When ip_output()/ip6_output() is supplied a struct route *ro argument,

it skips FLOWTABLE lookup. However, the non-NULL ro has dual meaning
here: it may be supplied to provide route, and it may be supplied to
store and return to caller the route that ip_output()/ip6_output()
finds. In the latter case skipping FLOWTABLE lookup is pessimisation.

The difference between struct route filled by FLOWTABLE and filled
by rtalloc() family is that the former doesn't hold a reference on
its rtentry. Reference is hold by flow entry, and it is about to
be released in future. Thus, route filled by FLOWTABLE shouldn't
be passed to RTFREE() macro.

- Introduce new flag for struct route/route_in6, that marks route
  not holding a reference on rtentry.
- Introduce new macro RO_RTFREE() that cleans up a struct route
  depending on its kind.
- All callers to ip_output()/ip6_output() that do supply non-NULL
  but empty route should use RO_RTFREE() to free results of
  lookup.
- ip_output()/ip6_output() now do FLOWTABLE lookup always when
  ro->ro_rt == NULL.

Tested by:	tuexen (SCTP part)

1 files changed, 6 insertions, 6 deletions

diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index 4b80dc2..a203558 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -595,9 +595,9 @@ nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
 	icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
 	ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
 
-	if (ro.ro_rt) {		/* we don't cache this route. */
-		RTFREE(ro.ro_rt);
-	}
+	/* We don't cache this route. */
+	RO_RTFREE(&ro);
+
 	return;
 
   bad:
@@ -1124,9 +1124,9 @@ nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
 	icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
 	ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
 
-	if (ro.ro_rt) {		/* we don't cache this route. */
-		RTFREE(ro.ro_rt);
-	}
+	/* We don't cache this route. */
+	RO_RTFREE(&ro);
+
 	return;
 
   bad: