Failing to do so causes trigger invocation to fail when they are nested
within a function invocation that changes the current package.
Backpatch to 9.1; previous releases used a different method to obtain
_TD. Per bug report from Mark Murawski (bug #6511)
Author: Alex Hunsaker
This patch restores the pre-9.1 behavior that pl/perl functions returning
VOID ignore the result value of their last Perl statement. 9.1.0
unintentionally threw an error if the last statement returned a reference,
as reported by Amit Khandekar.
Also, make sure it works to return a string value for a composite type,
so long as the string meets the type's input format. We already allowed
the equivalent behavior for arrays, so it seems inconsistent to not allow
it for composites.
In addition, ensure we throw errors for attempts to return arrays or hashes
when the function's declared result type is not an array or composite type,
respectively. Pre-9.1 versions rather uselessly returned strings like
ARRAY(0x221a9a0) or HASH(0x221aa90), while 9.1.0 threw an error for the
hash case and returned a garbage value for the array case.
Also, clean up assorted grotty coding in Perl array conversion, including
use of a session-lifespan memory context to accumulate the array value
(resulting in session-lifespan memory leak on error), failure to apply the
declared typmod if any, and failure to detect some cases of non-rectangular
multi-dimensional arrays.
Alex Hunsaker and Tom Lane
Rewrite plancache.c so that a "cached plan" (which is rather a misnomer
at this point) can support generation of custom, parameter-value-dependent
plans, and can make an intelligent choice between using custom plans and
the traditional generic-plan approach. The specific choice algorithm
implemented here can probably be improved in future, but this commit is
all about getting the mechanism in place, not the policy.
In addition, restructure the API to greatly reduce the amount of extraneous
data copying needed. The main compromise needed to make that possible was
to split the initial creation of a CachedPlanSource into two steps. It's
worth noting in particular that SPI_saveplan is now deprecated in favor of
SPI_keepplan, which accomplishes the same end result with zero data
copying, and no need to then spend even more cycles throwing away the
original SPIPlan. The risk of long-term memory leaks while manipulating
SPIPlans has also been greatly reduced. Most of this improvement is based
on use of the recently-added MemoryContextSetParent primitive.
According to perlguts, &PL_sv_undef is not the right thing to use in
those cases because it doesn't behave the same way as an undef value via
Perl code. Seems the intuitive way to deal with undef values is subtly
enough broken that it's hard to notice when misused.
The broken uses got inadvertently introduced in commit
87bb2ade2c by Alexey Klyukin, Alex
Hunsaker and myself on 2011-02-17; no backpatch is necessary.
Per testing report from Greg Mullane.
Author: Alex Hunsaker
This was broken in commit ef19dc6d39 by
the Bunce/Hunsaker/Dunstan team, which moved the declaration from
plperl_create_sub to plperl_call_perl_trigger_func. This doesn't
actually work because the validator code would not find the variable
declared; and even if you manage to get past the validator, it still
doesn't work because get_sv("_TD", GV_ADD) doesn't have the expected
effect. The only reason this got beyond testing is that it only fails
in strict mode.
We need to declare it as a global just like %_SHARED; it is simpler than
trying to actually do what the patch initially intended, and is said to
have the same performance benefit.
As a more serious issue, fix $_TD not being properly local()ized,
meaning nested trigger functions would clobber $_TD.
Alex Hunsaker, per test report from Greg Mullane
The previous functions of assign hooks are now split between check hooks
and assign hooks, where the former can fail but the latter shouldn't.
Aside from being conceptually clearer, this approach exposes the
"canonicalized" form of the variable value to guc.c without having to do
an actual assignment. And that lets us fix the problem recently noted by
Bernd Helmle that the auto-tune patch for wal_buffers resulted in bogus
log messages about "parameter "wal_buffers" cannot be changed without
restarting the server". There may be some speed advantage too, because
this design lets hook functions avoid re-parsing variable values when
restoring a previous state after a rollback (they can store a pre-parsed
representation of the value instead). This patch also resolves a
longstanding annoyance about custom error messages from variable assign
hooks: they should modify, not appear separately from, guc.c's own message
about "invalid parameter value".
This mostly just involves creating control, install, and
update-from-unpackaged scripts for them. However, I had to adjust plperl
and plpython to not share the same support functions between variants,
because we can't put the same function into multiple extensions.
catversion bump forced due to new contents of pg_pltemplate, and because
initdb now installs plpgsql as an extension not a bare language.
Add support for regression testing these as extensions not bare
languages.
Fix a couple of other issues that popped up while testing this: my initial
hack at pg_dump binary-upgrade support didn't work right, and we don't want
an extra schema permissions test after all.
Documentation changes still to come, but I'm committing now to see
whether the MSVC build scripts need work (likely they do).
More generally, arrays are turned in Perl array references, and row and
composite types are turned into Perl hash references. This is done
recursively, in a way that's natural to every Perl programmer.
To avoid a backwards compatibility hit, the string representation of
each structure is also available if the function requests it.
Authors: Alexey Klyukin and Alex Hunsaker.
Some code cleanups by me.
String are converted to UTF8 on the way into perl and to the
database encoding on the way back. This avoids a number of
observed anomalies, and ensures Perl a consistent view of the
world.
Some minor code cleanups are also accomplished.
Alex Hunsaker, reviewed by Andy Colson.
This is an efficiency change, and means we now no longer have to run
"out $_TD; local $_TD = shift;", which was especially pointless in the case of
non-trigger functions where the passed value was always undef anyway.
A tiny open issue is whether we should get rid of the $prolog argument of
mkfunc, and the corresponding pushed value, which is now just a constant "false".
Tim Bunce, reviewed by Alex Hunsaker.
Not sure why I'm seeing this on Fedora 14 and not earlier versions.
Seems like a regression that gcc no longer knows that DIE() doesn't return.
Still, adding a dummy return is harmless enough.
As noted by Jan Urbanski, this flag is in fact needed to ensure that the
function's input/result conversion functions are set up as expected.
Add a regression test to discourage anyone from making same mistake
in future.
This patch adds the SQL-standard concept of an INSTEAD OF trigger, which
is fired instead of performing a physical insert/update/delete. The
trigger function is passed the entire old and/or new rows of the view,
and must figure out what to do to the underlying tables to implement
the update. So this feature can be used to implement updatable views
using trigger programming style rather than rule hacking.
In passing, this patch corrects the names of some columns in the
information_schema.triggers view. It seems the SQL committee renamed
them somewhere between SQL:99 and SQL:2003.
Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
There are numerous methods by which a Perl or Tcl function can subvert
the behavior of another such function executed later; for example, by
redefining standard functions or operators called by the target function.
If the target function is SECURITY DEFINER, or is called by such a
function, this means that any ordinary SQL user with Perl or Tcl language
usage rights can do essentially anything with the privileges of the target
function's owner.
To close this security hole, create a separate Perl or Tcl interpreter for
each SQL userid under which plperl or pltcl functions are executed within
a session. However, all plperlu or pltclu functions run within a session
still share a single interpreter, since they all execute at the trust
level of a database superuser anyway.
Note: this change results in a functionality loss when libperl has been
built without the "multiplicity" option: it's no longer possible to call
plperl functions under different userids in one session, since such a
libperl can't support multiple interpreters in one process. However, such
a libperl already failed to support concurrent use of plperl and plperlu,
so it's likely that few people use such versions with Postgres.
Security: CVE-2010-3433
fundamentally insecure. Instead apply an opmask to the whole interpreter that
imposes restrictions on unsafe operations. These restrictions are much harder
to subvert than is Safe.pm, since there is no container to be broken out of.
Backported to release 7.4.
In releases 7.4, 8.0 and 8.1 this also includes the necessary backporting of
the two interpreters model for plperl and plperlu adopted in release 8.2.
In versions 8.0 and up, the use of Perl's POSIX module to undo its locale
mangling on Windows has become insecure with these changes, so it is
replaced by our own routine, which is also faster.
Nice side effects of the changes include that it is now possible to use perl's
"strict" pragma in a natural way in plperl, and that perl's $a and
$b variables now work as expected in sort routines, and that function
compilation is significantly faster.
Tim Bunce and Andrew Dunstan, with reviews from Alex Hunsaker and
Alexey Klyukin.
Security: CVE-2010-1169
The latter is considered unwarranted chumminess with the implementation,
and can lead to crashes with recent Perl versions.
Report and fix by Tim Bunce. Back-patch to all versions containing the
questionable coding pattern.
Prevent use of another buggy version of Safe.pm.
Only register the exit handler if we have successfully created an interpreter.
Change log level of perl warnings from NOTICE to WARNING.
The infrastructure is there if in future we decide to allow
DBAs to specify extra modules that will be allowed in trusted code.
However, for now the relevant variables are declared as lexicals
rather than as package variables, so that they are not (or should not be)
accessible.
Mostly code from Tim Bunce, reviewed by Alex Hunsaker, with some
tweaks by me.
and move the context information into errcontext instead of errmsg.
This makes them better conform to our guidelines.
Also remove a few errcode declarations that were providing the default
value ERRCODE_INTERNAL_ERROR.
The purpose of this change is to eliminate the need for every caller
of SearchSysCache, SearchSysCacheCopy, SearchSysCacheExists,
GetSysCacheOid, and SearchSysCacheList to know the maximum number
of allowable keys for a syscache entry (currently 4). This will
make it far easier to increase the maximum number of keys in a
future release should we choose to do so, and it makes the code
shorter, too.
Design and review by Tom Lane.
- Allow (ineffective) use of 'require' in plperl
If the required module is not already loaded then it dies.
So "use strict;" now works in plperl.
- Pre-load the feature module if perl >= 5.10.
So "use feature :5.10;" now works in plperl.
- Stored procedure subs are now given names.
The names are not visible in ordinary use, but they make
tools like Devel::NYTProf and Devel::Cover much more useful.
- Simplified and generalized the subroutine creation code.
Now one code path for generating sub source code, not four.
Can generate multiple 'use' statements with specific imports
(which handles plperl.use_strict currently and can easily
be extended to handle a plperl.use_feature=':5.12' in future).
- Disallows use of Safe version 2.20 which is broken for PL/Perl.
http://rt.perl.org/rt3/Ticket/Display.html?id=72068
- Assorted minor optimizations by pre-growing data structures.
Patch from Tim Bunce, reviewed by Alex Hunsaker.
quote_literal, quote_nullable, quote_ident,
encode_bytea, decode_bytea, looks_like_number,
encode_array_literal, encode_array_constructor.
Split SPI.xs into two - SPI.xs now contains only SPI functions. Remainder
are in new Util.xs.
Some more code and documentation cleanup along the way, as well as
adding some CVS markers to files missing them.
Original patch from Tim Bunce, with a little editing from me.
- Changed MULTIPLICITY check from runtime to compiletime.
No loads the large Config module.
- Changed plperl_init_interp() to return new interp
and not alter the global interp_state
- Moved plperl_safe_init() call into check_interp().
- Removed plperl_safe_init_done state variable
as interp_state now covers that role.
- Changed plperl_create_sub() to take a plperl_proc_desc argument.
- Simplified return value handling in plperl_create_sub.
- Changed perl.com link in the docs to perl.org and tweaked
wording to clarify that require, not use, is what's blocked.
- Moved perl code in large multi-line C string literal macros
out to plc_*.pl files.
- Added a test2macro.pl utility to convert the plc_*.pl files to
macros in a perlchunks.h file which is #included
- Simplifed plperl_safe_init() slightly
- Optimized pg_verifymbstr calls to avoid unneeded strlen()s.
Patch from Tim Bunce, with minor editing from me.
trigger tuple modification or SPI call, to ensure they are valid in the
server encoding. Along the way, replace uses of SvPV(foo, PL_na)
with SvPV_nolen(foo) as recommended in the perl docs. Bug report from
Hannu Krosing.
This is more in keeping with modern practice, and is a first step towards
porting to Win64 (which has sizeof(pointer) > sizeof(long)).
Tsutomu Yamada, Magnus Hagander, Tom Lane
Alvaro Herrera
Tom Lane
Andrew Dunstan
Bruce Momjian
Peter Eisentraut
Magnus Hagander
Robert Haas