From 5b441ac8784c1e7f3c619f14da4c3f52e87348d5 Mon Sep 17 00:00:00 2001 From: Robert Shearman Date: Fri, 10 Mar 2017 20:43:24 +0000 Subject: mpls: allow TTL propagation to IP packets to be configured Provide the ability to control on a per-route basis whether the TTL value from an MPLS packet is propagated to an IPv4/IPv6 packet when the last label is popped as per the theoretical model in RFC 3443 through a new route attribute, RTA_TTL_PROPAGATE which can be 0 to mean disable propagation and 1 to mean enable propagation. In order to provide the ability to change the behaviour for packets arriving with IPv4/IPv6 Explicit Null labels and to provide an easy way for a user to change the behaviour for all existing routes without having to reprogram them, a global knob is provided. This is done through the addition of a new per-namespace sysctl, "net.mpls.ip_ttl_propagate", which defaults to enabled. If the per-route attribute is set (either enabled or disabled) then it overrides the global configuration. Signed-off-by: Robert Shearman Acked-by: David Ahern Tested-by: David Ahern Signed-off-by: David S. Miller --- net/mpls/internal.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'net/mpls/internal.h') 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]; -- cgit v1.2.3