38 lines
1.1 KiB
Go
38 lines
1.1 KiB
Go
|
package netlink
|
||
|
|
|
||
|
|
import "unsafe"
|
||
|
|
|
||
|
|
// Functions and values used to properly align netlink messages, headers,
|
||
|
|
// and attributes. Definitions taken from Linux kernel source.
|
||
|
|
|
||
|
|
// #define NLMSG_ALIGNTO 4U
|
||
|
|
const nlmsgAlignTo = 4
|
||
|
|
|
||
|
|
// #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
|
||
|
|
func nlmsgAlign(len int) int {
|
||
|
|
return ((len) + nlmsgAlignTo - 1) & ^(nlmsgAlignTo - 1)
|
||
|
|
}
|
||
|
|
|
||
|
|
// #define NLMSG_LENGTH(len) ((len) + NLMSG_HDRLEN)
|
||
|
|
func nlmsgLength(len int) int {
|
||
|
|
return len + nlmsgHeaderLen
|
||
|
|
}
|
||
|
|
|
||
|
|
// #define NLMSG_HDRLEN ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
|
||
|
|
var nlmsgHeaderLen = nlmsgAlign(int(unsafe.Sizeof(Header{})))
|
||
|
|
|
||
|
|
// #define NLA_ALIGNTO 4
|
||
|
|
const nlaAlignTo = 4
|
||
|
|
|
||
|
|
// #define NLA_ALIGN(len) (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
|
||
|
|
func nlaAlign(len int) int {
|
||
|
|
return ((len) + nlaAlignTo - 1) & ^(nlaAlignTo - 1)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Because this package's Attribute type contains a byte slice, unsafe.Sizeof
|
||
|
|
// can't be used to determine the correct length.
|
||
|
|
const sizeofAttribute = 4
|
||
|
|
|
||
|
|
// #define NLA_HDRLEN ((int) NLA_ALIGN(sizeof(struct nlattr)))
|
||
|
|
var nlaHeaderLen = nlaAlign(sizeofAttribute)
|