From 23e62de33d179e229e4c1dfd93f90a3c7355c519 Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Thu, 13 Nov 2014 16:38:12 -0800 Subject: [PATCH] net: Add vxlan_gso_check() helper Most NICs that report NETIF_F_GSO_UDP_TUNNEL support VXLAN, and not other UDP-based encapsulation protocols where the format and size of the header differs. This patch implements a generic ndo_gso_check() for VXLAN which will only advertise GSO support when the skb looks like it contains VXLAN (or no UDP tunnelling at all). Implementation shamelessly stolen from Tom Herbert: http://thread.gmane.org/gmane.linux.network/332428/focus=333111 Signed-off-by: Joe Stringer Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 13 +++++++++++++ include/net/vxlan.h | 2 ++ 2 files changed, 15 insertions(+) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index fa9dc45b75a6..6b658638b456 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1571,6 +1571,19 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb) return false; } +bool vxlan_gso_check(struct sk_buff *skb) +{ + if ((skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL) && + (skb->inner_protocol_type != ENCAP_TYPE_ETHER || + skb->inner_protocol != htons(ETH_P_TEB) || + (skb_inner_mac_header(skb) - skb_transport_header(skb) != + sizeof(struct udphdr) + sizeof(struct vxlanhdr)))) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(vxlan_gso_check); + #if IS_ENABLED(CONFIG_IPV6) static int vxlan6_xmit_skb(struct vxlan_sock *vs, struct dst_entry *dst, struct sk_buff *skb, diff --git a/include/net/vxlan.h b/include/net/vxlan.h index d5f59f3fc35d..afadf8e53f20 100644 --- a/include/net/vxlan.h +++ b/include/net/vxlan.h @@ -45,6 +45,8 @@ int vxlan_xmit_skb(struct vxlan_sock *vs, __be32 src, __be32 dst, __u8 tos, __u8 ttl, __be16 df, __be16 src_port, __be16 dst_port, __be32 vni, bool xnet); +bool vxlan_gso_check(struct sk_buff *skb); + /* IP header + UDP + VXLAN + Ethernet header */ #define VXLAN_HEADROOM (20 + 8 + 8 + 14) /* IPv6 header + UDP + VXLAN + Ethernet header */ -- 2.20.1