From: Torben Nielsen <t8927095@gmail.com>
Date: Thu, 6 Mar 2025 11:25:20 +0000 (+0100)
Subject: tc: nat: ffs should operation on host byte ordered data
X-Git-Tag: v6.14.0~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=afbfd2f2b0a633d068990775f8e1b73b8ee83733;p=thirdparty%2Fiproute2.git

tc: nat: ffs should operation on host byte ordered data

In print_nat the mask length is calculated as

	len = ffs(sel->mask);
	len = len ? 33 - len : 0;

The mask is stored in network byte order, it should be converted
to host byte order before calculating first bit set.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---

diff --git a/tc/m_nat.c b/tc/m_nat.c
index da947aea..0ec3fd11 100644
--- a/tc/m_nat.c
+++ b/tc/m_nat.c
@@ -156,7 +156,7 @@ print_nat(const struct action_util *au, FILE * f, struct rtattr *arg)
 	}
 	sel = RTA_DATA(tb[TCA_NAT_PARMS]);
 
-	len = ffs(sel->mask);
+	len = ffs(ntohl(sel->mask));
 	len = len ? 33 - len : 0;
 
 	print_string(PRINT_ANY, "direction", "%s",