Implement the generic modify flow API to allow manipulations on
an arbitrary header field (as well as mark, metadata or tag) using
data from another field or a user-specified value.
This generic modify mechanism removes the necessity to implement
a separate RTE Flow action every time we need to modify a new packet
field in the future.
Supported operation are:
- set: copy data from source to destination.
- add: integer addition, stores the result in destination.
- sub: integer subtraction, stores the result in destination.
The field ID is used to specify the desired source/destination packet
field in order to simplify the API for various encapsulation models.
Specifying the packet field ID with the needed encapsulation level
is able to quickly get a packet field for any inner packet header.
Alternatively, the special ID (ITEM_START) can be used to point to
the very beginning of a packet. This ID in conjunction with the
offset parameter provides great flexibility to copy/modify any part of
a packet as needed.
The number of bits to use from a source as well as the offset can be
be specified to allow a partial copy or dividing a big packet field
into multiple small fields (e.g. copying 128 bits of IPv6 to 4 tags).
An immediate value (or a pointer to it) can be specified instead of the
level and the offset for the special FIELD_VALUE ID (or FIELD_POINTER).
Can be used as a source only.
Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
Acked-by: Ori Kam <orika@nvidia.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>