[src/trunk]: src/sys/arch/xen/xen Enable the VLAN mtu capability and check fo...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/5c8e96358d0c
branches:  trunk
changeset: 811855:5c8e96358d0c
user:      christos <christos%NetBSD.org@localhost>
date:      Thu Nov 19 17:01:40 2015 +0000

description:
Enable the VLAN mtu capability and check for the adjusted packet size
(Jean-Jacques.Puig at espci.fr).
Factor out the packet-size checking function for clarity.

diffstat:

 sys/arch/xen/xen/if_xennet_xenbus.c  |   5 ++-
 sys/arch/xen/xen/xennetback_xenbus.c |  43 ++++++++++++++++++++++-------------
 2 files changed, 30 insertions(+), 18 deletions(-)

diffs (112 lines):

diff -r 780e712444b6 -r 5c8e96358d0c sys/arch/xen/xen/if_xennet_xenbus.c
--- a/sys/arch/xen/xen/if_xennet_xenbus.c       Thu Nov 19 16:23:54 2015 +0000
+++ b/sys/arch/xen/xen/if_xennet_xenbus.c       Thu Nov 19 17:01:40 2015 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: if_xennet_xenbus.c,v 1.64 2015/04/13 21:18:40 riastradh Exp $      */
+/*      $NetBSD: if_xennet_xenbus.c,v 1.65 2015/11/19 17:01:40 christos Exp $      */
 
 /*
  * Copyright (c) 2006 Manuel Bouyer.
@@ -85,7 +85,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_xennet_xenbus.c,v 1.64 2015/04/13 21:18:40 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_xennet_xenbus.c,v 1.65 2015/11/19 17:01:40 christos Exp $");
 
 #include "opt_xen.h"
 #include "opt_nfs_boot.h"
@@ -362,6 +362,7 @@
            ether_sprintf(sc->sc_enaddr));
        /* Initialize ifnet structure and attach interface */
        strlcpy(ifp->if_xname, device_xname(self), IFNAMSIZ);
+       sc->sc_ethercom.ec_capabilities |= ETHERCAP_VLAN_MTU;
        ifp->if_softc = sc;
        ifp->if_start = xennet_start;
        ifp->if_ioctl = xennet_ioctl;
diff -r 780e712444b6 -r 5c8e96358d0c sys/arch/xen/xen/xennetback_xenbus.c
--- a/sys/arch/xen/xen/xennetback_xenbus.c      Thu Nov 19 16:23:54 2015 +0000
+++ b/sys/arch/xen/xen/xennetback_xenbus.c      Thu Nov 19 17:01:40 2015 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: xennetback_xenbus.c,v 1.52 2013/10/20 11:37:53 bouyer Exp $      */
+/*      $NetBSD: xennetback_xenbus.c,v 1.53 2015/11/19 17:01:40 christos Exp $      */
 
 /*
  * Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.52 2013/10/20 11:37:53 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xennetback_xenbus.c,v 1.53 2015/11/19 17:01:40 christos Exp $");
 
 #include "opt_xen.h"
 
@@ -301,6 +301,7 @@
        /* create pseudo-interface */
        aprint_verbose_ifnet(ifp, "Ethernet address %s\n",
            ether_sprintf(xneti->xni_enaddr));
+       xneti->xni_ec.ec_capabilities |= ETHERCAP_VLAN_MTU;
        ifp->if_flags =
            IFF_BROADCAST|IFF_SIMPLEX|IFF_NOTRAILERS|IFF_MULTICAST;
        ifp->if_snd.ifq_maxlen =
@@ -710,6 +711,23 @@
        }
 }
 
+static inline const char *
+xennetback_tx_check_packet(const netif_tx_request_t *txreq, int vlan)
+{
+       if (__predict_false(txreq->size < ETHER_HDR_LEN))
+               return "too small";
+
+       if (__predict_false(txreq->offset + txreq->size > PAGE_SIZE))
+               return "crossing a page boundary";
+
+       const int maxlen =
+           vlan ? (ETHER_VLAN_ENCAP_LEN + ETHER_MAX_LEN) : ETHER_MAX_LEN;
+       if (__predict_false(txreq->size > maxlen))
+               return "too big";
+
+       return NULL;
+}
+
 static int
 xennetback_evthandler(void *arg)
 {
@@ -745,28 +763,21 @@
                            NETIF_RSP_DROPPED);
                        continue;
                }
+
                /*
                 * Do some sanity checks, and map the packet's page.
                 */
-               if (__predict_false(txreq->size < ETHER_HDR_LEN ||
-                  txreq->size > (ETHER_MAX_LEN - ETHER_CRC_LEN))) {
-                       printf("%s: packet size %d too big\n",
-                           ifp->if_xname, txreq->size);
+               const char *msg = xennetback_tx_check_packet(txreq,
+                   xneti->xni_ec.ec_capenable & ETHERCAP_VLAN_MTU);
+               if (msg) {
+                       printf("%s: packet with size %d is %s\n",
+                           ifp->if_xname, txreq->size, msg);
                        xennetback_tx_response(xneti, txreq->id,
                            NETIF_RSP_ERROR);
                        ifp->if_ierrors++;
                        continue;
                }
-               /* don't cross page boundaries */
-               if (__predict_false(
-                   txreq->offset + txreq->size > PAGE_SIZE)) {
-                       printf("%s: packet cross page boundary\n",
-                           ifp->if_xname);
-                       xennetback_tx_response(xneti, txreq->id,
-                           NETIF_RSP_ERROR);
-                       ifp->if_ierrors++;
-                       continue;
-               }
+
                /* get a mbuf for this packet */
                MGETHDR(m, M_DONTWAIT, MT_DATA);
                if (__predict_false(m == NULL)) {