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Commit 0f4f4ffa authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

net: Add GSO support for UDP tunnels with checksum 



Added a new netif feature for GSO_UDP_TUNNEL_CSUM. This indicates
that a device is capable of computing the UDP checksum in the
encapsulating header of a UDP tunnel.

Signed-off-by: default avatarTom Herbert <therbert@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e9c3a24b

include/linux/netdev_features.h

+1 −0
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ enum { 
	NETIF_F_GSO_IPIP_BIT,		/* ... IPIP tunnel with TSO */

	NETIF_F_GSO_SIT_BIT,		/* ... SIT tunnel with TSO */

	NETIF_F_GSO_UDP_TUNNEL_BIT,	/* ... UDP TUNNEL with TSO */

	NETIF_F_GSO_UDP_TUNNEL_CSUM_BIT,/* ... UDP TUNNEL with TSO & CSUM */

	NETIF_F_GSO_MPLS_BIT,		/* ... MPLS segmentation */

	/**/NETIF_F_GSO_LAST =		/* last bit, see GSO_MASK */

		NETIF_F_GSO_MPLS_BIT,

include/linux/skbuff.h

+2 −0
Original line number Diff line number Diff line
@@ -345,6 +345,8 @@ enum { 
	SKB_GSO_UDP_TUNNEL = 1 << 9,



	SKB_GSO_MPLS = 1 << 10,



	SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,

};



#if BITS_PER_LONG > 32

net/ipv4/af_inet.c

+1 −0
Original line number Diff line number Diff line
@@ -1258,6 +1258,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, 
		       SKB_GSO_SIT |

		       SKB_GSO_TCPV6 |

		       SKB_GSO_UDP_TUNNEL |

		       SKB_GSO_UDP_TUNNEL_CSUM |

		       SKB_GSO_MPLS |

		       0)))

		goto out;

net/ipv4/tcp_offload.c

+1 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb, 
			       SKB_GSO_SIT |

			       SKB_GSO_MPLS |

			       SKB_GSO_UDP_TUNNEL |

			       SKB_GSO_UDP_TUNNEL_CSUM |

			       0) ||

			     !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))

			goto out;

net/ipv4/udp.c

+19 −21
Original line number Diff line number Diff line
@@ -2528,7 +2528,11 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 
	int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);

	__be16 protocol = skb->protocol;

	netdev_features_t enc_features;

	int outer_hlen;

	int udp_offset, outer_hlen;

	unsigned int oldlen;

	bool need_csum;



	oldlen = (u16)~skb->len;



	if (unlikely(!pskb_may_pull(skb, tnl_hlen)))

		goto out;
@@ -2540,6 +2544,10 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 
	skb->mac_len = skb_inner_network_offset(skb);

	skb->protocol = htons(ETH_P_TEB);



	need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);

	if (need_csum)

		skb->encap_hdr_csum = 1;



	/* segment inner packet. */

	enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);

	segs = skb_mac_gso_segment(skb, enc_features);
@@ -2550,10 +2558,11 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 
	}



	outer_hlen = skb_tnl_header_len(skb);

	udp_offset = outer_hlen - tnl_hlen;

	skb = segs;

	do {

		struct udphdr *uh;

		int udp_offset = outer_hlen - tnl_hlen;

		int len;



		skb_reset_inner_headers(skb);

		skb->encapsulation = 1;
@@ -2564,31 +2573,20 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 
		skb_reset_mac_header(skb);

		skb_set_network_header(skb, mac_len);

		skb_set_transport_header(skb, udp_offset);

		len = skb->len - udp_offset;

		uh = udp_hdr(skb);

		uh->len = htons(skb->len - udp_offset);



		/* csum segment if tunnel sets skb with csum. */

		if (protocol == htons(ETH_P_IP) && unlikely(uh->check)) {

			struct iphdr *iph = ip_hdr(skb);

		uh->len = htons(len);



			uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,

						       skb->len - udp_offset,

						       IPPROTO_UDP, 0);

			uh->check = csum_fold(skb_checksum(skb, udp_offset,

							   skb->len - udp_offset, 0));

			if (uh->check == 0)

				uh->check = CSUM_MANGLED_0;

		if (need_csum) {

			__be32 delta = htonl(oldlen + len);



		} else if (protocol == htons(ETH_P_IPV6)) {

			struct ipv6hdr *ipv6h = ipv6_hdr(skb);

			u32 len = skb->len - udp_offset;

			uh->check = ~csum_fold((__force __wsum)

					       ((__force u32)uh->check +

						(__force u32)delta));

			uh->check = gso_make_checksum(skb, ~uh->check);



			uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,

						     len, IPPROTO_UDP, 0);

			uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0));

			if (uh->check == 0)

				uh->check = CSUM_MANGLED_0;

			skb->ip_summed = CHECKSUM_NONE;

		}



		skb->protocol = protocol;