dont inherit the parent interfaces hardmtu as the vlan interfaces

mtu when it gets set up. instead, allow the vlan interfaces mtu to
be raised to the parents hardmtu in SIOCSIFMTU handling.

pointed out by claudio@

diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 98963e6..072b28b 100644 (file)
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_vlan.c,v 1.114 2015/04/07 10:46:20 mpi Exp $       */
+/*     $OpenBSD: if_vlan.c,v 1.115 2015/04/10 02:08:08 dlg Exp $       */
 
 /*
  * Copyright 1998 Massachusetts Institute of Technology
@@ -377,9 +377,9 @@ vlan_config(struct ifvlan *ifv, struct ifnet *p, u_int16_t tag)
        ifv->ifv_if.if_baudrate = p->if_baudrate;
 
        if (p->if_capabilities & IFCAP_VLAN_MTU)
-               ifv->ifv_if.if_mtu = p->if_hardmtu;
+               ifv->ifv_if.if_mtu = p->if_mtu;
        else
-               ifv->ifv_if.if_mtu = p->if_hardmtu - EVL_ENCAPLEN;
+               ifv->ifv_if.if_mtu = p->if_mtu - EVL_ENCAPLEN;
 
        ifv->ifv_if.if_flags = p->if_flags &
            (IFF_UP | IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
@@ -561,9 +561,9 @@ vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
        case SIOCSIFMTU:
                if (ifv->ifv_p != NULL) {
                        if (ifv->ifv_p->if_capabilities & IFCAP_VLAN_MTU)
-                               p_mtu = ifv->ifv_p->if_mtu;
+                               p_mtu = ifv->ifv_p->if_hardmtu;
                        else
-                               p_mtu = ifv->ifv_p->if_mtu - EVL_ENCAPLEN;
+                               p_mtu = ifv->ifv_p->if_hardmtu - EVL_ENCAPLEN;
                        
                        if (ifr->ifr_mtu > p_mtu || ifr->ifr_mtu < ETHERMIN)
                                error = EINVAL;