bonding/vlan: Fix mangled NAs on slaves without VLAN tag insertion

bond_na_send() attempts to insert a VLAN tag in between building and
sending packets of the respective formats.  If the slave does not
implement hardware VLAN tag insertion then vlan_put_tag() will mangle
the network-layer header because the Ethernet header is not present at
this point (unlike in bond_arp_send()).

Fix this by adding the tag out-of-line and relying on
dev_hard_start_xmit() to insert it inline if necessary.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Reviewed-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/net/bonding/bond_ipv6.c b/drivers/net/bonding/bond_ipv6.c
index 121b073a6c3f..84fbd4ebd778 100644
--- a/drivers/net/bonding/bond_ipv6.c
+++ b/drivers/net/bonding/bond_ipv6.c
@@ -88,7 +88,12 @@ static void bond_na_send(struct net_device *slave_dev,
         }
 
         if (vlan_id) {
-                skb = vlan_put_tag(skb, vlan_id);
+                /* The Ethernet header is not present yet, so it is
+                 * too early to insert a VLAN tag.  Force use of an
+                 * out-of-line tag here and let dev_hard_start_xmit()
+                 * insert it if the slave hardware can't.
+                 */
+                skb = __vlan_hwaccel_put_tag(skb, vlan_id);
                 if (!skb) {
                         pr_err("failed to insert VLAN tag\n");
                         return;