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.

4 files changed, 15 insertions, 0 deletions

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index 28479ff3..5fb88e03 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -858,6 +858,10 @@ cf_symbol_class_name(struct symbol *sym)
       return "routing table";
     case SYM_ATTRIBUTE:
       return "custom attribute";
+    case SYM_MPLS_DOMAIN:
+      return "MPLS domain";
+    case SYM_MPLS_RANGE:
+      return "MPLS label range";
     case SYM_CONSTANT_RANGE:
       return "constant";
     case SYM_VARIABLE_RANGE:
diff --git a/conf/conf.c b/conf/conf.c
index b9239d9b..d98d421c 100644
--- a/conf/conf.c
+++ b/conf/conf.c
@@ -49,6 +49,7 @@
 #include "nest/route.h"
 #include "nest/protocol.h"
 #include "nest/iface.h"
+#include "nest/mpls.h"
 #include "lib/resource.h"
 #include "lib/string.h"
 #include "lib/event.h"
@@ -139,6 +140,7 @@ config_parse(struct config *c)
   cf_lex_init(0, c);
   sysdep_preconfig(c);
   protos_preconfig(c);
+  mpls_preconfig(c);
   rt_preconfig(c);
   cf_parse();
   rt_postconfig(c);
@@ -299,6 +301,7 @@ config_do_commit(struct config *c, int type)
   int force_restart = sysdep_commit(c, old_config);
   DBG("global_commit\n");
   force_restart |= global_commit(c, old_config);
+  mpls_commit(c, old_config);
   DBG("rt_commit\n");
   rt_commit(c, old_config);
   DBG("protos_commit\n");
@@ -547,6 +550,7 @@ order_shutdown(int gr)
   memcpy(c, config, sizeof(struct config));
   init_list(&c->protos);
   init_list(&c->tables);
+  init_list(&c->mpls_domains);
   init_list(&c->symbols);
   memset(c->def_tables, 0, sizeof(c->def_tables));
   c->shutdown = 1;
diff --git a/conf/conf.h b/conf/conf.h
index b07b417c..8fd6713e 100644
--- a/conf/conf.h
+++ b/conf/conf.h
@@ -21,6 +21,7 @@ struct config {
   linpool *mem;				/* Linear pool containing configuration data */
   list protos;				/* Configured protocol instances (struct proto_config) */
   list tables;				/* Configured routing tables (struct rtable_config) */
+  list mpls_domains;			/* Configured MPLS domains (struct mpls_domain_config) */
   list logfiles;			/* Configured log files (sysdep) */
   list tests;				/* Configured unit tests (f_bt_test_suite) */
   list symbols;				/* Configured symbols in config order */
@@ -128,6 +129,8 @@ struct symbol {
     const struct filter *filter;	/* For SYM_FILTER */
     struct rtable_config *table;	/* For SYM_TABLE */
     struct f_dynamic_attr *attribute;	/* For SYM_ATTRIBUTE */
+    struct mpls_domain_config *mpls_domain;	/* For SYM_MPLS_DOMAIN */
+    struct mpls_range_config *mpls_range;	/* For SYM_MPLS_RANGE */
     struct f_val *val;			/* For SYM_CONSTANT */
     uint offset;			/* For SYM_VARIABLE */
     const struct keyword *keyword;	/* For SYM_KEYWORD */
@@ -167,6 +170,8 @@ extern linpool *global_root_scope_linpool;
 #define SYM_ATTRIBUTE 6
 #define SYM_KEYWORD 7
 #define SYM_METHOD 8
+#define SYM_MPLS_DOMAIN 9
+#define SYM_MPLS_RANGE 10
 
 #define SYM_VARIABLE 0x100	/* 0x100-0x1ff are variable types */
 #define SYM_VARIABLE_RANGE SYM_VARIABLE ... (SYM_VARIABLE | 0xff)
diff --git a/conf/confbase.Y b/conf/confbase.Y
index 69a7676c..63308290 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -43,6 +43,8 @@ static inline void cf_assert_symbol(const struct symbol *sym, uint class) {
     case SYM_FILTER: cf_assert(sym->class == SYM_FILTER, "Filter name required"); break;
     case SYM_TABLE: cf_assert(sym->class == SYM_TABLE, "Table name required"); break;
     case SYM_ATTRIBUTE: cf_assert(sym->class == SYM_ATTRIBUTE, "Custom attribute name required"); break;
+    case SYM_MPLS_DOMAIN: cf_assert(sym->class == SYM_MPLS_DOMAIN, "MPLS domain name required"); break;
+    case SYM_MPLS_RANGE: cf_assert(sym->class == SYM_MPLS_RANGE, "MPLS range name required"); break;
     case SYM_VARIABLE: cf_assert((sym->class & ~0xff) == SYM_VARIABLE, "Variable name required"); break;
     case SYM_CONSTANT: cf_assert((sym->class & ~0xff) == SYM_CONSTANT, "Constant name required"); break;
     default: bug("This shall not happen");