bgpd: add the bgp_label_per_nexthop_cache struct and apis

This commit introduces the necessary structs and apis to
create the cache entries that store the label information
associated to a given nexthop.

A hash table is created in each BGP instance for all the
AFIs: IPv4 and IPv6. That hash table is initialised.
An API to look and/or create an entry based on a given
nexthop.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>

diff --git a/bgpd/bgp_labelpool.c b/bgpd/bgp_labelpool.c
index 9f1a07cd23faad3f7b812ce0804ea2b0e82e0216..41d4eabe1fe2ff5572e1f193759cfd28998da1fd 100644 (file)
--- a/bgpd/bgp_labelpool.c
+++ b/bgpd/bgp_labelpool.c
@@ -23,6 +23,7 @@
 #include "bgpd/bgp_debug.h"
 #include "bgpd/bgp_errors.h"
 #include "bgpd/bgp_route.h"
+#include "bgpd/bgp_zebra.h"
 
 #define BGP_LABELPOOL_ENABLE_TESTS 0
 
@@ -1558,3 +1559,57 @@ void bgp_lp_vty_init(void)
        install_element(ENABLE_NODE, &clear_labelpool_perf_test_cmd);
 #endif /* BGP_LABELPOOL_ENABLE_TESTS */
 }
+
+DEFINE_MTYPE_STATIC(BGPD, LABEL_PER_NEXTHOP_CACHE,
+                   "BGP Label Per Nexthop entry");
+
+/* The nexthops values are compared to
+ * find in the tree the appropriate cache entry
+ */
+int bgp_label_per_nexthop_cache_cmp(const struct bgp_label_per_nexthop_cache *a,
+                                   const struct bgp_label_per_nexthop_cache *b)
+{
+       return prefix_cmp(&a->nexthop, &b->nexthop);
+}
+
+struct bgp_label_per_nexthop_cache *
+bgp_label_per_nexthop_new(struct bgp_label_per_nexthop_cache_head *tree,
+                         struct prefix *nexthop)
+{
+       struct bgp_label_per_nexthop_cache *blnc;
+
+       blnc = XCALLOC(MTYPE_LABEL_PER_NEXTHOP_CACHE,
+                      sizeof(struct bgp_label_per_nexthop_cache));
+       blnc->tree = tree;
+       blnc->label = MPLS_INVALID_LABEL;
+       prefix_copy(&blnc->nexthop, nexthop);
+       LIST_INIT(&(blnc->paths));
+       bgp_label_per_nexthop_cache_add(tree, blnc);
+
+       return blnc;
+}
+
+struct bgp_label_per_nexthop_cache *
+bgp_label_per_nexthop_find(struct bgp_label_per_nexthop_cache_head *tree,
+                          struct prefix *nexthop)
+{
+       struct bgp_label_per_nexthop_cache blnc = {};
+
+       if (!tree)
+               return NULL;
+
+       memcpy(&blnc.nexthop, nexthop, sizeof(struct prefix));
+       return bgp_label_per_nexthop_cache_find(tree, &blnc);
+}
+
+void bgp_label_per_nexthop_free(struct bgp_label_per_nexthop_cache *blnc)
+{
+       if (blnc->label != MPLS_INVALID_LABEL) {
+               bgp_zebra_send_nexthop_label(ZEBRA_MPLS_LABELS_DELETE,
+                                            blnc->label, ZEBRA_LSP_BGP,
+                                            &blnc->nexthop);
+               bgp_lp_release(LP_TYPE_NEXTHOP, blnc, blnc->label);
+       }
+       bgp_label_per_nexthop_cache_del(blnc->tree, blnc);
+       XFREE(MTYPE_LABEL_PER_NEXTHOP_CACHE, blnc);
+}

diff --git a/bgpd/bgp_labelpool.h b/bgpd/bgp_labelpool.h
index 649195498361929f4ada5d1e86eab5f411609eff..0e965f3b9a050842c63e77e5ee9624e16210a4c4 100644 (file)
--- a/bgpd/bgp_labelpool.h
+++ b/bgpd/bgp_labelpool.h
@@ -42,4 +42,47 @@ extern void bgp_lp_event_zebra_down(void);
 extern void bgp_lp_event_zebra_up(void);
 extern void bgp_lp_vty_init(void);
 
+struct bgp_label_per_nexthop_cache;
+PREDECL_RBTREE_UNIQ(bgp_label_per_nexthop_cache);
+
+extern int
+bgp_label_per_nexthop_cache_cmp(const struct bgp_label_per_nexthop_cache *a,
+                               const struct bgp_label_per_nexthop_cache *b);
+
+struct bgp_label_per_nexthop_cache {
+
+       /* RB-tree entry. */
+       struct bgp_label_per_nexthop_cache_item entry;
+
+       /* the nexthop is the key of the list */
+       struct prefix nexthop;
+
+       /* calculated label */
+       mpls_label_t label;
+
+       /* number of path_vrfs */
+       unsigned int path_count;
+
+       /* back pointer to bgp instance */
+       struct bgp *to_bgp;
+
+       /* list of path_vrfs using it */
+       LIST_HEAD(path_lists, bgp_path_info) paths;
+
+       /* Back pointer to the cache tree this entry belongs to. */
+       struct bgp_label_per_nexthop_cache_head *tree;
+};
+
+DECLARE_RBTREE_UNIQ(bgp_label_per_nexthop_cache,
+                   struct bgp_label_per_nexthop_cache, entry,
+                   bgp_label_per_nexthop_cache_cmp);
+
+void bgp_label_per_nexthop_free(struct bgp_label_per_nexthop_cache *blnc);
+
+struct bgp_label_per_nexthop_cache *
+bgp_label_per_nexthop_new(struct bgp_label_per_nexthop_cache_head *tree,
+                         struct prefix *nexthop);
+struct bgp_label_per_nexthop_cache *
+bgp_label_per_nexthop_find(struct bgp_label_per_nexthop_cache_head *tree,
+                          struct prefix *nexthop);
 #endif /* _FRR_BGP_LABELPOOL_H */

diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index f2ad51942fcf2e0249a8b636efd148f2f96ed65b..afca3df60a01dead3f9df05f726f8637dec4cae3 100644 (file)
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -3355,6 +3355,11 @@ static struct bgp *bgp_create(as_t *as, const char *name,
                SET_FLAG(bgp->af_flags[afi][SAFI_MPLS_VPN],
                         BGP_VPNVX_RETAIN_ROUTE_TARGET_ALL);
        }
+
+       for (afi = AFI_IP; afi < AFI_MAX; afi++)
+               bgp_label_per_nexthop_cache_init(
+                       &bgp->mpls_labels_per_nexthop[afi]);
+
        if (name)
                bgp->name = XSTRDUP(MTYPE_BGP, name);
 

diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index 3e1de5afc8bfd7f160d2cb9815e8f97f8f7bfddb..68b32b59458fb9f8913a32a729e29a1e44213204 100644 (file)
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -574,6 +574,10 @@ struct bgp {
        /* Allocate MPLS labels */
        uint8_t allocate_mpls_labels[AFI_MAX][SAFI_MAX];
 
+       /* Tree for next-hop lookup cache. */
+       struct bgp_label_per_nexthop_cache_head
+               mpls_labels_per_nexthop[AFI_MAX];
+
        /* Allocate hash entries to store policy routing information
         * The hash are used to host pbr rules somewhere.
         * Actually, pbr will only be used by flowspec