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: sta...@dpdk.org
Cc: Yuanhan Liu <yuanhan....@linux.intel.com>
Cc: Maxime Coquelin <maxime.coque...@redhat.com>
Cc: Jiayu Hu <jiayu...@intel.com>
Signed-off-by: Jianfeng Tan <jianfeng....@intel.com>
---
lib/librte_vhost/virtio_net.c | 9 +++++++++
1 file changed, 9 insertions(+)
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;
--
2.7.4
