From 7a7ffbabf99445704be01bff5d7e360da908cf8e Mon Sep 17 00:00:00 2001 From: Wei-Chun Chao Date: Thu, 26 Dec 2013 13:10:22 -0800 Subject: 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 --- net/ipv4/udp_offload.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) (limited to 'net/ipv4/udp_offload.c') diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 83206de2bc76..79c62bdcd3c5 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -41,6 +41,14 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, { 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 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 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; } -- cgit v1.2.3