[bgpd] Trim memory usage of BGP routes

2007-05-03 Paul Jakma <paul.jakma@sun.com>

	* bgp_route.h: (struct info) Move less frequently used
	  fields to a lazily allocated struct info_extra.
	  Export bgp_info_extra_get
	* bgp_route.c: (bgp_info_extra_new) allocate extra
	  (bgp_info_extra_free) Free damp info and the info_extra.
	  (bgp_info_extra_get) Retrieve the info_extra of a struct
	  info, allocating as required.
	  (generally) adjust to use info->extra
	* bgp_damp.c: (generally) use bgp_info_extra_get to access
	  dampinfo
	* bgp_attr.h: Move rarely allocated attributes from struct attr
	  to a struct attr_extra, for a substantial saving in size of
	  struct attr.
	* bgp_attr.c: (bgp_attr_extra_{new,free}), new, self-explanatory.
	  (bgp_attr_extra_get) Get the attr_extra for a given struct
	  attr, allocating it if needs be.
	  (bgp_attr_dup) Shallow copy the struct attr and its attr_extra.
	  (generally) adjust to know about attr->extra.
	* bgp_debug.c: (bgp_dump_attr) ditto
	* bgp_vty.c: (show_bgp_memory) print attr and info extra sizes.
	* bgp_nexthop.c: (generally) adjust to know about attr->extra
	  and info->extra.
	* bgp_{packet,routemap,snmp,zebra}.c: ditto
	* lib/memtypes.c: Add MTYPE_ATTR_EXTRA and MTYPE_BGP_ROUTE_EXTRA
diff --git a/bgpd/bgp_attr.h b/bgpd/bgp_attr.h
index 0734bc2..ac14947 100644
--- a/bgpd/bgp_attr.h
+++ b/bgpd/bgp_attr.h
@@ -45,24 +45,20 @@
 
 /* BGP attribute header must bigger than 2. */
 #define BGP_ATTR_MIN_LEN        2       /* Attribute flag and type. */
-
 #define BGP_ATTR_DEFAULT_WEIGHT 32768
 
-/* BGP attribute structure. */
-struct attr
+/* Additional/uncommon BGP attributes.
+ * lazily allocated as and when a struct attr
+ * requires it.
+ */
+struct attr_extra
 {
-  /* Attributes. */
+  /* Multi-Protocol Nexthop, AFI IPv6 */
 #ifdef HAVE_IPV6
   struct in6_addr mp_nexthop_global;
   struct in6_addr mp_nexthop_local;
 #endif /* HAVE_IPV6 */
 
-  /* AS Path structure */
-  struct aspath *aspath;
-
-  /* Community structure */
-  struct community *community;	
-
   /* Extended Communities attribute. */
   struct ecommunity *ecommunity;
   
@@ -72,6 +68,37 @@
   /* Unknown transitive attribute. */
   struct transit *transit;
 
+  struct in_addr mp_nexthop_global_in;
+  struct in_addr mp_nexthop_local_in;
+  
+  /* Aggregator Router ID attribute */
+  struct in_addr aggregator_addr;
+  
+  /* Route Reflector Originator attribute */
+  struct in_addr originator_id;
+  
+  /* Local weight, not actually an attribute */
+  u_int32_t weight;
+  
+  /* Aggregator ASN */
+  as_t aggregator_as;
+  
+  /* MP Nexthop length */
+  u_char mp_nexthop_len;
+};
+
+/* BGP core attribute structure. */
+struct attr
+{
+  /* AS Path structure */
+  struct aspath *aspath;
+
+  /* Community structure */
+  struct community *community;	
+  
+  /* Lazily allocated pointer to extra attributes */
+  struct attr_extra *extra;
+  
   /* Reference count of this attribute. */
   unsigned long refcnt;
 
@@ -82,14 +109,9 @@
   struct in_addr nexthop;
   u_int32_t med;
   u_int32_t local_pref;
-  struct in_addr aggregator_addr;
-  struct in_addr originator_id;
-  struct in_addr mp_nexthop_global_in;
-  struct in_addr mp_nexthop_local_in;
-  u_int32_t weight;
-  as_t aggregator_as;
+
+  /* Path origin attribute */
   u_char origin;
-  u_char mp_nexthop_len;
 };
 
 /* Router Reflector related structure. */
@@ -115,6 +137,9 @@
 extern int bgp_attr_parse (struct peer *, struct attr *, bgp_size_t,
 		    struct bgp_nlri *, struct bgp_nlri *);
 extern int bgp_attr_check (struct peer *, struct attr *);
+extern struct attr_extra *bgp_attr_extra_get (struct attr *);
+extern void bgp_attr_extra_free (struct attr *);
+extern void bgp_attr_dup (struct attr *, struct attr *);
 extern struct attr *bgp_attr_intern (struct attr *attr);
 extern void bgp_attr_unintern (struct attr *);
 extern void bgp_attr_flush (struct attr *);