Files
sing-box/protocol/cloudflare/special_service.go

241 lines
7.2 KiB
Go

//go:build with_cloudflare_tunnel
package cloudflare
import (
"context"
"crypto/sha1"
"encoding/base64"
"io"
"net"
"net/http"
"net/netip"
"net/url"
"strconv"
"strings"
"time"
"github.com/sagernet/sing-box/adapter"
"github.com/sagernet/sing-box/transport/v2raywebsocket"
"github.com/sagernet/sing/common"
"github.com/sagernet/sing/common/bufio"
E "github.com/sagernet/sing/common/exceptions"
M "github.com/sagernet/sing/common/metadata"
N "github.com/sagernet/sing/common/network"
"github.com/sagernet/sing/common/pipe"
"github.com/sagernet/ws"
)
var wsAcceptGUID = []byte("258EAFA5-E914-47DA-95CA-C5AB0DC85B11")
func (i *Inbound) handleBastionStream(ctx context.Context, stream io.ReadWriteCloser, respWriter ConnectResponseWriter, request *ConnectRequest, metadata adapter.InboundContext) {
destination, err := resolveBastionDestination(request)
if err != nil {
respWriter.WriteResponse(err, nil)
return
}
i.handleRouterBackedStream(ctx, stream, respWriter, request, M.ParseSocksaddr(destination))
}
func (i *Inbound) handleStreamService(ctx context.Context, stream io.ReadWriteCloser, respWriter ConnectResponseWriter, request *ConnectRequest, metadata adapter.InboundContext, destination M.Socksaddr) {
i.handleRouterBackedStream(ctx, stream, respWriter, request, destination)
}
func (i *Inbound) handleRouterBackedStream(ctx context.Context, stream io.ReadWriteCloser, respWriter ConnectResponseWriter, request *ConnectRequest, destination M.Socksaddr) {
targetConn, cleanup, err := i.dialRouterTCP(ctx, destination)
if err != nil {
respWriter.WriteResponse(err, nil)
return
}
defer cleanup()
err = respWriter.WriteResponse(nil, encodeResponseHeaders(http.StatusSwitchingProtocols, websocketResponseHeaders(request)))
if err != nil {
i.logger.ErrorContext(ctx, "write bastion websocket response: ", err)
return
}
wsConn := v2raywebsocket.NewConn(newStreamConn(stream), nil, ws.StateServerSide)
defer wsConn.Close()
_ = bufio.CopyConn(ctx, wsConn, targetConn)
}
func (i *Inbound) handleSocksProxyStream(ctx context.Context, stream io.ReadWriteCloser, respWriter ConnectResponseWriter, request *ConnectRequest, metadata adapter.InboundContext) {
err := respWriter.WriteResponse(nil, encodeResponseHeaders(http.StatusSwitchingProtocols, websocketResponseHeaders(request)))
if err != nil {
i.logger.ErrorContext(ctx, "write socks-proxy websocket response: ", err)
return
}
wsConn := v2raywebsocket.NewConn(newStreamConn(stream), nil, ws.StateServerSide)
defer wsConn.Close()
if err := i.serveSocksProxy(ctx, wsConn); err != nil && !E.IsClosedOrCanceled(err) {
i.logger.DebugContext(ctx, "socks-proxy stream closed: ", err)
}
}
func resolveBastionDestination(request *ConnectRequest) (string, error) {
headerValue := requestHeaderValue(request, "Cf-Access-Jump-Destination")
if headerValue == "" {
return "", E.New("missing Cf-Access-Jump-Destination header")
}
if parsed, err := url.Parse(headerValue); err == nil && parsed.Host != "" {
headerValue = parsed.Host
}
return strings.SplitN(headerValue, "/", 2)[0], nil
}
func websocketResponseHeaders(request *ConnectRequest) http.Header {
header := http.Header{}
header.Set("Connection", "Upgrade")
header.Set("Upgrade", "websocket")
secKey := requestHeaderValue(request, "Sec-WebSocket-Key")
if secKey != "" {
sum := sha1.Sum(append([]byte(secKey), wsAcceptGUID...))
header.Set("Sec-WebSocket-Accept", base64.StdEncoding.EncodeToString(sum[:]))
}
return header
}
func requestHeaderValue(request *ConnectRequest, headerName string) string {
for _, entry := range request.Metadata {
if !strings.HasPrefix(entry.Key, metadataHTTPHeader+":") {
continue
}
name := strings.TrimPrefix(entry.Key, metadataHTTPHeader+":")
if strings.EqualFold(name, headerName) {
return entry.Val
}
}
return ""
}
func (i *Inbound) dialRouterTCP(ctx context.Context, destination M.Socksaddr) (net.Conn, func(), error) {
input, output := pipe.Pipe()
done := make(chan struct{})
metadata := adapter.InboundContext{
Inbound: i.Tag(),
InboundType: i.Type(),
Network: N.NetworkTCP,
Destination: destination,
}
go i.router.RouteConnectionEx(ctx, output, metadata, N.OnceClose(func(it error) {
common.Close(input, output)
close(done)
}))
return input, func() {
common.Close(input, output)
select {
case <-done:
case <-time.After(time.Second):
}
}, nil
}
func (i *Inbound) serveSocksProxy(ctx context.Context, conn net.Conn) error {
version := make([]byte, 1)
if _, err := io.ReadFull(conn, version); err != nil {
return err
}
if version[0] != 5 {
return E.New("unsupported SOCKS version: ", version[0])
}
methodCount := make([]byte, 1)
if _, err := io.ReadFull(conn, methodCount); err != nil {
return err
}
methods := make([]byte, int(methodCount[0]))
if _, err := io.ReadFull(conn, methods); err != nil {
return err
}
if _, err := conn.Write([]byte{5, 0}); err != nil {
return err
}
requestHeader := make([]byte, 4)
if _, err := io.ReadFull(conn, requestHeader); err != nil {
return err
}
if requestHeader[0] != 5 {
return E.New("unsupported SOCKS request version: ", requestHeader[0])
}
if requestHeader[1] != 1 {
_, _ = conn.Write([]byte{5, 7, 0, 1, 0, 0, 0, 0, 0, 0})
return E.New("unsupported SOCKS command: ", requestHeader[1])
}
destination, err := readSocksDestination(conn, requestHeader[3])
if err != nil {
return err
}
targetConn, cleanup, err := i.dialRouterTCP(ctx, destination)
if err != nil {
_, _ = conn.Write([]byte{5, 4, 0, 1, 0, 0, 0, 0, 0, 0})
return err
}
defer cleanup()
if _, err := conn.Write([]byte{5, 0, 0, 1, 0, 0, 0, 0, 0, 0}); err != nil {
return err
}
return bufio.CopyConn(ctx, conn, targetConn)
}
func readSocksDestination(conn net.Conn, addressType byte) (M.Socksaddr, error) {
switch addressType {
case 1:
addr := make([]byte, 4)
if _, err := io.ReadFull(conn, addr); err != nil {
return M.Socksaddr{}, err
}
port, err := readSocksPort(conn)
if err != nil {
return M.Socksaddr{}, err
}
ipAddr, ok := netip.AddrFromSlice(addr)
if !ok {
return M.Socksaddr{}, E.New("invalid IPv4 SOCKS destination")
}
return M.SocksaddrFrom(ipAddr, port), nil
case 3:
length := make([]byte, 1)
if _, err := io.ReadFull(conn, length); err != nil {
return M.Socksaddr{}, err
}
host := make([]byte, int(length[0]))
if _, err := io.ReadFull(conn, host); err != nil {
return M.Socksaddr{}, err
}
port, err := readSocksPort(conn)
if err != nil {
return M.Socksaddr{}, err
}
return M.ParseSocksaddr(net.JoinHostPort(string(host), strconv.Itoa(int(port)))), nil
case 4:
addr := make([]byte, 16)
if _, err := io.ReadFull(conn, addr); err != nil {
return M.Socksaddr{}, err
}
port, err := readSocksPort(conn)
if err != nil {
return M.Socksaddr{}, err
}
ipAddr, ok := netip.AddrFromSlice(addr)
if !ok {
return M.Socksaddr{}, E.New("invalid IPv6 SOCKS destination")
}
return M.SocksaddrFrom(ipAddr, port), nil
default:
return M.Socksaddr{}, E.New("unsupported SOCKS address type: ", addressType)
}
}
func readSocksPort(conn net.Conn) (uint16, error) {
port := make([]byte, 2)
if _, err := io.ReadFull(conn, port); err != nil {
return 0, err
}
return uint16(port[0])<<8 | uint16(port[1]), nil
}