From 6a5536810180bb2c739df890a36cfa29da1914eb Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Wed, 18 May 2016 10:44:47 -0700 Subject: [PATCH] ip6_gre: Do not allow segmentation offloads GRE_CSUM is enabled with FOU/GUE This patch addresses the same issue we had for IPv4 where enabling GRE with an inner checksum cannot be supported with FOU/GUE due to the fact that they will jump past the GRE header at it is treated like a tunnel header. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- net/ipv6/ip6_gre.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 6fb1b89d0178..af503f518278 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -1355,11 +1355,15 @@ static int ip6gre_newlink(struct net *src_net, struct net_device *dev, dev->hw_features |= GRE6_FEATURES; if (!(nt->parms.o_flags & TUNNEL_SEQ)) { - /* TCP segmentation offload is not supported when we - * generate output sequences. + /* TCP offload with GRE SEQ is not supported, nor + * can we support 2 levels of outer headers requiring + * an update. */ - dev->features |= NETIF_F_GSO_SOFTWARE; - dev->hw_features |= NETIF_F_GSO_SOFTWARE; + if (!(nt->parms.o_flags & TUNNEL_CSUM) || + (nt->encap.type == TUNNEL_ENCAP_NONE)) { + dev->features |= NETIF_F_GSO_SOFTWARE; + dev->hw_features |= NETIF_F_GSO_SOFTWARE; + } /* Can use a lockless transmit, unless we generate * output sequences -- 2.20.1