[dpdk-dev] [PATCH 2/5] net/tap: do not touch Tx offload flags

[David Marchand <david.marchand@redhat.com>]

Tx offload flags are of the application responsibility.
Leave the mbuf alone and check for TSO where needed.

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 drivers/net/tap/rte_eth_tap.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index c36d4bf76e..285fe395c5 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -562,6 +562,7 @@ tap_tx_l3_cksum(char *packet, uint64_t ol_flags, unsigned int l2_len,
 		uint16_t *l4_phdr_cksum, uint32_t *l4_raw_cksum)
 {
 	void *l3_hdr = packet + l2_len;
+	uint64_t csum_l4;
 
 	if (ol_flags & (PKT_TX_IP_CKSUM | PKT_TX_IPV4)) {
 		struct rte_ipv4_hdr *iph = l3_hdr;
@@ -571,13 +572,17 @@ tap_tx_l3_cksum(char *packet, uint64_t ol_flags, unsigned int l2_len,
 		cksum = rte_raw_cksum(iph, l3_len);
 		iph->hdr_checksum = (cksum == 0xffff) ? cksum : ~cksum;
 	}
-	if (ol_flags & PKT_TX_L4_MASK) {
+
+	csum_l4 = ol_flags & PKT_TX_L4_MASK;
+	if (ol_flags & PKT_TX_TCP_SEG)
+		csum_l4 |= PKT_TX_TCP_CKSUM;
+	if (csum_l4) {
 		void *l4_hdr;
 
 		l4_hdr = packet + l2_len + l3_len;
-		if ((ol_flags & PKT_TX_L4_MASK) == PKT_TX_UDP_CKSUM)
+		if (csum_l4 == PKT_TX_UDP_CKSUM)
 			*l4_cksum = &((struct rte_udp_hdr *)l4_hdr)->dgram_cksum;
-		else if ((ol_flags & PKT_TX_L4_MASK) == PKT_TX_TCP_CKSUM)
+		else if (csum_l4 == PKT_TX_TCP_CKSUM)
 			*l4_cksum = &((struct rte_tcp_hdr *)l4_hdr)->cksum;
 		else
 			return;
@@ -648,7 +653,8 @@ tap_write_mbufs(struct tx_queue *txq, uint16_t num_mbufs,
 		if (txq->csum &&
 		    ((mbuf->ol_flags & (PKT_TX_IP_CKSUM | PKT_TX_IPV4) ||
 		     (mbuf->ol_flags & PKT_TX_L4_MASK) == PKT_TX_UDP_CKSUM ||
-		     (mbuf->ol_flags & PKT_TX_L4_MASK) == PKT_TX_TCP_CKSUM))) {
+		     (mbuf->ol_flags & PKT_TX_L4_MASK) == PKT_TX_TCP_CKSUM) ||
+		     (mbuf->ol_flags & PKT_TX_TCP_SEG))) {
 			is_cksum = 1;
 
 			/* Support only packets with at least layer 4
@@ -742,9 +748,6 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		if (tso) {
 			struct rte_gso_ctx *gso_ctx = &txq->gso_ctx;
 
-			/* TCP segmentation implies TCP checksum offload */
-			mbuf_in->ol_flags |= PKT_TX_TCP_CKSUM;
-
 			/* gso size is calculated without RTE_ETHER_CRC_LEN */
 			hdrs_len = mbuf_in->l2_len + mbuf_in->l3_len +
 					mbuf_in->l4_len;
-- 
2.23.0