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 <weichunc@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 83206de..79c62bd 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -41,6 +41,14 @@
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
unsigned int mss;
+ int offset;
+ __wsum csum;
+
+ if (skb->encapsulation &&
+ skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL) {
+ segs = skb_udp_tunnel_segment(skb, features);
+ goto out;
+ }
mss = skb_shinfo(skb)->gso_size;
if (unlikely(skb->len <= mss))
@@ -63,27 +71,20 @@
goto out;
}
+ /* Do software UFO. Complete and fill in the UDP checksum as
+ * HW cannot do checksum of UDP packets sent as multiple
+ * IP fragments.
+ */
+ offset = skb_checksum_start_offset(skb);
+ csum = skb_checksum(skb, offset, skb->len - offset, 0);
+ offset += skb->csum_offset;
+ *(__sum16 *)(skb->data + offset) = csum_fold(csum);
+ skb->ip_summed = CHECKSUM_NONE;
+
/* Fragment the skb. IP headers of the fragments are updated in
* inet_gso_segment()
*/
- if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL)
- segs = skb_udp_tunnel_segment(skb, features);
- else {
- int offset;
- __wsum csum;
-
- /* Do software UFO. Complete and fill in the UDP checksum as
- * HW cannot do checksum of UDP packets sent as multiple
- * IP fragments.
- */
- offset = skb_checksum_start_offset(skb);
- csum = skb_checksum(skb, offset, skb->len - offset, 0);
- offset += skb->csum_offset;
- *(__sum16 *)(skb->data + offset) = csum_fold(csum);
- skb->ip_summed = CHECKSUM_NONE;
-
- segs = skb_segment(skb, features);
- }
+ segs = skb_segment(skb, features);
out:
return segs;
}