/**
* @fn Datum get_table_and_inheritors(PG_FUNCTION_ARGS)
* @brief Return array containing Oids of parent table and its children.
* Note that this function does not release relation locks.
*
* get_table_and_inheritors(table)
*
* @param table parent table.
* @retval regclass[]
*/
Datum
repack_get_table_and_inheritors(PG_FUNCTION_ARGS)
{
Oid parent = PG_GETARG_OID(0);
List *relations;
Datum *relations_array;
int relations_array_size;
ArrayType *result;
ListCell *lc;
int i;
LockRelationOid(parent, AccessShareLock);
/* Check that parent table exists */
if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(parent)))
PG_RETURN_ARRAYTYPE_P(construct_empty_array(OIDOID));
/* Also check that children exist */
relations = find_all_inheritors(parent, AccessShareLock, NULL);
relations_array_size = list_length(relations);
if (relations_array_size == 0)
PG_RETURN_ARRAYTYPE_P(construct_empty_array(OIDOID));
relations_array = palloc(relations_array_size * sizeof(Datum));
i = 0;
foreach (lc, relations)
relations_array[i++] = ObjectIdGetDatum(lfirst_oid(lc));
result = construct_array(relations_array,
relations_array_size,
OIDOID, sizeof(Oid),
true, 'i');
pfree(relations_array);
PG_RETURN_ARRAYTYPE_P(result);
}
void LockSegfilesOnMaster(Relation rel, int32 segno) {
List *children = NIL;
ListCell *lc;
children = find_all_inheritors(rel->rd_id);
foreach(lc, children)
{
Relation child_rel = rel;
Oid oid = lfirst_oid(lc);
if (rel_is_partitioned(oid))
continue;
/* open/close the child relation. */
if (oid != rel->rd_id)
child_rel = heap_open(oid, AccessShareLock);
LockSegfilesOnMasterForSingleRel(child_rel, segno);
if (oid != rel->rd_id)
heap_close(child_rel, AccessShareLock);
}
/*
* sepgsql_dml_privileges
*
* Entrypoint of the DML permission checks
*/
bool
sepgsql_dml_privileges(List *rangeTabls, bool abort_on_violation)
{
ListCell *lr;
foreach(lr, rangeTabls)
{
RangeTblEntry *rte = lfirst(lr);
uint32 required = 0;
List *tableIds;
ListCell *li;
/*
* Only regular relations shall be checked
*/
if (rte->rtekind != RTE_RELATION)
continue;
/*
* Find out required permissions
*/
if (rte->requiredPerms & ACL_SELECT)
required |= SEPG_DB_TABLE__SELECT;
if (rte->requiredPerms & ACL_INSERT)
required |= SEPG_DB_TABLE__INSERT;
if (rte->requiredPerms & ACL_UPDATE)
{
if (!bms_is_empty(rte->updatedCols))
required |= SEPG_DB_TABLE__UPDATE;
else
required |= SEPG_DB_TABLE__LOCK;
}
if (rte->requiredPerms & ACL_DELETE)
required |= SEPG_DB_TABLE__DELETE;
/*
* Skip, if nothing to be checked
*/
if (required == 0)
continue;
/*
* If this RangeTblEntry is also supposed to reference inherited
* tables, we need to check security label of the child tables. So, we
* expand rte->relid into list of OIDs of inheritance hierarchy, then
* checker routine will be invoked for each relations.
*/
if (!rte->inh)
tableIds = list_make1_oid(rte->relid);
else
tableIds = find_all_inheritors(rte->relid, NoLock, NULL);
foreach(li, tableIds)
{
Oid tableOid = lfirst_oid(li);
Bitmapset *selectedCols;
Bitmapset *insertedCols;
Bitmapset *updatedCols;
/*
* child table has different attribute numbers, so we need to fix
* up them.
*/
selectedCols = fixup_inherited_columns(rte->relid, tableOid,
rte->selectedCols);
insertedCols = fixup_inherited_columns(rte->relid, tableOid,
rte->insertedCols);
updatedCols = fixup_inherited_columns(rte->relid, tableOid,
rte->updatedCols);
/*
* check permissions on individual tables
*/
if (!check_relation_privileges(tableOid,
selectedCols,
insertedCols,
updatedCols,
required, abort_on_violation))
return false;
}
/*
* expand_inherited_rtentry
* Check whether a rangetable entry represents an inheritance set.
* If so, add entries for all the child tables to the query's
* rangetable, and build AppendRelInfo nodes for all the child tables
* and add them to root->append_rel_list. If not, clear the entry's
* "inh" flag to prevent later code from looking for AppendRelInfos.
*
* Note that the original RTE is considered to represent the whole
* inheritance set. The first of the generated RTEs is an RTE for the same
* table, but with inh = false, to represent the parent table in its role
* as a simple member of the inheritance set.
*
* A childless table is never considered to be an inheritance set. For
* regular inheritance, a parent RTE must always have at least two associated
* AppendRelInfos: one corresponding to the parent table as a simple member of
* inheritance set and one or more corresponding to the actual children.
* Since a partitioned table is not scanned, it might have only one associated
* AppendRelInfo.
*/
static void
expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
{
Oid parentOID;
PlanRowMark *oldrc;
Relation oldrelation;
LOCKMODE lockmode;
List *inhOIDs;
ListCell *l;
/* Does RT entry allow inheritance? */
if (!rte->inh)
return;
/* Ignore any already-expanded UNION ALL nodes */
if (rte->rtekind != RTE_RELATION)
{
Assert(rte->rtekind == RTE_SUBQUERY);
return;
}
/* Fast path for common case of childless table */
parentOID = rte->relid;
if (!has_subclass(parentOID))
{
/* Clear flag before returning */
rte->inh = false;
return;
}
/*
* The rewriter should already have obtained an appropriate lock on each
* relation named in the query. However, for each child relation we add
* to the query, we must obtain an appropriate lock, because this will be
* the first use of those relations in the parse/rewrite/plan pipeline.
* Child rels should use the same lockmode as their parent.
*/
lockmode = rte->rellockmode;
/* Scan for all members of inheritance set, acquire needed locks */
inhOIDs = find_all_inheritors(parentOID, lockmode, NULL);
/*
* Check that there's at least one descendant, else treat as no-child
* case. This could happen despite above has_subclass() check, if table
* once had a child but no longer does.
*/
if (list_length(inhOIDs) < 2)
{
/* Clear flag before returning */
rte->inh = false;
return;
}
/*
* If parent relation is selected FOR UPDATE/SHARE, we need to mark its
* PlanRowMark as isParent = true, and generate a new PlanRowMark for each
* child.
*/
oldrc = get_plan_rowmark(root->rowMarks, rti);
if (oldrc)
oldrc->isParent = true;
/*
* Must open the parent relation to examine its tupdesc. We need not lock
* it; we assume the rewriter already did.
*/
oldrelation = heap_open(parentOID, NoLock);
/* Scan the inheritance set and expand it */
if (RelationGetPartitionDesc(oldrelation) != NULL)
{
Assert(rte->relkind == RELKIND_PARTITIONED_TABLE);
/*
* If this table has partitions, recursively expand them in the order
* in which they appear in the PartitionDesc. While at it, also
* extract the partition key columns of all the partitioned tables.
*/
expand_partitioned_rtentry(root, rte, rti, oldrelation, oldrc,
lockmode, &root->append_rel_list);
}
else
{
List *appinfos = NIL;
RangeTblEntry *childrte;
Index childRTindex;
/*
* This table has no partitions. Expand any plain inheritance
* children in the order the OIDs were returned by
* find_all_inheritors.
*/
foreach(l, inhOIDs)
{
Oid childOID = lfirst_oid(l);
Relation newrelation;
/* Open rel if needed; we already have required locks */
if (childOID != parentOID)
newrelation = heap_open(childOID, NoLock);
else
newrelation = oldrelation;
/*
* It is possible that the parent table has children that are temp
* tables of other backends. We cannot safely access such tables
* (because of buffering issues), and the best thing to do seems
* to be to silently ignore them.
*/
if (childOID != parentOID && RELATION_IS_OTHER_TEMP(newrelation))
{
heap_close(newrelation, lockmode);
continue;
}
expand_single_inheritance_child(root, rte, rti, oldrelation, oldrc,
newrelation,
&appinfos, &childrte,
&childRTindex);
/* Close child relations, but keep locks */
if (childOID != parentOID)
heap_close(newrelation, NoLock);
}
/*
* If all the children were temp tables, pretend it's a
* non-inheritance situation; we don't need Append node in that case.
* The duplicate RTE we added for the parent table is harmless, so we
* don't bother to get rid of it; ditto for the useless PlanRowMark
* node.
*/
if (list_length(appinfos) < 2)
rte->inh = false;
else
root->append_rel_list = list_concat(root->append_rel_list,
appinfos);
}
