ip6_tunnel: disable caching when the traffic class is inherited (b5c2d495) · Commits · 戴 / test

If an ip6 tunnel is configured to inherit the traffic class from the inner header, the dst_cache must be disabled or it will foul the policy routing. The issue is apprently there since at leat Linux-2.6.12-rc2. Reported-by:

Liam McBirnie <liam.mcbirnie@boeing.com> Cc: Liam McBirnie <liam.mcbirnie@boeing.com> Acked-by:

Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by:

Paolo Abeni <pabeni@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv6/ip6_tunnel.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -1034,6 +1034,7 @@ int ip6_tnl_xmit(struct sk_buff skb, struct net_device dev, __u8 dsfield,
		int mtu;
		unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
		unsigned int max_headroom = psh_hlen;
		bool use_cache = false;
		u8 hop_limit;
		int err = -1;

		@@ -1066,7 +1067,15 @@ int ip6_tnl_xmit(struct sk_buff skb, struct net_device dev, __u8 dsfield,

		memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
		neigh_release(neigh);
		} else if (!fl6->flowi6_mark)
		} else if (!(t->parms.flags &
		(IP6_TNL_F_USE_ORIG_TCLASS \| IP6_TNL_F_USE_ORIG_FWMARK))) {
		/* enable the cache only only if the routing decision does
		* not depend on the current inner header value
		*/
		use_cache = true;
		}

		if (use_cache)
		dst = dst_cache_get(&t->dst_cache);

		if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
		@@ -1150,7 +1159,7 @@ route_lookup:
		if (t->encap.type != TUNNEL_ENCAP_NONE)
		goto tx_err_dst_release;
		} else {
		if (!fl6->flowi6_mark && ndst)
		if (use_cache && ndst)
		dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
		}
		skb_dst_set(skb, dst);

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