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 <rshearma@brocade.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/mpls_iptunnel.h b/include/net/mpls_iptunnel.h
index 179253f..a18af6a 100644
--- a/include/net/mpls_iptunnel.h
+++ b/include/net/mpls_iptunnel.h
@@ -19,6 +19,8 @@
struct mpls_iptunnel_encap {
u32 label[MAX_NEW_LABELS];
u8 labels;
+ u8 ttl_propagate;
+ u8 default_ttl;
};
static inline struct mpls_iptunnel_encap *mpls_lwtunnel_encap(struct lwtunnel_state *lwtstate)
diff --git a/include/net/netns/mpls.h b/include/net/netns/mpls.h
index 08652ee..6608b36 100644
--- a/include/net/netns/mpls.h
+++ b/include/net/netns/mpls.h
@@ -10,6 +10,7 @@
struct netns_mpls {
int ip_ttl_propagate;
+ int default_ttl;
size_t platform_labels;
struct mpls_route __rcu * __rcu *platform_label;
diff --git a/include/uapi/linux/mpls_iptunnel.h b/include/uapi/linux/mpls_iptunnel.h
index d80a049..f5e4509 100644
--- a/include/uapi/linux/mpls_iptunnel.h
+++ b/include/uapi/linux/mpls_iptunnel.h
@@ -16,11 +16,13 @@
/* MPLS tunnel attributes
* [RTA_ENCAP] = {
* [MPLS_IPTUNNEL_DST]
+ * [MPLS_IPTUNNEL_TTL]
* }
*/
enum {
MPLS_IPTUNNEL_UNSPEC,
MPLS_IPTUNNEL_DST,
+ MPLS_IPTUNNEL_TTL,
__MPLS_IPTUNNEL_MAX,
};
#define MPLS_IPTUNNEL_MAX (__MPLS_IPTUNNEL_MAX - 1)