From 48a2e88f53aea4dface64883157ad3c428132f75 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Mon, 24 Feb 2020 17:37:50 +0200 Subject: [PATCH] uuid: Provide a GUID generator for raw buffer In some cases we would like to generate a GUID and export it. Though it would require either casting to internal kernel types or an intermediate buffer. Instead we may achieve this by supplying a pointer to raw buffer and make a complimentary API to existing one for UUIDs. Reviewed-by: Christoph Hellwig Signed-off-by: Andy Shevchenko Signed-off-by: David Sterba --- include/linux/uuid.h | 1 + lib/uuid.c | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/uuid.h b/include/linux/uuid.h index 8e4a5000da03..3780460a9a85 100644 --- a/include/linux/uuid.h +++ b/include/linux/uuid.h @@ -84,6 +84,7 @@ static inline bool uuid_is_null(const uuid_t *uuid) } void generate_random_uuid(unsigned char uuid[16]); +void generate_random_guid(unsigned char guid[16]); extern void guid_gen(guid_t *u); extern void uuid_gen(uuid_t *u); diff --git a/lib/uuid.c b/lib/uuid.c index b6a1edb61d87..562d53977cab 100644 --- a/lib/uuid.c +++ b/lib/uuid.c @@ -40,6 +40,16 @@ void generate_random_uuid(unsigned char uuid[16]) } EXPORT_SYMBOL(generate_random_uuid); +void generate_random_guid(unsigned char guid[16]) +{ + get_random_bytes(guid, 16); + /* Set GUID version to 4 --- truly random generation */ + guid[7] = (guid[7] & 0x0F) | 0x40; + /* Set the GUID variant to DCE */ + guid[8] = (guid[8] & 0x3F) | 0x80; +} +EXPORT_SYMBOL(generate_random_guid); + static void __uuid_gen_common(__u8 b[16]) { prandom_bytes(b, 16);