[PATCH v20 25/25] app/pdump: preserve VLAN tags in captured packets

Bruce Richardson bruce.richardson at intel.com
Mon Mar 16 16:33:36 CET 2026


On Tue, Mar 10, 2026 at 09:10:03AM -0700, Stephen Hemminger wrote:
> When the source port has VLAN strip enabled, captured packets have
> the VLAN tag in mbuf metadata (vlan_tci) but not in the packet data.
> Similarly, TX captures with pending VLAN insert have the tag only
> in metadata. The resulting pcap files contain untagged packets.
> 
> Convert RX_VLAN_STRIPPED metadata to TX_VLAN offload requests on
> dequeued mbufs and call rte_eth_tx_prepare() before rte_eth_tx_burst()
> so the pcap vdev inserts the tag into the packet data.
>

This is an example of something I previously flagged. Like with real
hardware, I think the PMD should be inserting the VLAN tag into the packet
as part of the Tx function, not the prepare function.
 
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
>  lib/pdump/rte_pdump.c | 32 +++++++++++++++++++++++++++++++-
>  1 file changed, 31 insertions(+), 1 deletion(-)
> 


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