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https://github.com/XTLS/Xray-core.git
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336b2daeb9
* dns header * fixed domain name encoding for dns header --------- Co-authored-by: kerry <lvhaiyangkerry@gmail.com>
58 lines
1.4 KiB
Go
58 lines
1.4 KiB
Go
package dns
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import (
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"context"
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"encoding/binary"
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"github.com/miekg/dns"
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"github.com/xtls/xray-core/common"
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"github.com/xtls/xray-core/common/dice"
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)
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type DNS struct {
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header []byte
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}
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func (d DNS) Size() int32 {
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return int32(len(d.header))
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}
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// Serialize implements PacketHeader.
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func (d DNS) Serialize(b []byte) {
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copy(b, d.header)
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binary.BigEndian.PutUint16(b[0:], dice.RollUint16()) // random transaction ID
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}
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// NewDNS returns a new DNS instance based on given config.
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func NewDNS(ctx context.Context, config interface{}) (interface{}, error) {
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var header []byte
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header = binary.BigEndian.AppendUint16(header, 0x0000) // Transaction ID
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header = binary.BigEndian.AppendUint16(header, 0x0100) // Flags: Standard query
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header = binary.BigEndian.AppendUint16(header, 0x0001) // Questions
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header = binary.BigEndian.AppendUint16(header, 0x0000) // Answer RRs
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header = binary.BigEndian.AppendUint16(header, 0x0000) // Authority RRs
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header = binary.BigEndian.AppendUint16(header, 0x0000) // Additional RRs
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buf := make([]byte, 0x100)
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off1, err := dns.PackDomainName(dns.Fqdn(config.(*Config).Domain), buf, 0, nil, false)
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if err != nil {
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return nil, err
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}
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header = append(header, buf[:off1]...)
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header = binary.BigEndian.AppendUint16(header, 0x0001) // Type: A
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header = binary.BigEndian.AppendUint16(header, 0x0001) // Class: IN
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return DNS{
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header: header,
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}, nil
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}
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func init() {
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common.Must(common.RegisterConfig((*Config)(nil), NewDNS))
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}
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