pimd: do static mroute loop check in NB VALIDATE

We can proactively check whether this mroute will be nacked by loopfree
MFC checks so let's do it in the apply phase and emit a useful error
message.

Signed-off-by: Quentin Young <qlyoung@nvidia.com>

diff --git a/pimd/pim_nb_config.c b/pimd/pim_nb_config.c
index 4bc78529a83a9b9c53dcc1fdfcc77f29c2a72043..11cfe09964389a7c6e99add26d4d03fc3b940be6 100644 (file)
--- a/pimd/pim_nb_config.c
+++ b/pimd/pim_nb_config.c
@@ -2394,6 +2394,13 @@ int lib_interface_pim_address_family_mroute_oif_modify(
        struct ipaddr group_addr;
        const struct lyd_node *if_dnode;
 
+       iif = nb_running_get_entry(args->dnode, NULL, true);
+       pim_iifp = iif->info;
+       pim = pim_iifp->pim;
+
+       oifname = yang_dnode_get_string(args->dnode, NULL);
+       oif = if_lookup_by_name(oifname, pim->vrf_id);
+
        switch (args->event) {
        case NB_EV_VALIDATE:
                if_dnode = yang_dnode_get_parent(args->dnode, "interface");
@@ -2402,18 +2409,20 @@ int lib_interface_pim_address_family_mroute_oif_modify(
                                 "%% Enable PIM and/or IGMP on this interface first");
                        return NB_ERR_VALIDATION;
                }
+
+#ifdef PIM_ENFORCE_LOOPFREE_MFC
+               if (iif->ifindex == oif->ifindex) {
+                       strlcpy(args->errmsg,
+                               "% IIF same as OIF and loopfree enforcement is enabled; rejecting",
+                               args->errmsg_len);
+                       return NB_ERR_VALIDATION;
+               }
+#endif
                break;
        case NB_EV_PREPARE:
        case NB_EV_ABORT:
                break;
        case NB_EV_APPLY:
-               iif = nb_running_get_entry(args->dnode, NULL, true);
-               pim_iifp = iif->info;
-               pim = pim_iifp->pim;
-
-               oifname = yang_dnode_get_string(args->dnode, NULL);
-               oif = if_lookup_by_name(oifname, pim->vrf_id);
-
                if (!oif) {
                        snprintf(args->errmsg, args->errmsg_len,
                                 "No such interface name %s",