[dpdk-stable] [PATCH] net: fix Intel prepare function for IP checksum offload

[Didier Pallard]

Current Intel tx prepare function does not properly handle the
case where only IP checksum is requested, without requesting
any L4 checksum or TSO: IP checksum is not properly reset to 0
and output packet may contain invalid IP checksum.

Fixes: 4fb7e803eb1a ("ethdev: add Tx preparation")
Cc: stable at dpdk.org

Signed-off-by: Didier Pallard <didier.pallard at 6wind.com>
---
 lib/librte_net/rte_net.h | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/lib/librte_net/rte_net.h b/lib/librte_net/rte_net.h
index b6ab6e1d57b2..e59760a0a108 100644
--- a/lib/librte_net/rte_net.h
+++ b/lib/librte_net/rte_net.h
@@ -122,14 +122,16 @@ rte_net_intel_cksum_flags_prepare(struct rte_mbuf *m, uint64_t ol_flags)
 		(ol_flags & PKT_TX_OUTER_IPV6))
 		inner_l3_offset += m->outer_l2_len + m->outer_l3_len;
 
-	if ((ol_flags & PKT_TX_UDP_CKSUM) == PKT_TX_UDP_CKSUM) {
-		if (ol_flags & PKT_TX_IPV4) {
-			ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
-					inner_l3_offset);
+	if (ol_flags & PKT_TX_IPV4) {
+		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
+				inner_l3_offset);
 
-			if (ol_flags & PKT_TX_IP_CKSUM)
-				ipv4_hdr->hdr_checksum = 0;
+		if (ol_flags & PKT_TX_IP_CKSUM)
+			ipv4_hdr->hdr_checksum = 0;
+	}
 
+	if ((ol_flags & PKT_TX_UDP_CKSUM) == PKT_TX_UDP_CKSUM) {
+		if (ol_flags & PKT_TX_IPV4) {
 			udp_hdr = (struct udp_hdr *)((char *)ipv4_hdr +
 					m->l3_len);
 			udp_hdr->dgram_cksum = rte_ipv4_phdr_cksum(ipv4_hdr,
@@ -146,12 +148,6 @@ rte_net_intel_cksum_flags_prepare(struct rte_mbuf *m, uint64_t ol_flags)
 	} else if ((ol_flags & PKT_TX_TCP_CKSUM) ||
 			(ol_flags & PKT_TX_TCP_SEG)) {
 		if (ol_flags & PKT_TX_IPV4) {
-			ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *,
-					inner_l3_offset);
-
-			if (ol_flags & PKT_TX_IP_CKSUM)
-				ipv4_hdr->hdr_checksum = 0;
-
 			/* non-TSO tcp or TSO */
 			tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr +
 					m->l3_len);
-- 
2.11.0