Re: [dpdk-dev] [PATCH] app/testpmd: add parsing for multiple VLAN headers

["Iremonger, Bernard" <bernard.iremonger@intel.com>]

Hi Ferruh, Raslan,

> -----Original Message-----
> From: Yigit, Ferruh <ferruh.yigit@intel.com>
> Sent: Tuesday, April 21, 2020 9:48 PM
> To: Raslan Darawsheh <rasland@mellanox.com>; Iremonger, Bernard
> <bernard.iremonger@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>; Lu,
> Wenzhuo <wenzhuo.lu@intel.com>
> Cc: dev@dpdk.org; stable@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] app/testpmd: add parsing for multiple
> VLAN headers
> 
> On 4/20/2020 4:32 PM, Raslan Darawsheh wrote:
> > When having multiple VLANs in the packet, parse_ethernet is cabable of
> > parsing only the first vlan.
> >
> > add parsing for mutliple VLAN headers in the packet.
> >
> > Fixes: 51f694dd40f5 ("app/testpmd: rework checksum forward engine")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Raslan Darawsheh <rasland@mellanox.com>
> > ---
> >  app/test-pmd/csumonly.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c index
> > fe19615..b0665f7 100644
> > --- a/app/test-pmd/csumonly.c
> > +++ b/app/test-pmd/csumonly.c
> > @@ -139,22 +139,22 @@ parse_ipv6(struct rte_ipv6_hdr *ipv6_hdr, struct
> > testpmd_offload_info *info)
> >
> >  /*
> >   * Parse an ethernet header to fill the ethertype, l2_len, l3_len and
> > - * ipproto. This function is able to recognize IPv4/IPv6 with one
> > optional vlan
> > - * header. The l4_len argument is only set in case of TCP (useful for TSO).
> > + * ipproto. This function is able to recognize IPv4/IPv6 with
> > + optional VLAN
> > + * headers. The l4_len argument is only set in case of TCP (useful for TSO).
> >   */
> >  static void
> >  parse_ethernet(struct rte_ether_hdr *eth_hdr, struct
> > testpmd_offload_info *info)  {
> >  	struct rte_ipv4_hdr *ipv4_hdr;
> >  	struct rte_ipv6_hdr *ipv6_hdr;
> > +	struct rte_vlan_hdr *vlan_hdr;
> >
> >  	info->l2_len = sizeof(struct rte_ether_hdr);
> >  	info->ethertype = eth_hdr->ether_type;
> >
> > -	if (info->ethertype == _htons(RTE_ETHER_TYPE_VLAN)) {
> > -		struct rte_vlan_hdr *vlan_hdr = (
> > -			struct rte_vlan_hdr *)(eth_hdr + 1);
> > -
> > +	while (info->ethertype == _htons(RTE_ETHER_TYPE_VLAN)) {
> > +		vlan_hdr = (struct rte_vlan_hdr *)
> > +			((char *)eth_hdr + info->l2_len);
> >  		info->l2_len  += sizeof(struct rte_vlan_hdr);
> >  		info->ethertype = vlan_hdr->eth_proto;
> >  	}
> >
> 
> Can an ethernet packet have multiple VLAN header, according IEEE 802.1Q
> there can be only single VLAN header, if this is for QinQ will both TPID be
> same and
> 0x8100 (RTE_ETHER_TYPE_VLAN)?

There is also 0x88a8 (RTE_ETHER_TYPE_QINQ), IEEE 802.1ad QinQ tagging, both values should probably be checked.

Regards,

Bernard.