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 indices arrays to lib/uuid.c to be shared accross modules.

Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
---
 include/linux/uuid.h | 13 ++++++++++
 lib/uuid.c           | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/vsprintf.c       |  9 +++----
 3 files changed, 87 insertions(+), 5 deletions(-)

diff --git a/include/linux/uuid.h b/include/linux/uuid.h
index 91c2b6d..616347f 100644
--- a/include/linux/uuid.h
+++ b/include/linux/uuid.h
@@ -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);

+int __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
diff --git a/lib/uuid.c b/lib/uuid.c
index 6c81c0b..995865c 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -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 +72,66 @@ 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: 0 on success, %-EINVAL otherwise.
+  */
+int uuid_is_valid(const char *uuid)
+{
+       unsigned int i;
+
+       if (strnlen(uuid, UUID_STRING_LEN) < UUID_STRING_LEN)
+               return -EINVAL;
+
+       for (i = 0; i < UUID_STRING_LEN; i++) {
+               if (i == 8 || i == 13 || i == 18 || i == 23) {
+                       if (uuid[i] != '-')
+                               return -EINVAL;
+               } else if (!isxdigit(uuid[i])) {
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+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;
+       int ret;
+
+       ret = uuid_is_valid(uuid);
+       if (ret)
+               return ret;
+
+       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);
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 17d976b..752e78d 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -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;
-- 
2.7.0

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