This change re-adds L2 caching for TCP and UDP, as originally added in D4306

but removed due to other changes in the system. Restore the llentry pointer
to the "struct route", and use it to cache the L2 lookup (ARP or ND6) as
appropriate.

Submitted by:	Mike Karels
Differential Revision:	https://reviews.freebsd.org/D6262

1 files changed, 12 insertions, 3 deletions

diff --git a/sys/net/route.h b/sys/net/route.h
index e0ff6b4..46e2ace 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -50,6 +50,11 @@
  */
 struct route {
 	struct	rtentry *ro_rt;
+	struct	llentry *ro_lle;
+	/*
+	 * ro_prepend and ro_plen are only used for bpf to pass in a
+	 * preformed header.  They are not cacheable.
+	 */
 	char		*ro_prepend;
 	uint16_t	ro_plen;
 	uint16_t	ro_flags;
@@ -71,6 +76,7 @@ struct route {
 #define	RT_REJECT		0x0020		/* Destination is reject */
 #define	RT_BLACKHOLE		0x0040		/* Destination is blackhole */
 #define	RT_HAS_GW		0x0080		/* Destination has GW  */
+#define	RT_LLE_CACHE		0x0100		/* Cache link layer  */
 
 struct rt_metrics {
 	u_long	rmx_locks;	/* Kernel must leave these values alone */
@@ -399,6 +405,7 @@ struct rt_addrinfo {
 		if ((_ro)->ro_flags & RT_NORTREF) {		\
 			(_ro)->ro_flags &= ~RT_NORTREF;		\
 			(_ro)->ro_rt = NULL;			\
+			(_ro)->ro_lle = NULL;			\
 		} else {					\
 			RT_LOCK((_ro)->ro_rt);			\
 			RTFREE_LOCKED((_ro)->ro_rt);		\
@@ -413,9 +420,11 @@ struct rt_addrinfo {
  */
 #define RT_VALIDATE(ro, cookiep, fibnum) do {				\
 	rt_gen_t cookie = RT_GEN(fibnum, (ro)->ro_dst.sa_family);	\
-	if (*(cookiep) != cookie && (ro)->ro_rt != NULL) {		\
-		RTFREE((ro)->ro_rt);					\
-		(ro)->ro_rt = NULL;					\
+	if (*(cookiep) != cookie) {					\
+		if ((ro)->ro_rt != NULL) {				\
+			RTFREE((ro)->ro_rt);				\
+			(ro)->ro_rt = NULL;				\
+		}							\
 		*(cookiep) = cookie;					\
 	}								\
 } while (0)