net: fix checksum offload for outer IPv4

Preparation of the headers for the hardware offload
misses the outer IPv4 checksum offload.
It results in bad checksum computed by hardware NIC.

This patch fixes the issue by setting the outer IPv4
checksum field to 0.

Fixes: 4fb7e803eb1a ("ethdev: add Tx preparation")
Cc: stable@dpdk.org
Signed-off-by: Mohsin Kazmi <mohsin.kazmi14@gmail.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>

diff --git a/lib/net/rte_net.h b/lib/net/rte_net.h
index 434435f..42639bc 100644 (file)
--- a/lib/net/rte_net.h
+++ b/lib/net/rte_net.h
@@ -125,11 +125,22 @@ rte_net_intel_cksum_flags_prepare(struct rte_mbuf *m, uint64_t ol_flags)
         * Mainly it is required to avoid fragmented headers check if
         * no offloads are requested.
         */
-       if (!(ol_flags & (PKT_TX_IP_CKSUM | PKT_TX_L4_MASK | PKT_TX_TCP_SEG)))
+       if (!(ol_flags & (PKT_TX_IP_CKSUM | PKT_TX_L4_MASK | PKT_TX_TCP_SEG |
+                         PKT_TX_OUTER_IP_CKSUM)))
                return 0;
 
-       if (ol_flags & (PKT_TX_OUTER_IPV4 | PKT_TX_OUTER_IPV6))
+       if (ol_flags & (PKT_TX_OUTER_IPV4 | PKT_TX_OUTER_IPV6)) {
                inner_l3_offset += m->outer_l2_len + m->outer_l3_len;
+               /*
+                * prepare outer IPv4 header checksum by setting it to 0,
+                * in order to be computed by hardware NICs.
+                */
+               if (ol_flags & PKT_TX_OUTER_IP_CKSUM) {
+                       ipv4_hdr = rte_pktmbuf_mtod_offset(m,
+                                       struct rte_ipv4_hdr *, m->outer_l2_len);
+                       ipv4_hdr->hdr_checksum = 0;
+               }
+       }
 
        /*
         * Check if headers are fragmented.