From f3c17d94e0b6826ed8ca3d47afaf3ae5214169e7 Mon Sep 17 00:00:00 2001
From: Philippe Guibert <philippe.guibert@6wind.com>
Date: Wed, 30 Oct 2024 09:45:47 +0100
Subject: [PATCH] bgpd: bmp, define hook for router-id updates

At startup, if bmp loc-rib is enabled, the peer_id of the
loc-rib per peer header message has the router-id set to 0.0.0.0.
Actually, the router-id has been updated after the peer up
message is sent, and the information is not refreshed.

Create a hook API to handle router id events: withdraw and
updates. Use that hook in BMP module to send peer down, and
peer up events when necessary.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
---
 bgpd/bgp_bmp.c | 23 +++++++++++++++++++++++
 bgpd/bgpd.c    |  4 ++++
 bgpd/bgpd.h    |  1 +
 3 files changed, 28 insertions(+)

diff --git a/bgpd/bgp_bmp.c b/bgpd/bgp_bmp.c
index 019ea2669d..c33313b3ce 100644
--- a/bgpd/bgp_bmp.c
+++ b/bgpd/bgp_bmp.c
@@ -3179,6 +3179,28 @@ static int bgp_bmp_early_fini(void)
 	return 0;
 }
 
+/* called when the routerid of an instance changes */
+static int bmp_routerid_update(struct bgp *bgp, bool withdraw)
+{
+	struct bmp_bgp *bmpbgp = bmp_bgp_find(bgp);
+
+	if (!bmpbgp)
+		return 0;
+
+	bmp_bgp_update_vrf_status(bmpbgp, vrf_state_unknown);
+
+	if (bmpbgp->vrf_state == vrf_state_down)
+		/* do not send peer events, router id will not be enough to set state to up
+		 */
+		return 0;
+
+	/* vrf_state is up: trigger a peer event
+	 */
+	bmp_send_all_safe(bmpbgp, bmp_peerstate(bgp->peer_self, withdraw));
+	return 1;
+}
+
+
 /* called when a bgp instance goes up/down, implying that the underlying VRF
  * has been created or deleted in zebra
  */
@@ -3232,6 +3254,7 @@ static int bgp_bmp_module_init(void)
 	hook_register(frr_early_fini, bgp_bmp_early_fini);
 	hook_register(bgp_instance_state, bmp_vrf_state_changed);
 	hook_register(bgp_vrf_status_changed, bmp_vrf_itf_state_changed);
+	hook_register(bgp_routerid_update, bmp_routerid_update);
 	return 0;
 }
 
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 74f79cdd72..f0b4f6c262 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -86,6 +86,7 @@ DEFINE_QOBJ_TYPE(bgp);
 DEFINE_QOBJ_TYPE(peer);
 DEFINE_HOOK(bgp_inst_delete, (struct bgp *bgp), (bgp));
 DEFINE_HOOK(bgp_instance_state, (struct bgp *bgp), (bgp));
+DEFINE_HOOK(bgp_routerid_update, (struct bgp *bgp, bool withdraw), (bgp, withdraw));
 
 /* BGP process wide configuration.  */
 static struct bgp_master bgp_master;
@@ -301,6 +302,8 @@ static int bgp_router_id_set(struct bgp *bgp, const struct in_addr *id,
 
 	vpn_handle_router_id_update(bgp, true, is_config);
 
+	hook_call(bgp_routerid_update, bgp, true);
+
 	IPV4_ADDR_COPY(&bgp->router_id, id);
 
 	/* Set all peer's local identifier with this value. */
@@ -318,6 +321,7 @@ static int bgp_router_id_set(struct bgp *bgp, const struct in_addr *id,
 
 	vpn_handle_router_id_update(bgp, false, is_config);
 
+	hook_call(bgp_routerid_update, bgp, false);
 	return 0;
 }
 
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index 47214e52e5..a493673e59 100644
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -907,6 +907,7 @@ DECLARE_HOOK(bgp_config_end, (struct bgp *bgp), (bgp));
 DECLARE_HOOK(bgp_hook_vrf_update, (struct vrf *vrf, bool enabled),
 	     (vrf, enabled));
 DECLARE_HOOK(bgp_instance_state, (struct bgp *bgp), (bgp));
+DECLARE_HOOK(bgp_routerid_update, (struct bgp *bgp, bool withdraw), (bgp, withdraw));
 
 /* Thread callback information */
 struct afi_safi_info {