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Commit 2b1b0d66 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Linus Torvalds
Browse files

lib/uuid.c: introduce a few more generic helpers 



There are new helpers in this patch:

  uuid_is_valid		checks if a UUID is valid
  uuid_be_to_bin	converts from string to binary (big endian)
  uuid_le_to_bin	converts from string to binary (little endian)

They will be used in future, i.e. in the following patches in the series.

This also moves the indices arrays to lib/uuid.c to be shared accross
modules.

[andriy.shevchenko@linux.intel.com: fix typo]
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8da4b8c4

include/linux/uuid.h

+13 −0
Original line number Diff line number Diff line
@@ -22,6 +22,11 @@ 


#include <uapi/linux/uuid.h>



/*

 * The length of a UUID string ("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee")

 * not including trailing NUL.

 */

#define	UUID_STRING_LEN		36



static inline int uuid_le_cmp(const uuid_le u1, const uuid_le u2)

{
@@ -38,4 +43,12 @@ void generate_random_uuid(unsigned char uuid[16]); 
extern void uuid_le_gen(uuid_le *u);

extern void uuid_be_gen(uuid_be *u);



bool __must_check uuid_is_valid(const char *uuid);



extern const u8 uuid_le_index[16];

extern const u8 uuid_be_index[16];



int uuid_le_to_bin(const char *uuid, uuid_le *u);

int uuid_be_to_bin(const char *uuid, uuid_be *u);



#endif

lib/uuid.c

+65 −0
Original line number Diff line number Diff line
@@ -19,10 +19,17 @@ 
 */



#include <linux/kernel.h>

#include <linux/ctype.h>

#include <linux/errno.h>

#include <linux/export.h>

#include <linux/uuid.h>

#include <linux/random.h>



const u8 uuid_le_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};

EXPORT_SYMBOL(uuid_le_index);

const u8 uuid_be_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};

EXPORT_SYMBOL(uuid_be_index);



/***************************************************************

 * Random UUID interface

 *
@@ -65,3 +72,61 @@ void uuid_be_gen(uuid_be *bu) 
	bu->b[6] = (bu->b[6] & 0x0F) | 0x40;

}

EXPORT_SYMBOL_GPL(uuid_be_gen);



/**

  * uuid_is_valid - checks if UUID string valid

  * @uuid:	UUID string to check

  *

  * Description:

  * It checks if the UUID string is following the format:

  *	xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

  * where x is a hex digit.

  *

  * Return: true if input is valid UUID string.

  */

bool uuid_is_valid(const char *uuid)

{

	unsigned int i;



	for (i = 0; i < UUID_STRING_LEN; i++) {

		if (i == 8 || i == 13 || i == 18 || i == 23) {

			if (uuid[i] != '-')

				return false;

		} else if (!isxdigit(uuid[i])) {

			return false;

		}

	}



	return true;

}

EXPORT_SYMBOL(uuid_is_valid);



static int __uuid_to_bin(const char *uuid, __u8 b[16], const u8 ei[16])

{

	static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};

	unsigned int i;



	if (!uuid_is_valid(uuid))

		return -EINVAL;



	for (i = 0; i < 16; i++) {

		int hi = hex_to_bin(uuid[si[i]] + 0);

		int lo = hex_to_bin(uuid[si[i]] + 1);



		b[ei[i]] = (hi << 4) | lo;

	}



	return 0;

}



int uuid_le_to_bin(const char *uuid, uuid_le *u)

{

	return __uuid_to_bin(uuid, u->b, uuid_le_index);

}

EXPORT_SYMBOL(uuid_le_to_bin);



int uuid_be_to_bin(const char *uuid, uuid_be *u)

{

	return __uuid_to_bin(uuid, u->b, uuid_be_index);

}

EXPORT_SYMBOL(uuid_be_to_bin);

lib/vsprintf.c

+4 −5
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/ioport.h>

#include <linux/dcache.h>

#include <linux/cred.h>

#include <linux/uuid.h>

#include <net/addrconf.h>

#ifdef CONFIG_BLOCK

#include <linux/blkdev.h>
@@ -1304,19 +1305,17 @@ static noinline_for_stack 
char *uuid_string(char *buf, char *end, const u8 *addr,

		  struct printf_spec spec, const char *fmt)

{

	char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")];

	char uuid[UUID_STRING_LEN + 1];

	char *p = uuid;

	int i;

	static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};

	static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};

	const u8 *index = be;

	const u8 *index = uuid_be_index;

	bool uc = false;



	switch (*(++fmt)) {

	case 'L':

		uc = true;		/* fall-through */

	case 'l':

		index = le;

		index = uuid_le_index;

		break;

	case 'B':

		uc = true;