macvtap: restore vlan header on user read
Ethernet vlan header is not on the packet and kept in the skb->vlan_tci
when it comes from lower dev. This patch inserts vlan header in user
buffer during skb copy on user read.
Signed-off-by: Basil Gor <basil.gor@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 0427c65..cb8fd50 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -1,5 +1,6 @@
#include <linux/etherdevice.h>
#include <linux/if_macvlan.h>
+#include <linux/if_vlan.h>
#include <linux/interrupt.h>
#include <linux/nsproxy.h>
#include <linux/compat.h>
@@ -759,6 +760,8 @@
struct macvlan_dev *vlan;
int ret;
int vnet_hdr_len = 0;
+ int vlan_offset = 0;
+ int copied;
if (q->flags & IFF_VNET_HDR) {
struct virtio_net_hdr vnet_hdr;
@@ -773,18 +776,48 @@
if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
return -EFAULT;
}
+ copied = vnet_hdr_len;
- len = min_t(int, skb->len, len);
+ if (!vlan_tx_tag_present(skb))
+ len = min_t(int, skb->len, len);
+ else {
+ int copy;
+ struct {
+ __be16 h_vlan_proto;
+ __be16 h_vlan_TCI;
+ } veth;
+ veth.h_vlan_proto = htons(ETH_P_8021Q);
+ veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
- ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len);
+ vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
+ len = min_t(int, skb->len + VLAN_HLEN, len);
+ copy = min_t(int, vlan_offset, len);
+ ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
+ len -= copy;
+ copied += copy;
+ if (ret || !len)
+ goto done;
+
+ copy = min_t(int, sizeof(veth), len);
+ ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
+ len -= copy;
+ copied += copy;
+ if (ret || !len)
+ goto done;
+ }
+
+ ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
+ copied += len;
+
+done:
rcu_read_lock_bh();
vlan = rcu_dereference_bh(q->vlan);
if (vlan)
- macvlan_count_rx(vlan, len, ret == 0, 0);
+ macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0);
rcu_read_unlock_bh();
- return ret ? ret : (len + vnet_hdr_len);
+ return ret ? ret : copied;
}
static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,