From 7b56cc430a261630677f614b1cf4283e6ebb34fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ermal=20Lu=C3=A7i?= <eri@FreeBSD.org>
Date: Wed, 19 Nov 2014 13:31:08 +0000
Subject: [PATCH] pf(4) needs to have a correct checksum during its processing.
 Calculate checksums for the IPv6 path when needed before delving into pf(4)
 code as required.

PR:     172648, 179392
Reviewed by:    glebius@
Approved by:    gnn@
Obtained from:  pfSense
MFC after:      1 week
Sponsored by:   Netgate
---
 sys/netpfil/pf/pf_ioctl.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c
index dba56745fae8..213e49cb52f5 100644
--- a/sys/netpfil/pf/pf_ioctl.c
+++ b/sys/netpfil/pf/pf_ioctl.c
@@ -76,6 +76,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/in.h>
 #include <netinet/ip.h>
 #include <netinet/ip_var.h>
+#include <netinet6/ip6_var.h>
 #include <netinet/ip_icmp.h>
 
 #ifdef INET6
@@ -3619,12 +3620,11 @@ pf_check6_out(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
 	int chk;
 
 	/* We need a proper CSUM before we start (s. OpenBSD ip_output) */
-	if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
-#ifdef INET
-		/* XXX-BZ copy&paste error from r126261? */
-		in_delayed_cksum(*m);
-#endif
-		(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
+	if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
+		in6_delayed_cksum(*m,
+		    (*m)->m_pkthdr.len - sizeof(struct ip6_hdr),
+		    sizeof(struct ip6_hdr));
+		(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
 	}
 	CURVNET_SET(ifp->if_vnet);
 	chk = pf_test6(PF_OUT, ifp, m, inp);