Finish r275196: do not dereference rtentry in if_output() routines.

The only piece of information that is required is rt_flags subset.

In particular, if_loop() requires RTF_REJECT and RTF_BLACKHOLE flags
  to check if this particular mbuf needs to be dropped (and what
  error should be returned).
Note that if_loop() will always return EHOSTUNREACH for "reject" routes
  regardless of RTF_HOST flag existence. This is due to upcoming routing
  changes where RTF_HOST value won't be available as lookup result.

All other functions require RTF_GATEWAY flag to check if they need
  to return EHOSTUNREACH instead of EHOSTDOWN error.

There are 11 places where non-zero 'struct route' is passed to if_output().
For most of the callers (forwarding, bpf, arp) does not care about exact
  error value. In fact, the only place where this result is propagated
  is ip_output(). (ip6_output() passes NULL route to nd6_output_ifp()).

Given that, add 3 new 'struct route' flags (RT_REJECT, RT_BLACKHOLE and
  RT_IS_GW) and inline function (rt_update_ro_flags()) to copy necessary
  rte flags to ro_flags. Call this function in ip_output() after looking up/
  verifying rte.

Reviewed by:	ae

1 files changed, 2 insertions, 6 deletions

diff --git a/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c b/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c
index e1f2dc082d33..6326bd211e1b 100644
--- a/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -1260,16 +1260,12 @@ ipoib_output(struct ifnet *ifp, struct mbuf *m,
 #if defined(INET) || defined(INET6)
 	struct llentry *lle = NULL;
 #endif
-	struct rtentry *rt0 = NULL;
 	struct ipoib_header *eh;
 	int error = 0, is_gw = 0;
 	short type;
 
-	if (ro != NULL) {
-		rt0 = ro->ro_rt;
-		if (rt0 != NULL && (rt0->rt_flags & RTF_GATEWAY) != 0)
-			is_gw = 1;
-	}
+	if (ro != NULL)
+		is_gw = (ro->ro_flags & RT_HAS_GW) != 0;
 #ifdef MAC
 	error = mac_ifnet_check_transmit(ifp, m);
 	if (error)