diff options
| author | Vlad Yasevich <vyasevic@redhat.com> | 2014-04-29 10:09:50 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-31 13:20:36 -0700 |
| commit | bdccb452699c0da6df5538904bbf4847de1cf4fc (patch) | |
| tree | 1891b917e02f89c09c15f1d2e67147b26623e0fe /drivers/net | |
| parent | 987c76c0af87c57566bd9cb99e7a9f04fcd949be (diff) | |
mactap: Fix checksum errors for non-gso packets in bridge mode
[ Upstream commit cbdb04279ccaefcc702c8757757eea8ed76e50cf ]
The following is a problematic configuration:
VM1: virtio-net device connected to macvtap0@eth0
VM2: e1000 device connect to macvtap1@eth0
The problem is is that virtio-net supports checksum offloading
and thus sends the packets to the host with CHECKSUM_PARTIAL set.
On the other hand, e1000 does not support any acceleration.
For small TCP packets (and this includes the 3-way handshake),
e1000 ends up receiving packets that only have a partial checksum
set. This causes TCP to fail checksum validation and to drop
packets. As a result tcp connections can not be established.
Commit 3e4f8b787370978733ca6cae452720a4f0c296b8
macvtap: Perform GSO on forwarding path.
fixes this issue for large packets wthat will end up undergoing GSO.
This commit adds a check for the non-GSO case and attempts to
compute the checksum for partially checksummed packets in the
non-GSO case.
CC: Daniel Lezcano <daniel.lezcano@free.fr>
CC: Patrick McHardy <kaber@trash.net>
CC: Andrian Nord <nightnord@gmail.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Michael S. Tsirkin <mst@redhat.com>
CC: Jason Wang <jasowang@redhat.com>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/macvtap.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index ff111a89e17f..3381c4f91a8c 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -322,6 +322,15 @@ static rx_handler_result_t macvtap_handle_frame(struct sk_buff **pskb) segs = nskb; } } else { + /* If we receive a partial checksum and the tap side + * doesn't support checksum offload, compute the checksum. + * Note: it doesn't matter which checksum feature to + * check, we either support them all or none. + */ + if (skb->ip_summed == CHECKSUM_PARTIAL && + !(features & NETIF_F_ALL_CSUM) && + skb_checksum_help(skb)) + goto drop; skb_queue_tail(&q->sk.sk_receive_queue, skb); } |