From b17f709a24013fcbb257f6f89b4d81ac9fdf0d18 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 4 Nov 2014 09:06:56 -0800 Subject: [PATCH] gue: TX support for using remote checksum offload option Add if_tunnel flag TUNNEL_ENCAP_FLAG_REMCSUM to configure remote checksum offload on an IP tunnel. Add logic in gue_build_header to insert remote checksum offload option. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/net/fou.h | 14 +++++++++++++- include/uapi/linux/if_tunnel.h | 1 + net/ipv4/fou.c | 35 +++++++++++++++++++++++++++++++--- 3 files changed, 46 insertions(+), 4 deletions(-) diff --git a/include/net/fou.h b/include/net/fou.h index cf4ce8874f92..25b26ffcf1df 100644 --- a/include/net/fou.h +++ b/include/net/fou.h @@ -20,7 +20,19 @@ static size_t fou_encap_hlen(struct ip_tunnel_encap *e) static size_t gue_encap_hlen(struct ip_tunnel_encap *e) { - return sizeof(struct udphdr) + sizeof(struct guehdr); + size_t len; + bool need_priv = false; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + + if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) { + len += GUE_PLEN_REMCSUM; + need_priv = true; + } + + len += need_priv ? GUE_LEN_PRIV : 0; + + return len; } #endif diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h index 280d9e092283..bd3cc11a431f 100644 --- a/include/uapi/linux/if_tunnel.h +++ b/include/uapi/linux/if_tunnel.h @@ -69,6 +69,7 @@ enum tunnel_encap_types { #define TUNNEL_ENCAP_FLAG_CSUM (1<<0) #define TUNNEL_ENCAP_FLAG_CSUM6 (1<<1) +#define TUNNEL_ENCAP_FLAG_REMCSUM (1<<2) /* SIT-mode i_flags */ #define SIT_ISATAP 0x0001 diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index a3b8c5b36303..fb0db99adf9e 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -562,11 +562,19 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM); int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL; struct guehdr *guehdr; - size_t optlen = 0; + size_t hdrlen, optlen = 0; __be16 sport; void *data; bool need_priv = false; + if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) && + skb->ip_summed == CHECKSUM_PARTIAL) { + csum = false; + optlen += GUE_PLEN_REMCSUM; + type |= SKB_GSO_TUNNEL_REMCSUM; + need_priv = true; + } + optlen += need_priv ? GUE_LEN_PRIV : 0; skb = iptunnel_handle_offloads(skb, csum, type); @@ -578,7 +586,9 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev), skb, 0, 0, false); - skb_push(skb, sizeof(struct guehdr) + optlen); + hdrlen = sizeof(struct guehdr) + optlen; + + skb_push(skb, hdrlen); guehdr = (struct guehdr *)skb->data; @@ -597,7 +607,26 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, *flags = 0; data += GUE_LEN_PRIV; - /* Add private flags */ + if (type & SKB_GSO_TUNNEL_REMCSUM) { + u16 csum_start = skb_checksum_start_offset(skb); + __be16 *pd = data; + + if (csum_start < hdrlen) + return -EINVAL; + + csum_start -= hdrlen; + pd[0] = htons(csum_start); + pd[1] = htons(csum_start + skb->csum_offset); + + if (!skb_is_gso(skb)) { + skb->ip_summed = CHECKSUM_NONE; + skb->encapsulation = 0; + } + + *flags |= GUE_PFLAG_REMCSUM; + data += GUE_PLEN_REMCSUM; + } + } fou_build_udp(skb, e, fl4, protocol, sport); -- 2.20.1