src/libudev/libudev-util.c - systemd-stable - Rivoreo Source Code Repositories

 /***
   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;
 }

 ssize_t util_get_sys_core_link_value(struct udev *udev, const char *slink, const char *syspath, char *value, size_t size)
 {
         char path[UTIL_PATH_SIZE];
         char target[UTIL_PATH_SIZE];
         ssize_t len;
         const char *pos;

         strscpyl(path, sizeof(path), syspath, "/", slink, NULL);
         len = readlink(path, target, sizeof(target));
         if (len <= 0 || len == (ssize_t)sizeof(target))
                 return -1;
         target[len] = '\0';
         pos = strrchr(target, '/');
         if (pos == NULL)
                 return -1;
         pos = &pos[1];
         return strscpy(value, size, pos);
 }

 int util_resolve_sys_link(struct udev *udev, char *syspath, size_t size)
 {
         char link_target[UTIL_PATH_SIZE];

         ssize_t len;
         int i;
         int back;
         char *base = NULL;

         len = readlink(syspath, link_target, sizeof(link_target));
         if (len <= 0 || len == (ssize_t)sizeof(link_target))
                 return -1;
         link_target[len] = '\0';

         for (back = 0; startswith(&link_target[back * 3], "../"); back++)
                 ;
         for (i = 0; i <= back; i++) {
                 base = strrchr(syspath, '/');
                 if (base == NULL)
                         return -EINVAL;
                 base[0] = '\0';
         }

         strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL);
         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;
 }
	/***
	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;
	}

	ssize_t util_get_sys_core_link_value(struct udev udev, const char slink, const char syspath, char value, size_t size)
	{
	char path[UTIL_PATH_SIZE];
	char target[UTIL_PATH_SIZE];
	ssize_t len;
	const char *pos;

	strscpyl(path, sizeof(path), syspath, "/", slink, NULL);
	len = readlink(path, target, sizeof(target));
	if (len <= 0 \|\| len == (ssize_t)sizeof(target))
	return -1;
	target[len] = '\0';
	pos = strrchr(target, '/');
	if (pos == NULL)
	return -1;
	pos = &pos[1];
	return strscpy(value, size, pos);
	}

	int util_resolve_sys_link(struct udev udev, char syspath, size_t size)
	{
	char link_target[UTIL_PATH_SIZE];

	ssize_t len;
	int i;
	int back;
	char *base = NULL;

	len = readlink(syspath, link_target, sizeof(link_target));
	if (len <= 0 \|\| len == (ssize_t)sizeof(link_target))
	return -1;
	link_target[len] = '\0';

	for (back = 0; startswith(&link_target[back * 3], "../"); back++)
	;
	for (i = 0; i <= back; i++) {
	base = strrchr(syspath, '/');
	if (base == NULL)
	return -EINVAL;
	base[0] = '\0';
	}

	strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL);
	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;
	}