Function sepgsql_attribute_post_create

contrib/sepgsql/relation.c:42–125

* sepgsql_attribute_post_create * * This routine assigns a default security label on a newly defined * column, using ALTER TABLE ... ADD COLUMN. * Note that this routine is not invoked in the case of CREATE TABLE, * although it also defines columns in addition to table. */

 * although it also defines columns in addition to table.
 */
void
sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum)
{
	Relation	rel;
	ScanKeyData skey[2];
	SysScanDesc sscan;
	HeapTuple	tuple;
	char	   *scontext;
	char	   *tcontext;
	char	   *ncontext;
	ObjectAddress object;
	Form_pg_attribute attForm;
	StringInfoData audit_name;
	char		relkind = get_rel_relkind(relOid);

	/*
	 * Only attributes within regular relations or partition relations have
	 * individual security labels.
	 */
	if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE)
		return;

	/*
	 * Compute a default security label of the new column underlying the
	 * specified relation, and check permission to create it.
	 */
	rel = table_open(AttributeRelationId, AccessShareLock);

	ScanKeyInit(&skey[0],
				Anum_pg_attribute_attrelid,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(relOid));
	ScanKeyInit(&skey[1],
				Anum_pg_attribute_attnum,
				BTEqualStrategyNumber, F_INT2EQ,
				Int16GetDatum(attnum));

	sscan = systable_beginscan(rel, AttributeRelidNumIndexId, true,
							   SnapshotSelf, 2, &skey[0]);

	tuple = systable_getnext(sscan);
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "could not find tuple for column %d of relation %u",
			 attnum, relOid);

	attForm = (Form_pg_attribute) GETSTRUCT(tuple);

	scontext = sepgsql_get_client_label();
	tcontext = sepgsql_get_label(RelationRelationId, relOid, 0);
	ncontext = sepgsql_compute_create(scontext, tcontext,
									  SEPG_CLASS_DB_COLUMN,
									  NameStr(attForm->attname));

	/*
	 * check db_column:{create} permission
	 */
	object.classId = RelationRelationId;
	object.objectId = relOid;