netpoll: handle vlan tags in netpoll tx and rx path

Without this patch, I can't get netconsole logs remotely over
vlan. The reason is probably we don't handle vlan tags in either
netpoll tx or rx path.

I am not sure if I use these vlan functions correctly, at
least this patch works.

Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 174346a..e4ba3e7 100644 (file)
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -26,6 +26,7 @@
 #include <linux/workqueue.h>
 #include <linux/slab.h>
 #include <linux/export.h>
+#include <linux/if_vlan.h>
 #include <net/tcp.h>
 #include <net/udp.h>
 #include <asm/unaligned.h>
@@ -334,6 +335,14 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
                     tries > 0; --tries) {
                        if (__netif_tx_trylock(txq)) {
                                if (!netif_xmit_stopped(txq)) {
+                                       if (vlan_tx_tag_present(skb) &&
+                                           !(netif_skb_features(skb) & NETIF_F_HW_VLAN_TX)) {
+                                               skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
+                                               if (unlikely(!skb))
+                                                       break;
+                                               skb->vlan_tci = 0;
+                                       }
+
                                        status = ops->ndo_start_xmit(skb, dev);
                                        if (status == NETDEV_TX_OK)
                                                txq_trans_update(txq);
@@ -567,6 +576,12 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
                return 1;
        }
 
+       if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
+               skb = vlan_untag(skb);
+               if (unlikely(!skb))
+                       goto out;
+       }
+
        proto = ntohs(eth_hdr(skb)->h_proto);
        if (proto != ETH_P_IP)
                goto out;