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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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Matt 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Andy Shevchenko 2016-05-20 17:01:04 -07:00 committed by Linus Torvalds
parent 8da4b8c48e
commit 2b1b0d6670
3 changed files with 82 additions and 5 deletions
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13
include/linux/uuid.h
View File

@ -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

65
lib/uuid.c
View File

@ -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);

9
lib/vsprintf.c
View File

@ -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;