#include "parser/parse_func.h"
#include "parser/parse_relation.h"
#include "parser/parse_type.h"
+#include "parser/parsetree.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
static FieldSelect *setup_field_select(Node *input, char *attname, Oid relid);
static void unknown_attribute(const char *schemaname, const char *relname,
const char *attname);
+static bool check_pg_get_expr_arg(ParseState *pstate, Node *arg, int netlevelsup);
/*
void
check_pg_get_expr_args(ParseState *pstate, Oid fnoid, List *args)
{
- bool allowed = false;
Node *arg;
- int netlevelsup;
/* if not being called for pg_get_expr, do nothing */
if (fnoid != F_PG_GET_EXPR && fnoid != F_PG_GET_EXPR_EXT)
/*
* The first argument must be a Var referencing one of the allowed
- * system-catalog columns. It could be a join alias Var, though.
+ * system-catalog columns. It could be a join alias Var or subquery
+ * reference Var, though, so we need a recursive subroutine to chase
+ * through those possibilities.
*/
Assert(args != NIL);
arg = (Node *) lfirst(args);
- netlevelsup = 0;
-restart:
- if (IsA(arg, Var))
+ if (!check_pg_get_expr_arg(pstate, arg, 0))
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("argument to pg_get_expr() must come from system catalogs")));
+}
+
+static bool
+check_pg_get_expr_arg(ParseState *pstate, Node *arg, int netlevelsup)
+{
+ if (arg && IsA(arg, Var))
{
Var *var = (Var *) arg;
RangeTblEntry *rte;
+ AttrNumber attnum;
netlevelsup += var->varlevelsup;
rte = GetRTEByRangeTablePosn(pstate, var->varno, netlevelsup);
+ attnum = var->varattno;
if (rte->rtekind == RTE_JOIN)
{
- /* Expand join alias reference */
- if (var->varattno > 0 &&
- var->varattno <= length(rte->joinaliasvars))
+ /* Recursively examine join alias variable */
+ if (attnum > 0 &&
+ attnum <= length(rte->joinaliasvars))
{
- arg = (Node *) nth(var->varattno - 1, rte->joinaliasvars);
- goto restart;
+ arg = (Node *) nth(attnum - 1, rte->joinaliasvars);
+ return check_pg_get_expr_arg(pstate, arg, netlevelsup);
}
}
+ else if (rte->rtekind == RTE_SUBQUERY)
+ {
+ /* Subselect-in-FROM: examine sub-select's output expr */
+ TargetEntry *ste = get_tle_by_resno(rte->subquery->targetList,
+ attnum);
+ ParseState mypstate;
+
+ if (ste == NULL || ste->resdom->resjunk)
+ elog(ERROR, "subquery %s does not have attribute %d",
+ rte->eref->aliasname, attnum);
+ arg = (Node *) ste->expr;
+
+ /*
+ * Recurse into the sub-select to see what its expr refers to.
+ * We have to build an additional level of ParseState to keep in
+ * step with varlevelsup in the subselect.
+ */
+ MemSet(&mypstate, 0, sizeof(mypstate));
+ mypstate.parentParseState = pstate;
+ mypstate.p_rtable = rte->subquery->rtable;
+ /* don't bother filling the rest of the fake pstate */
+
+ return check_pg_get_expr_arg(&mypstate, arg, 0);
+ }
else if (rte->rtekind == RTE_RELATION)
{
if (rte->relid == get_system_catalog_relid(IndexRelationName))
{
- if (var->varattno == Anum_pg_index_indexprs ||
- var->varattno == Anum_pg_index_indpred)
- allowed = true;
+ if (attnum == Anum_pg_index_indexprs ||
+ attnum == Anum_pg_index_indpred)
+ return true;
}
else if (rte->relid == get_system_catalog_relid(AttrDefaultRelationName))
{
- if (var->varattno == Anum_pg_attrdef_adbin)
- allowed = true;
+ if (attnum == Anum_pg_attrdef_adbin)
+ return true;
}
else if (rte->relid == get_system_catalog_relid(ConstraintRelationName))
{
- if (var->varattno == Anum_pg_constraint_conbin)
- allowed = true;
+ if (attnum == Anum_pg_constraint_conbin)
+ return true;
}
else if (rte->relid == get_system_catalog_relid(TypeRelationName))
{
- if (var->varattno == Anum_pg_type_typdefaultbin)
- allowed = true;
+ if (attnum == Anum_pg_type_typdefaultbin)
+ return true;
}
}
}
- if (!allowed)
- ereport(ERROR,
- (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
- errmsg("argument to pg_get_expr() must come from system catalogs")));
+ return false;
}
projects / postgresql.git / commitdiff