add dot & doh

This commit is contained in:
ginuerzh 2020-01-16 22:38:19 +08:00
parent 99b141e5be
commit 694c05b50a
4 changed files with 235 additions and 46 deletions

View File

@ -481,7 +481,8 @@ func (r *route) GenRouters() ([]router, error) {
ln, err = gost.DNSListener(
node.Addr,
&gost.DNSOptions{
TCPMode: node.GetBool("tcp"),
Mode: node.Get("mode"),
TLSConfig: tlsCfg,
},
)
default:
@ -525,7 +526,7 @@ func (r *route) GenRouters() ([]router, error) {
handler = gost.TunHandler()
case "tap":
handler = gost.TapHandler()
case "dns", "dot", "doh":
case "dns":
handler = gost.DNSHandler(node.Remote)
default:
// start from 2.5, if remote is not empty, then we assume that it is a forward tunnel.

253
dns.go
View File

@ -3,9 +3,15 @@ package gost
import (
"bytes"
"context"
"crypto/tls"
"encoding/base64"
"errors"
"io"
"io/ioutil"
"net"
"net/http"
"strconv"
"strings"
"time"
"github.com/go-log/log"
@ -112,15 +118,16 @@ func (h *dnsHandler) dumpMsgHeader(m *dns.Msg) string {
}
type DNSOptions struct {
TCPMode bool
Mode string
UDPSize int
ReadTimeout time.Duration
WriteTimeout time.Duration
TLSConfig *tls.Config
}
type dnsListener struct {
addr net.Addr
server *dns.Server
server dnsServer
connChan chan net.Conn
errc chan error
}
@ -130,31 +137,70 @@ func DNSListener(addr string, options *DNSOptions) (Listener, error) {
options = &DNSOptions{}
}
tlsConfig := options.TLSConfig
if tlsConfig == nil {
tlsConfig = DefaultTLSConfig
}
ln := &dnsListener{
connChan: make(chan net.Conn, 128),
errc: make(chan error, 1),
}
var nets string
var srv dnsServer
var err error
switch strings.ToLower(options.Mode) {
case "tcp":
srv = &dns.Server{
Net: "tcp",
Addr: addr,
Handler: ln,
ReadTimeout: options.ReadTimeout,
WriteTimeout: options.WriteTimeout,
}
case "tls":
srv = &dns.Server{
Net: "tcp-tls",
Addr: addr,
Handler: ln,
TLSConfig: tlsConfig,
ReadTimeout: options.ReadTimeout,
WriteTimeout: options.WriteTimeout,
}
case "https":
srv = &dohServer{
addr: addr,
tlsConfig: tlsConfig,
server: &http.Server{
Handler: ln,
ReadTimeout: options.ReadTimeout,
WriteTimeout: options.WriteTimeout,
},
}
if options.TCPMode {
nets = "tcp"
default:
ln.addr, err = net.ResolveTCPAddr("tcp", addr)
} else {
nets = "udp"
ln.addr, err = net.ResolveUDPAddr("udp", addr)
srv = &dns.Server{
Net: "udp",
Addr: addr,
Handler: ln,
UDPSize: options.UDPSize,
ReadTimeout: options.ReadTimeout,
WriteTimeout: options.WriteTimeout,
}
}
if err != nil {
return nil, err
}
ln.server = &dns.Server{
Addr: addr,
Net: nets,
if ln.addr == nil {
ln.addr, err = net.ResolveTCPAddr("tcp", addr)
if err != nil {
return nil, err
}
}
dns.HandleFunc(".", ln.handleRequest)
ln.server = srv
go func() {
if err := ln.server.ListenAndServe(); err != nil {
@ -172,30 +218,76 @@ func DNSListener(addr string, options *DNSOptions) (Listener, error) {
return ln, nil
}
func (l *dnsListener) handleRequest(w dns.ResponseWriter, m *dns.Msg) {
if w == nil || m == nil {
return
}
conn := &dnsServerConn{
mq: make(chan []byte, 1),
ResponseWriter: w,
}
buf := mPool.Get().([]byte)
defer mPool.Put(buf)
buf = buf[:0]
b, err := m.PackBuffer(buf)
if err != nil {
log.Logf("[dns] %s: %v", l.addr, err)
return
}
conn.mq <- b
func (l *dnsListener) serve(w dnsResponseWriter, mq []byte) (err error) {
conn := newDNSServerConn(l.addr, w.RemoteAddr())
conn.mq <- mq
select {
case l.connChan <- conn:
default:
log.Logf("[dns] %s: connection queue is full", l.addr)
return errors.New("connection queue is full")
}
select {
case mr := <-conn.mr:
_, err = w.Write(mr)
case <-conn.cclose:
err = io.EOF
}
return
}
func (l *dnsListener) ServeDNS(w dns.ResponseWriter, m *dns.Msg) {
b, err := m.Pack()
if err != nil {
log.Logf("[dns] %s: %v", l.addr, err)
return
}
if err := l.serve(w, b); err != nil {
log.Logf("[dns] %s: %v", l.addr, err)
}
}
// Based on https://github.com/semihalev/sdns
func (l *dnsListener) ServeHTTP(w http.ResponseWriter, r *http.Request) {
var buf []byte
var err error
switch r.Method {
case http.MethodGet:
buf, err = base64.RawURLEncoding.DecodeString(r.URL.Query().Get("dns"))
if len(buf) == 0 || err != nil {
http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
return
}
case http.MethodPost:
if r.Header.Get("Content-Type") != "application/dns-message" {
http.Error(w, http.StatusText(http.StatusUnsupportedMediaType), http.StatusUnsupportedMediaType)
return
}
buf, err = ioutil.ReadAll(r.Body)
if err != nil {
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
default:
http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
return
}
mq := &dns.Msg{}
if err := mq.Unpack(buf); err != nil {
http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
return
}
w.Header().Set("Server", "SDNS")
w.Header().Set("Content-Type", "application/dns-message")
raddr, _ := net.ResolveTCPAddr("tcp", r.RemoteAddr)
if err := l.serve(newDoHResponseWriter(raddr, w), buf); err != nil {
log.Logf("[dns] %s: %v", l.addr, err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
}
}
@ -215,21 +307,85 @@ func (l *dnsListener) Addr() net.Addr {
return l.addr
}
type dnsServer interface {
ListenAndServe() error
Shutdown() error
}
type dohServer struct {
addr string
tlsConfig *tls.Config
server *http.Server
}
func (s *dohServer) ListenAndServe() error {
ln, err := net.Listen("tcp", s.addr)
if err != nil {
return err
}
ln = tls.NewListener(tcpKeepAliveListener{ln.(*net.TCPListener)}, s.tlsConfig)
return s.server.Serve(ln)
}
func (s *dohServer) Shutdown() error {
return s.server.Shutdown(context.Background())
}
type dnsServerConn struct {
mq chan []byte
dns.ResponseWriter
mq chan []byte
mr chan []byte
cclose chan struct{}
laddr, raddr net.Addr
}
func newDNSServerConn(laddr, raddr net.Addr) *dnsServerConn {
return &dnsServerConn{
mq: make(chan []byte, 1),
mr: make(chan []byte, 1),
laddr: laddr,
raddr: raddr,
cclose: make(chan struct{}),
}
}
func (c *dnsServerConn) Read(b []byte) (n int, err error) {
var mb []byte
select {
case mb = <-c.mq:
default:
case mb := <-c.mq:
n = copy(b, mb)
case <-c.cclose:
err = errors.New("connection is closed")
}
n = copy(b, mb)
return
}
func (c *dnsServerConn) Write(b []byte) (n int, err error) {
select {
case c.mr <- b:
n = len(b)
case <-c.cclose:
err = errors.New("broken pipe")
}
return
}
func (c *dnsServerConn) Close() error {
select {
case <-c.cclose:
default:
close(c.cclose)
}
return nil
}
func (c *dnsServerConn) LocalAddr() net.Addr {
return c.laddr
}
func (c *dnsServerConn) RemoteAddr() net.Addr {
return c.raddr
}
func (c *dnsServerConn) SetDeadline(t time.Time) error {
return &net.OpError{Op: "set", Net: "dns", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
}
@ -241,3 +397,24 @@ func (c *dnsServerConn) SetReadDeadline(t time.Time) error {
func (c *dnsServerConn) SetWriteDeadline(t time.Time) error {
return &net.OpError{Op: "set", Net: "dns", Source: nil, Addr: nil, Err: errors.New("deadline not supported")}
}
type dnsResponseWriter interface {
io.Writer
RemoteAddr() net.Addr
}
type dohResponseWriter struct {
raddr net.Addr
http.ResponseWriter
}
func newDoHResponseWriter(raddr net.Addr, w http.ResponseWriter) dnsResponseWriter {
return &dohResponseWriter{
raddr: raddr,
ResponseWriter: w,
}
}
func (w *dohResponseWriter) RemoteAddr() net.Addr {
return w.raddr
}

View File

@ -84,7 +84,7 @@ func ParseNode(s string) (node Node, err error) {
case "ohttp": // obfs-http
case "tun", "tap": // tun/tap device
case "ftcp": // fake TCP
case "dns", "dot", "doh":
case "dns":
default:
node.Transport = "tcp"
}

View File

@ -187,11 +187,16 @@ func (r *resolver) Init(opts ...ResolverOption) error {
opt(&r.options)
}
timeout := r.timeout
if timeout <= 0 {
timeout = DefaultResolverTimeout
}
var nss []NameServer
for _, ns := range r.servers {
if err := ns.Init( // init all name servers
ChainNameServerOption(r.options.chain),
TimeoutNameServerOption(r.timeout),
TimeoutNameServerOption(timeout),
); err != nil {
continue // ignore invalid name servers
}
@ -255,8 +260,6 @@ func (r *resolver) resolve(ex Exchanger, host string) (ips []net.IP, err error)
prefer := r.prefer
r.mux.RUnlock()
prefer = "ipv6"
ctx := context.Background()
if prefer == "ipv6" { // prefer ipv6
mq := &dns.Msg{}
@ -614,10 +617,12 @@ func (ex *dnsExchanger) dial(ctx context.Context, network, address string) (conn
}
func (ex *dnsExchanger) Exchange(ctx context.Context, query []byte) ([]byte, error) {
t := time.Now()
c, err := ex.dial(ctx, "udp", ex.addr)
if err != nil {
return nil, err
}
c.SetDeadline(time.Now().Add(ex.options.timeout - time.Since(t)))
mq := &dns.Msg{}
if err = mq.Unpack(query); err != nil {
@ -672,10 +677,12 @@ func (ex *dnsTCPExchanger) dial(ctx context.Context, network, address string) (c
}
func (ex *dnsTCPExchanger) Exchange(ctx context.Context, query []byte) ([]byte, error) {
t := time.Now()
c, err := ex.dial(ctx, "tcp", ex.addr)
if err != nil {
return nil, err
}
c.SetDeadline(time.Now().Add(ex.options.timeout - time.Since(t)))
conn := &dns.Conn{
Conn: c,
@ -731,17 +738,21 @@ func (ex *dotExchanger) dial(ctx context.Context, network, address string) (conn
} else {
conn, err = ex.options.chain.Dial(address, TimeoutChainOption(ex.options.timeout))
}
if err == nil {
conn = tls.Client(conn, ex.tlsConfig)
if err != nil {
return
}
conn = tls.Client(conn, ex.tlsConfig)
return
}
func (ex *dotExchanger) Exchange(ctx context.Context, query []byte) ([]byte, error) {
t := time.Now()
c, err := ex.dial(ctx, "tcp", ex.addr)
if err != nil {
return nil, err
}
c.SetDeadline(time.Now().Add(ex.options.timeout - time.Since(t)))
conn := &dns.Conn{
Conn: c,