bgpd: Show hostname in `show [ip] bgp ...` only if nexthop is connected

The problem is when using kinda such topologies:
(192.168.1.1/32) r1 <-- eBGP --> r2 <-- iBGP --> r3

Looking at r3's nexthop for 192.168.1.1/32 we have it as r2, but really
it MUST be r1.

Checking if the nexthop is connected solves the problem even for cases
when route-reflectors are used.

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 5f4486b8004252115eed66fa33771999d78f33ca..7aad1e4ecda8ea5ab91b2b2736cbf7f20cd058bc 100644 (file)
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -7155,10 +7155,12 @@ static void route_vty_short_status_out(struct vty *vty,
                vty_out(vty, " ");
 }
 
-static char *bgp_nexthop_hostname(struct peer *peer, struct attr *attr)
+static char *bgp_nexthop_hostname(struct peer *peer,
+                                 struct bgp_nexthop_cache *bnc)
 {
-       if (peer->hostname && bgp_flag_check(peer->bgp, BGP_FLAG_SHOW_HOSTNAME)
-           && !(attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID)))
+       if (peer->hostname
+           && CHECK_FLAG(peer->bgp->flags, BGP_FLAG_SHOW_HOSTNAME)
+           && CHECK_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED))
                return peer->hostname;
        return NULL;
 }
@@ -7180,7 +7182,8 @@ void route_vty_out(struct vty *vty, struct prefix *p,
        bool nexthop_othervrf = false;
        vrf_id_t nexthop_vrfid = VRF_DEFAULT;
        const char *nexthop_vrfname = VRF_DEFAULT_NAME;
-       char *nexthop_hostname = bgp_nexthop_hostname(path->peer, attr);
+       char *nexthop_hostname =
+               bgp_nexthop_hostname(path->peer, path->nexthop);
 
        if (json_paths)
                json_path = json_object_new_object();
@@ -8308,7 +8311,8 @@ void route_vty_out_detail(struct vty *vty, struct bgp *bgp,
        bool nexthop_self =
                CHECK_FLAG(path->flags, BGP_PATH_ANNC_NH_SELF) ? true : false;
        int i;
-       char *nexthop_hostname = bgp_nexthop_hostname(path->peer, attr);
+       char *nexthop_hostname =
+               bgp_nexthop_hostname(path->peer, path->nexthop);
 
        if (json_paths) {
                json_path = json_object_new_object();