svn commit: r314484 - head/sys/dev/hyperv/netvsc

[Sepherosa Ziehau]

Author: sephe
Date: Wed Mar  1 08:50:41 2017
New Revision: 314484
URL: https://svnweb.freebsd.org/changeset/base/314484

Log:
  hyperv/hn: Make sure that RNDIS packet message is at least 4B aligned.
  
  MFC after:	1 week
  Sponsored by:	Microsoft
  Differential Revision:	https://reviews.freebsd.org/D9713

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

Modified: head/sys/dev/hyperv/netvsc/hn_rndis.c
==============================================================================
--- head/sys/dev/hyperv/netvsc/hn_rndis.c	Wed Mar  1 08:24:17 2017	(r314483)
+++ head/sys/dev/hyperv/netvsc/hn_rndis.c	Wed Mar  1 08:50:41 2017	(r314484)
@@ -841,9 +841,22 @@ hn_rndis_init(struct hn_softc *sc)
 	sc->hn_rndis_agg_pkts = comp->rm_pktmaxcnt;
 	sc->hn_rndis_agg_align = 1U << comp->rm_align;
 
+	if (sc->hn_rndis_agg_align < sizeof(uint32_t)) {
+		/*
+		 * The RNDIS packet messsage encap assumes that the RNDIS
+		 * packet message is at least 4 bytes aligned.  Fix up the
+		 * alignment here, if the remote side sets the alignment
+		 * too low.
+		 */
+		if_printf(sc->hn_ifp, "fixup RNDIS aggpkt align: %u -> %zu\n",
+		    sc->hn_rndis_agg_align, sizeof(uint32_t));
+		sc->hn_rndis_agg_align = sizeof(uint32_t);
+	}
+
 	if (bootverbose) {
-		if_printf(sc->hn_ifp, "RNDIS ver %u.%u, pktsz %u, pktcnt %u, "
-		    "align %u\n", comp->rm_ver_major, comp->rm_ver_minor,
+		if_printf(sc->hn_ifp, "RNDIS ver %u.%u, "
+		    "aggpkt size %u, aggpkt cnt %u, aggpkt align %u\n",
+		    comp->rm_ver_major, comp->rm_ver_minor,
 		    sc->hn_rndis_agg_size, sc->hn_rndis_agg_pkts,
 		    sc->hn_rndis_agg_align);
 	}