Resolves: bug 330121

Bug Description: uuid generator truncates clock_seq_hi_and_reserved field
Reviewed by: nkinder (Thanks!)
Fix Description:
The uuid code has this code (where clock_seq is unsigned16 - 2 bytes and
uuid->clock_seq_hi_and_reserved is unsigned8 - 1 byte):
    uuid->clock_seq_hi_and_reserved = (unsigned8)(clock_seq & 0x3F00) >> 8;
In this code, the cast to unsigned8 takes precedence over over the shift.  So
what happens is that (clock_seq & 0x3F00) is first cast to an 8 bit quantity,
then shifted by 8 bits.  The result is that the value is _always 0_.  The code
also does this:
    uuid->clock_seq_hi_and_reserved |= 0x80;

You can see this because every nsUniqueID looks like this:
XXXXXXXX-XXXXXXXX-80XXXXXXXX-XXXXXXXX
The first byte of the 3rd octet is always 80.
This may also be related to https://bugzilla.redhat.com/show_bug.cgi?id=197886 and may explain why the sequence numbers were exhausted so quickly.  Without this fix, we only have 256 sequence numbers available.  This fix adds another 6 bits.
The fix is to mask and shift as an unsigned16 quantity, then cast to unsigned8.
Platforms tested: RHEL5 x86_64
Flag Day: no - I think this will only impact new unique IDs that are generated.  It will not affect existing unique IDs.
Doc impact: no

1 files changed, 1 insertions, 1 deletions

diff --git a/ldap/servers/slapd/uuid.c b/ldap/servers/slapd/uuid.c
index 3089de09..2bc3c701 100644
--- a/ldap/servers/slapd/uuid.c
+++ b/ldap/servers/slapd/uuid.c
@@ -842,7 +842,7 @@ static void format_uuid_v1(guid_t * uuid, uuid_time_t timestamp, unsigned16 cloc
                                   ((timestamp >> 48) & 0x0FFF);                                                   
     uuid->time_hi_and_version |= (1 << 12);
     uuid->clock_seq_low = clock_seq & 0xFF;
-    uuid->clock_seq_hi_and_reserved = (unsigned8)(clock_seq & 0x3F00) >> 8;
+    uuid->clock_seq_hi_and_reserved = (unsigned8)((clock_seq & 0x3F00) >> 8);
     uuid->clock_seq_hi_and_reserved |= 0x80;
     memcpy(&uuid->node, &_state.genstate.node, sizeof (uuid->node));
 }