From 7222680eb328b5cebcea78b1dc6ccfacadeaa172 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Mon, 28 Nov 2016 18:51:43 +0100 Subject: parser_bison: Allow parens on RHS of relational_expr This is useful to allow a construct such as: | tcp flags & (syn|fin) == (syn|fin) Before, only the parentheses on the left side were allowed, but via a quite funny path through the parser: * expr might be a concat_expr * concat_expr might be a basic_expr * basic_expr is an inclusive_or_expr * inclusive_or_expr might be an exclusive_or_expr * exclusive_or_expr might be an and_expr * and_expr might be 'and_expr AMPERSAND shift_expr' -> here we eliminate 'flags &' in above statement * shift_expr might be a primary_expr * primary_expr might be '( basic_expr )' Commit a3e60492a684b ("parser: restrict relational rhs expression recursion") introduced rhs_expr to disallow recursion on RHS, so just reverting that change for relational_expr is a no go. Allowing rhs_expr to be '( rhs_expr )' though seems way too intrusive to me since it's being used in all kinds of places, so this patch is the safest way to allow the above I could come up with. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- src/parser_bison.y | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'src/parser_bison.y') diff --git a/src/parser_bison.y b/src/parser_bison.y index 981ffc81..f07303e2 100644 --- a/src/parser_bison.y +++ b/src/parser_bison.y @@ -2302,6 +2302,10 @@ relational_expr : expr /* implicit */ rhs_expr { $$ = relational_expr_alloc(&@2, $2, $1, $3); } + | expr relational_op '(' rhs_expr ')' + { + $$ = relational_expr_alloc(&@2, $2, $1, $4); + } ; list_rhs_expr : basic_rhs_expr COMMA basic_rhs_expr -- cgit v1.2.3