svn commit: r305965 - head/sys/dev/hyperv/netvsc

[Sepherosa Ziehau]

Author: sephe
Date: Mon Sep 19 07:32:08 2016
New Revision: 305965
URL: https://svnweb.freebsd.org/changeset/base/305965

Log:
  hyperv/hn: Don't allow MTU change, if it is not supported by the NVS.
  
  MFC after:	1 week
  Sponsored by:	Microsoft
  Differential Revision:	https://reviews.freebsd.org/D7923

Modified:
  head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c

Modified: head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
==============================================================================
--- head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c	Mon Sep 19 07:17:43 2016	(r305964)
+++ head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c	Mon Sep 19 07:32:08 2016	(r305965)
@@ -1572,6 +1572,13 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, 
 
 		HN_LOCK(sc);
 
+		if ((sc->hn_caps & HN_CAP_MTU) == 0) {
+			/* Can't change MTU */
+			HN_UNLOCK(sc);
+			error = EOPNOTSUPP;
+			break;
+		}
+
 		if (ifp->if_mtu == ifr->ifr_mtu) {
 			HN_UNLOCK(sc);
 			break;