Merge branch 'mpls-ttl-propagation'

Robert Shearman says:

====================
mpls: allow TTL propagation from IP packets to be configured

Allow TTL propagation from IP packets to MPLS packets to be
configured. Add a new optional LWT attribute, MPLS_IPTUNNEL_TTL, which
allows the TTL to be set in the resulting MPLS packet, with the value
of 0 having the semantics of enabling propagation of the TTL from the
IP header (i.e. non-zero values disable propagation).

Also allow the configuration to be overridden globally by reusing the
same sysctl to control whether the TTL is propagated from IP packets
into the MPLS header. If the per-LWT attribute is set then it
overrides the global configuration. If the TTL isn't propagated then a
default TTL value is used which can be configured via a new sysctl,
"net.mpls.default_ttl". This is kept separate from the configuration
of whether IP TTL propagation is enabled as it can be used in the
future when non-IP payloads are supported (i.e. where there is no
payload TTL that can be propagated).
====================

Signed-off-by: Robert Shearman <[email protected]>
Acked-by: Roopa Prabhu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

1 files changed, 7 insertions, 0 deletions

diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index 76360d8b9579..62928d8fabd1 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -90,6 +90,12 @@ struct mpls_nh { /* next hop label forwarding entry */
 	u8			nh_via_table;
 };
 
+enum mpls_ttl_propagation {
+	MPLS_TTL_PROP_DEFAULT,
+	MPLS_TTL_PROP_ENABLED,
+	MPLS_TTL_PROP_DISABLED,
+};
+
 /* The route, nexthops and vias are stored together in the same memory
  * block:
  *
@@ -116,6 +122,7 @@ struct mpls_route { /* next hop label forwarding entry */
 	u8			rt_protocol;
 	u8			rt_payload_type;
 	u8			rt_max_alen;
+	u8			rt_ttl_propagate;
 	unsigned int		rt_nhn;
 	unsigned int		rt_nhn_alive;
 	struct mpls_nh		rt_nh[0];