svn commit: r242802 - user/andre/tcp_workqueue/sys/net

[Andre Oppermann]

Author: andre
Date: Thu Nov  8 22:40:24 2012
New Revision: 242802
URL: http://svnweb.freebsd.org/changeset/base/242802

Log:
  Save this for later continuation: Different approach on ECMP
  (equal cost multi path) routing.  Instead of having shadow
  rtentry's linked behind the one in the trie, just have an
  array of different egress interface and next-hops.  This
  simplifies the code significantly.
  
  A normal add to the routing table then sets the main next-
  hop.  A ECMP aware add or modify can change any of the other
  next hops in the rtentry.
  
  The next-hop list is sorted by priority (distance in Cisco
  parlance) with the highest first.  Equal priority next-hops
  are next to each other sorted by next-hop IP address.  If
  the highest priority has more than one next-hop load is
  equally shared among them.  All other routes with lower
  weight are not used.  When a higher priority next-hop is
  removed or flagged as unavailable (eg. interface link down)
  the next higher priority prefix will become active.  When
  only unavailable next-hops are in the rtentry it is ignored
  and a less specific match is searched for.  If no route is
  found the lookup will fail.  When an unavailable next-hop
  becomes available again, the rtentry is valid again and will
  match on lookups.  This way we can implement suppression of
  routes on link state down interfaces without having to actually
  remove the rtentry.  Additionally it is automatically reinstated
  when the link comes back.  This way for example a OSPF route
  can take precedence and NLRI reachability is ensured.  This
  is the same behavior as of Cisco, Juniper and other router
  vendors.

Modified:
  user/andre/tcp_workqueue/sys/net/route.h

Modified: user/andre/tcp_workqueue/sys/net/route.h
==============================================================================
--- user/andre/tcp_workqueue/sys/net/route.h	Thu Nov  8 21:40:05 2012	(r242801)
+++ user/andre/tcp_workqueue/sys/net/route.h	Thu Nov  8 22:40:24 2012	(r242802)
@@ -112,6 +112,14 @@ struct mbuf;
 #include <net/radix_mpath.h>
 #endif
 #endif
+struct rtgw {
+	struct	ifnet *rtgw_ifp;	/* the answer: interface to use */
+	struct	sockaddr *rtgw_gateway;	/* value */
+	uint16_t rtgw_flags;		/* nexthop flags */
+	uint8_t	rtgw_priority;		/* nexthop weight */
+};
+#define	RTGW_VALID	0x00000001
+
 struct rtentry {
 	struct	radix_node rt_nodes[2];	/* tree glue, and other values */
 	/*
@@ -121,18 +129,19 @@ struct rtentry {
 	 */
 #define	rt_key(r)	(*((struct sockaddr **)(&(r)->rt_nodes->rn_key)))
 #define	rt_mask(r)	(*((struct sockaddr **)(&(r)->rt_nodes->rn_mask)))
-	struct	sockaddr *rt_gateway;	/* value */
 	int	rt_flags;		/* up/down?, host/net */
-	int	rt_refcnt;		/* # held references */
-	struct	ifnet *rt_ifp;		/* the answer: interface to use */
+	struct	rtgw rt_gw[8];		/* equal cost multipath */
 	struct	ifaddr *rt_ifa;		/* the answer: interface address to use */
 	struct	rt_metrics_lite rt_rmx;	/* metrics used by rx'ing protocols */
 	u_int	rt_fibnum;		/* which FIB */
+	int	rt_refcnt;		/* # held references */
 #ifdef _KERNEL
 	/* XXX ugly, user apps use this definition but don't have a mtx def */
 	struct	mtx rt_mtx;		/* mutex for routing entry */
 #endif
 };
+#define	rt_ifp		rt_gw[0].rtgw_ifp
+#define	rt_gateway	rt_gw[0].rtgw_gateway
 
 /*
  * Following structure necessary for 4.3 compatibility;
@@ -141,11 +150,11 @@ struct rtentry {
 struct ortentry {
 	u_long	rt_hash;		/* to speed lookups */
 	struct	sockaddr rt_dst;	/* key */
-	struct	sockaddr rt_gateway;	/* value */
+	struct	sockaddr rt_gateway_o;	/* value */
 	short	rt_flags;		/* up/down?, host/net */
 	short	rt_refcnt;		/* # held references */
 	u_long	rt_use;			/* raw # packets forwarded */
-	struct	ifnet *rt_ifp;		/* the answer: interface to use */
+	struct	ifnet *rt_ifp_o;	/* the answer: interface to use */
 };
 
 #define rt_use rt_rmx.rmx_pksent