mirror of
https://github.com/XTLS/Xray-core.git
synced 2026-07-13 23:28:46 +00:00
Finalmask: Add XDNS (relies mKCP, like DNSTT), header-*, mkcp-* (#5560)
And https://github.com/XTLS/Xray-core/pull/5560#issuecomment-3825430761
This commit is contained in:
LjhAUMEM
@@ -0,0 +1,373 @@
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package xdns
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import (
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"bytes"
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"context"
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"crypto/rand"
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"encoding/base32"
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"encoding/binary"
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"io"
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"net"
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"sync"
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"time"
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"github.com/xtls/xray-core/common/errors"
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)
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const (
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numPadding = 3
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numPaddingForPoll = 8
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initPollDelay = 500 * time.Millisecond
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maxPollDelay = 10 * time.Second
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pollDelayMultiplier = 2.0
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pollLimit = 16
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)
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var base32Encoding = base32.StdEncoding.WithPadding(base32.NoPadding)
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type packet struct {
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p []byte
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addr net.Addr
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}
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type xdnsConnClient struct {
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conn net.PacketConn
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clientID []byte
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domain Name
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pollChan chan struct{}
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readQueue chan *packet
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writeQueue chan *packet
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closed bool
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mutex sync.Mutex
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}
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func NewConnClient(c *Config, raw net.PacketConn, end bool) (net.PacketConn, error) {
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if !end {
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return nil, errors.New("xdns requires being at the outermost level")
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}
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domain, err := ParseName(c.Domain)
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if err != nil {
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return nil, err
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}
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conn := &xdnsConnClient{
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conn: raw,
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clientID: make([]byte, 8),
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domain: domain,
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pollChan: make(chan struct{}, pollLimit),
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readQueue: make(chan *packet, 128),
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writeQueue: make(chan *packet, 128),
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}
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rand.Read(conn.clientID)
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go conn.recvLoop()
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go conn.sendLoop()
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return conn, nil
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}
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func (c *xdnsConnClient) recvLoop() {
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for {
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if c.closed {
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break
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}
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var buf [4096]byte
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n, addr, err := c.conn.ReadFrom(buf[:])
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if err != nil {
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continue
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}
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resp, err := MessageFromWireFormat(buf[:n])
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if err != nil {
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continue
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}
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payload := dnsResponsePayload(&resp, c.domain)
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r := bytes.NewReader(payload)
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anyPacket := false
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for {
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p, err := nextPacket(r)
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if err != nil {
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break
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}
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anyPacket = true
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buf := make([]byte, len(p))
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copy(buf, p)
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select {
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case c.readQueue <- &packet{
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p: buf,
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addr: addr,
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}:
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default:
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}
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}
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if anyPacket {
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select {
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case c.pollChan <- struct{}{}:
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default:
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}
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}
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}
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close(c.pollChan)
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close(c.readQueue)
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}
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func (c *xdnsConnClient) sendLoop() {
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var addr net.Addr
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pollDelay := initPollDelay
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pollTimer := time.NewTimer(pollDelay)
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for {
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var p *packet
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pollTimerExpired := false
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select {
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case p = <-c.writeQueue:
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default:
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select {
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case p = <-c.writeQueue:
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case <-c.pollChan:
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case <-pollTimer.C:
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pollTimerExpired = true
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}
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}
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if p != nil {
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addr = p.addr
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select {
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case <-c.pollChan:
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default:
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}
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} else if addr != nil {
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encoded, _ := encode(nil, c.clientID, c.domain)
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p = &packet{
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p: encoded,
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addr: addr,
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}
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}
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if pollTimerExpired {
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pollDelay = time.Duration(float64(pollDelay) * pollDelayMultiplier)
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if pollDelay > maxPollDelay {
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pollDelay = maxPollDelay
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}
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} else {
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if !pollTimer.Stop() {
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<-pollTimer.C
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}
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pollDelay = initPollDelay
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}
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pollTimer.Reset(pollDelay)
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if c.closed {
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return
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}
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if p != nil {
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_, _ = c.conn.WriteTo(p.p, p.addr)
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}
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}
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}
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func (c *xdnsConnClient) Size() int32 {
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return 0
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}
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func (c *xdnsConnClient) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
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packet, ok := <-c.readQueue
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if !ok {
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return 0, nil, io.EOF
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}
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n = copy(p, packet.p)
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if n != len(packet.p) {
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return 0, nil, io.ErrShortBuffer
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}
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return n, packet.addr, nil
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}
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func (c *xdnsConnClient) WriteTo(p []byte, addr net.Addr) (n int, err error) {
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c.mutex.Lock()
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defer c.mutex.Unlock()
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if c.closed {
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return 0, errors.New("xdns closed")
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}
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encoded, err := encode(p, c.clientID, c.domain)
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if err != nil {
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errors.LogDebug(context.Background(), "xdns encode err", err)
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return 0, errors.New("xdns encode").Base(err)
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}
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select {
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case c.writeQueue <- &packet{
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p: encoded,
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addr: addr,
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}:
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return len(p), nil
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default:
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return 0, errors.New("xdns queue full")
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}
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}
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func (c *xdnsConnClient) Close() error {
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c.mutex.Lock()
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defer c.mutex.Unlock()
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if c.closed {
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return nil
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}
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c.closed = true
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close(c.writeQueue)
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return c.conn.Close()
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}
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func (c *xdnsConnClient) LocalAddr() net.Addr {
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return c.conn.LocalAddr()
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}
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func (c *xdnsConnClient) SetDeadline(t time.Time) error {
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return c.conn.SetDeadline(t)
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}
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func (c *xdnsConnClient) SetReadDeadline(t time.Time) error {
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return c.conn.SetReadDeadline(t)
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}
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func (c *xdnsConnClient) SetWriteDeadline(t time.Time) error {
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return c.conn.SetWriteDeadline(t)
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}
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func encode(p []byte, clientID []byte, domain Name) ([]byte, error) {
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var decoded []byte
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{
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if len(p) >= 224 {
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return nil, errors.New("too long")
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}
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var buf bytes.Buffer
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buf.Write(clientID[:])
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n := numPadding
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if len(p) == 0 {
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n = numPaddingForPoll
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}
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buf.WriteByte(byte(224 + n))
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_, _ = io.CopyN(&buf, rand.Reader, int64(n))
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if len(p) > 0 {
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buf.WriteByte(byte(len(p)))
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buf.Write(p)
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}
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decoded = buf.Bytes()
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}
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encoded := make([]byte, base32Encoding.EncodedLen(len(decoded)))
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base32Encoding.Encode(encoded, decoded)
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encoded = bytes.ToLower(encoded)
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labels := chunks(encoded, 63)
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labels = append(labels, domain...)
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name, err := NewName(labels)
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if err != nil {
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return nil, err
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}
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var id uint16
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_ = binary.Read(rand.Reader, binary.BigEndian, &id)
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query := &Message{
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ID: id,
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Flags: 0x0100,
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Question: []Question{
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{
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Name: name,
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Type: RRTypeTXT,
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Class: ClassIN,
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},
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},
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Additional: []RR{
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{
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Name: Name{},
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Type: RRTypeOPT,
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Class: 4096,
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TTL: 0,
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Data: []byte{},
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},
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},
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}
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buf, err := query.WireFormat()
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if err != nil {
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return nil, err
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}
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return buf, nil
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}
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func chunks(p []byte, n int) [][]byte {
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var result [][]byte
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for len(p) > 0 {
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sz := len(p)
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if sz > n {
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sz = n
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}
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result = append(result, p[:sz])
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p = p[sz:]
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}
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return result
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}
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func nextPacket(r *bytes.Reader) ([]byte, error) {
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var n uint16
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err := binary.Read(r, binary.BigEndian, &n)
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if err != nil {
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return nil, err
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}
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p := make([]byte, n)
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_, err = io.ReadFull(r, p)
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if err == io.EOF {
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err = io.ErrUnexpectedEOF
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}
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return p, err
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}
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func dnsResponsePayload(resp *Message, domain Name) []byte {
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if resp.Flags&0x8000 != 0x8000 {
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return nil
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}
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if resp.Flags&0x000f != RcodeNoError {
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return nil
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}
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if len(resp.Answer) != 1 {
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return nil
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}
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answer := resp.Answer[0]
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_, ok := answer.Name.TrimSuffix(domain)
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if !ok {
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return nil
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}
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if answer.Type != RRTypeTXT {
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return nil
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}
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payload, err := DecodeRDataTXT(answer.Data)
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||||
if err != nil {
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||||
return nil
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||||
}
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||||
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return payload
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}
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@@ -0,0 +1,16 @@
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package xdns
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import (
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"net"
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)
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func (c *Config) UDP() {
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||||
}
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||||
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||||
func (c *Config) WrapPacketConnClient(raw net.PacketConn, first bool, leaveSize int32, end bool) (net.PacketConn, error) {
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||||
return NewConnClient(c, raw, end)
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||||
}
|
||||
|
||||
func (c *Config) WrapPacketConnServer(raw net.PacketConn, first bool, leaveSize int32, end bool) (net.PacketConn, error) {
|
||||
return NewConnServer(c, raw, end)
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||||
}
|
||||
@@ -0,0 +1,123 @@
|
||||
// Code generated by protoc-gen-go. DO NOT EDIT.
|
||||
// versions:
|
||||
// protoc-gen-go v1.36.10
|
||||
// protoc v6.33.1
|
||||
// source: transport/internet/finalmask/xdns/config.proto
|
||||
|
||||
package xdns
|
||||
|
||||
import (
|
||||
protoreflect "google.golang.org/protobuf/reflect/protoreflect"
|
||||
protoimpl "google.golang.org/protobuf/runtime/protoimpl"
|
||||
reflect "reflect"
|
||||
sync "sync"
|
||||
unsafe "unsafe"
|
||||
)
|
||||
|
||||
const (
|
||||
// Verify that this generated code is sufficiently up-to-date.
|
||||
_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
|
||||
// Verify that runtime/protoimpl is sufficiently up-to-date.
|
||||
_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
|
||||
)
|
||||
|
||||
type Config struct {
|
||||
state protoimpl.MessageState `protogen:"open.v1"`
|
||||
Domain string `protobuf:"bytes,1,opt,name=domain,proto3" json:"domain,omitempty"`
|
||||
unknownFields protoimpl.UnknownFields
|
||||
sizeCache protoimpl.SizeCache
|
||||
}
|
||||
|
||||
func (x *Config) Reset() {
|
||||
*x = Config{}
|
||||
mi := &file_transport_internet_finalmask_xdns_config_proto_msgTypes[0]
|
||||
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
|
||||
ms.StoreMessageInfo(mi)
|
||||
}
|
||||
|
||||
func (x *Config) String() string {
|
||||
return protoimpl.X.MessageStringOf(x)
|
||||
}
|
||||
|
||||
func (*Config) ProtoMessage() {}
|
||||
|
||||
func (x *Config) ProtoReflect() protoreflect.Message {
|
||||
mi := &file_transport_internet_finalmask_xdns_config_proto_msgTypes[0]
|
||||
if x != nil {
|
||||
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
|
||||
if ms.LoadMessageInfo() == nil {
|
||||
ms.StoreMessageInfo(mi)
|
||||
}
|
||||
return ms
|
||||
}
|
||||
return mi.MessageOf(x)
|
||||
}
|
||||
|
||||
// Deprecated: Use Config.ProtoReflect.Descriptor instead.
|
||||
func (*Config) Descriptor() ([]byte, []int) {
|
||||
return file_transport_internet_finalmask_xdns_config_proto_rawDescGZIP(), []int{0}
|
||||
}
|
||||
|
||||
func (x *Config) GetDomain() string {
|
||||
if x != nil {
|
||||
return x.Domain
|
||||
}
|
||||
return ""
|
||||
}
|
||||
|
||||
var File_transport_internet_finalmask_xdns_config_proto protoreflect.FileDescriptor
|
||||
|
||||
const file_transport_internet_finalmask_xdns_config_proto_rawDesc = "" +
|
||||
"\n" +
|
||||
".transport/internet/finalmask/xdns/config.proto\x12&xray.transport.internet.finalmask.xdns\" \n" +
|
||||
"\x06Config\x12\x16\n" +
|
||||
"\x06domain\x18\x01 \x01(\tR\x06domainB\x94\x01\n" +
|
||||
"*com.xray.transport.internet.finalmask.xdnsP\x01Z;github.com/xtls/xray-core/transport/internet/finalmask/xdns\xaa\x02&Xray.Transport.Internet.Finalmask.Xdnsb\x06proto3"
|
||||
|
||||
var (
|
||||
file_transport_internet_finalmask_xdns_config_proto_rawDescOnce sync.Once
|
||||
file_transport_internet_finalmask_xdns_config_proto_rawDescData []byte
|
||||
)
|
||||
|
||||
func file_transport_internet_finalmask_xdns_config_proto_rawDescGZIP() []byte {
|
||||
file_transport_internet_finalmask_xdns_config_proto_rawDescOnce.Do(func() {
|
||||
file_transport_internet_finalmask_xdns_config_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_transport_internet_finalmask_xdns_config_proto_rawDesc), len(file_transport_internet_finalmask_xdns_config_proto_rawDesc)))
|
||||
})
|
||||
return file_transport_internet_finalmask_xdns_config_proto_rawDescData
|
||||
}
|
||||
|
||||
var file_transport_internet_finalmask_xdns_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1)
|
||||
var file_transport_internet_finalmask_xdns_config_proto_goTypes = []any{
|
||||
(*Config)(nil), // 0: xray.transport.internet.finalmask.xdns.Config
|
||||
}
|
||||
var file_transport_internet_finalmask_xdns_config_proto_depIdxs = []int32{
|
||||
0, // [0:0] is the sub-list for method output_type
|
||||
0, // [0:0] is the sub-list for method input_type
|
||||
0, // [0:0] is the sub-list for extension type_name
|
||||
0, // [0:0] is the sub-list for extension extendee
|
||||
0, // [0:0] is the sub-list for field type_name
|
||||
}
|
||||
|
||||
func init() { file_transport_internet_finalmask_xdns_config_proto_init() }
|
||||
func file_transport_internet_finalmask_xdns_config_proto_init() {
|
||||
if File_transport_internet_finalmask_xdns_config_proto != nil {
|
||||
return
|
||||
}
|
||||
type x struct{}
|
||||
out := protoimpl.TypeBuilder{
|
||||
File: protoimpl.DescBuilder{
|
||||
GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
|
||||
RawDescriptor: unsafe.Slice(unsafe.StringData(file_transport_internet_finalmask_xdns_config_proto_rawDesc), len(file_transport_internet_finalmask_xdns_config_proto_rawDesc)),
|
||||
NumEnums: 0,
|
||||
NumMessages: 1,
|
||||
NumExtensions: 0,
|
||||
NumServices: 0,
|
||||
},
|
||||
GoTypes: file_transport_internet_finalmask_xdns_config_proto_goTypes,
|
||||
DependencyIndexes: file_transport_internet_finalmask_xdns_config_proto_depIdxs,
|
||||
MessageInfos: file_transport_internet_finalmask_xdns_config_proto_msgTypes,
|
||||
}.Build()
|
||||
File_transport_internet_finalmask_xdns_config_proto = out.File
|
||||
file_transport_internet_finalmask_xdns_config_proto_goTypes = nil
|
||||
file_transport_internet_finalmask_xdns_config_proto_depIdxs = nil
|
||||
}
|
||||
@@ -0,0 +1,12 @@
|
||||
syntax = "proto3";
|
||||
|
||||
package xray.transport.internet.finalmask.xdns;
|
||||
option csharp_namespace = "Xray.Transport.Internet.Finalmask.Xdns";
|
||||
option go_package = "github.com/xtls/xray-core/transport/internet/finalmask/xdns";
|
||||
option java_package = "com.xray.transport.internet.finalmask.xdns";
|
||||
option java_multiple_files = true;
|
||||
|
||||
message Config {
|
||||
string domain = 1;
|
||||
}
|
||||
|
||||
@@ -0,0 +1,575 @@
|
||||
// Package dns deals with encoding and decoding DNS wire format.
|
||||
package xdns
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"encoding/binary"
|
||||
"errors"
|
||||
"fmt"
|
||||
"io"
|
||||
"strings"
|
||||
)
|
||||
|
||||
// The maximum number of DNS name compression pointers we are willing to follow.
|
||||
// Without something like this, infinite loops are possible.
|
||||
const compressionPointerLimit = 10
|
||||
|
||||
var (
|
||||
// ErrZeroLengthLabel is the error returned for names that contain a
|
||||
// zero-length label, like "example..com".
|
||||
ErrZeroLengthLabel = errors.New("name contains a zero-length label")
|
||||
|
||||
// ErrLabelTooLong is the error returned for labels that are longer than
|
||||
// 63 octets.
|
||||
ErrLabelTooLong = errors.New("name contains a label longer than 63 octets")
|
||||
|
||||
// ErrNameTooLong is the error returned for names whose encoded
|
||||
// representation is longer than 255 octets.
|
||||
ErrNameTooLong = errors.New("name is longer than 255 octets")
|
||||
|
||||
// ErrReservedLabelType is the error returned when reading a label type
|
||||
// prefix whose two most significant bits are not 00 or 11.
|
||||
ErrReservedLabelType = errors.New("reserved label type")
|
||||
|
||||
// ErrTooManyPointers is the error returned when reading a compressed
|
||||
// name that has too many compression pointers.
|
||||
ErrTooManyPointers = errors.New("too many compression pointers")
|
||||
|
||||
// ErrTrailingBytes is the error returned when bytes remain in the parse
|
||||
// buffer after parsing a message.
|
||||
ErrTrailingBytes = errors.New("trailing bytes after message")
|
||||
|
||||
// ErrIntegerOverflow is the error returned when trying to encode an
|
||||
// integer greater than 65535 into a 16-bit field.
|
||||
ErrIntegerOverflow = errors.New("integer overflow")
|
||||
)
|
||||
|
||||
const (
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.2.2
|
||||
RRTypeTXT = 16
|
||||
// https://tools.ietf.org/html/rfc6891#section-6.1.1
|
||||
RRTypeOPT = 41
|
||||
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.2.4
|
||||
ClassIN = 1
|
||||
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.1
|
||||
RcodeNoError = 0 // a.k.a. NOERROR
|
||||
RcodeFormatError = 1 // a.k.a. FORMERR
|
||||
RcodeNameError = 3 // a.k.a. NXDOMAIN
|
||||
RcodeNotImplemented = 4 // a.k.a. NOTIMPL
|
||||
// https://tools.ietf.org/html/rfc6891#section-9
|
||||
ExtendedRcodeBadVers = 16 // a.k.a. BADVERS
|
||||
)
|
||||
|
||||
// Name represents a domain name, a sequence of labels each of which is 63
|
||||
// octets or less in length.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.1
|
||||
type Name [][]byte
|
||||
|
||||
// NewName returns a Name from a slice of labels, after checking the labels for
|
||||
// validity. Does not include a zero-length label at the end of the slice.
|
||||
func NewName(labels [][]byte) (Name, error) {
|
||||
name := Name(labels)
|
||||
// https://tools.ietf.org/html/rfc1035#section-2.3.4
|
||||
// Various objects and parameters in the DNS have size limits.
|
||||
// labels 63 octets or less
|
||||
// names 255 octets or less
|
||||
for _, label := range labels {
|
||||
if len(label) == 0 {
|
||||
return nil, ErrZeroLengthLabel
|
||||
}
|
||||
if len(label) > 63 {
|
||||
return nil, ErrLabelTooLong
|
||||
}
|
||||
}
|
||||
// Check the total length.
|
||||
builder := newMessageBuilder()
|
||||
builder.WriteName(name)
|
||||
if len(builder.Bytes()) > 255 {
|
||||
return nil, ErrNameTooLong
|
||||
}
|
||||
return name, nil
|
||||
}
|
||||
|
||||
// ParseName returns a new Name from a string of labels separated by dots, after
|
||||
// checking the name for validity. A single dot at the end of the string is
|
||||
// ignored.
|
||||
func ParseName(s string) (Name, error) {
|
||||
b := bytes.TrimSuffix([]byte(s), []byte("."))
|
||||
if len(b) == 0 {
|
||||
// bytes.Split(b, ".") would return [""] in this case
|
||||
return NewName([][]byte{})
|
||||
} else {
|
||||
return NewName(bytes.Split(b, []byte(".")))
|
||||
}
|
||||
}
|
||||
|
||||
// String returns a reversible string representation of name. Labels are
|
||||
// separated by dots, and any bytes in a label that are outside the set
|
||||
// [0-9A-Za-z-] are replaced with a \xXX hex escape sequence.
|
||||
func (name Name) String() string {
|
||||
if len(name) == 0 {
|
||||
return "."
|
||||
}
|
||||
|
||||
var buf strings.Builder
|
||||
for i, label := range name {
|
||||
if i > 0 {
|
||||
buf.WriteByte('.')
|
||||
}
|
||||
for _, b := range label {
|
||||
if b == '-' ||
|
||||
('0' <= b && b <= '9') ||
|
||||
('A' <= b && b <= 'Z') ||
|
||||
('a' <= b && b <= 'z') {
|
||||
buf.WriteByte(b)
|
||||
} else {
|
||||
fmt.Fprintf(&buf, "\\x%02x", b)
|
||||
}
|
||||
}
|
||||
}
|
||||
return buf.String()
|
||||
}
|
||||
|
||||
// TrimSuffix returns a Name with the given suffix removed, if it was present.
|
||||
// The second return value indicates whether the suffix was present. If the
|
||||
// suffix was not present, the first return value is nil.
|
||||
func (name Name) TrimSuffix(suffix Name) (Name, bool) {
|
||||
if len(name) < len(suffix) {
|
||||
return nil, false
|
||||
}
|
||||
split := len(name) - len(suffix)
|
||||
fore, aft := name[:split], name[split:]
|
||||
for i := 0; i < len(aft); i++ {
|
||||
if !bytes.Equal(bytes.ToLower(aft[i]), bytes.ToLower(suffix[i])) {
|
||||
return nil, false
|
||||
}
|
||||
}
|
||||
return fore, true
|
||||
}
|
||||
|
||||
// Message represents a DNS message.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1
|
||||
type Message struct {
|
||||
ID uint16
|
||||
Flags uint16
|
||||
|
||||
Question []Question
|
||||
Answer []RR
|
||||
Authority []RR
|
||||
Additional []RR
|
||||
}
|
||||
|
||||
// Opcode extracts the OPCODE part of the Flags field.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.1
|
||||
func (message *Message) Opcode() uint16 {
|
||||
return (message.Flags >> 11) & 0xf
|
||||
}
|
||||
|
||||
// Rcode extracts the RCODE part of the Flags field.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.1
|
||||
func (message *Message) Rcode() uint16 {
|
||||
return message.Flags & 0x000f
|
||||
}
|
||||
|
||||
// Question represents an entry in the question section of a message.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.2
|
||||
type Question struct {
|
||||
Name Name
|
||||
Type uint16
|
||||
Class uint16
|
||||
}
|
||||
|
||||
// RR represents a resource record.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.3
|
||||
type RR struct {
|
||||
Name Name
|
||||
Type uint16
|
||||
Class uint16
|
||||
TTL uint32
|
||||
Data []byte
|
||||
}
|
||||
|
||||
// readName parses a DNS name from r. It leaves r positioned just after the
|
||||
// parsed name.
|
||||
func readName(r io.ReadSeeker) (Name, error) {
|
||||
var labels [][]byte
|
||||
// We limit the number of compression pointers we are willing to follow.
|
||||
numPointers := 0
|
||||
// If we followed any compression pointers, we must finally seek to just
|
||||
// past the first pointer.
|
||||
var seekTo int64
|
||||
loop:
|
||||
for {
|
||||
var labelType byte
|
||||
err := binary.Read(r, binary.BigEndian, &labelType)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
switch labelType & 0xc0 {
|
||||
case 0x00:
|
||||
// This is an ordinary label.
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.1
|
||||
length := int(labelType & 0x3f)
|
||||
if length == 0 {
|
||||
break loop
|
||||
}
|
||||
label := make([]byte, length)
|
||||
_, err := io.ReadFull(r, label)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
labels = append(labels, label)
|
||||
case 0xc0:
|
||||
// This is a compression pointer.
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.4
|
||||
upper := labelType & 0x3f
|
||||
var lower byte
|
||||
err := binary.Read(r, binary.BigEndian, &lower)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
offset := (uint16(upper) << 8) | uint16(lower)
|
||||
|
||||
if numPointers == 0 {
|
||||
// The first time we encounter a pointer,
|
||||
// remember our position so we can seek back to
|
||||
// it when done.
|
||||
seekTo, err = r.Seek(0, io.SeekCurrent)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
numPointers++
|
||||
if numPointers > compressionPointerLimit {
|
||||
return nil, ErrTooManyPointers
|
||||
}
|
||||
|
||||
// Follow the pointer and continue.
|
||||
_, err = r.Seek(int64(offset), io.SeekStart)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
default:
|
||||
// "The 10 and 01 combinations are reserved for future
|
||||
// use."
|
||||
return nil, ErrReservedLabelType
|
||||
}
|
||||
}
|
||||
// If we followed any pointers, then seek back to just after the first
|
||||
// one.
|
||||
if numPointers > 0 {
|
||||
_, err := r.Seek(seekTo, io.SeekStart)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
return NewName(labels)
|
||||
}
|
||||
|
||||
// readQuestion parses one entry from the Question section. It leaves r
|
||||
// positioned just after the parsed entry.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.2
|
||||
func readQuestion(r io.ReadSeeker) (Question, error) {
|
||||
var question Question
|
||||
var err error
|
||||
question.Name, err = readName(r)
|
||||
if err != nil {
|
||||
return question, err
|
||||
}
|
||||
for _, ptr := range []*uint16{&question.Type, &question.Class} {
|
||||
err := binary.Read(r, binary.BigEndian, ptr)
|
||||
if err != nil {
|
||||
return question, err
|
||||
}
|
||||
}
|
||||
|
||||
return question, nil
|
||||
}
|
||||
|
||||
// readRR parses one resource record. It leaves r positioned just after the
|
||||
// parsed resource record.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.3
|
||||
func readRR(r io.ReadSeeker) (RR, error) {
|
||||
var rr RR
|
||||
var err error
|
||||
rr.Name, err = readName(r)
|
||||
if err != nil {
|
||||
return rr, err
|
||||
}
|
||||
for _, ptr := range []*uint16{&rr.Type, &rr.Class} {
|
||||
err := binary.Read(r, binary.BigEndian, ptr)
|
||||
if err != nil {
|
||||
return rr, err
|
||||
}
|
||||
}
|
||||
err = binary.Read(r, binary.BigEndian, &rr.TTL)
|
||||
if err != nil {
|
||||
return rr, err
|
||||
}
|
||||
var rdLength uint16
|
||||
err = binary.Read(r, binary.BigEndian, &rdLength)
|
||||
if err != nil {
|
||||
return rr, err
|
||||
}
|
||||
rr.Data = make([]byte, rdLength)
|
||||
_, err = io.ReadFull(r, rr.Data)
|
||||
if err != nil {
|
||||
return rr, err
|
||||
}
|
||||
|
||||
return rr, nil
|
||||
}
|
||||
|
||||
// readMessage parses a complete DNS message. It leaves r positioned just after
|
||||
// the parsed message.
|
||||
func readMessage(r io.ReadSeeker) (Message, error) {
|
||||
var message Message
|
||||
|
||||
// Header section
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.1
|
||||
var qdCount, anCount, nsCount, arCount uint16
|
||||
for _, ptr := range []*uint16{
|
||||
&message.ID, &message.Flags,
|
||||
&qdCount, &anCount, &nsCount, &arCount,
|
||||
} {
|
||||
err := binary.Read(r, binary.BigEndian, ptr)
|
||||
if err != nil {
|
||||
return message, err
|
||||
}
|
||||
}
|
||||
|
||||
// Question section
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.2
|
||||
for i := 0; i < int(qdCount); i++ {
|
||||
question, err := readQuestion(r)
|
||||
if err != nil {
|
||||
return message, err
|
||||
}
|
||||
message.Question = append(message.Question, question)
|
||||
}
|
||||
|
||||
// Answer, Authority, and Additional sections
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.3
|
||||
for _, rec := range []struct {
|
||||
ptr *[]RR
|
||||
count uint16
|
||||
}{
|
||||
{&message.Answer, anCount},
|
||||
{&message.Authority, nsCount},
|
||||
{&message.Additional, arCount},
|
||||
} {
|
||||
for i := 0; i < int(rec.count); i++ {
|
||||
rr, err := readRR(r)
|
||||
if err != nil {
|
||||
return message, err
|
||||
}
|
||||
*rec.ptr = append(*rec.ptr, rr)
|
||||
}
|
||||
}
|
||||
|
||||
return message, nil
|
||||
}
|
||||
|
||||
// MessageFromWireFormat parses a message from buf and returns a Message object.
|
||||
// It returns ErrTrailingBytes if there are bytes remaining in buf after parsing
|
||||
// is done.
|
||||
func MessageFromWireFormat(buf []byte) (Message, error) {
|
||||
r := bytes.NewReader(buf)
|
||||
message, err := readMessage(r)
|
||||
if err == io.EOF {
|
||||
err = io.ErrUnexpectedEOF
|
||||
} else if err == nil {
|
||||
// Check for trailing bytes.
|
||||
_, err = r.ReadByte()
|
||||
if err == io.EOF {
|
||||
err = nil
|
||||
} else if err == nil {
|
||||
err = ErrTrailingBytes
|
||||
}
|
||||
}
|
||||
return message, err
|
||||
}
|
||||
|
||||
// messageBuilder manages the state of serializing a DNS message. Its main
|
||||
// function is to keep track of names already written for the purpose of name
|
||||
// compression.
|
||||
type messageBuilder struct {
|
||||
w bytes.Buffer
|
||||
nameCache map[string]int
|
||||
}
|
||||
|
||||
// newMessageBuilder creates a new messageBuilder with an empty name cache.
|
||||
func newMessageBuilder() *messageBuilder {
|
||||
return &messageBuilder{
|
||||
nameCache: make(map[string]int),
|
||||
}
|
||||
}
|
||||
|
||||
// Bytes returns the serialized DNS message as a slice of bytes.
|
||||
func (builder *messageBuilder) Bytes() []byte {
|
||||
return builder.w.Bytes()
|
||||
}
|
||||
|
||||
// WriteName appends name to the in-progress messageBuilder, employing
|
||||
// compression pointers to previously written names if possible.
|
||||
func (builder *messageBuilder) WriteName(name Name) {
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.1
|
||||
for i := range name {
|
||||
// Has this suffix already been encoded in the message?
|
||||
if ptr, ok := builder.nameCache[name[i:].String()]; ok && ptr&0x3fff == ptr {
|
||||
// If so, we can write a compression pointer.
|
||||
binary.Write(&builder.w, binary.BigEndian, uint16(0xc000|ptr))
|
||||
return
|
||||
}
|
||||
// Not cached; we must encode this label verbatim. Store a cache
|
||||
// entry pointing to the beginning of it.
|
||||
builder.nameCache[name[i:].String()] = builder.w.Len()
|
||||
length := len(name[i])
|
||||
if length == 0 || length > 63 {
|
||||
panic(length)
|
||||
}
|
||||
builder.w.WriteByte(byte(length))
|
||||
builder.w.Write(name[i])
|
||||
}
|
||||
builder.w.WriteByte(0)
|
||||
}
|
||||
|
||||
// WriteQuestion appends a Question section entry to the in-progress
|
||||
// messageBuilder.
|
||||
func (builder *messageBuilder) WriteQuestion(question *Question) {
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.2
|
||||
builder.WriteName(question.Name)
|
||||
binary.Write(&builder.w, binary.BigEndian, question.Type)
|
||||
binary.Write(&builder.w, binary.BigEndian, question.Class)
|
||||
}
|
||||
|
||||
// WriteRR appends a resource record to the in-progress messageBuilder. It
|
||||
// returns ErrIntegerOverflow if the length of rr.Data does not fit in 16 bits.
|
||||
func (builder *messageBuilder) WriteRR(rr *RR) error {
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.3
|
||||
builder.WriteName(rr.Name)
|
||||
binary.Write(&builder.w, binary.BigEndian, rr.Type)
|
||||
binary.Write(&builder.w, binary.BigEndian, rr.Class)
|
||||
binary.Write(&builder.w, binary.BigEndian, rr.TTL)
|
||||
rdLength := uint16(len(rr.Data))
|
||||
if int(rdLength) != len(rr.Data) {
|
||||
return ErrIntegerOverflow
|
||||
}
|
||||
binary.Write(&builder.w, binary.BigEndian, rdLength)
|
||||
builder.w.Write(rr.Data)
|
||||
return nil
|
||||
}
|
||||
|
||||
// WriteMessage appends a complete DNS message to the in-progress
|
||||
// messageBuilder. It returns ErrIntegerOverflow if the number of entries in any
|
||||
// section, or the length of the data in any resource record, does not fit in 16
|
||||
// bits.
|
||||
func (builder *messageBuilder) WriteMessage(message *Message) error {
|
||||
// Header section
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.1
|
||||
binary.Write(&builder.w, binary.BigEndian, message.ID)
|
||||
binary.Write(&builder.w, binary.BigEndian, message.Flags)
|
||||
for _, count := range []int{
|
||||
len(message.Question),
|
||||
len(message.Answer),
|
||||
len(message.Authority),
|
||||
len(message.Additional),
|
||||
} {
|
||||
count16 := uint16(count)
|
||||
if int(count16) != count {
|
||||
return ErrIntegerOverflow
|
||||
}
|
||||
binary.Write(&builder.w, binary.BigEndian, count16)
|
||||
}
|
||||
|
||||
// Question section
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.2
|
||||
for _, question := range message.Question {
|
||||
builder.WriteQuestion(&question)
|
||||
}
|
||||
|
||||
// Answer, Authority, and Additional sections
|
||||
// https://tools.ietf.org/html/rfc1035#section-4.1.3
|
||||
for _, rrs := range [][]RR{message.Answer, message.Authority, message.Additional} {
|
||||
for _, rr := range rrs {
|
||||
err := builder.WriteRR(&rr)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// WireFormat encodes a Message as a slice of bytes in DNS wire format. It
|
||||
// returns ErrIntegerOverflow if the number of entries in any section, or the
|
||||
// length of the data in any resource record, does not fit in 16 bits.
|
||||
func (message *Message) WireFormat() ([]byte, error) {
|
||||
builder := newMessageBuilder()
|
||||
err := builder.WriteMessage(message)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
return builder.Bytes(), nil
|
||||
}
|
||||
|
||||
// DecodeRDataTXT decodes TXT-DATA (as found in the RDATA for a resource record
|
||||
// with TYPE=TXT) as a raw byte slice, by concatenating all the
|
||||
// <character-string>s it contains.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.3.14
|
||||
func DecodeRDataTXT(p []byte) ([]byte, error) {
|
||||
var buf bytes.Buffer
|
||||
for {
|
||||
if len(p) == 0 {
|
||||
return nil, io.ErrUnexpectedEOF
|
||||
}
|
||||
n := int(p[0])
|
||||
p = p[1:]
|
||||
if len(p) < n {
|
||||
return nil, io.ErrUnexpectedEOF
|
||||
}
|
||||
buf.Write(p[:n])
|
||||
p = p[n:]
|
||||
if len(p) == 0 {
|
||||
break
|
||||
}
|
||||
}
|
||||
return buf.Bytes(), nil
|
||||
}
|
||||
|
||||
// EncodeRDataTXT encodes a slice of bytes as TXT-DATA, as appropriate for the
|
||||
// RDATA of a resource record with TYPE=TXT. No length restriction is enforced
|
||||
// here; that must be checked at a higher level.
|
||||
//
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.3.14
|
||||
func EncodeRDataTXT(p []byte) []byte {
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.3
|
||||
// https://tools.ietf.org/html/rfc1035#section-3.3.14
|
||||
// TXT data is a sequence of one or more <character-string>s, where
|
||||
// <character-string> is a length octet followed by that number of
|
||||
// octets.
|
||||
var buf bytes.Buffer
|
||||
for len(p) > 255 {
|
||||
buf.WriteByte(255)
|
||||
buf.Write(p[:255])
|
||||
p = p[255:]
|
||||
}
|
||||
// Must write here, even if len(p) == 0, because it's "*one or more*
|
||||
// <character-string>s".
|
||||
buf.WriteByte(byte(len(p)))
|
||||
buf.Write(p)
|
||||
return buf.Bytes()
|
||||
}
|
||||
@@ -0,0 +1,592 @@
|
||||
package xdns
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"fmt"
|
||||
"io"
|
||||
"strconv"
|
||||
"strings"
|
||||
"testing"
|
||||
)
|
||||
|
||||
func namesEqual(a, b Name) bool {
|
||||
if len(a) != len(b) {
|
||||
return false
|
||||
}
|
||||
for i := 0; i < len(a); i++ {
|
||||
if !bytes.Equal(a[i], b[i]) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func TestName(t *testing.T) {
|
||||
for _, test := range []struct {
|
||||
labels [][]byte
|
||||
err error
|
||||
s string
|
||||
}{
|
||||
{[][]byte{}, nil, "."},
|
||||
{[][]byte{[]byte("test")}, nil, "test"},
|
||||
{[][]byte{[]byte("a"), []byte("b"), []byte("c")}, nil, "a.b.c"},
|
||||
|
||||
{[][]byte{{}}, ErrZeroLengthLabel, ""},
|
||||
{[][]byte{[]byte("a"), {}, []byte("c")}, ErrZeroLengthLabel, ""},
|
||||
|
||||
// 63 octets.
|
||||
{[][]byte{[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE")}, nil,
|
||||
"0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE"},
|
||||
// 64 octets.
|
||||
{[][]byte{[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDEF")}, ErrLabelTooLong, ""},
|
||||
|
||||
// 64+64+64+62 octets.
|
||||
{[][]byte{
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE"),
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE"),
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE"),
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABC"),
|
||||
}, nil,
|
||||
"0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE.0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE.0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE.0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABC"},
|
||||
// 64+64+64+63 octets.
|
||||
{[][]byte{
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE"),
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE"),
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCDE"),
|
||||
[]byte("0123456789abcdef0123456789ABCDEF0123456789abcdef0123456789ABCD"),
|
||||
}, ErrNameTooLong, ""},
|
||||
// 127 one-octet labels.
|
||||
{[][]byte{
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'}, {'F'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'}, {'F'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'}, {'F'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'},
|
||||
}, nil,
|
||||
"0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.0.1.2.3.4.5.6.7.8.9.A.B.C.D.E.F.0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.0.1.2.3.4.5.6.7.8.9.A.B.C.D.E.F.0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.0.1.2.3.4.5.6.7.8.9.A.B.C.D.E.F.0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.0.1.2.3.4.5.6.7.8.9.A.B.C.D.E"},
|
||||
// 128 one-octet labels.
|
||||
{[][]byte{
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'}, {'F'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'}, {'F'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'}, {'F'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'a'}, {'b'}, {'c'}, {'d'}, {'e'}, {'f'},
|
||||
{'0'}, {'1'}, {'2'}, {'3'}, {'4'}, {'5'}, {'6'}, {'7'}, {'8'}, {'9'}, {'A'}, {'B'}, {'C'}, {'D'}, {'E'}, {'F'},
|
||||
}, ErrNameTooLong, ""},
|
||||
} {
|
||||
// Test that NewName returns proper error codes, and otherwise
|
||||
// returns an equal slice of labels.
|
||||
name, err := NewName(test.labels)
|
||||
if err != test.err || (err == nil && !namesEqual(name, test.labels)) {
|
||||
t.Errorf("%+q returned (%+q, %v), expected (%+q, %v)",
|
||||
test.labels, name, err, test.labels, test.err)
|
||||
continue
|
||||
}
|
||||
if test.err != nil {
|
||||
continue
|
||||
}
|
||||
|
||||
// Test that the string version of the name comes out as
|
||||
// expected.
|
||||
s := name.String()
|
||||
if s != test.s {
|
||||
t.Errorf("%+q became string %+q, expected %+q", test.labels, s, test.s)
|
||||
continue
|
||||
}
|
||||
|
||||
// Test that parsing from a string back to a Name results in the
|
||||
// original slice of labels.
|
||||
name, err = ParseName(s)
|
||||
if err != nil || !namesEqual(name, test.labels) {
|
||||
t.Errorf("%+q parsing %+q returned (%+q, %v), expected (%+q, %v)",
|
||||
test.labels, s, name, err, test.labels, nil)
|
||||
continue
|
||||
}
|
||||
// A trailing dot should be ignored.
|
||||
if !strings.HasSuffix(s, ".") {
|
||||
dotName, dotErr := ParseName(s + ".")
|
||||
if dotErr != err || !namesEqual(dotName, name) {
|
||||
t.Errorf("%+q parsing %+q returned (%+q, %v), expected (%+q, %v)",
|
||||
test.labels, s+".", dotName, dotErr, name, err)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestParseName(t *testing.T) {
|
||||
for _, test := range []struct {
|
||||
s string
|
||||
name Name
|
||||
err error
|
||||
}{
|
||||
// This case can't be tested by TestName above because String
|
||||
// will never produce "" (it produces "." instead).
|
||||
{"", [][]byte{}, nil},
|
||||
} {
|
||||
name, err := ParseName(test.s)
|
||||
if err != test.err || (err == nil && !namesEqual(name, test.name)) {
|
||||
t.Errorf("%+q returned (%+q, %v), expected (%+q, %v)",
|
||||
test.s, name, err, test.name, test.err)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func unescapeString(s string) ([][]byte, error) {
|
||||
if s == "." {
|
||||
return [][]byte{}, nil
|
||||
}
|
||||
|
||||
var result [][]byte
|
||||
for _, label := range strings.Split(s, ".") {
|
||||
var buf bytes.Buffer
|
||||
i := 0
|
||||
for i < len(label) {
|
||||
switch label[i] {
|
||||
case '\\':
|
||||
if i+3 >= len(label) {
|
||||
return nil, fmt.Errorf("truncated escape sequence at index %v", i)
|
||||
}
|
||||
if label[i+1] != 'x' {
|
||||
return nil, fmt.Errorf("malformed escape sequence at index %v", i)
|
||||
}
|
||||
b, err := strconv.ParseUint(string(label[i+2:i+4]), 16, 8)
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("malformed hex sequence at index %v", i+2)
|
||||
}
|
||||
buf.WriteByte(byte(b))
|
||||
i += 4
|
||||
default:
|
||||
buf.WriteByte(label[i])
|
||||
i++
|
||||
}
|
||||
}
|
||||
result = append(result, buf.Bytes())
|
||||
}
|
||||
return result, nil
|
||||
}
|
||||
|
||||
func TestNameString(t *testing.T) {
|
||||
for _, test := range []struct {
|
||||
name Name
|
||||
s string
|
||||
}{
|
||||
{[][]byte{}, "."},
|
||||
{[][]byte{[]byte("\x00"), []byte("a.b"), []byte("c\nd\\")}, "\\x00.a\\x2eb.c\\x0ad\\x5c"},
|
||||
{[][]byte{
|
||||
[]byte("\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !\"#$%&'()*+,-./0123456789:;<=>"),
|
||||
[]byte("?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}"),
|
||||
[]byte("~\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc"),
|
||||
[]byte("\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb"),
|
||||
[]byte("\xfc\xfd\xfe\xff"),
|
||||
}, "\\x00\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\x09\\x0a\\x0b\\x0c\\x0d\\x0e\\x0f\\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f\\x20\\x21\\x22\\x23\\x24\\x25\\x26\\x27\\x28\\x29\\x2a\\x2b\\x2c-\\x2e\\x2f0123456789\\x3a\\x3b\\x3c\\x3d\\x3e.\\x3f\\x40ABCDEFGHIJKLMNOPQRSTUVWXYZ\\x5b\\x5c\\x5d\\x5e\\x5f\\x60abcdefghijklmnopqrstuvwxyz\\x7b\\x7c\\x7d.\\x7e\\x7f\\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\\xb8\\xb9\\xba\\xbb\\xbc.\\xbd\\xbe\\xbf\\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb.\\xfc\\xfd\\xfe\\xff"},
|
||||
} {
|
||||
s := test.name.String()
|
||||
if s != test.s {
|
||||
t.Errorf("%+q escaped to %+q, expected %+q", test.name, s, test.s)
|
||||
continue
|
||||
}
|
||||
unescaped, err := unescapeString(s)
|
||||
if err != nil {
|
||||
t.Errorf("%+q unescaping %+q resulted in error %v", test.name, s, err)
|
||||
continue
|
||||
}
|
||||
if !namesEqual(Name(unescaped), test.name) {
|
||||
t.Errorf("%+q roundtripped through %+q to %+q", test.name, s, unescaped)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestNameTrimSuffix(t *testing.T) {
|
||||
for _, test := range []struct {
|
||||
name, suffix string
|
||||
trimmed string
|
||||
ok bool
|
||||
}{
|
||||
{"", "", ".", true},
|
||||
{".", ".", ".", true},
|
||||
{"abc", "", "abc", true},
|
||||
{"abc", ".", "abc", true},
|
||||
{"", "abc", ".", false},
|
||||
{".", "abc", ".", false},
|
||||
{"example.com", "com", "example", true},
|
||||
{"example.com", "net", ".", false},
|
||||
{"example.com", "example.com", ".", true},
|
||||
{"example.com", "test.com", ".", false},
|
||||
{"example.com", "xample.com", ".", false},
|
||||
{"example.com", "example", ".", false},
|
||||
{"example.com", "COM", "example", true},
|
||||
{"EXAMPLE.COM", "com", "EXAMPLE", true},
|
||||
} {
|
||||
tmp, ok := mustParseName(test.name).TrimSuffix(mustParseName(test.suffix))
|
||||
trimmed := tmp.String()
|
||||
if ok != test.ok || trimmed != test.trimmed {
|
||||
t.Errorf("TrimSuffix %+q %+q returned (%+q, %v), expected (%+q, %v)",
|
||||
test.name, test.suffix, trimmed, ok, test.trimmed, test.ok)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestReadName(t *testing.T) {
|
||||
// Good tests.
|
||||
for _, test := range []struct {
|
||||
start int64
|
||||
end int64
|
||||
input string
|
||||
s string
|
||||
}{
|
||||
// Empty name.
|
||||
{0, 1, "\x00abcd", "."},
|
||||
// No pointers.
|
||||
{12, 25, "AAAABBBBCCCC\x07example\x03com\x00", "example.com"},
|
||||
// Backward pointer.
|
||||
{25, 31, "AAAABBBBCCCC\x07example\x03com\x00\x03sub\xc0\x0c", "sub.example.com"},
|
||||
// Forward pointer.
|
||||
{0, 4, "\x01a\xc0\x04\x03bcd\x00", "a.bcd"},
|
||||
// Two backwards pointers.
|
||||
{31, 38, "AAAABBBBCCCC\x07example\x03com\x00\x03sub\xc0\x0c\x04sub2\xc0\x19", "sub2.sub.example.com"},
|
||||
// Forward then backward pointer.
|
||||
{25, 31, "AAAABBBBCCCC\x07example\x03com\x00\x03sub\xc0\x1f\x04sub2\xc0\x0c", "sub.sub2.example.com"},
|
||||
// Overlapping codons.
|
||||
{0, 4, "\x01a\xc0\x03bcd\x00", "a.bcd"},
|
||||
// Pointer to empty label.
|
||||
{0, 10, "\x07example\xc0\x0a\x00", "example"},
|
||||
{1, 11, "\x00\x07example\xc0\x00", "example"},
|
||||
// Pointer to pointer to empty label.
|
||||
{0, 10, "\x07example\xc0\x0a\xc0\x0c\x00", "example"},
|
||||
{1, 11, "\x00\x07example\xc0\x0c\xc0\x00", "example"},
|
||||
} {
|
||||
r := bytes.NewReader([]byte(test.input))
|
||||
_, err := r.Seek(test.start, io.SeekStart)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
name, err := readName(r)
|
||||
if err != nil {
|
||||
t.Errorf("%+q returned error %s", test.input, err)
|
||||
continue
|
||||
}
|
||||
s := name.String()
|
||||
if s != test.s {
|
||||
t.Errorf("%+q returned %+q, expected %+q", test.input, s, test.s)
|
||||
continue
|
||||
}
|
||||
cur, _ := r.Seek(0, io.SeekCurrent)
|
||||
if cur != test.end {
|
||||
t.Errorf("%+q left offset %d, expected %d", test.input, cur, test.end)
|
||||
continue
|
||||
}
|
||||
}
|
||||
|
||||
// Bad tests.
|
||||
for _, test := range []struct {
|
||||
start int64
|
||||
input string
|
||||
err error
|
||||
}{
|
||||
{0, "", io.ErrUnexpectedEOF},
|
||||
// Reserved label type.
|
||||
{0, "\x80example", ErrReservedLabelType},
|
||||
// Reserved label type.
|
||||
{0, "\x40example", ErrReservedLabelType},
|
||||
// No Terminating empty label.
|
||||
{0, "\x07example\x03com", io.ErrUnexpectedEOF},
|
||||
// Pointer past end of buffer.
|
||||
{0, "\x07example\xc0\xff", io.ErrUnexpectedEOF},
|
||||
// Pointer to self.
|
||||
{0, "\x07example\x03com\xc0\x0c", ErrTooManyPointers},
|
||||
// Pointer to self with intermediate label.
|
||||
{0, "\x07example\x03com\xc0\x08", ErrTooManyPointers},
|
||||
// Two pointers that point to each other.
|
||||
{0, "\xc0\x02\xc0\x00", ErrTooManyPointers},
|
||||
// Two pointers that point to each other, with intermediate labels.
|
||||
{0, "\x01a\xc0\x04\x01b\xc0\x00", ErrTooManyPointers},
|
||||
// EOF while reading label.
|
||||
{0, "\x0aexample", io.ErrUnexpectedEOF},
|
||||
// EOF before second byte of pointer.
|
||||
{0, "\xc0", io.ErrUnexpectedEOF},
|
||||
{0, "\x07example\xc0", io.ErrUnexpectedEOF},
|
||||
} {
|
||||
r := bytes.NewReader([]byte(test.input))
|
||||
_, err := r.Seek(test.start, io.SeekStart)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
name, err := readName(r)
|
||||
if err == io.EOF {
|
||||
err = io.ErrUnexpectedEOF
|
||||
}
|
||||
if err != test.err {
|
||||
t.Errorf("%+q returned (%+q, %v), expected %v", test.input, name, err, test.err)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func mustParseName(s string) Name {
|
||||
name, err := ParseName(s)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
return name
|
||||
}
|
||||
|
||||
func questionsEqual(a, b *Question) bool {
|
||||
if !namesEqual(a.Name, b.Name) {
|
||||
return false
|
||||
}
|
||||
if a.Type != b.Type || a.Class != b.Class {
|
||||
return false
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func rrsEqual(a, b *RR) bool {
|
||||
if !namesEqual(a.Name, b.Name) {
|
||||
return false
|
||||
}
|
||||
if a.Type != b.Type || a.Class != b.Class || a.TTL != b.TTL {
|
||||
return false
|
||||
}
|
||||
if !bytes.Equal(a.Data, b.Data) {
|
||||
return false
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func messagesEqual(a, b *Message) bool {
|
||||
if a.ID != b.ID || a.Flags != b.Flags {
|
||||
return false
|
||||
}
|
||||
if len(a.Question) != len(b.Question) {
|
||||
return false
|
||||
}
|
||||
for i := 0; i < len(a.Question); i++ {
|
||||
if !questionsEqual(&a.Question[i], &b.Question[i]) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
for _, rec := range []struct{ rrA, rrB []RR }{
|
||||
{a.Answer, b.Answer},
|
||||
{a.Authority, b.Authority},
|
||||
{a.Additional, b.Additional},
|
||||
} {
|
||||
if len(rec.rrA) != len(rec.rrB) {
|
||||
return false
|
||||
}
|
||||
for i := 0; i < len(rec.rrA); i++ {
|
||||
if !rrsEqual(&rec.rrA[i], &rec.rrB[i]) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func TestMessageFromWireFormat(t *testing.T) {
|
||||
for _, test := range []struct {
|
||||
buf string
|
||||
expected Message
|
||||
err error
|
||||
}{
|
||||
{
|
||||
"\x12\x34",
|
||||
Message{},
|
||||
io.ErrUnexpectedEOF,
|
||||
},
|
||||
{
|
||||
"\x12\x34\x01\x00\x00\x01\x00\x00\x00\x00\x00\x00\x03www\x07example\x03com\x00\x00\x01\x00\x01",
|
||||
Message{
|
||||
ID: 0x1234,
|
||||
Flags: 0x0100,
|
||||
Question: []Question{
|
||||
{
|
||||
Name: mustParseName("www.example.com"),
|
||||
Type: 1,
|
||||
Class: 1,
|
||||
},
|
||||
},
|
||||
Answer: []RR{},
|
||||
Authority: []RR{},
|
||||
Additional: []RR{},
|
||||
},
|
||||
nil,
|
||||
},
|
||||
{
|
||||
"\x12\x34\x01\x00\x00\x01\x00\x00\x00\x00\x00\x00\x03www\x07example\x03com\x00\x00\x01\x00\x01X",
|
||||
Message{},
|
||||
ErrTrailingBytes,
|
||||
},
|
||||
{
|
||||
"\x12\x34\x81\x80\x00\x01\x00\x01\x00\x00\x00\x00\x03www\x07example\x03com\x00\x00\x01\x00\x01\x03www\x07example\x03com\x00\x00\x01\x00\x01\x00\x00\x00\x80\x00\x04\xc0\x00\x02\x01",
|
||||
Message{
|
||||
ID: 0x1234,
|
||||
Flags: 0x8180,
|
||||
Question: []Question{
|
||||
{
|
||||
Name: mustParseName("www.example.com"),
|
||||
Type: 1,
|
||||
Class: 1,
|
||||
},
|
||||
},
|
||||
Answer: []RR{
|
||||
{
|
||||
Name: mustParseName("www.example.com"),
|
||||
Type: 1,
|
||||
Class: 1,
|
||||
TTL: 128,
|
||||
Data: []byte{192, 0, 2, 1},
|
||||
},
|
||||
},
|
||||
Authority: []RR{},
|
||||
Additional: []RR{},
|
||||
},
|
||||
nil,
|
||||
},
|
||||
} {
|
||||
message, err := MessageFromWireFormat([]byte(test.buf))
|
||||
if err != test.err || (err == nil && !messagesEqual(&message, &test.expected)) {
|
||||
t.Errorf("%+q\nreturned (%+v, %v)\nexpected (%+v, %v)",
|
||||
test.buf, message, err, test.expected, test.err)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestMessageWireFormatRoundTrip(t *testing.T) {
|
||||
for _, message := range []Message{
|
||||
{
|
||||
ID: 0x1234,
|
||||
Flags: 0x0100,
|
||||
Question: []Question{
|
||||
{
|
||||
Name: mustParseName("www.example.com"),
|
||||
Type: 1,
|
||||
Class: 1,
|
||||
},
|
||||
{
|
||||
Name: mustParseName("www2.example.com"),
|
||||
Type: 2,
|
||||
Class: 2,
|
||||
},
|
||||
},
|
||||
Answer: []RR{
|
||||
{
|
||||
Name: mustParseName("abc"),
|
||||
Type: 2,
|
||||
Class: 3,
|
||||
TTL: 0xffffffff,
|
||||
Data: []byte{1},
|
||||
},
|
||||
{
|
||||
Name: mustParseName("xyz"),
|
||||
Type: 2,
|
||||
Class: 3,
|
||||
TTL: 255,
|
||||
Data: []byte{},
|
||||
},
|
||||
},
|
||||
Authority: []RR{
|
||||
{
|
||||
Name: mustParseName("."),
|
||||
Type: 65535,
|
||||
Class: 65535,
|
||||
TTL: 0,
|
||||
Data: []byte("XXXXXXXXXXXXXXXXXXX"),
|
||||
},
|
||||
},
|
||||
Additional: []RR{},
|
||||
},
|
||||
} {
|
||||
buf, err := message.WireFormat()
|
||||
if err != nil {
|
||||
t.Errorf("%+v cannot make wire format: %v", message, err)
|
||||
continue
|
||||
}
|
||||
message2, err := MessageFromWireFormat(buf)
|
||||
if err != nil {
|
||||
t.Errorf("%+q cannot parse wire format: %v", buf, err)
|
||||
continue
|
||||
}
|
||||
if !messagesEqual(&message, &message2) {
|
||||
t.Errorf("messages unequal\nbefore: %+v\n after: %+v", message, message2)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestDecodeRDataTXT(t *testing.T) {
|
||||
for _, test := range []struct {
|
||||
p []byte
|
||||
decoded []byte
|
||||
err error
|
||||
}{
|
||||
{[]byte{}, nil, io.ErrUnexpectedEOF},
|
||||
{[]byte("\x00"), []byte{}, nil},
|
||||
{[]byte("\x01"), nil, io.ErrUnexpectedEOF},
|
||||
} {
|
||||
decoded, err := DecodeRDataTXT(test.p)
|
||||
if err != test.err || (err == nil && !bytes.Equal(decoded, test.decoded)) {
|
||||
t.Errorf("%+q\nreturned (%+q, %v)\nexpected (%+q, %v)",
|
||||
test.p, decoded, err, test.decoded, test.err)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestEncodeRDataTXT(t *testing.T) {
|
||||
// Encoding 0 bytes needs to return at least a single length octet of
|
||||
// zero, not an empty slice.
|
||||
p := make([]byte, 0)
|
||||
encoded := EncodeRDataTXT(p)
|
||||
if len(encoded) < 0 {
|
||||
t.Errorf("EncodeRDataTXT(%v) returned %v", p, encoded)
|
||||
}
|
||||
|
||||
// 255 bytes should be able to be encoded into 256 bytes.
|
||||
p = make([]byte, 255)
|
||||
encoded = EncodeRDataTXT(p)
|
||||
if len(encoded) > 256 {
|
||||
t.Errorf("EncodeRDataTXT(%d bytes) returned %d bytes", len(p), len(encoded))
|
||||
}
|
||||
}
|
||||
|
||||
func TestRDataTXTRoundTrip(t *testing.T) {
|
||||
for _, p := range [][]byte{
|
||||
{},
|
||||
[]byte("\x00"),
|
||||
{
|
||||
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
|
||||
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
|
||||
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
|
||||
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
|
||||
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
|
||||
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
|
||||
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
|
||||
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
|
||||
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
|
||||
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
|
||||
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
|
||||
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
|
||||
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
|
||||
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
|
||||
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
|
||||
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
|
||||
},
|
||||
} {
|
||||
rdata := EncodeRDataTXT(p)
|
||||
decoded, err := DecodeRDataTXT(rdata)
|
||||
if err != nil || !bytes.Equal(decoded, p) {
|
||||
t.Errorf("%+q returned (%+q, %v)", p, decoded, err)
|
||||
continue
|
||||
}
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,567 @@
|
||||
package xdns
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"context"
|
||||
"encoding/binary"
|
||||
"io"
|
||||
"net"
|
||||
"sync"
|
||||
"time"
|
||||
|
||||
"github.com/xtls/xray-core/common/errors"
|
||||
)
|
||||
|
||||
const (
|
||||
idleTimeout = 2 * time.Minute
|
||||
responseTTL = 60
|
||||
maxResponseDelay = 1 * time.Second
|
||||
)
|
||||
|
||||
var (
|
||||
maxUDPPayload = 1280 - 40 - 8
|
||||
maxEncodedPayload = computeMaxEncodedPayload(maxUDPPayload)
|
||||
)
|
||||
|
||||
func clientIDToAddr(clientID [8]byte) *net.UDPAddr {
|
||||
ip := make(net.IP, 16)
|
||||
|
||||
copy(ip, []byte{0xfd, 0x00, 0, 0, 0, 0, 0, 0})
|
||||
copy(ip[8:], clientID[:])
|
||||
|
||||
return &net.UDPAddr{
|
||||
IP: ip,
|
||||
}
|
||||
}
|
||||
|
||||
type record struct {
|
||||
Resp *Message
|
||||
Addr net.Addr
|
||||
// ClientID [8]byte
|
||||
ClientAddr net.Addr
|
||||
}
|
||||
|
||||
type queue struct {
|
||||
lash time.Time
|
||||
queue chan []byte
|
||||
stash chan []byte
|
||||
}
|
||||
|
||||
type xdnsConnServer struct {
|
||||
conn net.PacketConn
|
||||
|
||||
domain Name
|
||||
|
||||
ch chan *record
|
||||
readQueue chan *packet
|
||||
writeQueueMap map[string]*queue
|
||||
|
||||
closed bool
|
||||
mutex sync.Mutex
|
||||
}
|
||||
|
||||
func NewConnServer(c *Config, raw net.PacketConn, end bool) (net.PacketConn, error) {
|
||||
if !end {
|
||||
return nil, errors.New("xdns requires being at the outermost level")
|
||||
}
|
||||
|
||||
domain, err := ParseName(c.Domain)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
conn := &xdnsConnServer{
|
||||
conn: raw,
|
||||
|
||||
domain: domain,
|
||||
|
||||
ch: make(chan *record, 100),
|
||||
readQueue: make(chan *packet, 128),
|
||||
writeQueueMap: make(map[string]*queue),
|
||||
}
|
||||
|
||||
go conn.clean()
|
||||
go conn.recvLoop()
|
||||
go conn.sendLoop()
|
||||
|
||||
return conn, nil
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) clean() {
|
||||
f := func() bool {
|
||||
c.mutex.Lock()
|
||||
defer c.mutex.Unlock()
|
||||
|
||||
if c.closed {
|
||||
return true
|
||||
}
|
||||
|
||||
now := time.Now()
|
||||
|
||||
for key, q := range c.writeQueueMap {
|
||||
if now.Sub(q.lash) >= idleTimeout {
|
||||
close(q.queue)
|
||||
close(q.stash)
|
||||
delete(c.writeQueueMap, key)
|
||||
}
|
||||
}
|
||||
|
||||
return false
|
||||
}
|
||||
|
||||
for {
|
||||
time.Sleep(idleTimeout / 2)
|
||||
if f() {
|
||||
return
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) ensureQueue(addr net.Addr) *queue {
|
||||
c.mutex.Lock()
|
||||
defer c.mutex.Unlock()
|
||||
|
||||
if c.closed {
|
||||
return nil
|
||||
}
|
||||
|
||||
q, ok := c.writeQueueMap[addr.String()]
|
||||
if !ok {
|
||||
q = &queue{
|
||||
queue: make(chan []byte, 128),
|
||||
stash: make(chan []byte, 1),
|
||||
}
|
||||
c.writeQueueMap[addr.String()] = q
|
||||
}
|
||||
q.lash = time.Now()
|
||||
|
||||
return q
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) stash(queue *queue, p []byte) {
|
||||
c.mutex.Lock()
|
||||
defer c.mutex.Unlock()
|
||||
|
||||
if c.closed {
|
||||
return
|
||||
}
|
||||
|
||||
select {
|
||||
case queue.stash <- p:
|
||||
default:
|
||||
}
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) recvLoop() {
|
||||
for {
|
||||
if c.closed {
|
||||
break
|
||||
}
|
||||
|
||||
var buf [4096]byte
|
||||
n, addr, err := c.conn.ReadFrom(buf[:])
|
||||
if err != nil {
|
||||
continue
|
||||
}
|
||||
|
||||
query, err := MessageFromWireFormat(buf[:n])
|
||||
if err != nil {
|
||||
continue
|
||||
}
|
||||
|
||||
resp, payload := responseFor(&query, c.domain)
|
||||
|
||||
var clientID [8]byte
|
||||
n = copy(clientID[:], payload)
|
||||
payload = payload[n:]
|
||||
if n == len(clientID) {
|
||||
r := bytes.NewReader(payload)
|
||||
for {
|
||||
p, err := nextPacketServer(r)
|
||||
if err != nil {
|
||||
break
|
||||
}
|
||||
|
||||
buf := make([]byte, len(p))
|
||||
copy(buf, p)
|
||||
select {
|
||||
case c.readQueue <- &packet{
|
||||
p: buf,
|
||||
addr: clientIDToAddr(clientID),
|
||||
}:
|
||||
default:
|
||||
}
|
||||
}
|
||||
} else {
|
||||
if resp != nil && resp.Rcode() == RcodeNoError {
|
||||
resp.Flags |= RcodeNameError
|
||||
}
|
||||
}
|
||||
|
||||
if resp != nil {
|
||||
select {
|
||||
case c.ch <- &record{resp, addr, clientIDToAddr(clientID)}:
|
||||
default:
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
close(c.ch)
|
||||
close(c.readQueue)
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) sendLoop() {
|
||||
var nextRec *record
|
||||
for {
|
||||
rec := nextRec
|
||||
nextRec = nil
|
||||
|
||||
if rec == nil {
|
||||
var ok bool
|
||||
rec, ok = <-c.ch
|
||||
if !ok {
|
||||
break
|
||||
}
|
||||
}
|
||||
|
||||
if rec.Resp.Rcode() == RcodeNoError && len(rec.Resp.Question) == 1 {
|
||||
rec.Resp.Answer = []RR{
|
||||
{
|
||||
Name: rec.Resp.Question[0].Name,
|
||||
Type: rec.Resp.Question[0].Type,
|
||||
Class: rec.Resp.Question[0].Class,
|
||||
TTL: responseTTL,
|
||||
Data: nil,
|
||||
},
|
||||
}
|
||||
|
||||
var payload bytes.Buffer
|
||||
limit := maxEncodedPayload
|
||||
timer := time.NewTimer(maxResponseDelay)
|
||||
for {
|
||||
queue := c.ensureQueue(rec.ClientAddr)
|
||||
if queue == nil {
|
||||
return
|
||||
}
|
||||
|
||||
var p []byte
|
||||
|
||||
select {
|
||||
case p = <-queue.stash:
|
||||
default:
|
||||
select {
|
||||
case p = <-queue.stash:
|
||||
case p = <-queue.queue:
|
||||
default:
|
||||
select {
|
||||
case p = <-queue.stash:
|
||||
case p = <-queue.queue:
|
||||
case <-timer.C:
|
||||
case nextRec = <-c.ch:
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
timer.Reset(0)
|
||||
|
||||
if len(p) == 0 {
|
||||
break
|
||||
}
|
||||
|
||||
limit -= 2 + len(p)
|
||||
if payload.Len() == 0 {
|
||||
|
||||
} else if limit < 0 {
|
||||
c.stash(queue, p)
|
||||
|
||||
break
|
||||
}
|
||||
|
||||
if int(uint16(len(p))) != len(p) {
|
||||
panic(len(p))
|
||||
}
|
||||
|
||||
_ = binary.Write(&payload, binary.BigEndian, uint16(len(p)))
|
||||
payload.Write(p)
|
||||
}
|
||||
timer.Stop()
|
||||
|
||||
rec.Resp.Answer[0].Data = EncodeRDataTXT(payload.Bytes())
|
||||
}
|
||||
|
||||
buf, err := rec.Resp.WireFormat()
|
||||
if err != nil {
|
||||
continue
|
||||
}
|
||||
|
||||
if len(buf) > maxUDPPayload {
|
||||
errors.LogDebug(context.Background(), "xdns server truncate ", len(buf))
|
||||
buf = buf[:maxUDPPayload]
|
||||
buf[2] |= 0x02
|
||||
}
|
||||
|
||||
if c.closed {
|
||||
return
|
||||
}
|
||||
|
||||
_, _ = c.conn.WriteTo(buf, rec.Addr)
|
||||
}
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) Size() int32 {
|
||||
return 0
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
|
||||
packet, ok := <-c.readQueue
|
||||
if !ok {
|
||||
return 0, nil, io.EOF
|
||||
}
|
||||
n = copy(p, packet.p)
|
||||
if n != len(packet.p) {
|
||||
return 0, nil, io.ErrShortBuffer
|
||||
}
|
||||
return n, packet.addr, nil
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) WriteTo(p []byte, addr net.Addr) (n int, err error) {
|
||||
q := c.ensureQueue(addr)
|
||||
if q == nil {
|
||||
return 0, errors.New("xdns closed")
|
||||
}
|
||||
|
||||
c.mutex.Lock()
|
||||
defer c.mutex.Unlock()
|
||||
|
||||
if c.closed {
|
||||
return 0, errors.New("xdns closed")
|
||||
}
|
||||
|
||||
buf := make([]byte, len(p))
|
||||
copy(buf, p)
|
||||
|
||||
select {
|
||||
case q.queue <- buf:
|
||||
return len(p), nil
|
||||
default:
|
||||
return 0, errors.New("xdns queue full")
|
||||
}
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) Close() error {
|
||||
c.mutex.Lock()
|
||||
defer c.mutex.Unlock()
|
||||
|
||||
if c.closed {
|
||||
return nil
|
||||
}
|
||||
|
||||
c.closed = true
|
||||
for key, q := range c.writeQueueMap {
|
||||
close(q.queue)
|
||||
close(q.stash)
|
||||
delete(c.writeQueueMap, key)
|
||||
}
|
||||
|
||||
return c.conn.Close()
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) LocalAddr() net.Addr {
|
||||
return c.conn.LocalAddr()
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) SetDeadline(t time.Time) error {
|
||||
return c.conn.SetDeadline(t)
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) SetReadDeadline(t time.Time) error {
|
||||
return c.conn.SetReadDeadline(t)
|
||||
}
|
||||
|
||||
func (c *xdnsConnServer) SetWriteDeadline(t time.Time) error {
|
||||
return c.conn.SetWriteDeadline(t)
|
||||
}
|
||||
|
||||
func nextPacketServer(r *bytes.Reader) ([]byte, error) {
|
||||
eof := func(err error) error {
|
||||
if err == io.EOF {
|
||||
err = io.ErrUnexpectedEOF
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
for {
|
||||
prefix, err := r.ReadByte()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if prefix >= 224 {
|
||||
paddingLen := prefix - 224
|
||||
_, err := io.CopyN(io.Discard, r, int64(paddingLen))
|
||||
if err != nil {
|
||||
return nil, eof(err)
|
||||
}
|
||||
} else {
|
||||
p := make([]byte, int(prefix))
|
||||
_, err = io.ReadFull(r, p)
|
||||
return p, eof(err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func responseFor(query *Message, domain Name) (*Message, []byte) {
|
||||
resp := &Message{
|
||||
ID: query.ID,
|
||||
Flags: 0x8000,
|
||||
Question: query.Question,
|
||||
}
|
||||
|
||||
if query.Flags&0x8000 != 0 {
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
payloadSize := 0
|
||||
for _, rr := range query.Additional {
|
||||
if rr.Type != RRTypeOPT {
|
||||
continue
|
||||
}
|
||||
if len(resp.Additional) != 0 {
|
||||
resp.Flags |= RcodeFormatError
|
||||
return resp, nil
|
||||
}
|
||||
resp.Additional = append(resp.Additional, RR{
|
||||
Name: Name{},
|
||||
Type: RRTypeOPT,
|
||||
Class: 4096,
|
||||
TTL: 0,
|
||||
Data: []byte{},
|
||||
})
|
||||
additional := &resp.Additional[0]
|
||||
|
||||
version := (rr.TTL >> 16) & 0xff
|
||||
if version != 0 {
|
||||
resp.Flags |= ExtendedRcodeBadVers & 0xf
|
||||
additional.TTL = (ExtendedRcodeBadVers >> 4) << 24
|
||||
return resp, nil
|
||||
}
|
||||
|
||||
payloadSize = int(rr.Class)
|
||||
}
|
||||
if payloadSize < 512 {
|
||||
payloadSize = 512
|
||||
}
|
||||
|
||||
if len(query.Question) != 1 {
|
||||
resp.Flags |= RcodeFormatError
|
||||
return resp, nil
|
||||
}
|
||||
question := query.Question[0]
|
||||
|
||||
prefix, ok := question.Name.TrimSuffix(domain)
|
||||
if !ok {
|
||||
resp.Flags |= RcodeNameError
|
||||
return resp, nil
|
||||
}
|
||||
resp.Flags |= 0x0400
|
||||
|
||||
if query.Opcode() != 0 {
|
||||
resp.Flags |= RcodeNotImplemented
|
||||
return resp, nil
|
||||
}
|
||||
|
||||
if question.Type != RRTypeTXT {
|
||||
resp.Flags |= RcodeNameError
|
||||
return resp, nil
|
||||
}
|
||||
|
||||
encoded := bytes.ToUpper(bytes.Join(prefix, nil))
|
||||
payload := make([]byte, base32Encoding.DecodedLen(len(encoded)))
|
||||
n, err := base32Encoding.Decode(payload, encoded)
|
||||
if err != nil {
|
||||
resp.Flags |= RcodeNameError
|
||||
return resp, nil
|
||||
}
|
||||
payload = payload[:n]
|
||||
|
||||
if payloadSize < maxUDPPayload {
|
||||
resp.Flags |= RcodeFormatError
|
||||
return resp, nil
|
||||
}
|
||||
|
||||
return resp, payload
|
||||
}
|
||||
|
||||
func computeMaxEncodedPayload(limit int) int {
|
||||
maxLengthName, err := NewName([][]byte{
|
||||
[]byte("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"),
|
||||
[]byte("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"),
|
||||
[]byte("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"),
|
||||
[]byte("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"),
|
||||
})
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
{
|
||||
n := 0
|
||||
for _, label := range maxLengthName {
|
||||
n += len(label) + 1
|
||||
}
|
||||
n += 1
|
||||
if n != 255 {
|
||||
panic("computeMaxEncodedPayload n != 255")
|
||||
}
|
||||
}
|
||||
|
||||
queryLimit := uint16(limit)
|
||||
if int(queryLimit) != limit {
|
||||
queryLimit = 0xffff
|
||||
}
|
||||
query := &Message{
|
||||
Question: []Question{
|
||||
{
|
||||
Name: maxLengthName,
|
||||
Type: RRTypeTXT,
|
||||
Class: RRTypeTXT,
|
||||
},
|
||||
},
|
||||
|
||||
Additional: []RR{
|
||||
{
|
||||
Name: Name{},
|
||||
Type: RRTypeOPT,
|
||||
Class: queryLimit,
|
||||
TTL: 0,
|
||||
Data: []byte{},
|
||||
},
|
||||
},
|
||||
}
|
||||
resp, _ := responseFor(query, [][]byte{})
|
||||
|
||||
resp.Answer = []RR{
|
||||
{
|
||||
Name: query.Question[0].Name,
|
||||
Type: query.Question[0].Type,
|
||||
Class: query.Question[0].Class,
|
||||
TTL: responseTTL,
|
||||
Data: nil,
|
||||
},
|
||||
}
|
||||
|
||||
low := 0
|
||||
high := 32768
|
||||
for low+1 < high {
|
||||
mid := (low + high) / 2
|
||||
resp.Answer[0].Data = EncodeRDataTXT(make([]byte, mid))
|
||||
buf, err := resp.WireFormat()
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
if len(buf) <= limit {
|
||||
low = mid
|
||||
} else {
|
||||
high = mid
|
||||
}
|
||||
}
|
||||
|
||||
return low
|
||||
}
|
||||
Reference in New Issue
Block a user