github.com/inazumav/sing-box@v0.0.0-20230926072359-ab51429a14f1/adapter/fakeip_metadata.go (about)

     1  package adapter
     2  
     3  import (
     4  	"bytes"
     5  	"encoding"
     6  	"encoding/binary"
     7  	"io"
     8  	"net/netip"
     9  
    10  	"github.com/sagernet/sing/common"
    11  )
    12  
    13  type FakeIPMetadata struct {
    14  	Inet4Range   netip.Prefix
    15  	Inet6Range   netip.Prefix
    16  	Inet4Current netip.Addr
    17  	Inet6Current netip.Addr
    18  }
    19  
    20  func (m *FakeIPMetadata) MarshalBinary() (data []byte, err error) {
    21  	var buffer bytes.Buffer
    22  	for _, marshaler := range []encoding.BinaryMarshaler{m.Inet4Range, m.Inet6Range, m.Inet4Current, m.Inet6Current} {
    23  		data, err = marshaler.MarshalBinary()
    24  		if err != nil {
    25  			return
    26  		}
    27  		common.Must(binary.Write(&buffer, binary.BigEndian, uint16(len(data))))
    28  		buffer.Write(data)
    29  	}
    30  	data = buffer.Bytes()
    31  	return
    32  }
    33  
    34  func (m *FakeIPMetadata) UnmarshalBinary(data []byte) error {
    35  	reader := bytes.NewReader(data)
    36  	for _, unmarshaler := range []encoding.BinaryUnmarshaler{&m.Inet4Range, &m.Inet6Range, &m.Inet4Current, &m.Inet6Current} {
    37  		var length uint16
    38  		common.Must(binary.Read(reader, binary.BigEndian, &length))
    39  		element := make([]byte, length)
    40  		_, err := io.ReadFull(reader, element)
    41  		if err != nil {
    42  			return err
    43  		}
    44  		err = unmarshaler.UnmarshalBinary(element)
    45  		if err != nil {
    46  			return err
    47  		}
    48  	}
    49  	return nil
    50  }