path: root/net/ipv4/gre_offload.c
diff options
authorWei-Chun Chao <>2013-12-26 13:10:22 -0800
committerDavid S. Miller <>2014-01-02 19:06:47 -0500
commit7a7ffbabf99445704be01bff5d7e360da908cf8e (patch)
tree3b4f71699307ac2853a8fdffde60fb7055cb1b04 /net/ipv4/gre_offload.c
parent619a60ee04be33238721a15c1f9704a2a515a33e (diff)
ipv4: fix tunneled VM traffic over hw VXLAN/GRE GSO NIC
VM to VM GSO traffic is broken if it goes through VXLAN or GRE tunnel and the physical NIC on the host supports hardware VXLAN/GRE GSO offload (e.g. bnx2x and next-gen mlx4). Two issues - (VXLAN) VM traffic has SKB_GSO_DODGY and SKB_GSO_UDP_TUNNEL with SKB_GSO_TCP/UDP set depending on the inner protocol. GSO header integrity check fails in udp4_ufo_fragment if inner protocol is TCP. Also gso_segs is calculated incorrectly using skb->len that includes tunnel header. Fix: robust check should only be applied to the inner packet. (VXLAN & GRE) Once GSO header integrity check passes, NULL segs is returned and the original skb is sent to hardware. However the tunnel header is already pulled. Fix: tunnel header needs to be restored so that hardware can perform GSO properly on the original packet. Signed-off-by: Wei-Chun Chao <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'net/ipv4/gre_offload.c')
1 files changed, 7 insertions, 4 deletions
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index e5d436188464..2cd02f32f99f 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -28,6 +28,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
netdev_features_t enc_features;
struct gre_base_hdr *greh;
+ u16 mac_offset = skb->mac_header;
int mac_len = skb->mac_len;
__be16 protocol = skb->protocol;
int tnl_hlen;
@@ -58,13 +59,13 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
} else
csum = false;
+ if (unlikely(!pskb_may_pull(skb, ghl)))
+ goto out;
/* setup inner skb. */
skb->protocol = greh->protocol;
skb->encapsulation = 0;
- if (unlikely(!pskb_may_pull(skb, ghl)))
- goto out;
__skb_pull(skb, ghl);
skb_set_network_header(skb, skb_inner_network_offset(skb));
@@ -73,8 +74,10 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
/* segment inner packet. */
enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
segs = skb_mac_gso_segment(skb, enc_features);
- if (!segs || IS_ERR(segs))
+ if (!segs || IS_ERR(segs)) {
+ skb_gso_error_unwind(skb, protocol, ghl, mac_offset, mac_len);
goto out;
+ }
skb = segs;
tnl_hlen = skb_tnl_header_len(skb);