postgresql/src/backend/utils
Robert Haas ce6b672e44 Make role grant system more consistent with other privileges.
Previously, membership of role A in role B could be recorded in the
catalog tables only once. This meant that a new grant of role A to
role B would overwrite the previous grant. For other object types, a
new grant of permission on an object - in this case role A - exists
along side the existing grant provided that the grantor is different.
Either grant can be revoked independently of the other, and
permissions remain so long as at least one grant remains. Make role
grants work similarly.

Previously, when granting membership in a role, the superuser could
specify any role whatsoever as the grantor, but for other object types,
the grantor of record must be either the owner of the object, or a
role that currently has privileges to perform a similar GRANT.
Implement the same scheme for role grants, treating the bootstrap
superuser as the role owner since roles do not have owners. This means
that attempting to revoke a grant, or admin option on a grant, can now
fail if there are dependent privileges, and that CASCADE can be used
to revoke these. It also means that you can't grant ADMIN OPTION on
a role back to a user who granted it directly or indirectly to you,
similar to how you can't give WITH GRANT OPTION on a privilege back
to a role which granted it directly or indirectly to you.

Previously, only the superuser could specify GRANTED BY with a user
other than the current user. Relax that rule to allow the grantor
to be any role whose privileges the current user posseses. This
doesn't improve compatibility with what we do for other object types,
where support for GRANTED BY is entirely vestigial, but it makes this
feature more usable and seems to make sense to change at the same time
we're changing related behaviors.

Along the way, fix "ALTER GROUP group_name ADD USER user_name" to
require the same privileges as "GRANT group_name TO user_name".
Previously, CREATEROLE privileges were sufficient for either, but
only the former form was permissible with ADMIN OPTION on the role.
Now, either CREATEROLE or ADMIN OPTION on the role suffices for
either spelling.

Patch by me, reviewed by Stephen Frost.

Discussion: http://postgr.es/m/CA+TgmoaFr-RZeQ+WoQ5nKPv97oT9+aDgK_a5+qWHSgbDsMp1Vg@mail.gmail.com
2022-08-22 11:35:17 -04:00
..
activity Remove the restriction that the relmap must be 512 bytes. 2022-07-26 14:56:25 -04:00
adt Make role grant system more consistent with other privileges. 2022-08-22 11:35:17 -04:00
cache Make role grant system more consistent with other privileges. 2022-08-22 11:35:17 -04:00
error Provide log_status_format(), useful for an emit_log_hook. 2022-07-11 12:29:33 -07:00
fmgr Remove configure probe for dlopen, and refactor. 2022-08-05 09:12:45 +12:00
hash Update copyright for 2022 2022-01-07 19:04:57 -05:00
init Use hba_file/ident_file GUCs rather than pg_hba.conf/pg_ident.conf in logs 2022-08-05 09:37:12 +09:00
mb Update copyright for 2022 2022-01-07 19:04:57 -05:00
misc Remove HAVE_UNIX_SOCKETS. 2022-08-14 08:46:53 +12:00
mmgr Remove fls(), use pg_leftmost_one_pos32() instead. 2022-07-22 10:41:50 +12:00
resowner Remove extraneous blank lines before block-closing braces 2022-04-13 19:16:02 +02:00
sort Improve speed of hash index build. 2022-07-28 14:34:32 -04:00
time Optimize xid/subxid searches in XidInMVCCSnapshot(). 2022-08-11 09:17:42 +07:00
.gitignore Rearrange makefile rules for running Gen_fmgrtab.pl. 2018-05-03 17:54:18 -04:00
errcodes.txt Add another SQL/JSON error code 2022-07-18 14:26:43 +02:00
Gen_dummy_probes.pl Update copyright for 2022 2022-01-07 19:04:57 -05:00
Gen_dummy_probes.pl.prolog Update copyright for 2022 2022-01-07 19:04:57 -05:00
Gen_dummy_probes.sed Update copyright for 2022 2022-01-07 19:04:57 -05:00
Gen_fmgrtab.pl Update copyright for 2022 2022-01-07 19:04:57 -05:00
generate-errcodes.pl Add output file argument to generate-errcodes.pl 2022-07-18 12:24:35 -07:00
Makefile Clean up temp file from refactored dtrace rule 2022-07-19 07:31:58 +02:00
postprocess_dtrace.sed Refactor dtrace postprocessing make rules 2022-07-18 12:33:02 -07:00
probes.d Update copyright for 2022 2022-01-07 19:04:57 -05:00
README.Gen_dummy_probes Tweak generation of Gen_dummy_probes.pl 2021-05-11 20:02:02 -04:00

# Generating dummy probes

If Postgres isn't configured with dtrace enabled, we need to generate
dummy probes for the entries in probes.d, that do nothing.

This is accomplished in Unix via the sed script `Gen_dummy_probes.sed`. We
used to use this in MSVC builds using the perl utility `psed`, which mimicked
sed. However, that utility disappeared from Windows perl distributions and so
we converted the sed script to a perl script to be used in MSVC builds.

We still keep the sed script as the authoritative source for generating
these dummy probes because except on Windows perl is not a hard requirement
when building from a tarball.

So, if you need to change the way dummy probes are generated, first change
the sed script, and when it's working generate the perl script. This can
be accomplished by using the perl utility s2p.

s2p is no longer part of the perl core, so it might not be on your system,
but it is available on CPAN and also in many package systems. e.g.
on Fedora it can be installed using `cpan App::s2p` or
`dnf install perl-App-s2p`.

The Makefile contains a recipe for regenerating Gen_dummy_probes.pl, so all
you need to do is once you have s2p installed is `make Gen_dummy_probes.pl`
Note that in a VPATH build this will generate the file in the vpath tree,
not the source tree.