have pf_route bail out if it resolves a route with RTF_LOCAL set

[David Gwynne]

calling if_output with a route to a local IP is confusing, and I'm not
sure it makes sense anyway.

this treats a an RTF_LOCAL route like an invalid round and drops the
packet.

ok?

Index: pf.c
===================================================================
RCS file: /cvs/src/sys/net/pf.c,v
retrieving revision 1.1104
diff -u -p -r1.1104 pf.c
--- pf.c        27 Jan 2021 23:53:35 -0000      1.1104
+++ pf.c        27 Jan 2021 23:55:49 -0000
@@ -6054,7 +6054,7 @@ pf_route(struct pf_pdesc *pd, struct pf_
        }
 
        rt = rtalloc(sintosa(dst), RT_RESOLVE, rtableid);
-       if (!rtisvalid(rt)) {
+       if (!rtisvalid(rt) || ISSET(rt->rt_flags, RTF_LOCAL)) {
                if (r->rt != PF_DUPTO) {
                        pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_HOST,
                            0, pd->af, s->rule.ptr, pd->rdomain);
@@ -6213,7 +6213,7 @@ pf_route6(struct pf_pdesc *pd, struct pf
        if (IN6_IS_SCOPE_EMBED(&dst->sin6_addr))
                dst->sin6_addr.s6_addr16[1] = htons(ifp->if_index);
        rt = rtalloc(sin6tosa(dst), RT_RESOLVE, rtableid);
-       if (!rtisvalid(rt)) {
+       if (!rtisvalid(rt) || ISSET(rt->rt_flags, RTF_LOCAL)) {
                if (r->rt != PF_DUPTO) {
                        pf_send_icmp(m0, ICMP6_DST_UNREACH,
                            ICMP6_DST_UNREACH_NOROUTE, 0,