zebra: zebra_nhg_install_kernel incorrectly logs delay-install connected/kernel-learnt routes

Problem: Zebra incorrectly logs error messages for connected and kernel-learnt routes using the delayed-install optimization: zebra DPlane returned an invalid result code for attempt of installation of 10\[if 2 vrfid 11\] into the kernel

Fix: Handle SUCCESS case for routes with NEXTHOP_GROUP_INITIAL_DELAY_INSTALL. If NEXTHOP_GROUP_INITIAL_DELAY_INSTALL flag set -\> Expected (debug log only)

Signed-off-by: Vaideesh Ravi Shankar <[email protected]>

Author: rvaideesh

zebra/zebra_nhg.c

@@ -3490,6 +3490,16 @@ void zebra_nhg_install_kernel(struct nhg_hash_entry *nhe, uint8_t type)
 				nhe);
 			break;
 		case ZEBRA_DPLANE_REQUEST_SUCCESS:
+			if (CHECK_FLAG(nhe->flags, NEXTHOP_GROUP_INITIAL_DELAY_INSTALL)) {
+				/* Expected: delayed-install optimization */
+				if (IS_ZEBRA_DEBUG_NHG_DETAIL)
+					zlog_debug("%s: NHG %pNG delayed-install optimization (flags 0x%x)",
+						   __func__, nhe, nhe->flags);
+			} else {
+				flog_err(EC_ZEBRA_DP_INVALID_RC,
+					 "DPlane returned an invalid result code for attempt of installation of %pNG into the kernel",
+					 nhe);
+			}
 			break;
 		}
 	}