From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Mon, 18 Apr 2016 09:59:56 +0000 (+0200)
Subject: segtree: perform stricter expression type validation from expr_value()
X-Git-Tag: v0.6~61
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=93e4172d376045814c3775deb24da28e99e6b5fa;p=thirdparty%2Fnftables.git

segtree: perform stricter expression type validation from expr_value()

This helper function returns a expression value type that represents the
set element key. This functions currently expects two kind of
expressions: set elements and mappings.

Bail out otherwise, if we see anything else, we have to fix our code.

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

diff --git a/src/segtree.c b/src/segtree.c
index 060951c0..5b69ffb9 100644
--- a/src/segtree.c
+++ b/src/segtree.c
@@ -473,10 +473,14 @@ extern void interval_map_decompose(struct expr *set);
 
 static struct expr *expr_value(struct expr *expr)
 {
-	if (expr->ops->type == EXPR_MAPPING)
+	switch (expr->ops->type) {
+	case EXPR_MAPPING:
 		return expr->left->key;
-	else
+	case EXPR_SET_ELEM:
 		return expr->key;
+	default:
+		BUG("invalid expression type %s\n", expr->ops->name);
+	}
 }
 
 static int expr_value_cmp(const void *p1, const void *p2)