fabricd: add field with first and second nexthop to SPF paths

OpenFabric requires knowledge of the first two hops on each path
calculated by spf to implement its flooding optimization. Extend the
hopcount-spf to build such a datastructure.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>

diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index 79b3103237de6237c6205564706cde22392dd749..225ef22ec10a25678cefd4e6431fdf7db8dbf8c6 100644 (file)
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -179,7 +179,8 @@ static const char *vid2string(struct isis_vertex *vertex, char *buff, int size)
        return "UNKNOWN";
 }
 
-static struct isis_vertex *isis_vertex_new(union isis_N *n,
+static struct isis_vertex *isis_vertex_new(struct isis_spftree *spftree,
+                                          union isis_N *n,
                                           enum vertextype vtype)
 {
        struct isis_vertex *vertex;
@@ -191,6 +192,12 @@ static struct isis_vertex *isis_vertex_new(union isis_N *n,
        vertex->Adj_N = list_new();
        vertex->parents = list_new();
 
+       if (spftree->hopcount_metric) {
+               vertex->firsthops = hash_create(isis_vertex_queue_hash_key,
+                                               isis_vertex_queue_hash_cmp,
+                                               NULL);
+       }
+
        return vertex;
 }
 
@@ -334,7 +341,7 @@ static struct isis_vertex *isis_spf_add_root(struct isis_spftree *spftree,
                zlog_warn("ISIS-Spf: could not find own l%d LSP!",
                          spftree->level);
 
-       vertex = isis_vertex_new(&n,
+       vertex = isis_vertex_new(spftree, &n,
                                 spftree->area->oldmetric
                                         ? VTYPE_NONPSEUDO_IS
                                         : VTYPE_NONPSEUDO_TE_IS);
@@ -350,6 +357,26 @@ static struct isis_vertex *isis_spf_add_root(struct isis_spftree *spftree,
        return vertex;
 }
 
+static void vertex_add_parent_firsthop(struct hash_backet *backet, void *arg)
+{
+       struct isis_vertex *vertex = arg;
+       struct isis_vertex *hop = backet->data;
+
+       hash_get(vertex->firsthops, hop, hash_alloc_intern);
+}
+
+static void vertex_update_firsthops(struct isis_vertex *vertex,
+                                   struct isis_vertex *parent)
+{
+       if (vertex->d_N <= 2)
+               hash_get(vertex->firsthops, vertex, hash_alloc_intern);
+
+       if (vertex->d_N < 2 || !parent)
+               return;
+
+       hash_iterate(parent->firsthops, vertex_add_parent_firsthop, vertex);
+}
+
 /*
  * Add a vertex to TENT sorted by cost and by vertextype on tie break situation
  */
@@ -368,7 +395,7 @@ static struct isis_vertex *isis_spf_add2tent(struct isis_spftree *spftree,
 
        assert(isis_find_vertex(&spftree->paths, id, vtype) == NULL);
        assert(isis_find_vertex(&spftree->tents, id, vtype) == NULL);
-       vertex = isis_vertex_new(id, vtype);
+       vertex = isis_vertex_new(spftree, id, vtype);
        vertex->d_N = cost;
        vertex->depth = depth;
 
@@ -376,6 +403,9 @@ static struct isis_vertex *isis_spf_add2tent(struct isis_spftree *spftree,
                listnode_add(vertex->parents, parent);
        }
 
+       if (spftree->hopcount_metric)
+               vertex_update_firsthops(vertex, parent);
+
        if (parent && parent->Adj_N && listcount(parent->Adj_N) > 0) {
                for (ALL_LIST_ELEMENTS_RO(parent->Adj_N, node, parent_adj))
                        listnode_add(vertex->Adj_N, parent_adj);
@@ -497,6 +527,8 @@ static void process_N(struct isis_spftree *spftree, enum vertextype vtype,
                                if (listnode_lookup(vertex->Adj_N, parent_adj)
                                    == NULL)
                                        listnode_add(vertex->Adj_N, parent_adj);
+                       if (spftree->hopcount_metric)
+                               vertex_update_firsthops(vertex, parent);
                        /*      2) */
                        if (listcount(vertex->Adj_N) > ISIS_MAX_PATH_SPLITS)
                                remove_excess_adjs(vertex->Adj_N);
@@ -1062,7 +1094,8 @@ struct isis_spftree *isis_run_hopcount_spf(struct isis_area *area,
                isis_spf_preload_tent(spftree, sysid, root);
        } else {
                isis_vertex_queue_insert(&spftree->tents, isis_vertex_new(
-                                        sysid, VTYPE_NONPSEUDO_TE_IS));
+                                        spftree, sysid,
+                                        VTYPE_NONPSEUDO_TE_IS));
        }
 
        isis_spf_loop(spftree, sysid);

diff --git a/isisd/isis_spf_private.h b/isisd/isis_spf_private.h
index 3cd6a005bee5a8467161e865fad82ae076b13adb..4478c7a997ecf12ab4bee30d44978801c3cf39a7 100644 (file)
--- a/isisd/isis_spf_private.h
+++ b/isisd/isis_spf_private.h
@@ -64,6 +64,7 @@ struct isis_vertex {
        uint16_t depth; /* The depth in the imaginary tree */
        struct list *Adj_N;    /* {Adj(N)} next hop or neighbor list */
        struct list *parents;  /* list of parents for ECMP */
+       struct hash *firsthops; /* first two hops to neighbor */
        uint64_t insert_counter;
 };
 
@@ -170,6 +171,11 @@ static void isis_vertex_del(struct isis_vertex *vertex)
 {
        list_delete_and_null(&vertex->Adj_N);
        list_delete_and_null(&vertex->parents);
+       if (vertex->firsthops) {
+               hash_clean(vertex->firsthops, NULL);
+               hash_free(vertex->firsthops);
+               vertex->firsthops = NULL;
+       }
 
        memset(vertex, 0, sizeof(struct isis_vertex));
        XFREE(MTYPE_ISIS_VERTEX, vertex);

diff --git a/tests/isisd/test_isis_vertex_queue.c b/tests/isisd/test_isis_vertex_queue.c
index 3e31b833511d2ded04ba55ce053d4ab5cfa6b3ad..96c215dcff4c67017f10b4292cebfd5c376c8c9c 100644 (file)
--- a/tests/isisd/test_isis_vertex_queue.c
+++ b/tests/isisd/test_isis_vertex_queue.c
@@ -16,6 +16,8 @@ static size_t vertex_count;
 
 static void setup_test_vertices(void)
 {
+       struct isis_spftree t = {
+       };
        union isis_N nid, nip = {
                .ip.dest.family = AF_UNSPEC
        };
@@ -25,33 +27,35 @@ static void setup_test_vertices(void)
        nip.ip.dest.family = AF_INET;
        nip.ip.dest.prefixlen = 24;
        inet_pton(AF_INET, "192.168.1.0", &nip.ip.dest.u.prefix4);
-       vertices[vertex_count] = isis_vertex_new(&nip, VTYPE_IPREACH_TE);
+       vertices[vertex_count] = isis_vertex_new(&t, &nip, VTYPE_IPREACH_TE);
        vertices[vertex_count]->d_N = 20;
        vertex_count++;
 
        nip.ip.dest.family = AF_INET;
        nip.ip.dest.prefixlen = 24;
        inet_pton(AF_INET, "192.168.2.0", &nip.ip.dest.u.prefix4);
-       vertices[vertex_count] = isis_vertex_new(&nip, VTYPE_IPREACH_TE);
+       vertices[vertex_count] = isis_vertex_new(&t, &nip, VTYPE_IPREACH_TE);
        vertices[vertex_count]->d_N = 20;
        vertex_count++;
 
        memset(nid.id, 0, sizeof(nid.id));
        nid.id[6] = 1;
-       vertices[vertex_count] = isis_vertex_new(&nid, VTYPE_PSEUDO_TE_IS);
+       vertices[vertex_count] = isis_vertex_new(&t, &nid,
+                                                VTYPE_PSEUDO_TE_IS);
        vertices[vertex_count]->d_N = 15;
        vertex_count++;
 
        memset(nid.id, 0, sizeof(nid.id));
        nid.id[5] = 2;
-       vertices[vertex_count] = isis_vertex_new(&nid, VTYPE_NONPSEUDO_TE_IS);
+       vertices[vertex_count] = isis_vertex_new(&t, &nid,
+                                                VTYPE_NONPSEUDO_TE_IS);
        vertices[vertex_count]->d_N = 15;
        vertex_count++;
 
        nip.ip.dest.family = AF_INET;
        nip.ip.dest.prefixlen = 24;
        inet_pton(AF_INET, "192.168.3.0", &nip.ip.dest.u.prefix4);
-       vertices[vertex_count] = isis_vertex_new(&nip, VTYPE_IPREACH_TE);
+       vertices[vertex_count] = isis_vertex_new(&t, &nip, VTYPE_IPREACH_TE);
        vertices[vertex_count]->d_N = 20;
        vertex_count++;
 };