Add three new route flags to help determine what sort of address

the destination represents.  For IP:

- Iff it is a host route, RTF_LOCAL and RTF_BROADCAST indicate local
  (belongs to this host) and broadcast addresses, respectively.

- For all routes, RTF_MULTICAST is set if the destination is multicast.

The RTF_BROADCAST flag is used by ip_output() to eliminate a call to
in_broadcast() in a common case; this gives about 1% in our packet-generation
experiments.  All three flags might be used (although they aren't now)
to determine whether a packet can be forwarded; a given host route can
represent a forwardable address if:

	(rt->rt_flags & (RTF_HOST | RTF_LOCAL | RTF_BROADCAST | RTF_MULTICAST))
	== RTF_HOST

Obviously, one still has to do all the work if a host route is not present,
but this code allows one to cache the results of such a lookup if rtalloc1()
is called without masking RTF_PRCLONING.

1 files changed, 5 insertions, 2 deletions

diff --git a/sys/net/route.h b/sys/net/route.h
index e6e504a..fa1a1bb 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)route.h	8.3 (Berkeley) 4/19/94
- * $Id: route.h,v 1.19 1995/12/14 09:53:28 phk Exp $
+ * $Id: route.h,v 1.20 1996/01/30 22:58:00 mpp Exp $
  */
 
 #ifndef _NET_ROUTE_H_
@@ -154,7 +154,10 @@ struct ortentry {
 #define RTF_PROTO3	0x40000		/* protocol specific routing flag */
 #define RTF_CHAINDELETE	0x80000		/* chain is being deleted (internal) */
 #define RTF_PINNED	0x100000	/* future use */
-					/* 0x200000 and up unassigned */
+#define	RTF_LOCAL	0x200000 	/* route represents a local address */
+#define	RTF_BROADCAST	0x400000	/* route represents a bcast address */
+#define	RTF_MULTICAST	0x800000	/* route represents a mcast address */
+					/* 0x1000000 and up unassigned */
 
 /*
  * Routing statistics.