ripd: support BFD integration

Implement RIP peer monitoring with BFD.

RFC 5882 Generic Application of Bidirectional Forwarding Detection
(BFD), Section 10.3 Interactions with RIP.

Co-authored-by: Renato Westphal <renato@opensourcerouting.org>
Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

13 files changed, 549 insertions, 38 deletions

diff --git a/ripd/rip_bfd.c b/ripd/rip_bfd.c
new file mode 100644
index 000000000..ac5035f54
--- /dev/null
+++ b/ripd/rip_bfd.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RIP BFD integration.
+ * Copyright (C) 2021-2023 Network Device Education Foundation, Inc. ("NetDEF")
+ */
+
+#include <zebra.h>
+
+#include "lib/zclient.h"
+#include "lib/bfd.h"
+
+#include "ripd/ripd.h"
+#include "ripd/rip_bfd.h"
+#include "ripd/rip_debug.h"
+
+extern struct zclient *zclient;
+
+static const char *rip_bfd_interface_profile(struct rip_interface *ri)
+{
+	struct rip *rip = ri->rip;
+
+	if (ri->bfd.profile)
+		return ri->bfd.profile;
+
+	if (rip->default_bfd_profile)
+		return rip->default_bfd_profile;
+
+	return NULL;
+}
+
+static void rip_bfd_session_change(struct bfd_session_params *bsp,
+				   const struct bfd_session_status *bss,
+				   void *arg)
+{
+	struct rip_peer *rp = arg;
+
+	/* BFD peer went down. */
+	if (bss->state == BFD_STATUS_DOWN &&
+	    bss->previous_state == BFD_STATUS_UP) {
+		if (IS_RIP_DEBUG_EVENT)
+			zlog_debug("%s: peer %pI4: BFD Down", __func__,
+				   &rp->addr);
+
+		rip_peer_delete_routes(rp);
+		listnode_delete(rp->rip->peer_list, rp);
+		rip_peer_free(rp);
+		return;
+	}
+
+	/* BFD peer went up. */
+	if (bss->state == BSS_UP && bss->previous_state == BSS_DOWN)
+		if (IS_RIP_DEBUG_EVENT)
+			zlog_debug("%s: peer %pI4: BFD Up", __func__,
+				   &rp->addr);
+}
+
+void rip_bfd_session_update(struct rip_peer *rp)
+{
+	struct rip_interface *ri = rp->ri;
+
+	/* BFD configuration was removed. */
+	if (ri == NULL || !ri->bfd.enabled) {
+		bfd_sess_free(&rp->bfd_session);
+		return;
+	}
+
+	/* New BFD session. */
+	if (rp->bfd_session == NULL) {
+		rp->bfd_session = bfd_sess_new(rip_bfd_session_change, rp);
+		bfd_sess_set_ipv4_addrs(rp->bfd_session, NULL, &rp->addr);
+		bfd_sess_set_interface(rp->bfd_session, ri->ifp->name);
+		bfd_sess_set_vrf(rp->bfd_session, rp->rip->vrf->vrf_id);
+	}
+
+	/* Set new configuration. */
+	bfd_sess_set_timers(rp->bfd_session, BFD_DEF_DETECT_MULT,
+			    BFD_DEF_MIN_RX, BFD_DEF_MIN_TX);
+	bfd_sess_set_profile(rp->bfd_session, rip_bfd_interface_profile(ri));
+
+	bfd_sess_install(rp->bfd_session);
+}
+
+void rip_bfd_interface_update(struct rip_interface *ri)
+{
+	struct rip *rip;
+	struct rip_peer *rp;
+	struct listnode *node;
+
+	rip = ri->rip;
+	if (!rip)
+		return;
+
+	for (ALL_LIST_ELEMENTS_RO(rip->peer_list, node, rp)) {
+		if (rp->ri != ri)
+			continue;
+
+		rip_bfd_session_update(rp);
+	}
+}
+
+void rip_bfd_instance_update(struct rip *rip)
+{
+	struct interface *ifp;
+
+	FOR_ALL_INTERFACES (rip->vrf, ifp) {
+		struct rip_interface *ri;
+
+		ri = ifp->info;
+		if (!ri)
+			continue;
+
+		rip_bfd_interface_update(ri);
+	}
+}
+
+void rip_bfd_init(struct event_loop *tm)
+{
+	bfd_protocol_integration_init(zclient, tm);
+}
diff --git a/ripd/rip_bfd.h b/ripd/rip_bfd.h
new file mode 100644
index 000000000..d49ca1515
--- /dev/null
+++ b/ripd/rip_bfd.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RIP BFD integration.
+ * Copyright (C) 2021-2023 Network Device Education Foundation, Inc. ("NetDEF")
+ */
+
+#ifndef _RIP_BFD_
+#define _RIP_BFD_
+
+#include "frrevent.h"
+
+struct rip;
+struct rip_interface;
+struct rip_peer;
+
+void rip_bfd_session_update(struct rip_peer *rp);
+void rip_bfd_interface_update(struct rip_interface *ri);
+void rip_bfd_instance_update(struct rip *rip);
+void rip_bfd_init(struct event_loop *tm);
+
+#endif /* _RIP_BFD_ */
diff --git a/ripd/rip_cli.c b/ripd/rip_cli.c
index cac29c00d..ac9fc4b1a 100644
--- a/ripd/rip_cli.c
+++ b/ripd/rip_cli.c
@@ -582,6 +582,42 @@ void cli_show_rip_version(struct vty *vty, const struct lyd_node *dnode,
 }
 
 /*
+ * XPath: /frr-ripd:ripd/instance/default-bfd-profile
+ */
+DEFPY_YANG(rip_bfd_default_profile, rip_bfd_default_profile_cmd,
+	   "bfd default-profile BFDPROF$profile",
+	   "Bidirectional Forwarding Detection\n"
+	   "BFD default profile\n"
+	   "Profile name\n")
+{
+	nb_cli_enqueue_change(vty, "./default-bfd-profile", NB_OP_MODIFY,
+			      profile);
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+DEFPY_YANG(no_rip_bfd_default_profile, no_rip_bfd_default_profile_cmd,
+	   "no bfd default-profile [BFDPROF]",
+	   NO_STR
+	   "Bidirectional Forwarding Detection\n"
+	   "BFD default profile\n"
+	   "Profile name\n")
+{
+	nb_cli_enqueue_change(vty, "./default-bfd-profile", NB_OP_DESTROY,
+			      NULL);
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_ripd_instance_default_bfd_profile(struct vty *vty,
+						const struct lyd_node *dnode,
+						bool show_defaults)
+{
+	vty_out(vty, " bfd default-profile %s\n",
+		yang_dnode_get_string(dnode, NULL));
+}
+
+/*
  * XPath: /frr-interface:lib/interface/frr-ripd:rip/split-horizon
  */
 DEFPY_YANG (ip_rip_split_horizon,
@@ -980,6 +1016,66 @@ void cli_show_ip_rip_authentication_key_chain(struct vty *vty,
 }
 
 /*
+ * XPath: /frr-interface:lib/interface/frr-ripd:rip/bfd-monitoring/enable
+ */
+DEFPY_YANG(ip_rip_bfd, ip_rip_bfd_cmd, "[no] ip rip bfd",
+	   NO_STR IP_STR
+	   "Routing Information Protocol\n"
+	   "Enable BFD support\n")
+{
+	nb_cli_enqueue_change(vty, "./bfd-monitoring/enable", NB_OP_MODIFY,
+			      no ? "false" : "true");
+
+	return nb_cli_apply_changes(vty, "./frr-ripd:rip");
+}
+
+void cli_show_ip_rip_bfd_enable(struct vty *vty, const struct lyd_node *dnode,
+				bool show_defaults)
+{
+	vty_out(vty, " ip rip bfd\n");
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-ripd:rip/bfd/profile
+ */
+DEFPY_YANG(ip_rip_bfd_profile, ip_rip_bfd_profile_cmd,
+	   "[no] ip rip bfd profile BFDPROF$profile",
+	   NO_STR IP_STR
+	   "Routing Information Protocol\n"
+	   "Enable BFD support\n"
+	   "Use a pre-configured profile\n"
+	   "Profile name\n")
+{
+	if (no)
+		nb_cli_enqueue_change(vty, "./bfd-monitoring/profile",
+				      NB_OP_DESTROY, NULL);
+	else
+		nb_cli_enqueue_change(vty, "./bfd-monitoring/profile",
+				      NB_OP_MODIFY, profile);
+
+	return nb_cli_apply_changes(vty, "./frr-ripd:rip");
+}
+
+DEFPY_YANG(no_ip_rip_bfd_profile, no_ip_rip_bfd_profile_cmd,
+	   "no ip rip bfd profile",
+	   NO_STR IP_STR
+	   "Routing Information Protocol\n"
+	   "Enable BFD support\n"
+	   "Use a pre-configured profile\n")
+{
+	nb_cli_enqueue_change(vty, "./bfd-monitoring/profile", NB_OP_DESTROY,
+			      NULL);
+	return nb_cli_apply_changes(vty, "./frr-ripd:rip");
+}
+
+void cli_show_ip_rip_bfd_profile(struct vty *vty, const struct lyd_node *dnode,
+				 bool show_defaults)
+{
+	vty_out(vty, " ip rip bfd profile %s\n",
+		yang_dnode_get_string(dnode, NULL));
+}
+
+/*
  * XPath: /frr-ripd:clear-rip-route
  */
 DEFPY_YANG (clear_ip_rip,
@@ -1078,6 +1174,8 @@ void rip_cli_init(void)
 	install_element(RIP_NODE, &no_rip_timers_cmd);
 	install_element(RIP_NODE, &rip_version_cmd);
 	install_element(RIP_NODE, &no_rip_version_cmd);
+	install_element(RIP_NODE, &rip_bfd_default_profile_cmd);
+	install_element(RIP_NODE, &no_rip_bfd_default_profile_cmd);
 
 	install_element(INTERFACE_NODE, &ip_rip_split_horizon_cmd);
 	install_element(INTERFACE_NODE, &ip_rip_v2_broadcast_cmd);
@@ -1092,6 +1190,9 @@ void rip_cli_init(void)
 	install_element(INTERFACE_NODE, &ip_rip_authentication_key_chain_cmd);
 	install_element(INTERFACE_NODE,
 			&no_ip_rip_authentication_key_chain_cmd);
+	install_element(INTERFACE_NODE, &ip_rip_bfd_cmd);
+	install_element(INTERFACE_NODE, &ip_rip_bfd_profile_cmd);
+	install_element(INTERFACE_NODE, &no_ip_rip_bfd_profile_cmd);
 
 	install_element(ENABLE_NODE, &clear_ip_rip_cmd);
 }
diff --git a/ripd/rip_interface.c b/ripd/rip_interface.c
index 0b92f174b..b383be042 100644
--- a/ripd/rip_interface.c
+++ b/ripd/rip_interface.c
@@ -457,6 +457,7 @@ static void rip_interface_reset(struct rip_interface *ri)
 	ri->sent_updates = 0;
 
 	ri->passive = 0;
+	XFREE(MTYPE_TMP, ri->bfd.profile);
 
 	rip_interface_clean(ri);
 }
@@ -1109,6 +1110,7 @@ void rip_interface_sync(struct interface *ifp)
 	struct rip_interface *ri;
 
 	ri = ifp->info;
+	ri->ifp = ifp;
 	if (ri)
 		ri->rip = ifp->vrf->info;
 }
diff --git a/ripd/rip_main.c b/ripd/rip_main.c
index a6e4ad776..0e26662cd 100644
--- a/ripd/rip_main.c
+++ b/ripd/rip_main.c
@@ -21,8 +21,10 @@
 #include "if_rmap.h"
 #include "libfrr.h"
 #include "routemap.h"
+#include "bfd.h"
 
 #include "ripd/ripd.h"
+#include "ripd/rip_bfd.h"
 #include "ripd/rip_nb.h"
 #include "ripd/rip_errors.h"
 
@@ -65,6 +67,7 @@ static void sigint(void)
 {
 	zlog_notice("Terminating on signal");
 
+	bfd_protocol_integration_set_shutdown(true);
 	rip_vrf_terminate();
 	if_rmap_terminate();
 	rip_zclient_stop();
@@ -162,6 +165,7 @@ int main(int argc, char **argv)
 	rip_if_init();
 	rip_cli_init();
 	rip_zclient_init(master);
+	rip_bfd_init(master);
 
 	frr_config_fork();
 	frr_run(master);
diff --git a/ripd/rip_nb.c b/ripd/rip_nb.c
index fa6652faf..d11f1e1d3 100644
--- a/ripd/rip_nb.c
+++ b/ripd/rip_nb.c
@@ -240,6 +240,14 @@ const struct frr_yang_module_info frr_ripd_info = {
 			},
 		},
 		{
+			.xpath = "/frr-ripd:ripd/instance/default-bfd-profile",
+			.cbs = {
+				.modify = ripd_instance_default_bfd_profile_modify,
+				.destroy = ripd_instance_default_bfd_profile_destroy,
+				.cli_show = cli_show_ripd_instance_default_bfd_profile,
+			},
+		},
+		{
 			.xpath = "/frr-interface:lib/interface/frr-ripd:rip/split-horizon",
 			.cbs = {
 				.cli_show = cli_show_ip_rip_split_horizon,
@@ -303,6 +311,28 @@ const struct frr_yang_module_info frr_ripd_info = {
 			},
 		},
 		{
+			.xpath = "/frr-interface:lib/interface/frr-ripd:rip/bfd-monitoring",
+			.cbs = {
+				.create = lib_interface_rip_bfd_create,
+				.destroy = lib_interface_rip_bfd_destroy,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-ripd:rip/bfd-monitoring/enable",
+			.cbs = {
+				.cli_show = cli_show_ip_rip_bfd_enable,
+				.modify = lib_interface_rip_bfd_enable_modify,
+			},
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/frr-ripd:rip/bfd-monitoring/profile",
+			.cbs = {
+				.cli_show = cli_show_ip_rip_bfd_profile,
+				.modify = lib_interface_rip_bfd_profile_modify,
+				.destroy = lib_interface_rip_bfd_profile_destroy,
+			},
+		},
+		{
 			.xpath = "/frr-ripd:ripd/instance/state/neighbors/neighbor",
 			.cbs = {
 				.get_keys = ripd_instance_state_neighbors_neighbor_get_keys,
diff --git a/ripd/rip_nb.h b/ripd/rip_nb.h
index ebc60fefb..9929e0952 100644
--- a/ripd/rip_nb.h
+++ b/ripd/rip_nb.h
@@ -72,6 +72,8 @@ int ripd_instance_timers_holddown_interval_modify(
 int ripd_instance_timers_update_interval_modify(struct nb_cb_modify_args *args);
 int ripd_instance_version_receive_modify(struct nb_cb_modify_args *args);
 int ripd_instance_version_send_modify(struct nb_cb_modify_args *args);
+int ripd_instance_default_bfd_profile_modify(struct nb_cb_modify_args *args);
+int ripd_instance_default_bfd_profile_destroy(struct nb_cb_destroy_args *args);
 const void *ripd_instance_state_neighbors_neighbor_get_next(
 	struct nb_cb_get_next_args *args);
 int ripd_instance_state_neighbors_neighbor_get_keys(
@@ -151,6 +153,12 @@ int lib_interface_rip_authentication_key_chain_modify(
 	struct nb_cb_modify_args *args);
 int lib_interface_rip_authentication_key_chain_destroy(
 	struct nb_cb_destroy_args *args);
+int lib_interface_rip_bfd_create(struct nb_cb_create_args *args);
+int lib_interface_rip_bfd_destroy(struct nb_cb_destroy_args *args);
+int lib_interface_rip_bfd_enable_modify(struct nb_cb_modify_args *args);
+int lib_interface_rip_bfd_enable_destroy(struct nb_cb_destroy_args *args);
+int lib_interface_rip_bfd_profile_modify(struct nb_cb_modify_args *args);
+int lib_interface_rip_bfd_profile_destroy(struct nb_cb_destroy_args *args);
 
 /* Optional 'apply_finish' callbacks. */
 void ripd_instance_redistribute_apply_finish(
@@ -206,6 +214,9 @@ void cli_show_ip_rip_receive_version(struct vty *vty,
 				     bool show_defaults);
 void cli_show_ip_rip_send_version(struct vty *vty, const struct lyd_node *dnode,
 				  bool show_defaults);
+void cli_show_ripd_instance_default_bfd_profile(struct vty *vty,
+						const struct lyd_node *dnode,
+						bool show_defaults);
 void cli_show_ip_rip_authentication_scheme(struct vty *vty,
 					   const struct lyd_node *dnode,
 					   bool show_defaults);
@@ -215,6 +226,10 @@ void cli_show_ip_rip_authentication_string(struct vty *vty,
 void cli_show_ip_rip_authentication_key_chain(struct vty *vty,
 					      const struct lyd_node *dnode,
 					      bool show_defaults);
+void cli_show_ip_rip_bfd_enable(struct vty *vty, const struct lyd_node *dnode,
+				bool show_defaults);
+void cli_show_ip_rip_bfd_profile(struct vty *vty, const struct lyd_node *dnode,
+				 bool show_defaults);
 
 /* Notifications. */
 extern void ripd_notif_send_auth_type_failure(const char *ifname);
diff --git a/ripd/rip_nb_config.c b/ripd/rip_nb_config.c
index 343bb9bb5..cbc62f9f1 100644
--- a/ripd/rip_nb_config.c
+++ b/ripd/rip_nb_config.c
@@ -23,6 +23,9 @@
 #include "ripd/rip_nb.h"
 #include "ripd/rip_debug.h"
 #include "ripd/rip_interface.h"
+#include "ripd/rip_bfd.h"
+
+DEFINE_MTYPE_STATIC(RIPD, RIP_BFD_PROFILE, "RIP BFD profile name");
 
 /*
  * XPath: /frr-ripd:ripd/instance
@@ -906,6 +909,40 @@ int ripd_instance_version_send_modify(struct nb_cb_modify_args *args)
 }
 
 /*
+ * XPath: /frr-ripd:ripd/instance/default-bfd-profile
+ */
+int ripd_instance_default_bfd_profile_modify(struct nb_cb_modify_args *args)
+{
+	struct rip *rip;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	rip = nb_running_get_entry(args->dnode, NULL, true);
+	XFREE(MTYPE_RIP_BFD_PROFILE, rip->default_bfd_profile);
+	rip->default_bfd_profile =
+		XSTRDUP(MTYPE_RIP_BFD_PROFILE,
+			yang_dnode_get_string(args->dnode, NULL));
+	rip_bfd_instance_update(rip);
+
+	return NB_OK;
+}
+
+int ripd_instance_default_bfd_profile_destroy(struct nb_cb_destroy_args *args)
+{
+	struct rip *rip;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	rip = nb_running_get_entry(args->dnode, NULL, true);
+	XFREE(MTYPE_RIP_BFD_PROFILE, rip->default_bfd_profile);
+	rip_bfd_instance_update(rip);
+
+	return NB_OK;
+}
+
+/*
  * XPath: /frr-interface:lib/interface/frr-ripd:rip/split-horizon
  */
 int lib_interface_rip_split_horizon_modify(struct nb_cb_modify_args *args)
@@ -1071,6 +1108,104 @@ int lib_interface_rip_authentication_password_destroy(
 }
 
 /*
+ * XPath: /frr-interface:lib/interface/frr-ripd:rip/bfd-monitoring
+ */
+int lib_interface_rip_bfd_create(struct nb_cb_create_args *args)
+{
+	struct interface *ifp;
+	struct rip_interface *ri;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	ifp = nb_running_get_entry(args->dnode, NULL, true);
+	ri = ifp->info;
+	ri->bfd.enabled = yang_dnode_get_bool(args->dnode, "./enable");
+	XFREE(MTYPE_RIP_BFD_PROFILE, ri->bfd.profile);
+	if (yang_dnode_exists(args->dnode, "./profile"))
+		ri->bfd.profile = XSTRDUP(
+			MTYPE_RIP_BFD_PROFILE,
+			yang_dnode_get_string(args->dnode, "./profile"));
+
+	rip_bfd_interface_update(ri);
+
+	return NB_OK;
+}
+
+int lib_interface_rip_bfd_destroy(struct nb_cb_destroy_args *args)
+{
+	struct interface *ifp;
+	struct rip_interface *ri;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	ifp = nb_running_get_entry(args->dnode, NULL, true);
+	ri = ifp->info;
+	ri->bfd.enabled = false;
+	XFREE(MTYPE_RIP_BFD_PROFILE, ri->bfd.profile);
+	rip_bfd_interface_update(ri);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-ripd:rip/bfd-monitoring/enable
+ */
+int lib_interface_rip_bfd_enable_modify(struct nb_cb_modify_args *args)
+{
+	struct interface *ifp;
+	struct rip_interface *ri;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	ifp = nb_running_get_entry(args->dnode, NULL, true);
+	ri = ifp->info;
+	ri->bfd.enabled = yang_dnode_get_bool(args->dnode, NULL);
+	rip_bfd_interface_update(ri);
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/frr-ripd:rip/bfd-monitoring/profile
+ */
+int lib_interface_rip_bfd_profile_modify(struct nb_cb_modify_args *args)
+{
+	struct interface *ifp;
+	struct rip_interface *ri;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	ifp = nb_running_get_entry(args->dnode, NULL, true);
+	ri = ifp->info;
+	XFREE(MTYPE_RIP_BFD_PROFILE, ri->bfd.profile);
+	ri->bfd.profile = XSTRDUP(MTYPE_RIP_BFD_PROFILE,
+				  yang_dnode_get_string(args->dnode, NULL));
+	rip_bfd_interface_update(ri);
+
+	return NB_OK;
+}
+
+int lib_interface_rip_bfd_profile_destroy(struct nb_cb_destroy_args *args)
+{
+	struct interface *ifp;
+	struct rip_interface *ri;
+
+	if (args->event != NB_EV_APPLY)
+		return NB_OK;
+
+	ifp = nb_running_get_entry(args->dnode, NULL, true);
+	ri = ifp->info;
+	XFREE(MTYPE_RIP_BFD_PROFILE, ri->bfd.profile);
+	rip_bfd_interface_update(ri);
+
+	return NB_OK;
+}
+
+/*
  * XPath: /frr-interface:lib/interface/frr-ripd:rip/authentication-key-chain
  */
 int lib_interface_rip_authentication_key_chain_modify(
diff --git a/ripd/rip_peer.c b/ripd/rip_peer.c
index 9410ef380..449abe47b 100644
--- a/ripd/rip_peer.c
+++ b/ripd/rip_peer.c
@@ -11,8 +11,10 @@
 #include "linklist.h"
 #include "frrevent.h"
 #include "memory.h"
+#include "table.h"
 
 #include "ripd/ripd.h"
+#include "ripd/rip_bfd.h"
 
 DEFINE_MTYPE_STATIC(RIPD, RIP_PEER, "RIP peer");
 
@@ -21,8 +23,9 @@ static struct rip_peer *rip_peer_new(void)
 	return XCALLOC(MTYPE_RIP_PEER, sizeof(struct rip_peer));
 }
 
-static void rip_peer_free(struct rip_peer *peer)
+void rip_peer_free(struct rip_peer *peer)
 {
+	bfd_sess_free(&peer->bfd_session);
 	EVENT_OFF(peer->t_timeout);
 	XFREE(MTYPE_RIP_PEER, peer);
 }
@@ -62,7 +65,8 @@ static void rip_peer_timeout(struct event *t)
 }
 
 /* Get RIP peer.  At the same time update timeout thread. */
-static struct rip_peer *rip_peer_get(struct rip *rip, struct in_addr *addr)
+static struct rip_peer *rip_peer_get(struct rip *rip, struct rip_interface *ri,
+				     struct in_addr *addr)
 {
 	struct rip_peer *peer;
 
@@ -73,7 +77,9 @@ static struct rip_peer *rip_peer_get(struct rip *rip, struct in_addr *addr)
 	} else {
 		peer = rip_peer_new();
 		peer->rip = rip;
+		peer->ri = ri;
 		peer->addr = *addr;
+		rip_bfd_session_update(peer);
 		listnode_add_sort(rip->peer_list, peer);
 	}
 
@@ -87,24 +93,27 @@ static struct rip_peer *rip_peer_get(struct rip *rip, struct in_addr *addr)
 	return peer;
 }
 
-void rip_peer_update(struct rip *rip, struct sockaddr_in *from, uint8_t version)
+void rip_peer_update(struct rip *rip, struct rip_interface *ri,
+		     struct sockaddr_in *from, uint8_t version)
 {
 	struct rip_peer *peer;
-	peer = rip_peer_get(rip, &from->sin_addr);
+	peer = rip_peer_get(rip, ri, &from->sin_addr);
 	peer->version = version;
 }
 
-void rip_peer_bad_route(struct rip *rip, struct sockaddr_in *from)
+void rip_peer_bad_route(struct rip *rip, struct rip_interface *ri,
+			struct sockaddr_in *from)
 {
 	struct rip_peer *peer;
-	peer = rip_peer_get(rip, &from->sin_addr);
+	peer = rip_peer_get(rip, ri, &from->sin_addr);
 	peer->recv_badroutes++;
 }
 
-void rip_peer_bad_packet(struct rip *rip, struct sockaddr_in *from)
+void rip_peer_bad_packet(struct rip *rip, struct rip_interface *ri,
+			 struct sockaddr_in *from)
 {
 	struct rip_peer *peer;
-	peer = rip_peer_get(rip, &from->sin_addr);
+	peer = rip_peer_get(rip, ri, &from->sin_addr);
 	peer->recv_badpackets++;
 }
 
@@ -155,3 +164,46 @@ void rip_peer_list_del(void *arg)
 {
 	rip_peer_free(arg);
 }
+
+void rip_peer_delete_routes(const struct rip_peer *peer)
+{
+	struct route_node *route_node;
+
+	for (route_node = route_top(peer->rip->table); route_node;
+	     route_node = route_next(route_node)) {
+		struct rip_info *route_entry;
+		struct listnode *listnode;
+		struct listnode *listnode_next;
+		struct list *list;
+
+		list = route_node->info;
+		if (list == NULL)
+			continue;
+
+		for (ALL_LIST_ELEMENTS(list, listnode, listnode_next,
+				       route_entry)) {
+			if (!rip_route_rte(route_entry))
+				continue;
+			if (route_entry->from.s_addr != peer->addr.s_addr)
+				continue;
+
+			if (listcount(list) == 1) {
+				EVENT_OFF(route_entry->t_timeout);
+				EVENT_OFF(route_entry->t_garbage_collect);
+				listnode_delete(list, route_entry);
+				if (list_isempty(list)) {
+					list_delete((struct list **)&route_node
+							    ->info);
+					route_unlock_node(route_node);
+				}
+				rip_info_free(route_entry);
+
+				/* Signal the output process to trigger an
+				 * update (see section 2.5). */
+				rip_event(peer->rip, RIP_TRIGGERED_UPDATE, 0);
+			} else
+				rip_ecmp_delete(peer->rip, route_entry);
+			break;
+		}
+	}
+}
diff --git a/ripd/rip_zebra.c b/ripd/rip_zebra.c
index 35c4b1f1b..698dcb982 100644
--- a/ripd/rip_zebra.c
+++ b/ripd/rip_zebra.c
@@ -13,6 +13,7 @@
 #include "zclient.h"
 #include "log.h"
 #include "vrf.h"
+#include "bfd.h"
 #include "ripd/ripd.h"
 #include "ripd/rip_debug.h"
 #include "ripd/rip_interface.h"
@@ -196,6 +197,7 @@ void rip_zebra_vrf_register(struct vrf *vrf)
 			   vrf->name, vrf->vrf_id);
 
 	zclient_send_reg_requests(zclient, vrf->vrf_id);
+	bfd_client_sendmsg(zclient, ZEBRA_BFD_CLIENT_REGISTER, vrf->vrf_id);
 }
 
 void rip_zebra_vrf_deregister(struct vrf *vrf)
@@ -208,11 +210,13 @@ void rip_zebra_vrf_deregister(struct vrf *vrf)
 			   vrf->name, vrf->vrf_id);
 
 	zclient_send_dereg_requests(zclient, vrf->vrf_id);
+	bfd_client_sendmsg(zclient, ZEBRA_BFD_CLIENT_DEREGISTER, vrf->vrf_id);
 }
 
 static void rip_zebra_connected(struct zclient *zclient)
 {
 	zclient_send_reg_requests(zclient, VRF_DEFAULT);
+	bfd_client_sendmsg(zclient, ZEBRA_BFD_CLIENT_REGISTER, VRF_DEFAULT);
 }
 
 zclient_handler *const rip_handlers[] = {
diff --git a/ripd/ripd.c b/ripd/ripd.c
index fb3d574aa..48f266a94 100644
--- a/ripd/ripd.c
+++ b/ripd/ripd.c
@@ -1123,7 +1123,7 @@ static void rip_response_process(struct rip_packet *packet, int size,
 	if (from->sin_port != htons(RIP_PORT_DEFAULT)) {
 		zlog_info("response doesn't come from RIP port: %d",
 			  from->sin_port);
-		rip_peer_bad_packet(rip, from);
+		rip_peer_bad_packet(rip, ri, from);
 		return;
 	}
 
@@ -1137,7 +1137,7 @@ static void rip_response_process(struct rip_packet *packet, int size,
 		zlog_info(
 			"This datagram doesn't come from a valid neighbor: %pI4",
 			&from->sin_addr);
-		rip_peer_bad_packet(rip, from);
+		rip_peer_bad_packet(rip, ri, from);
 		return;
 	}
 
@@ -1147,7 +1147,7 @@ static void rip_response_process(struct rip_packet *packet, int size,
 	; /* Alredy done in rip_read () */
 
 	/* Update RIP peer. */
-	rip_peer_update(rip, from, packet->version);
+	rip_peer_update(rip, ri, from, packet->version);
 
 	/* Set RTE pointer. */
 	rte = packet->rte;
@@ -1176,7 +1176,7 @@ static void rip_response_process(struct rip_packet *packet, int size,
 		if (!rip_destination_check(rte->prefix)) {
 			zlog_info(
 				"Network is net 0 or net 127 or it is not unicast network");
-			rip_peer_bad_route(rip, from);
+			rip_peer_bad_route(rip, ri, from);
 			continue;
 		}
 
@@ -1186,7 +1186,7 @@ static void rip_response_process(struct rip_packet *packet, int size,
 		/* - is the metric valid (i.e., between 1 and 16, inclusive) */
 		if (!(rte->metric >= 1 && rte->metric <= 16)) {
 			zlog_info("Route's metric is not in the 1-16 range.");
-			rip_peer_bad_route(rip, from);
+			rip_peer_bad_route(rip, ri, from);
 			continue;
 		}
 
@@ -1195,7 +1195,7 @@ static void rip_response_process(struct rip_packet *packet, int size,
 		    && rte->nexthop.s_addr != INADDR_ANY) {
 			zlog_info("RIPv1 packet with nexthop value %pI4",
 				  &rte->nexthop);
-			rip_peer_bad_route(rip, from);
+			rip_peer_bad_route(rip, ri, from);
 			continue;
 		}
 
@@ -1326,7 +1326,7 @@ static void rip_response_process(struct rip_packet *packet, int size,
 			zlog_warn(
 				"RIPv2 address %pI4 is not mask /%d applied one",
 				&rte->prefix, ip_masklen(rte->mask));
-			rip_peer_bad_route(rip, from);
+			rip_peer_bad_route(rip, ri, from);
 			continue;
 		}
 
@@ -1643,7 +1643,7 @@ static void rip_request_process(struct rip_packet *packet, int size,
 		return;
 
 	/* RIP peer update. */
-	rip_peer_update(rip, from, packet->version);
+	rip_peer_update(rip, ri, from, packet->version);
 
 	lim = ((caddr_t)packet) + size;
 	rte = packet->rte;
@@ -1711,7 +1711,7 @@ static void rip_read(struct event *t)
 	socklen_t fromlen;
 	struct interface *ifp = NULL;
 	struct connected *ifc;
-	struct rip_interface *ri;
+	struct rip_interface *ri = NULL;
 	struct prefix p;
 
 	/* Fetch socket then register myself. */
@@ -1743,8 +1743,10 @@ static void rip_read(struct event *t)
 	/* Which interface is this packet comes from. */
 	ifc = if_lookup_address((void *)&from.sin_addr, AF_INET,
 				rip->vrf->vrf_id);
-	if (ifc)
+	if (ifc) {
 		ifp = ifc->ifp;
+		ri = ifp->info;
+	}
 
 	/* RIP packet received */
 	if (IS_RIP_DEBUG_EVENT)
@@ -1753,7 +1755,7 @@ static void rip_read(struct event *t)
 			   ifp ? ifp->name : "unknown", rip->vrf_name);
 
 	/* If this packet come from unknown interface, ignore it. */
-	if (ifp == NULL) {
+	if (ifp == NULL || ri == NULL) {
 		zlog_info(
 			"%s: cannot find interface for packet from %pI4 port %d (VRF %s)",
 			__func__, &from.sin_addr, ntohs(from.sin_port),
@@ -1779,13 +1781,13 @@ static void rip_read(struct event *t)
 	if (len < RIP_PACKET_MINSIZ) {
 		zlog_warn("packet size %d is smaller than minimum size %d", len,
 			  RIP_PACKET_MINSIZ);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		return;
 	}
 	if (len > RIP_PACKET_MAXSIZ) {
 		zlog_warn("packet size %d is larger than max size %d", len,
 			  RIP_PACKET_MAXSIZ);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		return;
 	}
 
@@ -1793,7 +1795,7 @@ static void rip_read(struct event *t)
 	if ((len - RIP_PACKET_MINSIZ) % 20) {
 		zlog_warn("packet size %d is wrong for RIP packet alignment",
 			  len);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		return;
 	}
 
@@ -1807,7 +1809,7 @@ static void rip_read(struct event *t)
 	if (packet->version == 0) {
 		zlog_info("version 0 with command %d received.",
 			  packet->command);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		return;
 	}
 
@@ -1823,12 +1825,11 @@ static void rip_read(struct event *t)
 		packet->version = RIPv2;
 
 	/* Is RIP running or is this RIP neighbor ?*/
-	ri = ifp->info;
 	if (!ri->running && !rip_neighbor_lookup(rip, &from)) {
 		if (IS_RIP_DEBUG_EVENT)
 			zlog_debug("RIP is not enabled on interface %s.",
 				   ifp->name);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		return;
 	}
 
@@ -1842,7 +1843,7 @@ static void rip_read(struct event *t)
 			zlog_debug(
 				"  packet's v%d doesn't fit to if version spec",
 				packet->version);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		return;
 	}
 
@@ -1857,7 +1858,7 @@ static void rip_read(struct event *t)
 				"packet RIPv%d is dropped because authentication disabled",
 				packet->version);
 		ripd_notif_send_auth_type_failure(ifp->name);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		return;
 	}
 
@@ -1893,7 +1894,7 @@ static void rip_read(struct event *t)
 				zlog_debug(
 					"RIPv1 dropped because authentication enabled");
 			ripd_notif_send_auth_type_failure(ifp->name);
-			rip_peer_bad_packet(rip, &from);
+			rip_peer_bad_packet(rip, ri, &from);
 			return;
 		}
 	} else if (ri->auth_type != RIP_NO_AUTH) {
@@ -1906,7 +1907,7 @@ static void rip_read(struct event *t)
 				zlog_debug(
 					"RIPv2 authentication failed: no auth RTE in packet");
 			ripd_notif_send_auth_type_failure(ifp->name);
-			rip_peer_bad_packet(rip, &from);
+			rip_peer_bad_packet(rip, ri, &from);
 			return;
 		}
 
@@ -1916,7 +1917,7 @@ static void rip_read(struct event *t)
 				zlog_debug(
 					"RIPv2 dropped because authentication enabled");
 			ripd_notif_send_auth_type_failure(ifp->name);
-			rip_peer_bad_packet(rip, &from);
+			rip_peer_bad_packet(rip, ri, &from);
 			return;
 		}
 
@@ -1952,7 +1953,7 @@ static void rip_read(struct event *t)
 				zlog_debug("RIPv2 %s authentication failure",
 					   auth_desc);
 			ripd_notif_send_auth_failure(ifp->name);
-			rip_peer_bad_packet(rip, &from);
+			rip_peer_bad_packet(rip, ri, &from);
 			return;
 		}
 	}
@@ -1971,16 +1972,16 @@ static void rip_read(struct event *t)
 		zlog_info(
 			"Obsolete command %s received, please sent it to routed",
 			lookup_msg(rip_msg, packet->command, NULL));
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		break;
 	case RIP_POLL_ENTRY:
 		zlog_info("Obsolete command %s received",
 			  lookup_msg(rip_msg, packet->command, NULL));
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		break;
 	default:
 		zlog_info("Unknown RIP command %d received", packet->command);
-		rip_peer_bad_packet(rip, &from);
+		rip_peer_bad_packet(rip, ri, &from);
 		break;
 	}
 }
@@ -3339,6 +3340,7 @@ void rip_clean(struct rip *rip)
 	route_table_finish(rip->distance_table);
 
 	RB_REMOVE(rip_instance_head, &rip_instances, rip);
+	XFREE(MTYPE_TMP, rip->default_bfd_profile);
 	XFREE(MTYPE_RIP_VRF_NAME, rip->vrf_name);
 	XFREE(MTYPE_RIP, rip);
 }
diff --git a/ripd/ripd.h b/ripd/ripd.h
index 176a3bfc3..bba3c2806 100644
--- a/ripd/ripd.h
+++ b/ripd/ripd.h
@@ -10,6 +10,7 @@
 #include "nexthop.h"
 #include "distribute.h"
 #include "memory.h"
+#include "bfd.h"
 
 /* RIP version number. */
 #define RIPv1                            1
@@ -182,6 +183,9 @@ struct rip {
 		/* RIP queries. */
 		long queries;
 	} counters;
+
+	/* Default BFD profile to use with BFD sessions. */
+	char *default_bfd_profile;
 };
 RB_HEAD(rip_instance_head, rip);
 RB_PROTOTYPE(rip_instance_head, rip, entry, rip_instance_compare)
@@ -265,6 +269,9 @@ struct rip_interface {
 	/* Parent routing instance. */
 	struct rip *rip;
 
+	/* Interface data from zebra. */
+	struct interface *ifp;
+
 	/* RIP is enabled on this interface. */
 	int enable_network;
 	int enable_interface;
@@ -318,6 +325,12 @@ struct rip_interface {
 
 	/* Passive interface. */
 	int passive;
+
+	/* BFD information. */
+	struct {
+		bool enabled;
+		char *profile;
+	} bfd;
 };
 
 /* RIP peer information. */
@@ -325,6 +338,9 @@ struct rip_peer {
 	/* Parent routing instance. */
 	struct rip *rip;
 
+	/* Back-pointer to RIP interface. */
+	struct rip_interface *ri;
+
 	/* Peer address. */
 	struct in_addr addr;
 
@@ -343,6 +359,9 @@ struct rip_peer {
 
 	/* Timeout thread. */
 	struct event *t_timeout;
+
+	/* BFD information */
+	struct bfd_session_params *bfd_session;
 };
 
 struct rip_distance {
@@ -461,16 +480,20 @@ extern void rip_if_rmap_update_interface(struct interface *ifp);
 extern int rip_show_network_config(struct vty *vty, struct rip *rip);
 extern void rip_show_redistribute_config(struct vty *vty, struct rip *rip);
 
-extern void rip_peer_update(struct rip *rip, struct sockaddr_in *from,
-			    uint8_t version);
-extern void rip_peer_bad_route(struct rip *rip, struct sockaddr_in *from);
-extern void rip_peer_bad_packet(struct rip *rip, struct sockaddr_in *from);
+extern void rip_peer_free(struct rip_peer *peer);
+extern void rip_peer_update(struct rip *rip, struct rip_interface *ri,
+			    struct sockaddr_in *from, uint8_t version);
+extern void rip_peer_bad_route(struct rip *rip, struct rip_interface *ri,
+			       struct sockaddr_in *from);
+extern void rip_peer_bad_packet(struct rip *rip, struct rip_interface *ri,
+				struct sockaddr_in *from);
 extern void rip_peer_display(struct vty *vty, struct rip *rip);
 extern struct rip_peer *rip_peer_lookup(struct rip *rip, struct in_addr *addr);
 extern struct rip_peer *rip_peer_lookup_next(struct rip *rip,
 					     struct in_addr *addr);
 extern int rip_peer_list_cmp(struct rip_peer *p1, struct rip_peer *p2);
 extern void rip_peer_list_del(void *arg);
+void rip_peer_delete_routes(const struct rip_peer *peer);
 
 extern void rip_info_free(struct rip_info *);
 extern struct rip *rip_info_get_instance(const struct rip_info *rinfo);
diff --git a/ripd/subdir.am b/ripd/subdir.am
index 98cc765c9..294a05e57 100644
--- a/ripd/subdir.am
+++ b/ripd/subdir.am
@@ -13,6 +13,7 @@ man8 += $(MANBUILD)/frr-ripd.8
 endif
 
 ripd_ripd_SOURCES = \
+	ripd/rip_bfd.c \
 	ripd/rip_cli.c \
 	ripd/rip_debug.c \
 	ripd/rip_errors.c \
@@ -31,10 +32,12 @@ ripd_ripd_SOURCES = \
 	# end
 
 clippy_scan += \
+	ripd/rip_bfd.c \
 	ripd/rip_cli.c \
 	# end
 
 noinst_HEADERS += \
+	ripd/rip_bfd.h \
 	ripd/rip_debug.h \
 	ripd/rip_errors.h \
 	ripd/rip_interface.h \