Commit 9e7c5b39 authored Oct 29, 2020 by Alexander Ovechkin Committed by Jakub Kicinski Oct 30, 2020

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: Alexander Ovechkin <ovov@yandex-team.ru>
Link: https://lore.kernel.org/r/20201029171012.20904-1-ovov@yandex-team.ru


Signed-off-by: Jakub 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 @@ route_lookup:
		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 @@ route_lookup:
		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);

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