Re: Reworks of DML permission checks

2010/7/12 KaiGai Kohei <kaigai(at)ak(dot)jp(dot)nec(dot)com>:
> (2010/07/10 5:53), Robert Haas wrote:
>> 2010/6/14 KaiGai Kohei<kaigai(at)ak(dot)jp(dot)nec(dot)com>:
>>> The attached patch tries to rework DML permission checks.
>>>
>>> It was mainly checked at the ExecCheckRTEPerms(), but same logic was
>>> implemented in COPY TO/FROM statement and RI_Initial_Check().
>>>
>>> This patch tries to consolidate these permission checks into a common
>>> function to make access control decision on DML permissions. It enables
>>> to eliminate the code duplication, and improve consistency of access
>>> controls.
>>
>> This patch is listed on the CommitFest page, but I'm not sure if it
>> represents the latest work on this topic.  At a minimum, it needs to
>> be rebased.
>>
>> I am not excited about moving ExecCheckRT[E]Perms to some other place
>> in the code.  It seems to me that will complicate back-patching with
>> no corresponding advantage.  I'd suggest we not do that.    The COPY
>> and RI code can call ExecCheckRTPerms() where it is. Maybe at some
>> point we will have a grand master plan for how this should all be laid
>> out, but right now I'd prefer localized changes.
>>
>
> OK, I rebased and revised the patch not to move ExecCheckRTPerms()
> from executor/execMain.c.
> In the attached patch, DoCopy() and RI_Initial_Check() calls that
> function to consolidate dml access control logic.

This patch contains a number of copies of the following code:

+ {
+ if (ereport_on_violation)
+ aclcheck_error(ACLCHECK_NO_PRIV, ACL_KIND_CLASS,
+
get_rel_name(relOid));
+ return false;
+ }

What if we don't pass ereport_on_violation down to
ExecCheckRTEPerms(), and just have it return a boolean? Then
ExecCheckRTPerms() can throw the error if ereport_on_violation is
true, and return false otherwise.

With this patch, ri_triggers.c emits a compiler warning, apparently
due to a missing include.

Otherwise, the changes look pretty sensible, though I haven't tested them yet.

--
Robert Haas
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