Remove superuser checks in pgstattuple

Now that we track initial privileges on extension objects and changes to
those permissions, we can drop the superuser() checks from the various
functions which are part of the pgstattuple extension and rely on the
GRANT system to control access to those functions.

Since a pg_upgrade will preserve the version of the extension which
existed prior to the upgrade, we can't simply modify the existing
functions but instead need to create new functions which remove the
checks and update the SQL-level functions to use the new functions
(and to REVOKE EXECUTE rights on those functions from PUBLIC).

Thanks to Tom and Andres for adding support for extensions to follow
update paths (see: 40b449a), allowing this patch to be much smaller
since no new base version script needed to be included.

Approach suggested by Noah.

Reviewed by Michael Paquier.
This commit is contained in:
Stephen Frost 2016-09-29 22:13:38 -04:00
parent f2af8dc5ba
commit fd321a1dfd
7 changed files with 315 additions and 15 deletions

View File

@ -4,9 +4,10 @@ MODULE_big = pgstattuple
OBJS = pgstattuple.o pgstatindex.o pgstatapprox.o $(WIN32RES)
EXTENSION = pgstattuple
DATA = pgstattuple--1.4.sql pgstattuple--1.3--1.4.sql \
pgstattuple--1.2--1.3.sql pgstattuple--1.1--1.2.sql \
pgstattuple--1.0--1.1.sql pgstattuple--unpackaged--1.0.sql
DATA = pgstattuple--1.4.sql pgstattuple--1.4--1.5.sql \
pgstattuple--1.3--1.4.sql pgstattuple--1.2--1.3.sql \
pgstattuple--1.1--1.2.sql pgstattuple--1.0--1.1.sql \
pgstattuple--unpackaged--1.0.sql
PGFILEDESC = "pgstattuple - tuple-level statistics"
REGRESS = pgstattuple

View File

@ -29,6 +29,9 @@
#include "commands/vacuum.h"
PG_FUNCTION_INFO_V1(pgstattuple_approx);
PG_FUNCTION_INFO_V1(pgstattuple_approx_v1_5);
Datum pgstattuple_approx_internal(Oid relid, FunctionCallInfo fcinfo);
typedef struct output_type
{
@ -204,11 +207,42 @@ statapprox_heap(Relation rel, output_type *stat)
/*
* Returns estimated live/dead tuple statistics for the given relid.
*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.5 installations
* these functions could be called by any user.
*/
Datum
pgstattuple_approx(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use pgstattuple functions"))));
PG_RETURN_DATUM(pgstattuple_approx_internal(relid, fcinfo));
}
/*
* As of pgstattuple version 1.5, we no longer need to check if the user
* is a superuser because we REVOKE EXECUTE on the SQL function from PUBLIC.
* Users can then grant access to it based on their policies.
*
* Otherwise identical to pgstattuple_approx (above).
*/
Datum
pgstattuple_approx_v1_5(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
PG_RETURN_DATUM(pgstattuple_approx_internal(relid, fcinfo));
}
Datum
pgstattuple_approx_internal(Oid relid, FunctionCallInfo fcinfo)
{
Relation rel;
output_type stat = {0};
TupleDesc tupdesc;
@ -217,11 +251,6 @@ pgstattuple_approx(PG_FUNCTION_ARGS)
HeapTuple ret;
int i = 0;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use pgstattuple functions"))));
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");

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@ -54,6 +54,14 @@ PG_FUNCTION_INFO_V1(pg_relpages);
PG_FUNCTION_INFO_V1(pg_relpagesbyid);
PG_FUNCTION_INFO_V1(pgstatginindex);
PG_FUNCTION_INFO_V1(pgstatindex_v1_5);
PG_FUNCTION_INFO_V1(pgstatindexbyid_v1_5);
PG_FUNCTION_INFO_V1(pg_relpages_v1_5);
PG_FUNCTION_INFO_V1(pg_relpagesbyid_v1_5);
PG_FUNCTION_INFO_V1(pgstatginindex_v1_5);
Datum pgstatginindex_internal(Oid relid, FunctionCallInfo fcinfo);
#define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
#define IS_GIN(r) ((r)->rd_rel->relam == GIN_AM_OID)
@ -99,6 +107,10 @@ static Datum pgstatindex_impl(Relation rel, FunctionCallInfo fcinfo);
* pgstatindex()
*
* Usage: SELECT * FROM pgstatindex('t1_pkey');
*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.5 installations
* these functions could be called by any user.
* ------------------------------------------------------
*/
Datum
@ -119,6 +131,31 @@ pgstatindex(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(pgstatindex_impl(rel, fcinfo));
}
/*
* As of pgstattuple version 1.5, we no longer need to check if the user
* is a superuser because we REVOKE EXECUTE on the function from PUBLIC.
* Users can then grant access to it based on their policies.
*
* Otherwise identical to pgstatindex (above).
*/
Datum
pgstatindex_v1_5(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
Relation rel;
RangeVar *relrv;
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
PG_RETURN_DATUM(pgstatindex_impl(rel, fcinfo));
}
/*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.5 installations
* these functions could be called by any user.
*/
Datum
pgstatindexbyid(PG_FUNCTION_ARGS)
{
@ -135,6 +172,18 @@ pgstatindexbyid(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(pgstatindex_impl(rel, fcinfo));
}
/* No need for superuser checks in v1.5, see above */
Datum
pgstatindexbyid_v1_5(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
Relation rel;
rel = relation_open(relid, AccessShareLock);
PG_RETURN_DATUM(pgstatindex_impl(rel, fcinfo));
}
static Datum
pgstatindex_impl(Relation rel, FunctionCallInfo fcinfo)
{
@ -292,6 +341,8 @@ pgstatindex_impl(Relation rel, FunctionCallInfo fcinfo)
*
* Usage: SELECT pg_relpages('t1');
* SELECT pg_relpages('t1_pkey');
*
* Must keep superuser() check, see above.
* --------------------------------------------------------
*/
Datum
@ -319,6 +370,28 @@ pg_relpages(PG_FUNCTION_ARGS)
PG_RETURN_INT64(relpages);
}
/* No need for superuser checks in v1.5, see above */
Datum
pg_relpages_v1_5(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
int64 relpages;
Relation rel;
RangeVar *relrv;
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
/* note: this will work OK on non-local temp tables */
relpages = RelationGetNumberOfBlocks(rel);
relation_close(rel, AccessShareLock);
PG_RETURN_INT64(relpages);
}
/* Must keep superuser() check, see above. */
Datum
pg_relpagesbyid(PG_FUNCTION_ARGS)
{
@ -342,16 +415,58 @@ pg_relpagesbyid(PG_FUNCTION_ARGS)
PG_RETURN_INT64(relpages);
}
/* No need for superuser checks in v1.5, see above */
Datum
pg_relpagesbyid_v1_5(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
int64 relpages;
Relation rel;
rel = relation_open(relid, AccessShareLock);
/* note: this will work OK on non-local temp tables */
relpages = RelationGetNumberOfBlocks(rel);
relation_close(rel, AccessShareLock);
PG_RETURN_INT64(relpages);
}
/* ------------------------------------------------------
* pgstatginindex()
*
* Usage: SELECT * FROM pgstatginindex('ginindex');
*
* Must keep superuser() check, see above.
* ------------------------------------------------------
*/
Datum
pgstatginindex(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use pgstattuple functions"))));
PG_RETURN_DATUM(pgstatginindex_internal(relid, fcinfo));
}
/* No need for superuser checks in v1.5, see above */
Datum
pgstatginindex_v1_5(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
PG_RETURN_DATUM(pgstatginindex_internal(relid, fcinfo));
}
Datum
pgstatginindex_internal(Oid relid, FunctionCallInfo fcinfo)
{
Relation rel;
Buffer buffer;
Page page;
@ -363,11 +478,6 @@ pgstatginindex(PG_FUNCTION_ARGS)
bool nulls[3] = {false, false, false};
Datum result;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use pgstattuple functions"))));
rel = relation_open(relid, AccessShareLock);
if (!IS_INDEX(rel) || !IS_GIN(rel))
@ -415,5 +525,5 @@ pgstatginindex(PG_FUNCTION_ARGS)
tuple = heap_form_tuple(tupleDesc, values, nulls);
result = HeapTupleGetDatum(tuple);
PG_RETURN_DATUM(result);
return (result);
}

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@ -0,0 +1,111 @@
/* contrib/pgstattuple/pgstattuple--1.4--1.5.sql */
-- complain if script is sourced in psql, rather than via ALTER EXTENSION
\echo Use "ALTER EXTENSION pgstattuple UPDATE TO '1.5'" to load this file. \quit
CREATE OR REPLACE FUNCTION pgstattuple(IN relname text,
OUT table_len BIGINT, -- physical table length in bytes
OUT tuple_count BIGINT, -- number of live tuples
OUT tuple_len BIGINT, -- total tuples length in bytes
OUT tuple_percent FLOAT8, -- live tuples in %
OUT dead_tuple_count BIGINT, -- number of dead tuples
OUT dead_tuple_len BIGINT, -- total dead tuples length in bytes
OUT dead_tuple_percent FLOAT8, -- dead tuples in %
OUT free_space BIGINT, -- free space in bytes
OUT free_percent FLOAT8) -- free space in %
AS 'MODULE_PATHNAME', 'pgstattuple_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pgstattuple(text) FROM PUBLIC;
CREATE OR REPLACE FUNCTION pgstatindex(IN relname text,
OUT version INT,
OUT tree_level INT,
OUT index_size BIGINT,
OUT root_block_no BIGINT,
OUT internal_pages BIGINT,
OUT leaf_pages BIGINT,
OUT empty_pages BIGINT,
OUT deleted_pages BIGINT,
OUT avg_leaf_density FLOAT8,
OUT leaf_fragmentation FLOAT8)
AS 'MODULE_PATHNAME', 'pgstatindex_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pgstatindex(text) FROM PUBLIC;
CREATE OR REPLACE FUNCTION pg_relpages(IN relname text)
RETURNS BIGINT
AS 'MODULE_PATHNAME', 'pg_relpages_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pg_relpages(text) FROM PUBLIC;
/* New stuff in 1.1 begins here */
CREATE OR REPLACE FUNCTION pgstatginindex(IN relname regclass,
OUT version INT4,
OUT pending_pages INT4,
OUT pending_tuples BIGINT)
AS 'MODULE_PATHNAME', 'pgstatginindex_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pgstatginindex(regclass) FROM PUBLIC;
/* New stuff in 1.2 begins here */
CREATE OR REPLACE FUNCTION pgstattuple(IN reloid regclass,
OUT table_len BIGINT, -- physical table length in bytes
OUT tuple_count BIGINT, -- number of live tuples
OUT tuple_len BIGINT, -- total tuples length in bytes
OUT tuple_percent FLOAT8, -- live tuples in %
OUT dead_tuple_count BIGINT, -- number of dead tuples
OUT dead_tuple_len BIGINT, -- total dead tuples length in bytes
OUT dead_tuple_percent FLOAT8, -- dead tuples in %
OUT free_space BIGINT, -- free space in bytes
OUT free_percent FLOAT8) -- free space in %
AS 'MODULE_PATHNAME', 'pgstattuplebyid_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pgstattuple(regclass) FROM PUBLIC;
CREATE OR REPLACE FUNCTION pgstatindex(IN relname regclass,
OUT version INT,
OUT tree_level INT,
OUT index_size BIGINT,
OUT root_block_no BIGINT,
OUT internal_pages BIGINT,
OUT leaf_pages BIGINT,
OUT empty_pages BIGINT,
OUT deleted_pages BIGINT,
OUT avg_leaf_density FLOAT8,
OUT leaf_fragmentation FLOAT8)
AS 'MODULE_PATHNAME', 'pgstatindexbyid_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pgstatindex(regclass) FROM PUBLIC;
CREATE OR REPLACE FUNCTION pg_relpages(IN relname regclass)
RETURNS BIGINT
AS 'MODULE_PATHNAME', 'pg_relpagesbyid_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pg_relpages(regclass) FROM PUBLIC;
/* New stuff in 1.3 begins here */
CREATE OR REPLACE FUNCTION pgstattuple_approx(IN reloid regclass,
OUT table_len BIGINT, -- physical table length in bytes
OUT scanned_percent FLOAT8, -- what percentage of the table's pages was scanned
OUT approx_tuple_count BIGINT, -- estimated number of live tuples
OUT approx_tuple_len BIGINT, -- estimated total length in bytes of live tuples
OUT approx_tuple_percent FLOAT8, -- live tuples in % (based on estimate)
OUT dead_tuple_count BIGINT, -- exact number of dead tuples
OUT dead_tuple_len BIGINT, -- exact total length in bytes of dead tuples
OUT dead_tuple_percent FLOAT8, -- dead tuples in % (based on estimate)
OUT approx_free_space BIGINT, -- estimated free space in bytes
OUT approx_free_percent FLOAT8) -- free space in % (based on estimate)
AS 'MODULE_PATHNAME', 'pgstattuple_approx_v1_5'
LANGUAGE C STRICT PARALLEL SAFE;
REVOKE EXECUTE ON FUNCTION pgstattuple_approx(regclass) FROM PUBLIC;

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@ -40,7 +40,9 @@
PG_MODULE_MAGIC;
PG_FUNCTION_INFO_V1(pgstattuple);
PG_FUNCTION_INFO_V1(pgstattuple_v1_5);
PG_FUNCTION_INFO_V1(pgstattuplebyid);
PG_FUNCTION_INFO_V1(pgstattuplebyid_v1_5);
/*
* struct pgstattuple_type
@ -152,6 +154,10 @@ build_pgstattuple_type(pgstattuple_type *stat, FunctionCallInfo fcinfo)
*
* C FUNCTION definition
* pgstattuple(text) returns pgstattuple_type
*
* The superuser() check here must be kept as the library might be upgraded
* without the extension being upgraded, meaning that in pre-1.5 installations
* these functions could be called by any user.
* ----------
*/
@ -174,6 +180,28 @@ pgstattuple(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
}
/*
* As of pgstattuple version 1.5, we no longer need to check if the user
* is a superuser because we REVOKE EXECUTE on the function from PUBLIC.
* Users can then grant access to it based on their policies.
*
* Otherwise identical to pgstattuple (above).
*/
Datum
pgstattuple_v1_5(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
RangeVar *relrv;
Relation rel;
/* open relation */
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
}
/* Must keep superuser() check, see above. */
Datum
pgstattuplebyid(PG_FUNCTION_ARGS)
{
@ -191,6 +219,19 @@ pgstattuplebyid(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
}
/* Remove superuser() check for 1.5 version, see above */
Datum
pgstattuplebyid_v1_5(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
Relation rel;
/* open relation */
rel = relation_open(relid, AccessShareLock);
PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
}
/*
* pgstat_relation
*/

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@ -1,5 +1,5 @@
# pgstattuple extension
comment = 'show tuple-level statistics'
default_version = '1.4'
default_version = '1.5'
module_pathname = '$libdir/pgstattuple'
relocatable = true

View File

@ -12,6 +12,14 @@
obtain tuple-level statistics.
</para>
<para>
As these functions return detailed page-level information, only the superuser
has EXECUTE privileges on them upon installation. After the functions have
been installed, users may issue <command>GRANT</command> commands to change
the privileges on the functions to allow non-superusers to execute them. See
the description of the <xref linkend="sql-grant"> command for specifics.
</para>
<sect2>
<title>Functions</title>