58 lines
1.4 KiB
Go
58 lines
1.4 KiB
Go
package xt
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import (
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"github.com/google/nftables/alignedbuff"
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)
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// Tcp is the Match.Info payload for the tcp xtables extension
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// (https://wiki.nftables.org/wiki-nftables/index.php/Supported_features_compared_to_xtables#tcp).
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//
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// See
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// https://elixir.bootlin.com/linux/v5.17.7/source/include/uapi/linux/netfilter/xt_tcpudp.h#L25
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type Udp struct {
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SrcPorts [2]uint16 // min, max source port range
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DstPorts [2]uint16 // min, max destination port range
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InvFlags UdpInvFlagset // Inverse flags
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}
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type UdpInvFlagset uint8
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const (
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UdpInvSrcPorts UdpInvFlagset = 1 << iota
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UdpInvDestPorts
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UdpInvMask UdpInvFlagset = (1 << iota) - 1
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)
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func (x *Udp) marshal(fam TableFamily, rev uint32) ([]byte, error) {
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ab := alignedbuff.New()
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ab.PutUint16(x.SrcPorts[0])
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ab.PutUint16(x.SrcPorts[1])
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ab.PutUint16(x.DstPorts[0])
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ab.PutUint16(x.DstPorts[1])
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ab.PutUint8(byte(x.InvFlags))
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return ab.Data(), nil
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}
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func (x *Udp) unmarshal(fam TableFamily, rev uint32, data []byte) error {
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ab := alignedbuff.NewWithData(data)
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var err error
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if x.SrcPorts[0], err = ab.Uint16(); err != nil {
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return err
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}
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if x.SrcPorts[1], err = ab.Uint16(); err != nil {
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return err
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}
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if x.DstPorts[0], err = ab.Uint16(); err != nil {
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return err
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}
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if x.DstPorts[1], err = ab.Uint16(); err != nil {
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return err
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}
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var invFlags uint8
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if invFlags, err = ab.Uint8(); err != nil {
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return err
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}
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x.InvFlags = UdpInvFlagset(invFlags)
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return nil
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}
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