Turn the content of uuid_t into a union and add the fields for the v1 interpretation to it.
Signed-off-by: Christoph Hellwig <[email protected]> --- include/uapi/linux/uuid.h | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/uuid.h b/include/uapi/linux/uuid.h index 1a2914d8b225..1039d2f3e114 100644 --- a/include/uapi/linux/uuid.h +++ b/include/uapi/linux/uuid.h @@ -25,7 +25,34 @@ typedef struct { } guid_t; typedef struct { - __u8 b[16]; + union { + __u8 b[16]; + + /* + * V1 (time-based) UUID definition [RFC 4122]: + * - the timestamp is a 60-bit value, split 32/16/12, and goes + * in 100ns increments since midnight 15th October 1582 + * - add UUID_TO_UNIX_TIME to convert unix time in 100ns + * units to UUID time + * - the clock sequence is a 14-bit counter to avoid duplicate + * times + */ + struct { + __be32 time_low; + __be16 time_mid; + __be16 time_hi_and_version; +#define UUID_TO_UNIX_TIME 0x01b21dd213814000ULL +#define UUID_TIMEHI_MASK 0x0fff +#define UUID_VERSION_TIME 0x1000 /* time-based UUID */ +#define UUID_VERSION_NAME 0x3000 /* name-based UUID */ +#define UUID_VERSION_RANDOM 0x4000 /* (pseudo-)random generated UUID */ + u8 clock_seq_hi_and_reserved; +#define UUID_CLOCKHI_MASK 0x3f +#define UUID_VARIANT_STD 0x80 + u8 clock_seq_low; + u8 node[6]; + } v1; + }; } uuid_t; #define GUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \ -- 2.11.0
