Commit 62ebaeae authored Jan 20, 2020 by Yuki Taguchi Committed by David S. Miller Jan 21, 2020

ipv6: sr: remove SKB_GSO_IPXIP6 on End.D* actions



After LRO/GRO is applied, SRv6 encapsulated packets have
SKB_GSO_IPXIP6 feature flag, and this flag must be removed right after
decapulation procedure.

Currently, SKB_GSO_IPXIP6 flag is not removed on End.D* actions, which
creates inconsistent packet state, that is, a normal TCP/IP packets
have the SKB_GSO_IPXIP6 flag. This behavior can cause unexpected
fallback to GSO on routing to netdevices that do not support
SKB_GSO_IPXIP6. For example, on inter-VRF forwarding, decapsulated
packets separated into small packets by GSO because VRF devices do not
support TSO for packets with SKB_GSO_IPXIP6 flag, and this degrades
forwarding performance.

This patch removes encapsulation related GSO flags from the skb right
after the End.D* action is applied.

Fixes: d7a669dd ("ipv6: sr: add helper functions for seg6local")
Signed-off-by: Yuki Taguchi <tagyounit@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 9c5ed2f8

net/ipv6/seg6_local.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@
		#include <net/addrconf.h>
		#include <net/ip6_route.h>
		#include <net/dst_cache.h>
		#include <net/ip_tunnels.h>
		#ifdef CONFIG_IPV6_SEG6_HMAC
		#include <net/seg6_hmac.h>
		#endif
		@@ -135,7 +136,8 @@ static bool decap_and_validate(struct sk_buff *skb, int proto)

		skb_reset_network_header(skb);
		skb_reset_transport_header(skb);
		skb->encapsulation = 0;
		if (iptunnel_pull_offloads(skb))
		return false;

		return true;
		}

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