Bruce Momjian wrote:
KaiGai Kohei wrote:
Bruce Momjian wrote:
KaiGai Kohei wrote:
- Two new system columns ("security_acl" and "security_label") are added.
The first one is for the Row-level ACLs, and the other is for the guest
of PGACE security framework which is chosen by user.
This is certainly an impressive patch. I see you went with storing the
values inline rather than using pg_security, which is wise, I think.
"security_acl" is 'aclitem' (12 bytes) and "security_label" is 'text'.
No, the "security_acl" also uses pg_security to translate between
security id (4bytes) and "aclitem[]" (variable length).
The Row-level ACLs facility internally translate the given acl array
into its own text representation, and stores it within pg_security.
We can use a common facility here to manage both of "acl" and "label".
OK, then I am confused. I see this added to
src/include/catalog/pg_attribute.h:
+ DATA(insert ( 1247 security_acl 1034 0 -1 -8 1 -1 -1 f x i t f f t 0));
+ DATA(insert ( 1247 security_label 25 0 -1 -9 0 -1 -1 f x i t f f t 0));
1034 and 25 are the oids for 'acllist' and 'text' and they are being
added to system tables. Are you saying system tables don't use
pg_security but other tables do?
It means users can refer the "security_acl" and "security_label",
as if they have proper types. However, in actually, they are stroed
as security identifiers.
When user refers "security_acl", the patched heap_getsysattr() invokes
rowaclHeapGetSecurityAclSysattr() to translate the security identifier
of Row-level ACLs into an array of ACLs. User will see the translated
representation, as if there is a variable length array, not an oid.
The rowaclHeapGetSecurityAclSysattr() fetch a tuple for the given
security identifier from pg_security. It contains a text representation
of ACLs, so the function exchange it into Acl *.
rowaclHeapGetSecurityAclSysattr()
-> rowaclSidToSecurityAcl()
-> pgaceLookupSecurityLabel() ... It fetch a tuple from pg_security
-> rawAclTextToAclArray() ... It translate from TEXT -> AclItem[]
I do see pg_security being defined:
+ CATALOG(pg_security,3400) BKI_SHARED_RELATION
+ {
+ text seclabel; /* text representation of security
label */
+ } FormData_pg_security;
and I assume both security columns reference that.
Yes, AclItem[] is internally translated into text representation to store
it on pg_security.
Thanks,
--
KaiGai Kohei <kai...@kaigai.gr.jp>
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