[PATCH v3 1/3] net/tap: fix L4 checksum offloading

[David Marchand]

The L4 checksum offloading API does not require l4_len to be set.
Make the driver discover the L4 headers size by itself.

Fixes: 6546e76056e3 ("net/tap: calculate checksums of multi segs packets")
Cc: sta...@dpdk.org

Signed-off-by: David Marchand <david.march...@redhat.com>
Tested-by: Ales Musil <amu...@redhat.com>
---
 .mailmap                      |  1 +
 drivers/net/tap/rte_eth_tap.c | 13 +++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/.mailmap b/.mailmap
index 864d33ee46..b6a21b35cb 100644
--- a/.mailmap
+++ b/.mailmap
@@ -40,6 +40,7 @@ Aleksandr Loktionov <aleksandr.loktio...@intel.com>
 Aleksandr Miloshenko <a.miloshe...@f5.com>
 Aleksey Baulin <aleksey.bau...@gmail.com>
 Aleksey Katargin <gure...@gmail.com>
+Ales Musil <amu...@redhat.com>
 Alexander Bechikov <asb.t...@gmail.com>
 Alexander Belyakov <abely...@gmail.com>
 Alexander Chernavin <acherna...@netgate.com>
diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index bf98f75559..0ab214847a 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -645,13 +645,22 @@ tap_write_mbufs(struct tx_queue *txq, uint16_t num_mbufs,
                    ((mbuf->ol_flags & (RTE_MBUF_F_TX_IP_CKSUM | 
RTE_MBUF_F_TX_IPV4) ||
                      (mbuf->ol_flags & RTE_MBUF_F_TX_L4_MASK) == 
RTE_MBUF_F_TX_UDP_CKSUM ||
                      (mbuf->ol_flags & RTE_MBUF_F_TX_L4_MASK) == 
RTE_MBUF_F_TX_TCP_CKSUM))) {
+                       unsigned int l4_len = 0;
+
                        is_cksum = 1;
 
+                       if ((mbuf->ol_flags & RTE_MBUF_F_TX_L4_MASK) ==
+                                       RTE_MBUF_F_TX_UDP_CKSUM)
+                               l4_len = sizeof(struct rte_udp_hdr);
+                       else if ((mbuf->ol_flags & RTE_MBUF_F_TX_L4_MASK) ==
+                                       RTE_MBUF_F_TX_TCP_CKSUM)
+                               l4_len = sizeof(struct rte_tcp_hdr);
+
                        /* Support only packets with at least layer 4
                         * header included in the first segment
                         */
                        seg_len = rte_pktmbuf_data_len(mbuf);
-                       l234_hlen = mbuf->l2_len + mbuf->l3_len + mbuf->l4_len;
+                       l234_hlen = mbuf->l2_len + mbuf->l3_len + l4_len;
                        if (seg_len < l234_hlen)
                                return -1;
 
@@ -661,7 +670,7 @@ tap_write_mbufs(struct tx_queue *txq, uint16_t num_mbufs,
                        rte_memcpy(m_copy, rte_pktmbuf_mtod(mbuf, void *),
                                        l234_hlen);
                        tap_tx_l3_cksum(m_copy, mbuf->ol_flags,
-                                      mbuf->l2_len, mbuf->l3_len, mbuf->l4_len,
+                                      mbuf->l2_len, mbuf->l3_len, l4_len,
                                       &l4_cksum, &l4_phdr_cksum,
                                       &l4_raw_cksum);
                        iovecs[k].iov_base = m_copy;
-- 
2.41.0