1 files changed, 627 insertions, 0 deletions

diff --git a/bgpd/bgp_bfd.c b/bgpd/bgp_bfd.c
new file mode 100644
index 0000000..21864cf
--- /dev/null
+++ b/bgpd/bgp_bfd.c
@@ -0,0 +1,627 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * bgp_bfd.c: BGP BFD handling routines
+ *
+ * @copyright Copyright (C) 2015 Cumulus Networks, Inc.
+ */
+
+#include <zebra.h>
+
+#include "command.h"
+#include "linklist.h"
+#include "memory.h"
+#include "prefix.h"
+#include "frrevent.h"
+#include "buffer.h"
+#include "stream.h"
+#include "vrf.h"
+#include "zclient.h"
+#include "bfd.h"
+#include "lib/json.h"
+#include "filter.h"
+
+#include "bgpd/bgpd.h"
+#include "bgp_fsm.h"
+#include "bgpd/bgp_bfd.h"
+#include "bgpd/bgp_debug.h"
+#include "bgpd/bgp_vty.h"
+#include "bgpd/bgp_packet.h"
+
+DEFINE_MTYPE_STATIC(BGPD, BFD_CONFIG, "BFD configuration data");
+
+extern struct zclient *zclient;
+
+static void bfd_session_status_update(struct bfd_session_params *bsp,
+				      const struct bfd_session_status *bss,
+				      void *arg)
+{
+	struct peer *peer = arg;
+
+	if (BGP_DEBUG(bfd, BFD_LIB))
+		zlog_debug("%s: neighbor %s vrf %s(%u) bfd state %s -> %s",
+			   __func__, peer->conf_if ? peer->conf_if : peer->host,
+			   bfd_sess_vrf(bsp), bfd_sess_vrf_id(bsp),
+			   bfd_get_status_str(bss->previous_state),
+			   bfd_get_status_str(bss->state));
+
+	if (bss->state == BSS_DOWN && bss->previous_state == BSS_UP) {
+		if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_MODE)
+		    && bfd_sess_cbit(bsp) && !bss->remote_cbit) {
+			if (BGP_DEBUG(bfd, BFD_LIB))
+				zlog_debug(
+					"%s BFD DOWN message ignored in the process of graceful restart when C bit is cleared",
+					peer->host);
+			return;
+		}
+		peer->last_reset = PEER_DOWN_BFD_DOWN;
+
+		/* rfc9384 */
+		if (BGP_IS_VALID_STATE_FOR_NOTIF(peer->connection->status))
+			bgp_notify_send(peer->connection, BGP_NOTIFY_CEASE,
+					BGP_NOTIFY_CEASE_BFD_DOWN);
+
+		BGP_EVENT_ADD(peer->connection, BGP_Stop);
+	}
+
+	if (bss->state == BSS_UP && bss->previous_state != BSS_UP &&
+	    !peer_established(peer->connection)) {
+		if (!BGP_PEER_START_SUPPRESSED(peer)) {
+			bgp_fsm_nht_update(peer->connection, peer, true);
+			BGP_EVENT_ADD(peer->connection, BGP_Start);
+		}
+	}
+}
+
+void bgp_peer_config_apply(struct peer *p, struct peer_group *pg)
+{
+	struct listnode *n;
+	struct peer *pn;
+	struct peer *gconfig;
+
+	/* When called on a group, apply to all peers. */
+	if (CHECK_FLAG(p->sflags, PEER_STATUS_GROUP)) {
+		for (ALL_LIST_ELEMENTS_RO(p->group->peer, n, pn))
+			bgp_peer_config_apply(pn, pg);
+		return;
+	}
+
+	/* No group, just use current configuration. */
+	if (pg == NULL || pg->conf->bfd_config == NULL) {
+		bfd_sess_set_timers(p->bfd_config->session,
+				    p->bfd_config->detection_multiplier,
+				    p->bfd_config->min_rx,
+				    p->bfd_config->min_tx);
+		bfd_sess_set_cbit(p->bfd_config->session, p->bfd_config->cbit);
+		bfd_sess_set_profile(p->bfd_config->session,
+				     p->bfd_config->profile);
+		bfd_sess_install(p->bfd_config->session);
+		return;
+	}
+
+	/*
+	 * Check if the group configuration was overwritten or apply group
+	 * configuration.
+	 */
+	gconfig = pg->conf;
+
+	/*
+	 * If using default control plane independent configuration,
+	 * then prefer group's (e.g. it means it wasn't manually configured).
+	 */
+	if (!p->bfd_config->cbit)
+		bfd_sess_set_cbit(p->bfd_config->session,
+				  gconfig->bfd_config->cbit);
+	else
+		bfd_sess_set_cbit(p->bfd_config->session, p->bfd_config->cbit);
+
+	/* If no profile was specified in peer, then use the group profile. */
+	if (p->bfd_config->profile[0] == 0)
+		bfd_sess_set_profile(p->bfd_config->session,
+				     gconfig->bfd_config->profile);
+	else
+		bfd_sess_set_profile(p->bfd_config->session,
+				     p->bfd_config->profile);
+
+	/* If no specific timers were configured, then use the group timers. */
+	if (p->bfd_config->detection_multiplier == BFD_DEF_DETECT_MULT
+	    || p->bfd_config->min_rx == BFD_DEF_MIN_RX
+	    || p->bfd_config->min_tx == BFD_DEF_MIN_TX)
+		bfd_sess_set_timers(p->bfd_config->session,
+				    gconfig->bfd_config->detection_multiplier,
+				    gconfig->bfd_config->min_rx,
+				    gconfig->bfd_config->min_tx);
+	else
+		bfd_sess_set_timers(p->bfd_config->session,
+				    p->bfd_config->detection_multiplier,
+				    p->bfd_config->min_rx,
+				    p->bfd_config->min_tx);
+
+	bfd_sess_install(p->bfd_config->session);
+}
+
+void bgp_peer_bfd_update_source(struct peer *p)
+{
+	struct bfd_session_params *session = p->bfd_config->session;
+	const union sockunion *source;
+	bool changed = false;
+	int family;
+	union {
+		struct in_addr v4;
+		struct in6_addr v6;
+	} src, dst;
+
+	/* Nothing to do for groups. */
+	if (CHECK_FLAG(p->sflags, PEER_STATUS_GROUP))
+		return;
+
+	/* Figure out the correct source to use. */
+	if (CHECK_FLAG(p->flags, PEER_FLAG_UPDATE_SOURCE) && p->update_source)
+		source = p->update_source;
+	else
+		source = p->su_local;
+
+	/* Update peer's source/destination addresses. */
+	bfd_sess_addresses(session, &family, &src.v6, &dst.v6);
+	if (family == AF_INET) {
+		if ((source && source->sin.sin_addr.s_addr != src.v4.s_addr) ||
+		    p->connection->su.sin.sin_addr.s_addr != dst.v4.s_addr) {
+			if (BGP_DEBUG(bfd, BFD_LIB))
+				zlog_debug("%s: address [%pI4->%pI4] to [%pI4->%pI4]",
+					   __func__, &src.v4, &dst.v4,
+					   source ? &source->sin.sin_addr
+						  : &src.v4,
+					   &p->connection->su.sin.sin_addr);
+
+			bfd_sess_set_ipv4_addrs(session,
+						source ? &source->sin.sin_addr
+						       : NULL,
+						&p->connection->su.sin.sin_addr);
+			changed = true;
+		}
+	} else {
+		if ((source && memcmp(&source->sin6, &src.v6, sizeof(src.v6))) ||
+		    memcmp(&p->connection->su.sin6, &dst.v6, sizeof(dst.v6))) {
+			if (BGP_DEBUG(bfd, BFD_LIB))
+				zlog_debug("%s: address [%pI6->%pI6] to [%pI6->%pI6]",
+					   __func__, &src.v6, &dst.v6,
+					   source ? &source->sin6.sin6_addr
+						  : &src.v6,
+					   &p->connection->su.sin6.sin6_addr);
+
+			bfd_sess_set_ipv6_addrs(session,
+						source ? &source->sin6.sin6_addr
+						       : NULL,
+						&p->connection->su.sin6.sin6_addr);
+			changed = true;
+		}
+	}
+
+	/* Update interface. */
+	if (p->nexthop.ifp && bfd_sess_interface(session) == NULL) {
+		if (BGP_DEBUG(bfd, BFD_LIB))
+			zlog_debug("%s: interface none to %s", __func__,
+				   p->nexthop.ifp->name);
+
+		bfd_sess_set_interface(session, p->nexthop.ifp->name);
+		changed = true;
+	}
+
+	/*
+	 * Update TTL.
+	 *
+	 * Two cases:
+	 * - We detected that the peer is a hop away from us (remove multi hop).
+	 *   (this happens when `p->shared_network` is set to `true`)
+	 * - eBGP multi hop / TTL security changed.
+	 */
+	if (!PEER_IS_MULTIHOP(p) && bfd_sess_hop_count(session) > 1) {
+		if (BGP_DEBUG(bfd, BFD_LIB))
+			zlog_debug("%s: TTL %d to 1", __func__,
+				   bfd_sess_hop_count(session));
+
+		bfd_sess_set_hop_count(session, 1);
+		changed = true;
+	}
+	if (PEER_IS_MULTIHOP(p) && p->ttl != bfd_sess_hop_count(session)) {
+		if (BGP_DEBUG(bfd, BFD_LIB))
+			zlog_debug("%s: TTL %d to %d", __func__,
+				   bfd_sess_hop_count(session), p->ttl);
+
+		bfd_sess_set_hop_count(session, p->ttl);
+		changed = true;
+	}
+
+	/* Update VRF. */
+	if (bfd_sess_vrf_id(session) != p->bgp->vrf_id) {
+		if (BGP_DEBUG(bfd, BFD_LIB))
+			zlog_debug(
+				"%s: VRF %s(%d) to %s(%d)", __func__,
+				bfd_sess_vrf(session), bfd_sess_vrf_id(session),
+				vrf_id_to_name(p->bgp->vrf_id), p->bgp->vrf_id);
+
+		bfd_sess_set_vrf(session, p->bgp->vrf_id);
+		changed = true;
+	}
+
+	if (changed)
+		bfd_sess_install(session);
+}
+
+/**
+ * Reset BFD configuration data structure to its defaults settings.
+ */
+static void bgp_peer_bfd_reset(struct peer *p)
+{
+	/* Set defaults. */
+	p->bfd_config->detection_multiplier = BFD_DEF_DETECT_MULT;
+	p->bfd_config->min_rx = BFD_DEF_MIN_RX;
+	p->bfd_config->min_tx = BFD_DEF_MIN_TX;
+	p->bfd_config->cbit = false;
+	p->bfd_config->profile[0] = 0;
+}
+
+void bgp_peer_configure_bfd(struct peer *p, bool manual)
+{
+	/* Groups should not call this. */
+	assert(!CHECK_FLAG(p->sflags, PEER_STATUS_GROUP));
+
+	/* Already configured, skip it. */
+	if (p->bfd_config) {
+		/* If manually active update flag. */
+		if (!p->bfd_config->manual)
+			p->bfd_config->manual = manual;
+
+		return;
+	}
+
+	/* Allocate memory for configuration overrides. */
+	p->bfd_config = XCALLOC(MTYPE_BFD_CONFIG, sizeof(*p->bfd_config));
+	p->bfd_config->manual = manual;
+
+	/* Create new session and assign callback. */
+	p->bfd_config->session = bfd_sess_new(bfd_session_status_update, p);
+	bgp_peer_bfd_reset(p);
+
+	/* Configure session with basic BGP peer data. */
+	if (p->connection->su.sa.sa_family == AF_INET)
+		bfd_sess_set_ipv4_addrs(p->bfd_config->session,
+					p->su_local ? &p->su_local->sin.sin_addr
+						    : NULL,
+					&p->connection->su.sin.sin_addr);
+	else
+		bfd_sess_set_ipv6_addrs(p->bfd_config->session,
+					p->su_local
+						? &p->su_local->sin6.sin6_addr
+						: NULL,
+					&p->connection->su.sin6.sin6_addr);
+
+	bfd_sess_set_vrf(p->bfd_config->session, p->bgp->vrf_id);
+	bfd_sess_set_hop_count(p->bfd_config->session,
+			       PEER_IS_MULTIHOP(p) ? p->ttl : 1);
+
+	if (p->nexthop.ifp)
+		bfd_sess_set_interface(p->bfd_config->session,
+				       p->nexthop.ifp->name);
+}
+
+static void bgp_peer_remove_bfd(struct peer *p)
+{
+	/* Groups should not call this. */
+	assert(!CHECK_FLAG(p->sflags, PEER_STATUS_GROUP));
+
+	/*
+	 * Peer configuration was removed, however we must check if there
+	 * is still a group configuration to keep this running.
+	 */
+	if (p->group && p->group->conf->bfd_config) {
+		p->bfd_config->manual = false;
+		bgp_peer_bfd_reset(p);
+		bgp_peer_config_apply(p, p->group);
+		return;
+	}
+
+	if (p->bfd_config)
+		bfd_sess_free(&p->bfd_config->session);
+
+	XFREE(MTYPE_BFD_CONFIG, p->bfd_config);
+}
+
+static void bgp_group_configure_bfd(struct peer *p)
+{
+	struct listnode *n;
+	struct peer *pn;
+
+	/* Peers should not call this. */
+	assert(CHECK_FLAG(p->sflags, PEER_STATUS_GROUP));
+
+	/* Already allocated: do nothing. */
+	if (p->bfd_config)
+		return;
+
+	p->bfd_config = XCALLOC(MTYPE_BFD_CONFIG, sizeof(*p->bfd_config));
+
+	/* Set defaults. */
+	p->bfd_config->detection_multiplier = BFD_DEF_DETECT_MULT;
+	p->bfd_config->min_rx = BFD_DEF_MIN_RX;
+	p->bfd_config->min_tx = BFD_DEF_MIN_TX;
+
+	for (ALL_LIST_ELEMENTS_RO(p->group->peer, n, pn))
+		bgp_peer_configure_bfd(pn, false);
+}
+
+static void bgp_group_remove_bfd(struct peer *p)
+{
+	struct listnode *n;
+	struct peer *pn;
+
+	/* Peers should not call this. */
+	assert(CHECK_FLAG(p->sflags, PEER_STATUS_GROUP));
+
+	/* Already freed: do nothing. */
+	if (p->bfd_config == NULL)
+		return;
+
+	/* Free configuration and point to `NULL`. */
+	XFREE(MTYPE_BFD_CONFIG, p->bfd_config);
+
+	/* Now that it is `NULL` recalculate configuration for all peers. */
+	for (ALL_LIST_ELEMENTS_RO(p->group->peer, n, pn)) {
+		if (pn->bfd_config->manual)
+			bgp_peer_config_apply(pn, NULL);
+		else
+			bgp_peer_remove_bfd(pn);
+	}
+}
+
+void bgp_peer_remove_bfd_config(struct peer *p)
+{
+	if (CHECK_FLAG(p->sflags, PEER_STATUS_GROUP))
+		bgp_group_remove_bfd(p);
+	else
+		bgp_peer_remove_bfd(p);
+}
+
+/*
+ * bgp_bfd_peer_config_write - Write the peer BFD configuration.
+ */
+void bgp_bfd_peer_config_write(struct vty *vty, const struct peer *peer,
+			       const char *addr)
+{
+	/*
+	 * Always show group BFD configuration, but peer only when explicitly
+	 * configured.
+	 */
+	if ((!CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP)
+	     && peer->bfd_config->manual)
+	    || CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP)) {
+#if HAVE_BFDD > 0
+		vty_out(vty, " neighbor %s bfd\n", addr);
+#else
+		vty_out(vty, " neighbor %s bfd %d %d %d\n", addr,
+			peer->bfd_config->detection_multiplier,
+			peer->bfd_config->min_rx, peer->bfd_config->min_tx);
+#endif /* HAVE_BFDD */
+	}
+
+	if (peer->bfd_config->profile[0])
+		vty_out(vty, " neighbor %s bfd profile %s\n", addr,
+			peer->bfd_config->profile);
+
+	if (peer->bfd_config->cbit)
+		vty_out(vty, " neighbor %s bfd check-control-plane-failure\n",
+			addr);
+}
+
+/*
+ * bgp_bfd_show_info - Show the peer BFD information.
+ */
+void bgp_bfd_show_info(struct vty *vty, const struct peer *peer,
+		       json_object *json_neigh)
+{
+	bfd_sess_show(vty, json_neigh, peer->bfd_config->session);
+}
+
+DEFUN (neighbor_bfd,
+       neighbor_bfd_cmd,
+       "neighbor <A.B.C.D|X:X::X:X|WORD> bfd",
+       NEIGHBOR_STR
+       NEIGHBOR_ADDR_STR2
+       "Enables BFD support\n")
+{
+	int idx_peer = 1;
+	struct peer *peer;
+
+	peer = peer_and_group_lookup_vty(vty, argv[idx_peer]->arg);
+	if (!peer)
+		return CMD_WARNING_CONFIG_FAILED;
+
+	if (CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP))
+		bgp_group_configure_bfd(peer);
+	else
+		bgp_peer_configure_bfd(peer, true);
+
+	bgp_peer_config_apply(peer, peer->group);
+
+	return CMD_SUCCESS;
+}
+
+#if HAVE_BFDD > 0
+DEFUN_HIDDEN(
+#else
+DEFUN(
+#endif /* HAVE_BFDD */
+       neighbor_bfd_param,
+       neighbor_bfd_param_cmd,
+       "neighbor <A.B.C.D|X:X::X:X|WORD> bfd (2-255) (50-60000) (50-60000)",
+       NEIGHBOR_STR
+       NEIGHBOR_ADDR_STR2
+       "Enables BFD support\n"
+       "Detect Multiplier\n"
+       "Required min receive interval\n"
+       "Desired min transmit interval\n")
+{
+	int idx_peer = 1;
+	int idx_number_1 = 3;
+	int idx_number_2 = 4;
+	int idx_number_3 = 5;
+	long detection_multiplier, min_rx, min_tx;
+	struct peer *peer;
+
+	peer = peer_and_group_lookup_vty(vty, argv[idx_peer]->arg);
+	if (!peer)
+		return CMD_WARNING_CONFIG_FAILED;
+
+	detection_multiplier = strtol(argv[idx_number_1]->arg, NULL, 10);
+	min_rx = strtol(argv[idx_number_2]->arg, NULL, 10);
+	min_tx = strtol(argv[idx_number_3]->arg, NULL, 10);
+
+	if (CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP))
+		bgp_group_configure_bfd(peer);
+	else
+		bgp_peer_configure_bfd(peer, true);
+
+	peer->bfd_config->detection_multiplier = detection_multiplier;
+	peer->bfd_config->min_rx = min_rx;
+	peer->bfd_config->min_tx = min_tx;
+	bgp_peer_config_apply(peer, peer->group);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN (neighbor_bfd_check_controlplane_failure,
+       neighbor_bfd_check_controlplane_failure_cmd,
+       "[no] neighbor <A.B.C.D|X:X::X:X|WORD> bfd check-control-plane-failure",
+       NO_STR
+       NEIGHBOR_STR
+       NEIGHBOR_ADDR_STR2
+       "BFD support\n"
+       "Link dataplane status with BGP controlplane\n")
+{
+	const char *no = strmatch(argv[0]->text, "no") ? "no" : NULL;
+	int idx_peer = 0;
+	struct peer *peer;
+
+	if (no)
+		idx_peer = 2;
+	else
+		idx_peer = 1;
+	peer = peer_and_group_lookup_vty(vty, argv[idx_peer]->arg);
+	if (!peer)
+		return CMD_WARNING_CONFIG_FAILED;
+
+	if (CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP))
+		bgp_group_configure_bfd(peer);
+	else
+		bgp_peer_configure_bfd(peer, true);
+
+	peer->bfd_config->cbit = no == NULL;
+	bgp_peer_config_apply(peer, peer->group);
+
+	return CMD_SUCCESS;
+ }
+
+DEFUN (no_neighbor_bfd,
+       no_neighbor_bfd_cmd,
+#if HAVE_BFDD > 0
+       "no neighbor <A.B.C.D|X:X::X:X|WORD> bfd",
+#else
+       "no neighbor <A.B.C.D|X:X::X:X|WORD> bfd [(2-255) (50-60000) (50-60000)]",
+#endif /* HAVE_BFDD */
+       NO_STR
+       NEIGHBOR_STR
+       NEIGHBOR_ADDR_STR2
+       "Disables BFD support\n"
+#if HAVE_BFDD == 0
+       "Detect Multiplier\n"
+       "Required min receive interval\n"
+       "Desired min transmit interval\n"
+#endif /* !HAVE_BFDD */
+)
+{
+	int idx_peer = 2;
+	struct peer *peer;
+
+	peer = peer_and_group_lookup_vty(vty, argv[idx_peer]->arg);
+	if (!peer)
+		return CMD_WARNING_CONFIG_FAILED;
+
+	if (CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP))
+		bgp_group_remove_bfd(peer);
+	else
+		bgp_peer_remove_bfd(peer);
+
+	return CMD_SUCCESS;
+}
+
+#if HAVE_BFDD > 0
+DEFUN(neighbor_bfd_profile, neighbor_bfd_profile_cmd,
+      "neighbor <A.B.C.D|X:X::X:X|WORD> bfd profile BFDPROF",
+      NEIGHBOR_STR
+      NEIGHBOR_ADDR_STR2
+      "BFD integration\n"
+      BFD_PROFILE_STR
+      BFD_PROFILE_NAME_STR)
+{
+	int idx_peer = 1, idx_prof = 4;
+	struct peer *peer;
+
+	peer = peer_and_group_lookup_vty(vty, argv[idx_peer]->arg);
+	if (!peer)
+		return CMD_WARNING_CONFIG_FAILED;
+
+	if (CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP))
+		bgp_group_configure_bfd(peer);
+	else
+		bgp_peer_configure_bfd(peer, true);
+
+	strlcpy(peer->bfd_config->profile, argv[idx_prof]->arg,
+		sizeof(peer->bfd_config->profile));
+	bgp_peer_config_apply(peer, peer->group);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(no_neighbor_bfd_profile, no_neighbor_bfd_profile_cmd,
+      "no neighbor <A.B.C.D|X:X::X:X|WORD> bfd profile [BFDPROF]",
+      NO_STR
+      NEIGHBOR_STR
+      NEIGHBOR_ADDR_STR2
+      "BFD integration\n"
+      BFD_PROFILE_STR
+      BFD_PROFILE_NAME_STR)
+{
+	int idx_peer = 2;
+	struct peer *peer;
+
+	peer = peer_and_group_lookup_vty(vty, argv[idx_peer]->arg);
+	if (!peer)
+		return CMD_WARNING_CONFIG_FAILED;
+
+	if (CHECK_FLAG(peer->sflags, PEER_STATUS_GROUP))
+		bgp_group_configure_bfd(peer);
+	else
+		bgp_peer_configure_bfd(peer, true);
+
+	peer->bfd_config->profile[0] = 0;
+	bgp_peer_config_apply(peer, peer->group);
+
+	return CMD_SUCCESS;
+}
+#endif /* HAVE_BFDD */
+
+void bgp_bfd_init(struct event_loop *tm)
+{
+	/* Initialize BFD client functions */
+	bfd_protocol_integration_init(zclient, tm);
+
+	/* "neighbor bfd" commands. */
+	install_element(BGP_NODE, &neighbor_bfd_cmd);
+	install_element(BGP_NODE, &neighbor_bfd_param_cmd);
+	install_element(BGP_NODE, &neighbor_bfd_check_controlplane_failure_cmd);
+	install_element(BGP_NODE, &no_neighbor_bfd_cmd);
+
+#if HAVE_BFDD > 0
+	install_element(BGP_NODE, &neighbor_bfd_profile_cmd);
+	install_element(BGP_NODE, &no_neighbor_bfd_profile_cmd);
+#endif /* HAVE_BFDD */
+}