[PATCH net-next 2/8] net: udp: always set up for CHECKSUM_PARTIAL offload

[Edward Cree]

If the dst device doesn't support it, it'll get fixed up later anyway
 by validate_xmit_skb().  Also, this allows us to take advantage of LCO
 to avoid summing the payload multiple times.

Signed-off-by: Edward Cree <ec...@solarflare.com>
---
 net/ipv4/udp.c          | 14 +-------------
 net/ipv6/ip6_checksum.c | 13 +------------
 2 files changed, 2 insertions(+), 25 deletions(-)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 005280d..c6bca27 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -857,23 +857,11 @@ void udp_set_csum(bool nocheck, struct sk_buff *skb,
                uh->check = udp_v4_check(len, saddr, daddr, lco_csum(skb));
                if (uh->check == 0)
                        uh->check = CSUM_MANGLED_0;
-       } else if (skb_dst(skb) && skb_dst(skb)->dev &&
-                  (skb_dst(skb)->dev->features &
-                   (NETIF_F_IP_CSUM | NETIF_F_HW_CSUM))) {
+       } else {
                skb->ip_summed = CHECKSUM_PARTIAL;
                skb->csum_start = skb_transport_header(skb) - skb->head;
                skb->csum_offset = offsetof(struct udphdr, check);
                uh->check = ~udp_v4_check(len, saddr, daddr, 0);
-       } else {
-               __wsum csum;
-
-               uh->check = 0;
-               csum = skb_checksum(skb, 0, len, 0);
-               uh->check = udp_v4_check(len, saddr, daddr, csum);
-               if (uh->check == 0)
-                       uh->check = CSUM_MANGLED_0;
-
-               skb->ip_summed = CHECKSUM_UNNECESSARY;
        }
 }
 EXPORT_SYMBOL(udp_set_csum);
diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c
index 4924bd7..8f92058 100644
--- a/net/ipv6/ip6_checksum.c
+++ b/net/ipv6/ip6_checksum.c
@@ -103,22 +103,11 @@ void udp6_set_csum(bool nocheck, struct sk_buff *skb,
                uh->check = udp_v6_check(len, saddr, daddr, lco_csum(skb));
                if (uh->check == 0)
                        uh->check = CSUM_MANGLED_0;
-       } else if (skb_dst(skb) && skb_dst(skb)->dev &&
-                  (skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
+       } else {
                skb->ip_summed = CHECKSUM_PARTIAL;
                skb->csum_start = skb_transport_header(skb) - skb->head;
                skb->csum_offset = offsetof(struct udphdr, check);
                uh->check = ~udp_v6_check(len, saddr, daddr, 0);
-       } else {
-               __wsum csum;
-
-               uh->check = 0;
-               csum = skb_checksum(skb, 0, len, 0);
-               uh->check = udp_v6_check(len, saddr, daddr, csum);
-               if (uh->check == 0)
-                       uh->check = CSUM_MANGLED_0;
-
-               skb->ip_summed = CHECKSUM_UNNECESSARY;
        }
 }
 EXPORT_SYMBOL(udp6_set_csum);