[PATCH net] ipv6: Paritially checksum full MTU frames

[PATCH net] ipv6: Paritially checksum full MTU frames

[Vladislav Yasevich]

IPv6 will mark data that is smaller that mtu - headersize as
CHECKSUM_PARTIAL, but if the data will completely fill the mtu,
the packet checksum will be computed in software instead.
Extend the conditional to include the data that fills the mtu
as well.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
---
 net/ipv6/ip6_output.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 2c0df09..b6a94ff 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1344,7 +1344,7 @@ static int __ip6_append_data(struct sock *sk,
 	 */
 	if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
 	    headersize == sizeof(struct ipv6hdr) &&
-	    length < mtu - headersize &&
+	    length <= mtu - headersize &&
 	    !(flags & MSG_MORE) &&
 	    rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM))
 		csummode = CHECKSUM_PARTIAL;
-- 
2.7.4

Re: [PATCH net] ipv6: Paritially checksum full MTU frames

[David Miller]

From: Vladislav Yasevich <vyasevich@gmail.com>
Date: Sun, 29 Jan 2017 22:52:53 -0500

> IPv6 will mark data that is smaller that mtu - headersize as
> CHECKSUM_PARTIAL, but if the data will completely fill the mtu,
> the packet checksum will be computed in software instead.
> Extend the conditional to include the data that fills the mtu
> as well.
> 
> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>

Looks good, applied, thanks!