take egre(4) packets out early in gre input

this lets us look up the gre(4) interface before looking at the
protocols it might be carrying.

diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index 88e6149..7a73b73 100644 (file)
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: if_gre.c,v 1.100 2018/02/12 03:15:32 dlg Exp $ */
+/*      $OpenBSD: if_gre.c,v 1.101 2018/02/15 01:03:17 dlg Exp $ */
 /*     $NetBSD: if_gre.c,v 1.9 1999/10/25 19:18:11 drochner Exp $ */
 
 /*
@@ -554,6 +554,15 @@ gre_input_key(struct mbuf **mp, int *offp, int type, int af,
 
        key->t_rtableid = m->m_pkthdr.ph_rtableid;
 
+       if (gh->gre_proto == htons(ETHERTYPE_TRANSETHER)) {
+               if (egre_input(key, m, hlen) == -1)
+                       goto decline;
+       }
+
+       sc = gre_find(key);
+       if (sc == NULL)
+               goto decline;
+
        switch (gh->gre_proto) {
        case htons(GRE_WCCP):
                /* WCCP/GRE:
@@ -616,17 +625,10 @@ gre_input_key(struct mbuf **mp, int *offp, int type, int af,
                input = gre_keepalive_recv;
                break;
 
-       case htons(ETHERTYPE_TRANSETHER):
-               if (egre_input(key, m, hlen) == -1)
-                       goto decline;
        default:
                goto decline;
        }
 
-       sc = gre_find(key);
-       if (sc == NULL)
-               goto decline;
-
        ifp = &sc->sc_if;
 
        m_adj(m, hlen);