Merge pull request #12650 from isabelladeleon12/advertise_high_metrics

isisd: Add support for advertise-high-metrics
FRRouting · Mar 2, 2023 · 15424f5 · 15424f5
2 parents 48cdfc1 + 102a6e2
commit 15424f5
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diff --git a/doc/user/isisd.rst b/doc/user/isisd.rst
@@ -79,6 +79,12 @@ writing, *isisd* does not support multiple ISIS processes.
    - wide
      Use new style of TLVs to carry wider metric. FRR uses this as a default value
 
+.. clicmd:: advertise-high-metrics
+
+   Advertise high metric value on all interfaces to gracefully shift traffic off the router. Reference: :rfc:`3277`
+
+   For narrow metrics, the high metric value is 63; for wide metrics, 16777215; for transition metrics, 62.
+
 .. clicmd:: set-overload-bit
 
    Set overload bit to avoid any transit traffic.

diff --git a/isisd/isis_circuit.c b/isisd/isis_circuit.c
@@ -1499,6 +1499,10 @@ ferr_r isis_circuit_metric_set(struct isis_circuit *circuit, int level,
 		return ferr_cfg_invalid("metric %d too large for narrow metric",
 					metric);
 
+	/* Don't modify metric if advertise high metrics is configured */
+	if (circuit->area && circuit->area->advertise_high_metrics)
+		return ferr_ok();
+
 	/* inform ldp-sync of metric change
          *   if ldp-sync is running need to save metric
          *   and restore new values after ldp-sync completion.

diff --git a/isisd/isis_cli.c b/isisd/isis_cli.c
@@ -439,6 +439,29 @@ void cli_show_isis_overload_on_startup(struct vty *vty,
 		yang_dnode_get_string(dnode, NULL));
 }
 
+/*
+ * XPath: /frr-isisd:isis/instance/advertise-high-metrics
+ */
+DEFPY_YANG(advertise_high_metrics, advertise_high_metrics_cmd,
+	   "[no] advertise-high-metrics",
+	   NO_STR "Advertise high metric value on all interfaces\n")
+{
+	nb_cli_enqueue_change(vty, "./advertise-high-metrics", NB_OP_MODIFY,
+			      no ? "false" : "true");
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_advertise_high_metrics(struct vty *vty,
+				     const struct lyd_node *dnode,
+				     bool show_defaults)
+{
+	if (yang_dnode_get_bool(dnode, NULL))
+		vty_out(vty, " advertise-high-metrics\n");
+	else if (show_defaults)
+		vty_out(vty, " no advertise-high-metrics\n");
+}
+
 /*
  * XPath: /frr-isisd:isis/instance/attach-send
  */
@@ -3160,6 +3183,8 @@ void isis_cli_init(void)
 	install_element(ISIS_NODE, &metric_style_cmd);
 	install_element(ISIS_NODE, &no_metric_style_cmd);
 
+	install_element(ISIS_NODE, &advertise_high_metrics_cmd);
+
 	install_element(ISIS_NODE, &area_passwd_cmd);
 	install_element(ISIS_NODE, &domain_passwd_cmd);
 	install_element(ISIS_NODE, &no_area_passwd_cmd);

diff --git a/isisd/isis_nb.c b/isisd/isis_nb.c
@@ -81,6 +81,13 @@ const struct frr_yang_module_info frr_isisd_info = {
 				.modify = isis_instance_overload_on_startup_modify,
 			}
 		},
+		{
+			.xpath = "/frr-isisd:isis/instance/advertise-high-metrics",
+			.cbs = {
+				.cli_show = cli_show_advertise_high_metrics,
+				.modify = isis_instance_advertise_high_metrics_modify,
+			}
+		},
 		{
 			.xpath = "/frr-isisd:isis/instance/metric-style",
 			.cbs = {

diff --git a/isisd/isis_nb.h b/isisd/isis_nb.h
@@ -26,6 +26,7 @@ int isis_instance_attached_receive_modify(struct nb_cb_modify_args *args);
 int isis_instance_attached_modify(struct nb_cb_modify_args *args);
 int isis_instance_overload_enabled_modify(struct nb_cb_modify_args *args);
 int isis_instance_overload_on_startup_modify(struct nb_cb_modify_args *args);
+int isis_instance_advertise_high_metrics_modify(struct nb_cb_modify_args *args);
 int isis_instance_metric_style_modify(struct nb_cb_modify_args *args);
 int isis_instance_purge_originator_modify(struct nb_cb_modify_args *args);
 int isis_instance_lsp_mtu_modify(struct nb_cb_modify_args *args);
@@ -464,6 +465,9 @@ void cli_show_isis_overload(struct vty *vty, const struct lyd_node *dnode,
 void cli_show_isis_overload_on_startup(struct vty *vty,
 				       const struct lyd_node *dnode,
 				       bool show_defaults);
+void cli_show_advertise_high_metrics(struct vty *vty,
+				     const struct lyd_node *dnode,
+				     bool show_defaults);
 void cli_show_isis_metric_style(struct vty *vty, const struct lyd_node *dnode,
 				bool show_defaults);
 void cli_show_isis_area_pwd(struct vty *vty, const struct lyd_node *dnode,

diff --git a/isisd/isis_nb_config.c b/isisd/isis_nb_config.c
@@ -360,6 +360,24 @@ int isis_instance_overload_on_startup_modify(struct nb_cb_modify_args *args)
 	return NB_OK;
 }
 
+/*
+ * XPath: /frr-isisd:isis/instance/advertise-high-metrics
+ */
+int isis_instance_advertise_high_metrics_modify(struct nb_cb_modify_args *args)
+{
+	struct isis_area *area;
+	bool advertise_high_metrics;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	advertise_high_metrics = yang_dnode_get_bool(args->dnode, NULL);
+	area = nb_running_get_entry(args->dnode, NULL, true);
+	isis_area_advertise_high_metrics_set(area, advertise_high_metrics);
+
+	return NB_OK;
+}
+
 /*
  * XPath: /frr-isisd:isis/instance/metric-style
  */

diff --git a/isisd/isisd.c b/isisd/isisd.c
@@ -2503,6 +2503,9 @@ static void common_isis_summary_vty(struct vty *vty, struct isis *isis)
 		vty_out(vty, "  RX counters per PDU type:\n");
 		pdu_counter_print(vty, "    ", area->pdu_rx_counters);
 
+		vty_out(vty, "  Advertise high metrics: %s\n",
+			area->advertise_high_metrics ? "Enabled" : "Disabled");
+
 		for (level = ISIS_LEVEL1; level <= ISIS_LEVELS; level++) {
 			if ((area->is_type & level) == 0)
 				continue;
@@ -3247,6 +3250,58 @@ void config_end_lsp_generate(struct isis_area *area)
 	}
 }
 
+void isis_area_advertise_high_metrics_set(struct isis_area *area,
+					  bool advertise_high_metrics)
+{
+	struct listnode *node;
+	struct isis_circuit *circuit;
+	int max_metric;
+	char xpath[XPATH_MAXLEN];
+	struct lyd_node *dnode;
+	int configured_metric_l1;
+	int configured_metric_l2;
+
+	if (area->advertise_high_metrics == advertise_high_metrics)
+		return;
+
+	if (advertise_high_metrics) {
+		if (area->oldmetric && area->newmetric)
+			max_metric = ISIS_NARROW_METRIC_INFINITY;
+		else if (area->newmetric)
+			max_metric = MAX_WIDE_LINK_METRIC;
+		else
+			max_metric = MAX_NARROW_LINK_METRIC;
+
+		for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
+			isis_circuit_metric_set(circuit, IS_LEVEL_1,
+						max_metric);
+			isis_circuit_metric_set(circuit, IS_LEVEL_2,
+						max_metric);
+		}
+
+		area->advertise_high_metrics = true;
+	} else {
+		area->advertise_high_metrics = false;
+		for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
+			/* Get configured metric */
+			snprintf(xpath, XPATH_MAXLEN,
+				 "/frr-interface:lib/interface[name='%s']",
+				 circuit->interface->name);
+			dnode = yang_dnode_get(running_config->dnode, xpath);
+
+			configured_metric_l1 = yang_dnode_get_uint32(
+				dnode, "./frr-isisd:isis/metric/level-1");
+			configured_metric_l2 = yang_dnode_get_uint32(
+				dnode, "./frr-isisd:isis/metric/level-2");
+
+			isis_circuit_metric_set(circuit, IS_LEVEL_1,
+						configured_metric_l1);
+			isis_circuit_metric_set(circuit, IS_LEVEL_2,
+						configured_metric_l2);
+		}
+	}
+}
+
 /*
  * Returns the path of the file (non-volatile memory) that contains restart
  * information.

diff --git a/isisd/isisd.h b/isisd/isisd.h
@@ -175,6 +175,8 @@ struct isis_area {
 	uint32_t overload_on_startup_time;
 	/* advertise prefixes of passive interfaces only? */
 	bool advertise_passive_only;
+	/* Are we advertising high metrics? */
+	bool advertise_high_metrics;
 	/* L1/L2 router identifier for inter-area traffic */
 	char attached_bit_send;
 	char attached_bit_rcv_ignore;
@@ -289,6 +291,8 @@ void isis_area_switchover_routes(struct isis_area *area, int family,
 void isis_area_overload_bit_set(struct isis_area *area, bool overload_bit);
 void isis_area_overload_on_startup_set(struct isis_area *area,
 				       uint32_t startup_time);
+void isis_area_advertise_high_metrics_set(struct isis_area *area,
+					  bool advertise_high_metrics);
 void isis_area_attached_bit_send_set(struct isis_area *area, bool attached_bit);
 void isis_area_attached_bit_receive_set(struct isis_area *area,
 					bool attached_bit);

diff --git a/tests/topotests/isis_advertise_high_metrics/__init__.py b/tests/topotests/isis_advertise_high_metrics/__init__.py
diff --git a/tests/topotests/isis_advertise_high_metrics/r1/isisd.conf b/tests/topotests/isis_advertise_high_metrics/r1/isisd.conf
@@ -0,0 +1,19 @@
+hostname r1
+! debug isis adj-packets
+! debug isis events
+! debug isis update-packets
+interface eth-r2
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis network point-to-point
+!
+interface eth-r3
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis metric 20
+ isis network point-to-point
+!
+router isis 1
+ is-type level-2-only
+ net 10.0000.0000.0000.0000.0000.0000.0000.0000.0000.00
+!
diff --git a/tests/topotests/isis_advertise_high_metrics/r1/zebra.conf b/tests/topotests/isis_advertise_high_metrics/r1/zebra.conf
@@ -0,0 +1,5 @@
+interface eth-r2
+  ip address 192.168.1.0/31
+
+interface eth-r3
+  ip address 192.168.1.2/31
diff --git a/tests/topotests/isis_advertise_high_metrics/r2/isisd.conf b/tests/topotests/isis_advertise_high_metrics/r2/isisd.conf
@@ -0,0 +1,18 @@
+hostname r2
+! debug isis adj-packets
+! debug isis events
+! debug isis update-packets
+interface eth-r1
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis network point-to-point
+!
+interface eth-r4
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis network point-to-point
+!
+router isis 1
+ is-type level-2-only
+ net 10.0000.0000.0000.0000.0000.0000.0000.0000.0001.00
+!
diff --git a/tests/topotests/isis_advertise_high_metrics/r2/zebra.conf b/tests/topotests/isis_advertise_high_metrics/r2/zebra.conf
@@ -0,0 +1,5 @@
+interface eth-r1
+  ip address 192.168.1.1/31
+
+interface eth-r4
+  ip address 192.168.1.7/31
diff --git a/tests/topotests/isis_advertise_high_metrics/r3/isisd.conf b/tests/topotests/isis_advertise_high_metrics/r3/isisd.conf
@@ -0,0 +1,20 @@
+hostname r3
+! debug isis adj-packets
+! debug isis events
+! debug isis update-packets
+interface eth-r1
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis metric 20
+ isis network point-to-point
+!
+interface eth-r4
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis metric 20
+ isis network point-to-point
+!
+router isis 1
+ is-type level-2-only
+ net 10.0000.0000.0000.0000.0000.0000.0000.0000.0002.00
+!
diff --git a/tests/topotests/isis_advertise_high_metrics/r3/zebra.conf b/tests/topotests/isis_advertise_high_metrics/r3/zebra.conf
@@ -0,0 +1,5 @@
+interface eth-r1
+  ip address 192.168.1.3/31
+
+interface eth-r4
+  ip address 192.168.1.4/31
diff --git a/tests/topotests/isis_advertise_high_metrics/r4/isisd.conf b/tests/topotests/isis_advertise_high_metrics/r4/isisd.conf
@@ -0,0 +1,19 @@
+hostname r4
+! debug isis adj-packets
+! debug isis events
+! debug isis update-packets
+interface eth-r2
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis network point-to-point
+!
+interface eth-r3
+ ip router isis 1
+ isis circuit-type level-2-only
+ isis metric 20
+ isis network point-to-point
+!
+router isis 1
+ is-type level-2-only
+ net 10.0000.0000.0000.0000.0000.0000.0000.0000.0003.00
+!
diff --git a/tests/topotests/isis_advertise_high_metrics/r4/zebra.conf b/tests/topotests/isis_advertise_high_metrics/r4/zebra.conf
@@ -0,0 +1,5 @@
+interface eth-r2
+  ip address 192.168.1.6/31
+
+interface eth-r3
+  ip address 192.168.1.5/31