On 17-07-24 07:18 AM, Jiri Pirko wrote:
Mon, Jul 24, 2017 at 03:35:43AM CEST, j...@mojatatu.com wrote:
From: Jamal Hadi Salim <j...@mojatatu.com>
Generic bitflags attribute content sent to the kernel by user.
With this type the user can either set or unset a flag in the
kernel.
The nla_value is a bitmap that defines the values being set
The nla_selector is a bitmask that defines which value is legit.
A check is made to ensure the rules that a kernel subsystem always
conforms to bitflags the kernel already knows about. i.e
if the user tries to set a bit flag that is not understood then
the _it will be rejected_.
In the most basic form, the user specifies the attribute policy as:
[ATTR_GOO] = { .type = NLA_BITFIELD_32, .validation_data = &myvalidflags },
where myvalidflags is the bit mask of the flags the kernel understands.
If the user _does not_ provide myvalidflags then the attribute will
also be rejected.
Examples:
nla_value = 0x0, and nla_selector = 0x1
implies we are selecting bit 1 and we want to set its value to 0.
nla_value = 0x2, and nla_selector = 0x2
implies we are selecting bit 2 and we want to set its value to 1.
Oh, 2 more things:
[...]
;-> ok will do that next opportunity (probably at 30K feet).
cheers,
jamal
