On Tue, Jul 06, 2021 at 10:56:10AM +0000, Ananyev, Konstantin wrote:
>
> >
> > From: Nithin Dabilpuram <ndabilpu...@marvell.com>
> >
> > For Tx inline processing, when RTE_SECURITY_TX_OLOAD_NEED_MDATA is
> > set, rte_security_set_pkt_metadata() needs to be called for pkts
> > to associate a Security session with a mbuf before submitting
> > to Ethdev Tx. This is apart from setting PKT_TX_SEC_OFFLOAD in
> > mbuf.ol_flags. rte_security_set_pkt_metadata() is also used to
> > set some opaque metadata in mbuf for PMD's use.
> > This patch updates documentation that rte_security_set_pkt_metadata()
> > should be called only with mbuf containing Layer 3 and above data.
> > This behaviour is consistent with existing PMD's such as ixgbe.
> >
> > On Tx, not all net PMD's/HW can parse packet and identify
> > L2 header and L3 header locations on Tx. This is inline with other
> > Tx offloads requirements such as L3 checksum, L4 checksum offload,
> > etc, where mbuf.l2_len, mbuf.l3_len etc, needs to be set for
> > HW to be able to generate checksum. Since Inline IPSec is also
> > such a Tx offload, some PMD's at least need mbuf.l2_len to be
> > valid to find L3 header and perform Outbound IPSec processing.
> > Hence, this patch updates documentation to enforce setting
> > mbuf.l2_len while setting PKT_TX_SEC_OFFLOAD in mbuf.ol_flags
> > for Inline IPSec Crypto / Protocol offload processing to
> > work on Tx.
> >
> > Signed-off-by: Nithin Dabilpuram <ndabilpu...@marvell.com>
> > Reviewed-by: Akhil Goyal <gak...@marvell.com>
> > ---
> > doc/guides/nics/features.rst | 2 ++
> > doc/guides/prog_guide/rte_security.rst | 6 +++++-
> > lib/mbuf/rte_mbuf_core.h | 2 ++
> > 3 files changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
> > index 403c2b03a..414baf14f 100644
> > --- a/doc/guides/nics/features.rst
> > +++ b/doc/guides/nics/features.rst
> > @@ -430,6 +430,7 @@ of protocol operations. See Security library and PMD
> > documentation for more deta
> >
> > * **[uses] rte_eth_rxconf,rte_eth_rxmode**:
> > ``offloads:DEV_RX_OFFLOAD_SECURITY``,
> > * **[uses] rte_eth_txconf,rte_eth_txmode**:
> > ``offloads:DEV_TX_OFFLOAD_SECURITY``.
> > +* **[uses] mbuf**: ``mbuf.l2_len``.
> > * **[implements] rte_security_ops**: ``session_create``,
> > ``session_update``,
> > ``session_stats_get``, ``session_destroy``, ``set_pkt_metadata``,
> > ``capabilities_get``.
> > * **[provides] rte_eth_dev_info**:
> > ``rx_offload_capa,rx_queue_offload_capa:DEV_RX_OFFLOAD_SECURITY``,
> > @@ -451,6 +452,7 @@ protocol operations. See security library and PMD
> > documentation for more details
> >
> > * **[uses] rte_eth_rxconf,rte_eth_rxmode**:
> > ``offloads:DEV_RX_OFFLOAD_SECURITY``,
> > * **[uses] rte_eth_txconf,rte_eth_txmode**:
> > ``offloads:DEV_TX_OFFLOAD_SECURITY``.
> > +* **[uses] mbuf**: ``mbuf.l2_len``.
> > * **[implements] rte_security_ops**: ``session_create``,
> > ``session_update``,
> > ``session_stats_get``, ``session_destroy``, ``set_pkt_metadata``,
> > ``get_userdata``,
> > ``capabilities_get``.
> > diff --git a/doc/guides/prog_guide/rte_security.rst
> > b/doc/guides/prog_guide/rte_security.rst
> > index f72bc8a78..7b68c698d 100644
> > --- a/doc/guides/prog_guide/rte_security.rst
> > +++ b/doc/guides/prog_guide/rte_security.rst
> > @@ -560,7 +560,11 @@ created by the application is attached to the security
> > session by the API
> >
> > For Inline Crypto and Inline protocol offload, device specific defined
> > metadata is
> > updated in the mbuf using ``rte_security_set_pkt_metadata()`` if
> > -``DEV_TX_OFFLOAD_SEC_NEED_MDATA`` is set.
> > +``RTE_SECURITY_TX_OLOAD_NEED_MDATA`` is set.
> > ``rte_security_set_pkt_metadata()``
> > +should be called on mbuf only with Layer 3 and above data present and
> > +``mbuf.data_off`` should be pointing to Layer 3 Header.
>
> Hmm... not sure why mbuf.data_off should point to L3 hdr.
> Who will add L2 hdr to the packet in that case?
> Or did you mean ``mbuf.data_off + mbuf.l2_len`` here?
That is the semantics I was trying to define. I think below are the sequence of
operations to be done for ipsec processing,
1. receive_pkt()
2. strip_l2_hdr()
3. Do policy lookup ()
4. Call rte_security_set_pkt_metadata() if pkt needs to be encrypted with a
particular SA. Now pkt only has L3 and above data.
5. Do route_lookup()
6. add_l2hdr() which might be different from stripped l2hdr.
7. Send packet out.
The above sequence is what I believe the current poll mode worker thread in
ipsec-secgw is following. While in event mode, step 2 and step 6 are missing.
This patch is trying to enforce semantics as above so that
rte_security_set_pkt_metadata() can predict what comes in the pkt when he is
called.
I also think above sequence is what Linux kernel stack or other stacks follow.
Does it makes sense ?
>
> > Once called,
> > +Layer 3 and above data cannot be modified or moved around unless
> > +``rte_security_set_pkt_metadata()`` is called again.
> >
> > For inline protocol offloaded ingress traffic, the application can
> > register a
> > pointer, ``userdata`` , in the security session. When the packet is
> > received,
> > diff --git a/lib/mbuf/rte_mbuf_core.h b/lib/mbuf/rte_mbuf_core.h
> > index bb38d7f58..9d8e3ddc8 100644
> > --- a/lib/mbuf/rte_mbuf_core.h
> > +++ b/lib/mbuf/rte_mbuf_core.h
> > @@ -228,6 +228,8 @@ extern "C" {
> >
> > /**
> > * Request security offload processing on the TX packet.
> > + * To use Tx security offload, the user needs to fill l2_len in mbuf
> > + * indicating L2 header size and where L3 header starts.
> > */
> > #define PKT_TX_SEC_OFFLOAD (1ULL << 43)
> >
> > --
> > 2.25.1
>
