veth: Fix the byte counters
Commit 44540960 "veth: move loopback logic to common location" introduced
a bug in the packet counters. I don't understand why that happened as it
is not explained in the comments and the mut check in dev_forward_skb
retains the assumption that skb->len is the total length of the packet.
I just measured this emperically by setting up a veth pair between two
noop network namespaces setting and attempting a telnet connection between
the two. I saw three packets in each direction and the byte counters were
exactly 14*3 = 42 bytes high in each direction. I got the actual
packet lengths with tcpdump.
So remove the extra ETH_HLEN from the veth byte count totals.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 105d7f0..2de9b90 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -171,7 +171,7 @@
if (skb->ip_summed == CHECKSUM_NONE)
skb->ip_summed = rcv_priv->ip_summed;
- length = skb->len + ETH_HLEN;
+ length = skb->len;
if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
goto rx_drop;