From: mk <mk@openbsd.org>
Date: Wed, 14 Jul 2010 20:44:17 +0000 (+0000)
Subject: In urndis_decap(), delay the memcpy() for as long as possible.  There is
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2ebf542f019c47d598627f03d196c2ff9a161139;p=openbsd

In urndis_decap(), delay the memcpy() for as long as possible.  There is
no point in copying before having done the final sanity check (we copied
before the last one).

ok armani
---

diff --git a/sys/dev/usb/if_urndis.c b/sys/dev/usb/if_urndis.c
index 42b047acae5..26aa0a8f2cd 100644
--- a/sys/dev/usb/if_urndis.c
+++ b/sys/dev/usb/if_urndis.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_urndis.c,v 1.22 2010/07/14 20:21:55 mk Exp $ */
+/*	$OpenBSD: if_urndis.c,v 1.23 2010/07/14 20:44:17 mk Exp $ */
 
 /*
  * Copyright (c) 2010 Jonathan Armani <armani@openbsd.org>
@@ -850,20 +850,21 @@ urndis_decap(struct urndis_softc *sc, struct urndis_chain *c, u_int32_t len)
 			return;
 		}
 
-		memcpy(mtod(m, char*),
-		    ((char*)&msg->rm_dataoffset + letoh32(msg->rm_dataoffset)),
-		    letoh32(msg->rm_datalen));
-		m->m_pkthdr.len = m->m_len = letoh32(msg->rm_datalen);
-
-		if (m->m_len < sizeof(struct ether_header)) {
+		if (letoh32(msg->rm_datalen) < sizeof(struct ether_header)) {
 			ifp->if_ierrors++;
 			printf("%s: urndis_decap invalid ethernet size "
 			    "%d < %d\n",
 			    DEVNAME(sc),
-			    m->m_len,
+			    letoh32(msg->rm_datalen),
 			    sizeof(struct ether_header));
 			return;
 		}
+
+		memcpy(mtod(m, char*),
+		    ((char*)&msg->rm_dataoffset + letoh32(msg->rm_dataoffset)),
+		    letoh32(msg->rm_datalen));
+		m->m_pkthdr.len = m->m_len = letoh32(msg->rm_datalen);
+
 		ifp->if_ipackets++;
 		m->m_pkthdr.rcvif = ifp;