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Find file Copy path
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package dns
import (
"encoding/binary"
"sync"
"golang.org/x/net/dns/dnsmessage"
"v2ray.com/core/common"
"v2ray.com/core/common/buf"
"v2ray.com/core/common/serial"
)
func PackMessage(msg *dnsmessage.Message) (*buf.Buffer, error) {
buffer := buf.New()
rawBytes := buffer.Extend(buf.Size)
packed, err := msg.AppendPack(rawBytes[:0])
if err != nil {
buffer.Release()
return nil, err
}
buffer.Resize(0, int32(len(packed)))
return buffer, nil
}
type MessageReader interface {
ReadMessage() (*buf.Buffer, error)
}
type UDPReader struct {
buf.Reader
access sync.Mutex
cache buf.MultiBuffer
}
func (r *UDPReader) readCache() *buf.Buffer {
r.access.Lock()
defer r.access.Unlock()
mb, b := buf.SplitFirst(r.cache)
r.cache = mb
return b
}
func (r *UDPReader) refill() error {
mb, err := r.Reader.ReadMultiBuffer()
if err != nil {
return err
}
r.access.Lock()
r.cache = mb
r.access.Unlock()
return nil
}
// ReadMessage implements MessageReader.
func (r *UDPReader) ReadMessage() (*buf.Buffer, error) {
for {
b := r.readCache()
if b != nil {
return b, nil
}
if err := r.refill(); err != nil {
return nil, err
}
}
}
// Close implements common.Closable.
func (r *UDPReader) Close() error {
defer func() {
r.access.Lock()
buf.ReleaseMulti(r.cache)
r.cache = nil
r.access.Unlock()
}()
return common.Close(r.Reader)
}
type TCPReader struct {
reader *buf.BufferedReader
}
func NewTCPReader(reader buf.Reader) *TCPReader {
return &TCPReader{
reader: &buf.BufferedReader{
Reader: reader,
},
}
}
func (r *TCPReader) ReadMessage() (*buf.Buffer, error) {
size, err := serial.ReadUint16(r.reader)
if err != nil {
return nil, err
}
if size > buf.Size {
return nil, newError("message size too large: ", size)
}
b := buf.New()
if _, err := b.ReadFullFrom(r.reader, int32(size)); err != nil {
return nil, err
}
return b, nil
}
func (r *TCPReader) Interrupt() {
common.Interrupt(r.reader)
}
func (r *TCPReader) Close() error {
return common.Close(r.reader)
}
type MessageWriter interface {
WriteMessage(msg *buf.Buffer) error
}
type UDPWriter struct {
buf.Writer
}
func (w *UDPWriter) WriteMessage(b *buf.Buffer) error {
return w.WriteMultiBuffer(buf.MultiBuffer{b})
}
type TCPWriter struct {
buf.Writer
}
func (w *TCPWriter) WriteMessage(b *buf.Buffer) error {
if b.IsEmpty() {
return nil
}
mb := make(buf.MultiBuffer, 0, 2)
size := buf.New()
binary.BigEndian.PutUint16(size.Extend(2), uint16(b.Len()))
mb = append(mb, size, b)
return w.WriteMultiBuffer(mb)
}
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