Index: sys/sys/mbuf.h
===================================================================
--- sys/sys/mbuf.h
+++ sys/sys/mbuf.h
@@ -187,35 +187,46 @@
 		};
 	};
 	union {
-		uint8_t  eight[8];
-		uint16_t sixteen[4];
-		uint32_t thirtytwo[2];
-		uint64_t sixtyfour[1];
-		uintptr_t unintptr[1];
-		void	*ptr;
-	} PH_per;
+		union {
+			uint8_t  eight[8];
+			uint16_t sixteen[4];
+			uint32_t thirtytwo[2];
+			uint64_t sixtyfour[1];
+			uintptr_t unintptr[1];
+			void	*ptr;
+		} PH_per;
+		struct { /* Ethernet */
+			uint16_t ether_vtag;	/* in and out */
+			uint32_t csum_data;	/* inbound */
+		};
+		uint16_t vt_nrecs;	/* IGMP and MLD6 */
+		struct { /* TCP */
+			uint16_t tcp_tun_port;	/* in and out (tcp_respond) */
+			struct {
+				uint16_t tso_segsz;	/* outbound */
+				uint16_t lro_nsegs;	/* inbound after LRO */
+			};
+		};
+	};
 
 	/* Layer specific non-persistent local storage for reassembly, etc. */
 	union {
-		uint8_t  eight[8];
-		uint16_t sixteen[4];
-		uint32_t thirtytwo[2];
-		uint64_t sixtyfour[1];
-		uintptr_t unintptr[1];
-		void 	*ptr;
-	} PH_loc;
+		union {
+			uint8_t  eight[8];
+			uint16_t sixteen[4];
+			uint32_t thirtytwo[2];
+			uint64_t sixtyfour[1];
+			uintptr_t unintptr[1];
+			void 	*ptr;
+		} PH_loc;
+		struct { /* TCP: inbound during LRO (no reassembly) */
+			uint16_t lro_tcp_d_len;
+			uint16_t lro_tcp_d_csum;
+			uint16_t lro_tcp_h_off;
+			uint16_t lro_etype;
+		};
+	};
 };
-#define	ether_vtag	PH_per.sixteen[0]
-#define tcp_tun_port	PH_per.sixteen[0] /* outbound */
-#define	vt_nrecs	PH_per.sixteen[0]	  /* mld and v6-ND */
-#define	tso_segsz	PH_per.sixteen[1] /* inbound after LRO */
-#define	lro_nsegs	tso_segsz	  /* inbound after LRO */
-#define	csum_data	PH_per.thirtytwo[1] /* inbound from hardware up */
-#define	lro_tcp_d_len	PH_loc.sixteen[0] /* inbound during LRO (no reassembly) */
-#define	lro_tcp_d_csum	PH_loc.sixteen[1] /* inbound during LRO (no reassembly) */
-#define	lro_tcp_h_off	PH_loc.sixteen[2] /* inbound during LRO (no reassembly) */
-#define	lro_etype	PH_loc.sixteen[3] /* inbound during LRO (no reassembly) */
-/* Note PH_loc is used during IP reassembly (all 8 bytes as a ptr) */
 
 /*
  * TLS records for TLS 1.0-1.2 can have the following header lengths: