From d6120b8afacec587f5feb37781bc751bc5d68a10 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Tue, 21 Sep 2010 21:17:33 +0000 Subject: [PATCH] netfilter: nf_nat_snmp: fix checksum calculation (v4) Fix checksum calculation in nf_nat_snmp_basic. Based on patches by Clark Wang and Stephen Hemminger . https://bugzilla.kernel.org/show_bug.cgi?id=17622 Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/nf_nat_snmp_basic.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.c b/net/ipv4/netfilter/nf_nat_snmp_basic.c index 1679e2c0963d..ee5f419d0a56 100644 --- a/net/ipv4/netfilter/nf_nat_snmp_basic.c +++ b/net/ipv4/netfilter/nf_nat_snmp_basic.c @@ -893,13 +893,15 @@ static void fast_csum(__sum16 *csum, unsigned char s[4]; if (offset & 1) { - s[0] = s[2] = 0; + s[0] = ~0; s[1] = ~*optr; + s[2] = 0; s[3] = *nptr; } else { - s[1] = s[3] = 0; s[0] = ~*optr; + s[1] = ~0; s[2] = *nptr; + s[3] = 0; } *csum = csum_fold(csum_partial(s, 4, ~csum_unfold(*csum))); -- 2.39.5