Re: [dpdk-dev] [PATCH 09/11] examples/ipsec-secgw: Fixed ip length in case of transport

[Sergio Gonzalez Monroy]

On 16/10/2017 12:44, Aviad Yehezkel wrote:
On 10/16/2017 12:43 PM, Sergio Gonzalez Monroy wrote:
On 14/10/2017 14:28, avia...@dev.mellanox.co.il wrote:
From: Aviad Yehezkel <avia...@mellanox.com>
IP length was incorrect causing corrupted ICMP packets for example

Signed-off-by: Aviad Yehezkel <avia...@mellanox.com>
---
  examples/ipsec-secgw/esp.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/ipsec-secgw/esp.c b/examples/ipsec-secgw/esp.c
index 81ebf55..12c6f8c 100644
--- a/examples/ipsec-secgw/esp.c
+++ b/examples/ipsec-secgw/esp.c
@@ -205,13 +205,13 @@ esp_inbound_post(struct rte_mbuf *m, struct 
ipsec_sa *sa,
          if (likely(ip->ip_v == IPVERSION)) {
              memmove(ip4, ip, ip->ip_hl * 4);
              ip4->ip_p = *nexthdr;
-            ip4->ip_len = htons(rte_pktmbuf_data_len(m));
+            ip4->ip_len = htons(rte_pktmbuf_pkt_len(m));
          } else {
              ip6 = (struct ip6_hdr *)ip4;
              /* XXX No option headers supported */
              memmove(ip6, ip, sizeof(struct ip6_hdr));
              ip6->ip6_nxt = *nexthdr;
-            ip6->ip6_plen = htons(rte_pktmbuf_data_len(m));
+            ip6->ip6_plen = htons(rte_pktmbuf_pkt_len(m));
          }
      } else
          ipip_inbound(m, sizeof(struct esp_hdr) + sa->iv_len);

AFAIK the app does not support multi-segments (chain mbufs), so 
data_len should be the same as pkt_len.
Is that not the case?

This is the inbound function (RX side), so mbufs are allocated by PMD.
PMD is allocating mbuf with additional 14 bytes for ETH header but 
trim it before passing the mbuf.
As a result seg len is 14 bytes smaller than data len.


Sorry, I am still missing something here.
rte_pktmbuf_trim updates both data_len and pkt_len, so how can they not 
be the same when we have a single mbuf?

I think to remember using data_len instead of pkt_len so it is easy to 
see that the application does not support multi-segments (aka. chained 
mbufs)

Thanks,
Sergio

Thanks,
Aviad

Thanks,
Sergio