Currently the IPv4 header checksum is calculated including its
current value, which can be a valid checksum or just garbage.
In any case, if the original value is not zero, then the result
is always wrong.
The IPv4 checksum is defined in RFC791, page 14 says:
Header Checksum: 16 bits
The checksum algorithm is:
The checksum field is the 16 bit one's complement of the one's
complement sum of all 16 bit words in the header. For purposes of
computing the checksum, the value of the checksum field is zero.
Thus force the csum field to always be zero.
Fixes: b08b8cfeb2ae ("vhost: fix IP checksum")
Cc: sta...@dpdk.org
Signed-off-by: Flavio Leitner <f...@sysclose.org>
---
lib/librte_vhost/virtio_net.c | 1 +
1 file changed, 1 insertion(+)
v2:
CC stable
Added 'Fixes:' line.
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index eae7825f04..cde7498c76 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -445,6 +445,7 @@ virtio_enqueue_offload(struct rte_mbuf *m_buf, struct
virtio_net_hdr *net_hdr)
ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct rte_ipv4_hdr *,
m_buf->l2_len);
+ ipv4_hdr->hdr_checksum = 0;
ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
}
--
2.20.1
