Hi David,
On Tue, Aug 22, 2023 at 09:32:44AM +0200, David Marchand wrote:
> 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))) {
While looking at the patch, I noticed this line:
mbuf->ol_flags & (RTE_MBUF_F_TX_IP_CKSUM | RTE_MBUF_F_TX_IPV4)
I think only RTE_MBUF_F_TX_IP_CKSUM should be checked.
> + 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
>
Using rte_ipv4_udptcp_cksum() in this code would probably simplify it, and may
solve other issues (for instance the 0 checksum for UDP which has a special
meaning).
