From 9b03990a13b1d8207e59dde00e03432fbf20c768 Mon Sep 17 00:00:00 2001
From: Randall Stewart <rrs@FreeBSD.org>
Date: Fri, 12 Mar 2010 08:10:30 +0000
Subject: [PATCH] With the recent change of the sctp checksum  to support
 offload, no delayed checksum was added to the ip6 output code. This causes
 cards that do not support SCTP checksum offload to have SCTP packets that are
 IPv6 NOT have the sctp checksum performed. Thus you could not communicate
 with a peer. This adds the missing bits to make the checksum happen for these
 cards.

PR:		144529
MFC after:	2 weeks
---
 sys/netinet6/ip6_output.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index c2ec49aa3509..aadb51fd760a 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_inet.h"
 #include "opt_inet6.h"
 #include "opt_ipsec.h"
+#include "opt_sctp.h"
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -102,6 +103,10 @@ __FBSDID("$FreeBSD$");
 #include <netipsec/key.h>
 #include <netinet6/ip6_ipsec.h>
 #endif /* IPSEC */
+#ifdef SCTP
+#include <netinet/sctp.h>
+#include <netinet/sctp_crc32.h>
+#endif
 
 #include <netinet6/ip6protosw.h>
 #include <netinet6/scope6_var.h>
@@ -208,6 +213,9 @@ ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 	struct route_in6 *ro_pmtu = NULL;
 	int hdrsplit = 0;
 	int needipsec = 0;
+#ifdef SCTP
+	int sw_csum;
+#endif
 #ifdef IPSEC
 	struct ipsec_output_state state;
 	struct ip6_rthdr *rh = NULL;
@@ -829,6 +837,10 @@ skip_ipsec2:;
 			}
 			m->m_pkthdr.csum_flags |=
 			    CSUM_IP_CHECKED | CSUM_IP_VALID;
+#ifdef SCTP
+			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
+				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
+#endif
 			error = netisr_queue(NETISR_IPV6, m);
 			goto done;
 		} else
@@ -857,6 +869,13 @@ skip_ipsec2:;
 	 * 4: if dontfrag == 1 && alwaysfrag == 1
 	 *	error, as we cannot handle this conflicting request
 	 */
+#ifdef SCTP
+	sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
+	if (sw_csum & CSUM_SCTP) {
+		sctp_delayed_cksum(m);
+		sw_csum &= ~CSUM_SCTP;
+	}
+#endif
 	tlen = m->m_pkthdr.len;
 
 	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))