From 4bcb877d257c87298aedead1ffeaba0d5df1991d Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 4 Nov 2014 09:06:52 -0800 Subject: [PATCH] udp: Offload outer UDP tunnel csum if available In __skb_udp_tunnel_segment if outer UDP checksums are enabled and ip_summed is not already CHECKSUM_PARTIAL, set up checksum offload if device features allow it. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- net/ipv4/udp_offload.c | 52 +++++++++++++++++++++++++++++------------- 1 file changed, 36 insertions(+), 16 deletions(-) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 6480cea7aa53..a774711a88b9 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -29,7 +29,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, netdev_features_t features, struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, netdev_features_t features), - __be16 new_protocol) + __be16 new_protocol, bool is_ipv6) { struct sk_buff *segs = ERR_PTR(-EINVAL); u16 mac_offset = skb->mac_header; @@ -39,7 +39,9 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, netdev_features_t enc_features; int udp_offset, outer_hlen; unsigned int oldlen; - bool need_csum; + bool need_csum = !!(skb_shinfo(skb)->gso_type & + SKB_GSO_UDP_TUNNEL_CSUM); + bool offload_csum = false, dont_encap = need_csum; oldlen = (u16)~skb->len; @@ -52,10 +54,12 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, skb_set_network_header(skb, skb_inner_network_offset(skb)); skb->mac_len = skb_inner_network_offset(skb); skb->protocol = new_protocol; + skb->encap_hdr_csum = need_csum; - need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); - if (need_csum) - skb->encap_hdr_csum = 1; + /* Try to offload checksum if possible */ + offload_csum = !!(need_csum && + (skb->dev->features & + (is_ipv6 ? NETIF_F_V6_CSUM : NETIF_F_V4_CSUM))); /* segment inner packet. */ enc_features = skb->dev->hw_enc_features & features; @@ -72,11 +76,21 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, do { struct udphdr *uh; int len; - - skb_reset_inner_headers(skb); - skb->encapsulation = 1; + __be32 delta; + + if (dont_encap) { + skb->encapsulation = 0; + skb->ip_summed = CHECKSUM_NONE; + } else { + /* Only set up inner headers if we might be offloading + * inner checksum. + */ + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + } skb->mac_len = mac_len; + skb->protocol = protocol; skb_push(skb, outer_hlen); skb_reset_mac_header(skb); @@ -86,19 +100,25 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, uh = udp_hdr(skb); uh->len = htons(len); - if (need_csum) { - __be32 delta = htonl(oldlen + len); + if (!need_csum) + continue; + + delta = htonl(oldlen + len); + + uh->check = ~csum_fold((__force __wsum) + ((__force u32)uh->check + + (__force u32)delta)); - uh->check = ~csum_fold((__force __wsum) - ((__force u32)uh->check + - (__force u32)delta)); + if (offload_csum) { + skb->ip_summed = CHECKSUM_PARTIAL; + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + } else { uh->check = gso_make_checksum(skb, ~uh->check); if (uh->check == 0) uh->check = CSUM_MANGLED_0; } - - skb->protocol = protocol; } while ((skb = skb->next)); out: return segs; @@ -134,7 +154,7 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, } segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, - protocol); + protocol, is_ipv6); out_unlock: rcu_read_unlock(); -- 2.20.1