Commit 9e7c5b39 authored by Alexander Ovechkin's avatar Alexander Ovechkin Committed by Jakub Kicinski
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ip6_tunnel: set inner ipproto before ip6_tnl_encap 



ip6_tnl_encap assigns to proto transport protocol which
encapsulates inner packet, but we must pass to set_inner_ipproto
protocol of that inner packet.

Calling set_inner_ipproto after ip6_tnl_encap might break gso.
For example, in case of encapsulating ipv6 packet in fou6 packet, inner_ipproto
would be set to IPPROTO_UDP instead of IPPROTO_IPV6. This would lead to
incorrect calling sequence of gso functions:
ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment -> udp6_ufo_fragment
instead of:
ipv6_gso_segment -> udp6_ufo_fragment -> skb_udp_tunnel_segment -> ip6ip6_gso_segment

Fixes: 6c11fbf9 ("ip6_tunnel: add MPLS transmit support")
Signed-off-by: default avatarAlexander Ovechkin <ovov@yandex-team.ru>
Link: https://lore.kernel.org/r/20201029171012.20904-1-ovov@yandex-team.ru


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 07e08873

net/ipv6/ip6_tunnel.c

+2 −2
Original line number Diff line number Diff line
@@ -1271,6 +1271,8 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, 
	if (max_headroom > dev->needed_headroom)

		dev->needed_headroom = max_headroom;



	skb_set_inner_ipproto(skb, proto);



	err = ip6_tnl_encap(skb, t, &proto, fl6);

	if (err)

		return err;
@@ -1280,8 +1282,6 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, 
		ipv6_push_frag_opts(skb, &opt.ops, &proto);

	}



	skb_set_inner_ipproto(skb, proto);



	skb_push(skb, sizeof(struct ipv6hdr));

	skb_reset_network_header(skb);

	ipv6h = ipv6_hdr(skb);