp, sizeof(temp), string);
subsys = &temp[1];
sysname = strchr(subsys, '/');
if (sysname == NULL)
return -1;
sysname[0] = '\0';
sysname = &sysname[1];
attr = strchr(sysname, ']');
if (attr == NULL)
return -1;
attr[0] = '\0';
attr = &attr[1];
if (attr[0] == '/')
attr = &attr[1];
if (attr[0] == '\0')
attr = NULL;
if (read_value && attr == NULL)
return -1;
dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname);
if (dev == NULL)
return -1;
if (read_value) {
const char *val;
val = udev_device_get_sysattr_value(dev, attr);
if (val != NULL)
strscpy(result, maxsize, val);
else
result[0] = '\0';
log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
} else {
size_t l;
char *s;
s = result;
l = strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL);
if (attr != NULL)
strpcpyl(&s, l, "/", attr, NULL);
log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
}
udev_device_unref(dev);
return 0;
}
int util_log_priority(const char *priority)
{
char *endptr;
int prio;
prio = strtoul(priority, &endptr, 10);
if (endptr[0] == '\0' || isspace(endptr[0])) {
if (prio >= 0 && prio <= 7)
return prio;
else
return -ERANGE;
}
return log_level_from_string(priority);
}
size_t util_path_encode(const char *src, char *dest, size_t size)
{
size_t i, j;
for (i = 0, j = 0; src[i] != '\0'; i++) {
if (src[i] == '/') {
if (j+4 >= size) {
j = 0;
break;
}
memcpy(&dest[j], "\\x2f", 4);
j += 4;
} else if (src[i] == '\\') {
if (j+4 >= size) {
j = 0;
break;
}
memcpy(&dest[j], "\\x5c", 4);
j += 4;
} else {
if (j+1 >= size) {
j = 0;
break;
}
dest[j] = src[i];
j++;
}
}
dest[j] = '\0';
return j;
}
void util_remove_trailing_chars(char *path, char c)
{
size_t len;
if (path == NULL)
return;
len = strlen(path);
while (len > 0 && path[len-1] == c)
path[--len] = '\0';
}
int util_replace_whitespace(const char *str, char *to, size_t len)
{
size_t i, j;
/* strip trailing whitespace */
len = strnlen(str, len);
while (len && isspace(str[len-1]))
len--;
/* strip leading whitespace */
i = 0;
while ((i < len) && isspace(str[i]))
i++;
j = 0;
while (i < len) {
/* substitute multiple whitespace with a single '_' */
if (isspace(str[i])) {
while (isspace(str[i]))
i++;
to[j++] = '_';
}
to[j++] = str[i++];
}
to[j] = '\0';
return 0;
}
/* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */
int util_replace_chars(char *str, const char *white)
{
size_t i = 0;
int replaced = 0;
while (str[i] != '\0') {
int len;
if (whitelisted_char_for_devnode(str[i], white)) {
i++;
continue;
}
/* accept hex encoding */
if (str[i] == '\\' && str[i+1] == 'x') {
i += 2;
continue;
}
/* 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)
{
return encode_devnode_name(str, str_enc, len);
}
unsigned int util_string_hash32(const char *str)
{
return MurmurHash2(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;
}