From a34911f038f5591fdf115909eff494adde1606ce Mon Sep 17 00:00:00 2001

From: Phil Sutter <phil@nwl.cc>

Date: Mon, 2 Sep 2019 18:39:51 +0200

Subject: [PATCH] conntrack: Fix CIDR to mask conversion on Big Endian

Code assumed host architecture to be Little Endian. Instead produce a

proper mask by pushing the set bits into most significant position and

apply htonl() on the result.

Fixes: 3f6a2e90936bb ("conntrack: add support for CIDR notation")

Signed-off-by: Phil Sutter <phil@nwl.cc>

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

(cherry picked from commit f27901afb038b07532b4c31cb77bbc0bd8068253)

---

 src/conntrack.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/conntrack.c b/src/conntrack.c

index cbf03c7be8834..725e85d329c98 100644

--- a/src/conntrack.c

+++ b/src/conntrack.c

@@ -2175,7 +2175,7 @@ nfct_build_netmask(uint32_t *dst, int b, int n)

 			dst[i] = 0xffffffff;

 			b -= 32;

 		} else if (b > 0) {

-			dst[i] = (1 << b) - 1;

+			dst[i] = htonl(~0u << (32 - b));

 			b = 0;

 		} else {

 			dst[i] = 0;

-- 

2.22.0