Commit d9483f5a authored Sep 13, 2023 by Mika Westerberg Committed by Greg Kroah-Hartman Oct 10, 2023

net: thunderbolt: Fix TCPv6 GSO checksum calculation



commit e0b65f9b81fef180cf5f103adecbe5505c961153 upstream.

Alex reported that running ssh over IPv6 does not work with
Thunderbolt/USB4 networking driver. The reason for that is that driver
should call skb_is_gso() before calling skb_is_gso_v6(), and it should
not return false after calculates the checksum successfully. This probably
was a copy paste error from the original driver where it was done properly.

Reported-by: Alex Balcanquall <alex@alexbal.com>
Fixes: e69b6c02 ("net: Add support for networking over Thunderbolt cable")
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 47062af8

drivers/net/thunderbolt.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -958,12 +958,11 @@ static bool tbnet_xmit_csum_and_map(struct tbnet net, struct sk_buff skb,
		*tucso = ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
		ip_hdr(skb)->daddr, 0,
		ip_hdr(skb)->protocol, 0);
		} else if (skb_is_gso_v6(skb)) {
		} else if (skb_is_gso(skb) && skb_is_gso_v6(skb)) {
		tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
		*tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
		&ipv6_hdr(skb)->daddr, 0,
		IPPROTO_TCP, 0);
		return false;
		} else if (protocol == htons(ETH_P_IPV6)) {
		tucso = dest + skb_checksum_start_offset(skb) + skb->csum_offset;
		*tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,