MPLS subsystem

The MPLS subsystem manages MPLS labels and handles their allocation to
MPLS-aware routing protocols. These labels are then attached to IP or VPN
routes representing label switched paths -- LSPs.

There was already a preliminary MPLS support consisting of MPLS label
net_addr, MPLS routing tables with static MPLS routes, remote labels in
next hops, and kernel protocol support.

This patch adds the MPLS domain as a basic structure representing local
label space with dynamic label allocator and configurable label ranges.
To represent LSPs, allocated local labels can be attached as route
attributes to IP or VPN routes with local labels as attributes.

There are several steps for handling LSP routes in routing protocols --
deciding to which forwarding equivalence class (FEC) the LSP route
belongs, allocating labels for new FECs, announcing MPLS routes for new
FECs, attaching labels to LSP routes. The FEC map structure implements
basic code for managing FECs in routing protocols, therefore existing
protocols can be made MPLS-aware by adding FEC map and delegating
most work related to local label management to it.

1 files changed, 6 insertions, 2 deletions

diff --git a/nest/route.h b/nest/route.h
index 4fe43e6f..694e3c5d 100644
--- a/nest/route.h
+++ b/nest/route.h
@@ -200,6 +200,7 @@ typedef struct rtable {
   struct timer *settle_timer;		/* Settle time for notifications */
   list flowspec_links;			/* List of flowspec links, src for NET_IPx and dst for NET_FLOWx */
   struct f_trie *flowspec_trie;		/* Trie for evaluation of flowspec notifications */
+  // struct mpls_domain *mpls_domain;	/* Label allocator for MPLS */
 } rtable;
 
 struct rt_subscription {
@@ -527,7 +528,10 @@ typedef struct eattr {
 
 const char *ea_custom_name(uint ea);
 
-#define EA_GEN_IGP_METRIC EA_CODE(PROTOCOL_NONE, 0)
+#define EA_GEN_IGP_METRIC	EA_CODE(PROTOCOL_NONE, 0)
+#define EA_MPLS_LABEL		EA_CODE(PROTOCOL_NONE, 1)
+#define EA_MPLS_POLICY		EA_CODE(PROTOCOL_NONE, 2)
+#define EA_MPLS_CLASS		EA_CODE(PROTOCOL_NONE, 3)
 
 #define EA_CODE_MASK 0xffff
 #define EA_CUSTOM_BIT 0x8000
@@ -687,7 +691,7 @@ static inline int nexthop_same(struct nexthop *x, struct nexthop *y)
 { return (x == y) || nexthop__same(x, y); }
 struct nexthop *nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp);
 struct nexthop *nexthop_sort(struct nexthop *x);
-static inline void nexthop_link(struct rta *a, struct nexthop *from)
+static inline void nexthop_link(struct rta *a, const struct nexthop *from)
 { memcpy(&a->nh, from, nexthop_size(from)); }
 void nexthop_insert(struct nexthop **n, struct nexthop *y);
 int nexthop_is_sorted(struct nexthop *x);