Re: Updates of SE-PostgreSQL 8.4devel patches (r1268)

I understood objections for "enable/disable something on compile-time"
approach. The following items are my revised proposal.
It does not conflicts to the policy Peter said before in this thread.

Items to be revised:

- It allows to compile multiple security mechanis within a single binary.

- It provides "--enable-selinux" configure option to build SELinux support,
but the Row-level ACLs is always built because it does not require any
platform specific libraries and so on.

- User choose one (or no) security mechanism on initdb and postmaster
starting up via $PGDATA/postgresql.conf. The current available options
are selinux, rowacl and nothing.
(*) What should be the default? rowacl? or, nothing?

The modified initdb interface is as follows:
$ initdb --pgace-security=(selinux|rowacl|nothing)

- It add a new system column for security purpose. It enables to store
a security attribute of tuple, so working security mechanism has to
handle it properly. For example, SE-PostgreSQL handles a tuple without
valid security context as a "unlabeled_t" tuple.

- The security mechanism can control whether the new tuple has its
security field, or not. If no security field is necessary, t_infomask
is not set HEAP_HASSECURITY bit, and it does not consume any additional
storage space.

Thanks,
--
OSS Platform Development Division, NEC
KaiGai Kohei <kaigai(at)ak(dot)jp(dot)nec(dot)com>