[PATCH net-next 04/15] udp: support sctp over udp in skb_udp_tunnel_segment

[Xin Long]

To call sctp_gso_segment() properly in skb_udp_tunnel_segment() for sctp
over udp packets, we need to set transport_header to sctp header. When
skb->ip_summed == CHECKSUM_PARTIAL, skb_crc32c_csum_help() should be
called for the inner sctp packet.

Signed-off-by: Xin Long <lucien....@gmail.com>
---
 net/ipv4/udp_offload.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index c0b010b..a484405 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -49,6 +49,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct 
sk_buff *skb,
        __skb_pull(skb, tnl_hlen);
        skb_reset_mac_header(skb);
        skb_set_network_header(skb, skb_inner_network_offset(skb));
+       skb_set_transport_header(skb, skb_inner_transport_offset(skb));
        skb->mac_len = skb_inner_network_offset(skb);
        skb->protocol = new_protocol;
 
@@ -131,8 +132,12 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct 
sk_buff *skb,
                uh->check = ~csum_fold(csum_add(partial,
                                       (__force __wsum)htonl(len)));
 
-               if (skb->encapsulation)
-                       skb_checksum_help(skb);
+               if (skb->encapsulation) {
+                       if (skb->csum_not_inet)
+                               skb_crc32c_csum_help(skb);
+                       else
+                               skb_checksum_help(skb);
+               }
 
                if (offload_csum) {
                        skb->ip_summed = CHECKSUM_PARTIAL;
-- 
2.1.0