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: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index c26d0ec..f1338e0 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -45,6 +45,7 @@
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,
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index d8d397a..5a6d10a 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -345,6 +345,8 @@
SKB_GSO_UDP_TUNNEL = 1 << 9,
SKB_GSO_MPLS = 1 << 10,
+
+ SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
};
#if BITS_PER_LONG > 32
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 0e9bb08..0070ab8 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1258,6 +1258,7 @@
SKB_GSO_SIT |
SKB_GSO_TCPV6 |
SKB_GSO_UDP_TUNNEL |
+ SKB_GSO_UDP_TUNNEL_CSUM |
SKB_GSO_MPLS |
0)))
goto out;
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index d8de7b9..c02f2d2 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -61,6 +61,7 @@
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;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index a84f676..8d8c33d 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2528,7 +2528,11 @@
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 @@
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 @@
}
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 @@
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);
+ uh->len = htons(len);
- /* csum segment if tunnel sets skb with csum. */
- if (protocol == htons(ETH_P_IP) && unlikely(uh->check)) {
- struct iphdr *iph = ip_hdr(skb);
+ if (need_csum) {
+ __be32 delta = htonl(oldlen + 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));
+ uh->check = ~csum_fold((__force __wsum)
+ ((__force u32)uh->check +
+ (__force u32)delta));
+ uh->check = gso_make_checksum(skb, ~uh->check);
+
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
-
- } else if (protocol == htons(ETH_P_IPV6)) {
- struct ipv6hdr *ipv6h = ipv6_hdr(skb);
- u32 len = skb->len - udp_offset;
-
- 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;
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 88b4023..5c23f47 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -56,7 +56,8 @@
__wsum csum;
if (skb->encapsulation &&
- skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL) {
+ (skb_shinfo(skb)->gso_type &
+ (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
segs = skb_udp_tunnel_segment(skb, features);
goto out;
}
@@ -71,6 +72,7 @@
if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
SKB_GSO_UDP_TUNNEL |
+ SKB_GSO_UDP_TUNNEL_CSUM |
SKB_GSO_IPIP |
SKB_GSO_GRE | SKB_GSO_MPLS) ||
!(type & (SKB_GSO_UDP))))
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index b2f0915..d54c574 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -100,6 +100,7 @@
SKB_GSO_IPIP |
SKB_GSO_SIT |
SKB_GSO_UDP_TUNNEL |
+ SKB_GSO_UDP_TUNNEL_CSUM |
SKB_GSO_MPLS |
SKB_GSO_TCPV6 |
0)))
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index b261ee8..79da8b3 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -63,6 +63,7 @@
if (unlikely(type & ~(SKB_GSO_UDP |
SKB_GSO_DODGY |
SKB_GSO_UDP_TUNNEL |
+ SKB_GSO_UDP_TUNNEL_CSUM |
SKB_GSO_GRE |
SKB_GSO_IPIP |
SKB_GSO_SIT |
@@ -76,7 +77,8 @@
goto out;
}
- if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL)
+ if (skb->encapsulation && skb_shinfo(skb)->gso_type &
+ (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
segs = skb_udp_tunnel_segment(skb, features);
else {
/* Do software UFO. Complete and fill in the UDP checksum as HW cannot