Re: [PATCH] ipsec: fix NAT-T length calculation

[Konstantin Ananyev]

18/04/2023 09:46, Xiao Liang пишет:

UDP header length is included in sa->hdr_len. Take care of that in
L3 header and pakcet length calculation.

Fixes: 01eef5907fc3 ("ipsec: support NAT-T")

Signed-off-by: Xiao Liang <shaw.l...@gmail.com>
---
  lib/ipsec/esp_outb.c | 2 +-
  lib/ipsec/sa.c       | 2 +-
  2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/ipsec/esp_outb.c b/lib/ipsec/esp_outb.c
index 9cbd9202f6..ec87b1dce2 100644
--- a/lib/ipsec/esp_outb.c
+++ b/lib/ipsec/esp_outb.c
@@ -198,7 +198,7 @@ outb_tun_pkt_prepare(struct rte_ipsec_sa *sa, rte_be64_t 
sqc,
                struct rte_udp_hdr *udph = (struct rte_udp_hdr *)
                        (ph + sa->hdr_len - sizeof(struct rte_udp_hdr));
                udph->dgram_len = rte_cpu_to_be_16(mb->pkt_len - sqh_len -
-                               sa->hdr_l3_off - sa->hdr_len);
+                               sa->hdr_len + sizeof(struct rte_udp_hdr));
        }

/* update original and new ip header fields */

diff --git a/lib/ipsec/sa.c b/lib/ipsec/sa.c
index 59a547637d..2297bd6d72 100644
--- a/lib/ipsec/sa.c
+++ b/lib/ipsec/sa.c
@@ -371,7 +371,7 @@ esp_outb_tun_init(struct rte_ipsec_sa *sa, const struct 
rte_ipsec_sa_prm *prm)

/* update l2_len and l3_len fields for outbound mbuf */

        sa->tx_offload.val = rte_mbuf_tx_offload(sa->hdr_l3_off,
-               sa->hdr_len - sa->hdr_l3_off, 0, 0, 0, 0, 0);
+               prm->tun.hdr_len - sa->hdr_l3_off, 0, 0, 0, 0, 0);

esp_outb_init(sa, sa->hdr_len, prm->ipsec_xform.esn.value);

  }

Acked-by: Konstantin Ananyev <konstantin.v.anan...@yandex.ru>


Thanks for explanation and for the fix.
One thing that still bothers me with UDP encap support:
we still don't have a test-case for it in examples/ipsec-secgw/test.