From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Thu, 21 Aug 2025 09:17:40 +0000 (+0200)
Subject: evaluate: simplify set to list normalisation for device expressions
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3c9486b2af430a19495f0bc7a3794260a67241e7;p=thirdparty%2Fnftables.git

evaluate: simplify set to list normalisation for device expressions

When evaluating the list of devices, two expressions are possible:

- EXPR_LIST, which is the expected expression type to store the list of
  chain/flowtable devices.

- EXPR_SET, in case that a variable is used to express the device list.
  This is because it is not possible to know if the variable defines
  set elements or devices. Since sets are more common, EXPR_SET is used.

In the latter case, this list expressed as EXPR_SET gets translated to
EXPR_LIST. Before such translation, the EXPR_VARIABLE is evaluated,
therefore all variables are gone and only EXPR_SET_ELEM are possible in
expr_set_to_list().

Remove the EXPR_VALUE and EXPR_VARIABLE cases in expr_set_to_list()
since those are never seen. Add BUG() in case any other expressions than
EXPR_SET_ELEM is seen.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---

diff --git a/src/evaluate.c b/src/evaluate.c
index 2b1f1c55..b7e4f71f 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -5468,27 +5468,13 @@ static struct expr *expr_set_to_list(struct eval_ctx *ctx, struct expr *dev_expr
 		list_del(&expr->list);
 
 		switch (expr->etype) {
-		case EXPR_VARIABLE:
-			expr_set_context(&ctx->ectx, &ifname_type,
-					 IFNAMSIZ * BITS_PER_BYTE);
-			if (!evaluate_expr_variable(ctx, &expr))
-				return false;
-
-			if (expr->etype == EXPR_SET) {
-				expr = expr_set_to_list(ctx, expr);
-				list_splice_init(&expr_list(expr)->expressions, &tmp);
-				expr_free(expr);
-				continue;
-			}
-			break;
 		case EXPR_SET_ELEM:
 			key = expr_clone(expr->key);
 			expr_free(expr);
 			expr = key;
 			break;
-		case EXPR_VALUE:
-			break;
 		default:
+			BUG("invalid expression type %s\n", expr_name(expr));
 			break;
 		}