[dpdk-dev,2/2] vhost: fix IP csum not calculated
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Commit Message
There is no way to bypass IP checksum verification in Linux
kernel, no matter skb->ip_summed is assigned as CHECKSUM_UNNECESSARY
or CHECKSUM_PARTIAL.
So any packets with bad IP checksum will be dropped at VM IP layer.
To correct, we check this flag PKT_TX_IP_CKSUM to calculate IP csum.
Fixes: 859b480d5afd ("vhost: add guest offload setting")
Cc: stable@dpdk.org
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: Jiayu Hu <jiayu.hu@intel.com>
Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
---
lib/librte_vhost/virtio_net.c | 9 +++++++++
1 file changed, 9 insertions(+)
Comments
On 06/07/2017 08:41 AM, Jianfeng Tan wrote:
> There is no way to bypass IP checksum verification in Linux
> kernel, no matter skb->ip_summed is assigned as CHECKSUM_UNNECESSARY
> or CHECKSUM_PARTIAL.
>
> So any packets with bad IP checksum will be dropped at VM IP layer.
>
> To correct, we check this flag PKT_TX_IP_CKSUM to calculate IP csum.
>
> Fixes: 859b480d5afd ("vhost: add guest offload setting")
> Cc: stable@dpdk.org
>
> Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Cc: Jiayu Hu <jiayu.hu@intel.com>
> Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
> ---
> lib/librte_vhost/virtio_net.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
>
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 0a7e023..cf7c5ac 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -143,6 +143,15 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
> ASSIGN_UNLESS_EQUAL(net_hdr->flags, 0);
> }
>
> + /* IP cksum verification cannot be bypassed, then calculate here */
> + if (m_buf->ol_flags & PKT_TX_IP_CKSUM) {
> + struct ipv4_hdr *ipv4_hdr;
> +
> + ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct ipv4_hdr *,
> + m_buf->l2_len);
> + ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
> + }
> +
> if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
> if (m_buf->ol_flags & PKT_TX_IPV4)
> net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
>
@@ -143,6 +143,15 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
ASSIGN_UNLESS_EQUAL(net_hdr->flags, 0);
}
+ /* IP cksum verification cannot be bypassed, then calculate here */
+ if (m_buf->ol_flags & PKT_TX_IP_CKSUM) {
+ struct ipv4_hdr *ipv4_hdr;
+
+ ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct ipv4_hdr *,
+ m_buf->l2_len);
+ ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
+ }
+
if (m_buf->ol_flags & PKT_TX_TCP_SEG) {
if (m_buf->ol_flags & PKT_TX_IPV4)
net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;