3.16.42-rc1 review patch. If anyone has any objections, please let me know.
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From: Paolo Abeni <pabeni@xxxxxxxxxx>
[ Upstream commit b5c2d49544e5930c96e2632a7eece3f4325a1888 ]
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@xxxxxxxxxx>
Cc: Liam McBirnie <liam.mcbirnie@xxxxxxxxxx>
Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
net/ipv6/ip6_tunnel.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -958,12 +958,21 @@ static int ip6_tnl_xmit2(struct sk_buff
struct ipv6_tel_txoption opt;
struct dst_entry *dst = NULL, *ndst = NULL;
struct net_device *tdev;
+ bool use_cache = false;
int mtu;
unsigned int max_headroom = sizeof(struct ipv6hdr);
u8 proto;
int err = -1;
- if (!fl6->flowi6_mark)
+ 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 = ip6_tnl_dst_check(t);
if (!dst) {
ndst = ip6_route_output(net, NULL, fl6);
@@ -1021,7 +1030,7 @@ static int ip6_tnl_xmit2(struct sk_buff
consume_skb(skb);
skb = new_skb;
}
- if (fl6->flowi6_mark) {
+ if (!use_cache) {
skb_dst_set(skb, dst);
ndst = NULL;
} else {