bgpd: Fix display when using `missing-as-worst`

The usage of the `bgp bestpath med missing-as-worst` command
was being accepted and applied during bestpath, but during output
of the routes affected by this it would not give any indication
that this was happening or what med value was being used.

Fixes: #15718
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
(cherry picked from commit bc9885b22e79ac14fd931517582d0d6d80f68c85)

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 38983e29913db083919417184e2bb0a0828650cb..ac54b9612d7d4c545b28f380dc74e526e49f1549 100644 (file)
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -553,6 +553,15 @@ void bgp_path_info_unset_flag(struct bgp_dest *dest, struct bgp_path_info *pi,
        bgp_pcount_adjust(dest, pi);
 }
 
+static bool use_bgp_med_value(struct attr *attr, struct bgp *bgp)
+{
+       if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC) ||
+           CHECK_FLAG(bgp->flags, BGP_FLAG_MED_MISSING_AS_WORST))
+               return true;
+
+       return false;
+}
+
 /* Get MED value.  If MED value is missing and "bgp bestpath
    missing-as-worst" is specified, treat it as the worst value. */
 static uint32_t bgp_med_value(struct attr *attr, struct bgp *bgp)
@@ -9400,14 +9409,16 @@ void route_vty_out(struct vty *vty, const struct prefix *p,
        }
 
        /* MED/Metric */
-       if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC))
+       if (use_bgp_med_value(attr, path->peer->bgp)) {
+               uint32_t value = bgp_med_value(attr, path->peer->bgp);
+
                if (json_paths)
-                       json_object_int_add(json_path, "metric", attr->med);
+                       json_object_int_add(json_path, "metric", value);
                else if (wide)
-                       vty_out(vty, "%7u", attr->med);
+                       vty_out(vty, "%7u", value);
                else
-                       vty_out(vty, "%10u", attr->med);
-       else if (!json_paths) {
+                       vty_out(vty, "%10u", value);
+       } else if (!json_paths) {
                if (wide)
                        vty_out(vty, "%*s", 7, " ");
                else
@@ -9528,7 +9539,7 @@ void route_vty_out(struct vty *vty, const struct prefix *p,
 }
 
 /* called from terminal list command */
-void route_vty_out_tmp(struct vty *vty, struct bgp_dest *dest,
+void route_vty_out_tmp(struct vty *vty, struct bgp *bgp, struct bgp_dest *dest,
                       const struct prefix *p, struct attr *attr, safi_t safi,
                       bool use_json, json_object *json_ar, bool wide)
 {
@@ -9587,10 +9598,11 @@ void route_vty_out_tmp(struct vty *vty, struct bgp_dest *dest,
                                        &attr->mp_nexthop_global_in);
                        }
 
-                       if (attr->flag
-                           & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC))
-                               json_object_int_add(json_net, "metric",
-                                                   attr->med);
+                       if (use_bgp_med_value(attr, bgp)) {
+                               uint32_t value = bgp_med_value(attr, bgp);
+
+                               json_object_int_add(json_net, "metric", value);
+                       }
 
                        if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF))
                                json_object_int_add(json_net, "locPrf",
@@ -9630,13 +9642,15 @@ void route_vty_out_tmp(struct vty *vty, struct bgp_dest *dest,
                                else
                                        vty_out(vty, "%*s", len, " ");
                        }
-                       if (attr->flag
-                           & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC))
+
+                       if (use_bgp_med_value(attr, bgp)) {
+                               uint32_t value = bgp_med_value(attr, bgp);
+
                                if (wide)
-                                       vty_out(vty, "%7u", attr->med);
+                                       vty_out(vty, "%7u", value);
                                else
-                                       vty_out(vty, "%10u", attr->med);
-                       else if (wide)
+                                       vty_out(vty, "%10u", value);
+                       } else if (wide)
                                vty_out(vty, "       ");
                        else
                                vty_out(vty, "          ");
@@ -10631,11 +10645,13 @@ void route_vty_out_detail(struct vty *vty, struct bgp *bgp, struct bgp_dest *bn,
                vty_out(vty, "      Origin %s",
                        bgp_origin_long_str[attr->origin]);
 
-       if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC)) {
+       if (use_bgp_med_value(attr, bgp)) {
+               uint32_t value = bgp_med_value(attr, bgp);
+
                if (json_paths)
-                       json_object_int_add(json_path, "metric", attr->med);
+                       json_object_int_add(json_path, "metric", value);
                else
-                       vty_out(vty, ", metric %u", attr->med);
+                       vty_out(vty, ", metric %u", value);
        }
 
        if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF)) {
@@ -14279,7 +14295,7 @@ show_adj_route(struct vty *vty, struct peer *peer, struct bgp_table *table,
                                                        json_ar, json_net,
                                                        "%pFX", rn_p);
                                } else
-                                       route_vty_out_tmp(vty, dest, rn_p,
+                                       route_vty_out_tmp(vty, bgp, dest, rn_p,
                                                          &attr, safi, use_json,
                                                          json_ar, wide);
                                bgp_attr_flush(&attr);
@@ -14342,11 +14358,15 @@ show_adj_route(struct vty *vty, struct peer *peer, struct bgp_table *table,
                                                                        "%pFX",
                                                                        rn_p);
                                                } else
-                                                       route_vty_out_tmp(
-                                                               vty, dest, rn_p,
-                                                               &attr, safi,
-                                                               use_json,
-                                                               json_ar, wide);
+                                                       route_vty_out_tmp(vty,
+                                                                         bgp,
+                                                                         dest,
+                                                                         rn_p,
+                                                                         &attr,
+                                                                         safi,
+                                                                         use_json,
+                                                                         json_ar,
+                                                                         wide);
                                                (*output_count)++;
                                        } else {
                                                (*filtered_count)++;
@@ -14384,9 +14404,10 @@ show_adj_route(struct vty *vty, struct peer *peer, struct bgp_table *table,
                                                        json_ar, json_net,
                                                        "%pFX", rn_p);
                                } else
-                                       route_vty_out_tmp(
-                                               vty, dest, rn_p, pi->attr, safi,
-                                               use_json, json_ar, wide);
+                                       route_vty_out_tmp(vty, bgp, dest, rn_p,
+                                                         pi->attr, safi,
+                                                         use_json, json_ar,
+                                                         wide);
                                (*output_count)++;
                        }
                }

diff --git a/bgpd/bgp_route.h b/bgpd/bgp_route.h
index 2d82f0f206f743ebb826ee525b09f375ab602cf3..2929c75df76fa7ae87ac8c01465b8cd407a9179d 100644 (file)
--- a/bgpd/bgp_route.h
+++ b/bgpd/bgp_route.h
@@ -845,10 +845,10 @@ extern void route_vty_out(struct vty *vty, const struct prefix *p,
 extern void route_vty_out_tag(struct vty *vty, const struct prefix *p,
                              struct bgp_path_info *path, int display,
                              safi_t safi, json_object *json);
-extern void route_vty_out_tmp(struct vty *vty, struct bgp_dest *dest,
-                             const struct prefix *p, struct attr *attr,
-                             safi_t safi, bool use_json, json_object *json_ar,
-                             bool wide);
+extern void route_vty_out_tmp(struct vty *vty, struct bgp *bgp,
+                             struct bgp_dest *dest, const struct prefix *p,
+                             struct attr *attr, safi_t safi, bool use_json,
+                             json_object *json_ar, bool wide);
 extern void route_vty_out_overlay(struct vty *vty, const struct prefix *p,
                                  struct bgp_path_info *path, int display,
                                  json_object *json);

diff --git a/bgpd/bgp_updgrp_adv.c b/bgpd/bgp_updgrp_adv.c
index 267a7567dc9be8610737e069c848362ae639bb40..9d6226558d61e7b5ace2b6a73c8e186a32063f02 100644 (file)
--- a/bgpd/bgp_updgrp_adv.c
+++ b/bgpd/bgp_updgrp_adv.c
@@ -304,15 +304,16 @@ static void subgrp_show_adjq_vty(struct update_subgroup *subgrp,
                        }
                        if ((flags & UPDWALK_FLAGS_ADVQUEUE) && adj->adv &&
                            adj->adv->baa) {
-                               route_vty_out_tmp(
-                                       vty, dest, dest_p, adj->adv->baa->attr,
-                                       SUBGRP_SAFI(subgrp), 0, NULL, false);
+                               route_vty_out_tmp(vty, bgp, dest, dest_p,
+                                                 adj->adv->baa->attr,
+                                                 SUBGRP_SAFI(subgrp), 0, NULL,
+                                                 false);
                                output_count++;
                        }
                        if ((flags & UPDWALK_FLAGS_ADVERTISED) && adj->attr) {
-                               route_vty_out_tmp(vty, dest, dest_p, adj->attr,
-                                                 SUBGRP_SAFI(subgrp), 0, NULL,
-                                                 false);
+                               route_vty_out_tmp(vty, bgp, dest, dest_p,
+                                                 adj->attr, SUBGRP_SAFI(subgrp),
+                                                 0, NULL, false);
                                output_count++;
                        }
                }

diff --git a/bgpd/bgp_vpn.c b/bgpd/bgp_vpn.c
index 8fe24ebe20fc892fe495c59d1b9aa898516a4768..2470fb8844097438452e0b6b6a00527afe7253d6 100644 (file)
--- a/bgpd/bgp_vpn.c
+++ b/bgpd/bgp_vpn.c
@@ -191,7 +191,7 @@ int show_adj_route_vpn(struct vty *vty, struct peer *peer,
                                }
                                rd_header = 0;
                        }
-                       route_vty_out_tmp(vty, rm, bgp_dest_get_prefix(rm),
+                       route_vty_out_tmp(vty, bgp, rm, bgp_dest_get_prefix(rm),
                                          attr, safi, use_json, json_routes,
                                          false);
                        output_count++;

diff --git a/doc/user/bgp.rst b/doc/user/bgp.rst
index 53dc551ca3530b22740c1ff7c9c72a4698f879ca..99d2a8c355d9e9a7bbb4e775081e07f853122392 100644 (file)
--- a/doc/user/bgp.rst
+++ b/doc/user/bgp.rst
@@ -425,6 +425,11 @@ Route Selection
 
    Disabled by default.
 
+.. clicmd:: bgp bestpath med missing-as-worst
+
+   If the paths MED value is missing and this command is configured
+   then treat it as the worse possible value that it can be.
+
 .. clicmd:: maximum-paths (1-128)
 
    Sets the maximum-paths value used for ecmp calculations for this