wenyifan
154 lines
3.2 KiB
Go
154 lines
3.2 KiB
Go
package dns
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import (
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"context"
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"crypto/tls"
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"errors"
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"net"
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"sync"
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"github.com/go-gost/core/dialer"
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"github.com/go-gost/core/logger"
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md "github.com/go-gost/core/metadata"
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dns_util "github.com/go-gost/x/internal/util/dns"
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"github.com/go-gost/x/registry"
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"github.com/quic-go/quic-go"
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)
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func init() {
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registry.DialerRegistry().Register("dns", NewDialer)
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registry.DialerRegistry().Register("dns-tunnel", NewDialer)
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registry.DialerRegistry().Register("dnst", NewDialer)
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}
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type dnsDialer struct {
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sessions map[string]*quicSession
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sessionMutex sync.Mutex
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logger logger.Logger
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md metadata
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options dialer.Options
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}
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func NewDialer(opts ...dialer.Option) dialer.Dialer {
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options := dialer.Options{}
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for _, opt := range opts {
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opt(&options)
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}
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return &dnsDialer{
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sessions: make(map[string]*quicSession),
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logger: options.Logger,
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options: options,
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}
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}
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func (d *dnsDialer) Init(md md.Metadata) (err error) {
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if err = d.parseMetadata(md); err != nil {
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return
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}
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return nil
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}
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func (d *dnsDialer) Dial(ctx context.Context, addr string, opts ...dialer.DialOption) (conn net.Conn, err error) {
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if _, _, err := net.SplitHostPort(addr); err != nil {
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addr = net.JoinHostPort(addr, "0")
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}
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udpAddr, err := net.ResolveUDPAddr("udp", addr)
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if err != nil {
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return nil, err
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}
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d.sessionMutex.Lock()
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session, ok := d.sessions[addr]
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if session != nil && session.IsClosed() {
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delete(d.sessions, addr)
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ok = false
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}
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if !ok {
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options := &dialer.DialOptions{}
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for _, opt := range opts {
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opt(options)
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}
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c, err := options.Dialer.Dial(ctx, "udp", "")
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if err != nil {
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d.sessionMutex.Unlock()
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return nil, err
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}
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pc, ok := c.(net.PacketConn)
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if !ok {
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c.Close()
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d.sessionMutex.Unlock()
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return nil, errors.New("dns: wrong connection type")
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}
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pc = dns_util.ClientConn(
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pc,
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dns_util.DomainOption(d.md.domain),
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dns_util.UDPSizeOption(d.md.udpSize),
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)
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session, err = d.initSession(ctx, udpAddr, pc)
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if err != nil {
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d.logger.Error(err)
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pc.Close()
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d.sessionMutex.Unlock()
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return nil, err
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}
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d.sessions[addr] = session
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}
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d.sessionMutex.Unlock()
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conn, err = session.GetConn()
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if err != nil {
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d.sessionMutex.Lock()
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if d.sessions[addr] == session {
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delete(d.sessions, addr)
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}
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session.Close()
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d.sessionMutex.Unlock()
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return nil, err
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}
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return
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}
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func (d *dnsDialer) initSession(ctx context.Context, addr net.Addr, conn net.PacketConn) (*quicSession, error) {
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quicConfig := &quic.Config{
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KeepAlivePeriod: d.md.keepAlivePeriod,
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HandshakeIdleTimeout: d.md.handshakeTimeout,
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MaxIdleTimeout: d.md.maxIdleTimeout,
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Versions: []quic.Version{
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quic.Version1,
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quic.Version2,
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},
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MaxIncomingStreams: int64(d.md.maxStreams),
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EnableDatagrams: d.md.enableDatagram,
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}
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tlsCfg := d.options.TLSConfig
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if tlsCfg == nil {
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tlsCfg = &tls.Config{}
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} else {
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tlsCfg = tlsCfg.Clone()
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}
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if len(tlsCfg.NextProtos) == 0 {
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tlsCfg.NextProtos = []string{"h3", "quic/v1"}
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}
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session, err := quic.DialEarly(ctx, conn, addr, tlsCfg, quicConfig)
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if err != nil {
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return nil, err
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}
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return &quicSession{session: session}, nil
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}
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// Multiplex implements dialer.Multiplexer interface.
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func (d *dnsDialer) Multiplex() bool {
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return true
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}
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