pimd: Update show ip pim nexthop-lookup... command

Allow group to be optional in the command. Only validate group if
source is ANY. Documented setting source via RP if not provided.
Added new output if ANY source + group lookup is performed and no
RP is found for the group. Updated output to include souce and
group for lookup.

Signed-off-by: Nathan Bahr <nbahr@atcorp.com>

pimd/pim_cmd.c

@@ -2930,7 +2930,7 @@ DEFPY (show_ip_pim_nexthop,
 
 DEFPY (show_ip_pim_nexthop_lookup,
        show_ip_pim_nexthop_lookup_cmd,
-       "show ip pim [vrf NAME] nexthop-lookup A.B.C.D$source A.B.C.D$group",
+       "show ip pim [vrf NAME] nexthop-lookup A.B.C.D$source [A.B.C.D$group]",
        SHOW_STR
        IP_STR
        PIM_STR

pimd/pim_cmd_common.c

@@ -2989,31 +2989,36 @@ int pim_show_nexthop_lookup_cmd_helper(const char *vrf, struct vty *vty,
 
 #if PIM_IPV == 4
 	if (pim_is_group_224_4(source)) {
-		vty_out(vty,
-			"Invalid argument. Expected Valid Source Address.\n");
+		vty_out(vty, "Invalid argument. Expected Valid Source Address.\n");
 		return CMD_WARNING;
 	}
-
-	if (!pim_is_group_224_4(group)) {
-		vty_out(vty,
-			"Invalid argument. Expected Valid Multicast Group Address.\n");
+	/* Only require group if source is not provided */
+	if (pim_addr_is_any(source) && !pim_is_group_224_4(group)) {
+		vty_out(vty, "Invalid argument. Expected Valid Multicast Group Address.\n");
 		return CMD_WARNING;
 	}
 #endif
 
-	if (!pim_rp_set_upstream_addr(v->info, &vif_source, source, group))
+	/* This call will set vif_source=source, if source is not ANY. Otherwise vif_source
+	 * will be set to the RP address according to the group address. If no RP is configured
+	 * for the group, then return 0 and set vif_source to ANY
+	 */
+	if (!pim_rp_set_upstream_addr(v->info, &vif_source, source, group)) {
+		vty_out(vty, "(%pPAs, %pPA) --- Nexthop Lookup failed, no RP.\n", &source, &group);
 		return CMD_SUCCESS;
+	}
+
 
 	pim_addr_to_prefix(&grp, group);
 	memset(&nexthop, 0, sizeof(nexthop));
 
 	if (!pim_nht_lookup_ecmp(v->info, &nexthop, vif_source, &grp, false)) {
-		vty_out(vty,
-			"Nexthop Lookup failed, no usable routes returned.\n");
+		vty_out(vty, "(%pPAs, %pPA) --- Nexthop Lookup failed, no usable routes returned.\n",
+			&source, &group);
 		return CMD_SUCCESS;
 	}
 
-	vty_out(vty, "Group %pFXh --- Nexthop %pPAs Interface %s\n", &grp,
+	vty_out(vty, "(%pPAs, %pPA) --- Nexthop %pPAs Interface %s\n", &source, &group,
 		&nexthop.mrib_nexthop_addr, nexthop.interface->name);
 
 	return CMD_SUCCESS;