pimd: Update nexthops when lookup mode changes

Link up the RPF lookup mode changing to a force update to RP's and upstreams registered for nexthop lookup cache updates. Signed-off-by: Nathan Bahr <[email protected]>
FRRouting · Oct 27, 2024 · 5c606a4 · 5c606a4
1 parent 4585f61
commit 5c606a4
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Showing 3 changed files with 48 additions and 5 deletions.
diff --git a/pimd/pim_nb_config.c b/pimd/pim_nb_config.c
@@ -1681,6 +1681,7 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_mc
 	struct vrf *vrf;
 	struct pim_instance *pim;
 	const char *mode;
+	enum pim_rpf_lookup_mode old_mode;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
@@ -1692,9 +1693,8 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_mc
 		pim = vrf->info;
 		mode = yang_dnode_get_string(args->dnode, NULL);
 
-		if (strmatch(mode, "none"))
-			pim->rpf_mode = MCAST_NO_CONFIG;
-		else if (strmatch(mode, "urib-only"))
+		old_mode = pim->rpf_mode;
+		if (strmatch(mode, "urib-only"))
 			pim->rpf_mode = MCAST_URIB_ONLY;
 		else if (strmatch(mode, "mrib-only"))
 			pim->rpf_mode = MCAST_MRIB_ONLY;
@@ -1710,7 +1710,12 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_mc
 			return CMD_WARNING_CONFIG_FAILED;
 		}
 
-		/* TODO: Signal to redo lookups? */
+		if (pim->rpf_mode != old_mode &&
+		    /* MCAST_MIX_MRIB_FIRST is the default if not configured */
+		    (old_mode != MCAST_NO_CONFIG && pim->rpf_mode != MCAST_MIX_MRIB_FIRST)) {
+			pim_nht_mode_changed(pim);
+		}
+
 		break;
 	}
 
@@ -1722,6 +1727,7 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_mc
 {
 	struct vrf *vrf;
 	struct pim_instance *pim;
+	enum pim_rpf_lookup_mode old_mode;
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
@@ -1731,8 +1737,12 @@ int routing_control_plane_protocols_control_plane_protocol_pim_address_family_mc
 	case NB_EV_APPLY:
 		vrf = nb_running_get_entry(args->dnode, NULL, true);
 		pim = vrf->info;
+		old_mode = pim->rpf_mode;
 		pim->rpf_mode = MCAST_NO_CONFIG;
-		/* TODO: Signal to redo lookups? */
+		/* MCAST_MIX_MRIB_FIRST is the default if not configured */
+		if (old_mode != MCAST_NO_CONFIG && old_mode != MCAST_MIX_MRIB_FIRST) {
+			pim_nht_mode_changed(pim);
+		}
 		break;
 	}
 

diff --git a/pimd/pim_nht.c b/pimd/pim_nht.c
@@ -1327,6 +1327,36 @@ void pim_nexthop_update(struct vrf *vrf, struct prefix *match, struct zapi_route
 		pim_nht_crp_update(pim, pnc);
 }
 
+static int pim_nht_hash_mode_update_helper(struct hash_bucket *bucket, void *arg)
+{
+	struct pim_nexthop_cache *pnc = bucket->data;
+	struct pnc_hash_walk_data *pwd = arg;
+	struct pim_instance *pim = pwd->pim;
+
+	if (listcount(pnc->rp_list))
+		pim_update_rp_nh(pim, pnc);
+
+	if (pnc->upstream_hash->count)
+		pim_update_upstream_nh(pim, pnc);
+
+	if (pnc->candrp_count)
+		pim_nht_crp_update(pim, pnc);
+
+	return HASHWALK_CONTINUE;
+}
+
+void pim_nht_mode_changed(struct pim_instance *pim)
+{
+	struct pnc_hash_walk_data pwd;
+
+	/* Update the refresh time to force new lookups if needed */
+	pim_rpf_set_refresh_time(pim);
+
+	/* Force update the registered RP and upstreams for all cache entries */
+	pwd.pim = pim;
+	hash_walk(pim->nht_hash, pim_nht_hash_mode_update_helper, &pwd);
+}
+
 /* Cleanup pim->nht_hash each node data */
 static void pim_nht_hash_clean(void *data)
 {

diff --git a/pimd/pim_nht.h b/pimd/pim_nht.h
@@ -117,6 +117,9 @@ int pim_nht_lookup_ecmp_if_vif_index(struct pim_instance *pim, pim_addr src, str
 /* Tracked nexthop update from zebra */
 void pim_nexthop_update(struct vrf *vrf, struct prefix *match, struct zapi_route *nhr);
 
+/* RPF lookup mode changed via configuration */
+void pim_nht_mode_changed(struct pim_instance *pim);
+
 /* NHT init and finish funcitons */
 void pim_nht_init(struct pim_instance *pim);
 void pim_nht_terminate(struct pim_instance *pim);