net netlink: Add new type NLA_BITFIELD32
Generic bitflags attribute content sent to the kernel by user.
With this netlink attr type the user can either set or unset a
flag in the kernel.
The value is a bitmap that defines the bit values being set
The selector is a bitmask that defines which value bit is to be
considered.
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_BITFIELD32, .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:
value = 0x0, and selector = 0x1
implies we are selecting bit 1 and we want to set its value to 0.
value = 0x2, and selector = 0x2
implies we are selecting bit 2 and we want to set its value to 1.
Suggested-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3 files changed