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