diff options
| author | Nithin Dabilpuram <ndabilpuram@marvell.com> | 2020-10-14 16:08:24 +0530 |
|---|---|---|
| committer | Matias Elo <matias.elo@nokia.com> | 2020-11-02 13:31:11 +0200 |
| commit | 08771b030fe2a6dca947678924e47d7dadfe741f (patch) | |
| tree | 592bc2b907072d1a6bfaf31d2d36399edf7eece8 /doc/users-guide | |
| parent | 486b362a60d925f3f7e077776cae929d0709fdb5 (diff) | |
doc: userguide: change checksum insertion API documentation
Change checksum insertion API documentation with updated
API semantics.
Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Reviewed-by: Petri Savolainen <petri.savolainen@nokia.com>
Reviewed-by: Janne Peltonen <janne.peltonen@nokia.com>
Diffstat (limited to 'doc/users-guide')
| -rw-r--r-- | doc/users-guide/users-guide-pktio.adoc | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/doc/users-guide/users-guide-pktio.adoc b/doc/users-guide/users-guide-pktio.adoc index 73d6e0485..0457aa56c 100644 --- a/doc/users-guide/users-guide-pktio.adoc +++ b/doc/users-guide/users-guide-pktio.adoc @@ -371,14 +371,16 @@ transmitted: * These defaults may be overridden on per packet basis using e.g. * odp_packet_l4_chksum_insert(). * - * For correct operation, packet metadata must provide valid offsets for the - * appropriate protocols. For example, UDP checksum calculation needs both L3 - * and L4 offsets (to access IP and UDP headers). When application - * (e.g. a switch) does not modify L3/L4 data and thus checksum does not need - * to be updated, checksum insertion should be disabled for optimal performance. - * - * Packet flags (odp_packet_has_*()) are ignored for the purpose of checksum - * insertion in packet output. + * For correct operation, packet metadata must provide valid offsets and type + * flags for the appropriate layer 3 and layer 4 protocols. L3 and L4 offsets + * can be updated with odp_packet_l3_offset_set() and odp_packet_l4_offset_set() + * calls. L3 and L4 type flags can be updated using odp_packet_has_*_set() calls + * For example, UDP checksum calculation needs both L3 and L4 types (IP and UDP) and + * L3 and L4 offsets (to access IP and UDP headers), while IP checksum + * calculation only needs L3 type (IP) and L3 offset (to access IP header). + * When application (e.g. a switch) does not modify L3/L4 data and thus checksum + * does not need to be updated, checksum insertion should be disabled for optimal + * performance. * * UDP, TCP and SCTP checksum insertion must not be requested for IP fragments. * Use checksum override function (odp_packet_l4_chksum_insert()) to disable |