[NETLINK]: Introduce nested and byteorder flag to netlink attribute

This change allows the generic attribute interface to be used within
the netfilter subsystem where this flag was initially introduced.

The byte-order flag is yet unused, it's intended use is to
allow automatic byte order convertions for all atomic types.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Thomas Graf 2007-09-12 14:44:36 +02:00 committed by David S. Miller
parent 9d5010db7e
commit 8f4c1f9b04
7 changed files with 38 additions and 15 deletions

View file

@ -131,6 +131,20 @@ struct nlattr
__u16 nla_type;
};
/*
* nla_type (16 bits)
* +---+---+-------------------------------+
* | N | O | Attribute Type |
* +---+---+-------------------------------+
* N := Carries nested attributes
* O := Payload stored in network byte order
*
* Note: The N and O flag are mutually exclusive.
*/
#define NLA_F_NESTED (1 << 15)
#define NLA_F_NET_BYTEORDER (1 << 14)
#define NLA_TYPE_MASK ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
#define NLA_ALIGNTO 4
#define NLA_ALIGN(len) (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
#define NLA_HDRLEN ((int) NLA_ALIGN(sizeof(struct nlattr)))